SDL_wave.c File Reference

#include "../SDL_internal.h"
#include "SDL_hints.h"
#include "SDL_audio.h"
#include "SDL_wave.h"
#include "SDL_audio_c.h"

Include dependency graph for SDL_wave.c:

Go to the source code of this file.

Data Structures
struct	ADPCM_DecoderState
struct	MS_ADPCM_CoeffData
struct	MS_ADPCM_ChannelState
struct	WaveExtensibleGUID

Macros
#define	INT_MAX   SDL_MAX_SINT32
#define	SIZE_MAX   ((size_t)-1)
#define	WAVE_FORMATTAG_GUID(tag)   {(tag) & 0xff, (tag) >> 8, 0, 0, 0, 0, 16, 0, 128, 0, 0, 170, 0, 56, 155, 113}

Functions
static int	SafeMult (size_t *f1, size_t f2)
static Sint64	WaveAdjustToFactValue (WaveFile *file, Sint64 sampleframes)
static int	MS_ADPCM_CalculateSampleFrames (WaveFile *file, size_t datalength)
static int	MS_ADPCM_Init (WaveFile *file, size_t datalength)
static Sint16	MS_ADPCM_ProcessNibble (MS_ADPCM_ChannelState *cstate, Sint32 sample1, Sint32 sample2, Uint8 nybble)
static int	MS_ADPCM_DecodeBlockHeader (ADPCM_DecoderState *state)
static int	MS_ADPCM_DecodeBlockData (ADPCM_DecoderState *state)
static int	MS_ADPCM_Decode (WaveFile *file, Uint8 **audio_buf, Uint32 *audio_len)
static int	IMA_ADPCM_CalculateSampleFrames (WaveFile *file, size_t datalength)
static int	IMA_ADPCM_Init (WaveFile *file, size_t datalength)
static Sint16	IMA_ADPCM_ProcessNibble (Sint8 *cindex, Sint16 lastsample, Uint8 nybble)
static int	IMA_ADPCM_DecodeBlockHeader (ADPCM_DecoderState *state)
static int	IMA_ADPCM_DecodeBlockData (ADPCM_DecoderState *state)
static int	IMA_ADPCM_Decode (WaveFile *file, Uint8 **audio_buf, Uint32 *audio_len)
static int	LAW_Init (WaveFile *file, size_t datalength)
static int	LAW_Decode (WaveFile *file, Uint8 **audio_buf, Uint32 *audio_len)
static int	PCM_Init (WaveFile *file, size_t datalength)
static int	PCM_ConvertSint24ToSint32 (WaveFile *file, Uint8 **audio_buf, Uint32 *audio_len)
static int	PCM_Decode (WaveFile *file, Uint8 **audio_buf, Uint32 *audio_len)
static WaveRiffSizeHint	WaveGetRiffSizeHint ()
static WaveTruncationHint	WaveGetTruncationHint ()
static WaveFactChunkHint	WaveGetFactChunkHint ()
static void	WaveFreeChunkData (WaveChunk *chunk)
static int	WaveNextChunk (SDL_RWops *src, WaveChunk *chunk)
static int	WaveReadPartialChunkData (SDL_RWops *src, WaveChunk *chunk, size_t length)
static int	WaveReadChunkData (SDL_RWops *src, WaveChunk *chunk)
static Uint16	WaveGetFormatGUIDEncoding (WaveFormat *format)
static int	WaveReadFormat (WaveFile *file)
static int	WaveCheckFormat (WaveFile *file, size_t datalength)
static int	WaveLoad (SDL_RWops *src, WaveFile *file, SDL_AudioSpec *spec, Uint8 **audio_buf, Uint32 *audio_len)
SDL_AudioSpec *	SDL_LoadWAV_RW (SDL_RWops *src, int freesrc, SDL_AudioSpec *spec, Uint8 **audio_buf, Uint32 *audio_len)
	Load the audio data of a WAVE file into memory. More...
void	SDL_FreeWAV (Uint8 *audio_buf)

Variables
static WaveExtensibleGUID	extensible_guids []

Macro Definition Documentation

INT_MAX

#define INT_MAX   SDL_MAX_SINT32

Definition at line 28 of file SDL_wave.c.

SIZE_MAX

#define SIZE_MAX   ((size_t)-1)

Definition at line 31 of file SDL_wave.c.

WAVE_FORMATTAG_GUID

#define WAVE_FORMATTAG_GUID

(

tag

)

{(tag) & 0xff, (tag) >> 8, 0, 0, 0, 0, 16, 0, 128, 0, 0, 170, 0, 56, 155, 113}

Definition at line 1594 of file SDL_wave.c.

Function Documentation

IMA_ADPCM_CalculateSampleFrames()

static int IMA_ADPCM_CalculateSampleFrames ( WaveFile *  file, size_t  datalength  )

static

Definition at line 740 of file SDL_wave.c.

{
    WaveFormat *format = &file->format;
    const size_t blockheadersize = (size_t)format->channels * 4;
    const size_t subblockframesize = (size_t)format->channels * 4;
    const size_t availableblocks = datalength / format->blockalign;
    const size_t trailingdata = datalength % format->blockalign;
 
    if (file->trunchint == TruncVeryStrict || file->trunchint == TruncStrict) {
        /* The size of the data chunk must be a multiple of the block size. */
        if (datalength < blockheadersize || trailingdata > 0) {
            return SDL_SetError("Truncated IMA ADPCM block");
        }
    }
 
    /* Calculate number of sample frames that will be decoded. */
    file->sampleframes = (Uint64)availableblocks * format->samplesperblock;
    if (trailingdata > 0) {
        /* The last block is truncated. Check if we can get any samples out of it. */
        if (file->trunchint == TruncDropFrame && trailingdata > blockheadersize - 2) {
            /* The sample frame in the header of the truncated block is present.
             * Drop incomplete sample frames.
             */
            size_t trailingsamples = 1;
 
            if (trailingdata > blockheadersize) {
                /* More data following after the header. */
                const size_t trailingblockdata = trailingdata - blockheadersize;
                const size_t trailingsubblockdata = trailingblockdata % subblockframesize;
                trailingsamples += (trailingblockdata / subblockframesize) * 8;
                /* Due to the interleaved sub-blocks, the last 4 bytes determine
                 * how many samples of the truncated sub-block are lost.
                 */
                if (trailingsubblockdata > subblockframesize - 4) {
                    trailingsamples += (trailingsubblockdata % 4) * 2;
                }
            }
 
            if (trailingsamples > format->samplesperblock) {
                trailingsamples = format->samplesperblock;
            }
            file->sampleframes += trailingsamples;
        }
    }
 
    file->sampleframes = WaveAdjustToFactValue(file, file->sampleframes);
    if (file->sampleframes < 0) {
        return -1;
    }
 
    return 0;
}

References WaveFormat::channels, WaveFile::format, if, WaveFile::sampleframes, SDL_SetError, TruncDropFrame, WaveFile::trunchint, TruncStrict, TruncVeryStrict, and WaveAdjustToFactValue().

Referenced by IMA_ADPCM_Decode(), and IMA_ADPCM_Init().

IMA_ADPCM_Decode()

static int IMA_ADPCM_Decode ( WaveFile *  file, Uint8 **  audio_buf, Uint32 *  audio_len  )

static

Definition at line 1036 of file SDL_wave.c.

{
    int result;
    size_t bytesleft, outputsize;
    WaveChunk *chunk = &file->chunk;
    ADPCM_DecoderState state;
    Sint8 *cstate;
 
    if (chunk->size != chunk->length) {
        /* Could not read everything. Recalculate number of sample frames. */
        if (IMA_ADPCM_CalculateSampleFrames(file, chunk->size) < 0) {
            return -1;
        }
    }
 
    /* Nothing to decode, nothing to return. */
    if (file->sampleframes == 0) {
        *audio_buf = NULL;
        *audio_len = 0;
        return 0;
    }
 
    SDL_zero(state);
    state.channels = file->format.channels;
    state.blocksize = file->format.blockalign;
    state.blockheadersize = (size_t)state.channels * 4;
    state.samplesperblock = file->format.samplesperblock;
    state.framesize = state.channels * sizeof(Sint16);
    state.framestotal = file->sampleframes;
    state.framesleft = state.framestotal;
 
    state.input.data = chunk->data;
    state.input.size = chunk->size;
    state.input.pos = 0;
 
    /* The output size in bytes. May get modified if data is truncated. */
    outputsize = (size_t)state.framestotal;
    if (SafeMult(&outputsize, state.framesize)) {
        return SDL_OutOfMemory();
    } else if (outputsize > SDL_MAX_UINT32 || state.framestotal > SIZE_MAX) {
        return SDL_SetError("WAVE file too big");
    }
 
    state.output.pos = 0;
    state.output.size = outputsize / sizeof(Sint16);
    state.output.data = (Sint16 *)SDL_malloc(outputsize);
    if (state.output.data == NULL) {
        return SDL_OutOfMemory();
    }
 
    cstate = (Sint8 *)SDL_calloc(state.channels, sizeof(Sint8));
    if (cstate == NULL) {
        SDL_free(state.output.data);
        return SDL_OutOfMemory();
    }
    state.cstate = cstate;
 
    /* Decode block by block. A truncated block will stop the decoding. */
    bytesleft = state.input.size - state.input.pos;
    while (state.framesleft > 0 && bytesleft >= state.blockheadersize) {
        state.block.data = state.input.data + state.input.pos;
        state.block.size = bytesleft < state.blocksize ? bytesleft : state.blocksize;
        state.block.pos = 0;
 
        if (state.output.size - state.output.pos < (Uint64)state.framesleft * state.channels) {
            /* Somehow didn't allocate enough space for the output. */
            SDL_free(state.output.data);
            SDL_free(cstate);
            return SDL_SetError("Unexpected overflow in IMA ADPCM decoder");
        }
 
        /* Initialize decoder with the values from the block header. */
        result = IMA_ADPCM_DecodeBlockHeader(&state);
        if (result == 0) {
            /* Decode the block data. It stores the samples directly in the output. */
            result = IMA_ADPCM_DecodeBlockData(&state);
        }
 
        if (result == -1) {
            /* Unexpected end. Stop decoding and return partial data if necessary. */
            if (file->trunchint == TruncVeryStrict || file->trunchint == TruncStrict) {
                SDL_free(state.output.data);
                SDL_free(cstate);
                return SDL_SetError("Truncated data chunk");
            } else if (file->trunchint != TruncDropFrame) {
                state.output.pos -= state.output.pos % (state.samplesperblock * state.channels);
            }
            outputsize = state.output.pos * sizeof(Sint16); /* Can't overflow, is always smaller. */
            break;
        }
 
        state.input.pos += state.block.size;
        bytesleft = state.input.size - state.input.pos;
    }
 
    *audio_buf = (Uint8 *)state.output.data;
    *audio_len = (Uint32)outputsize;
 
    SDL_free(cstate);
 
    return 0;
}

References WaveFormat::blockalign, WaveFormat::channels, WaveFile::chunk, WaveChunk::data, WaveFile::format, if, IMA_ADPCM_CalculateSampleFrames(), IMA_ADPCM_DecodeBlockData(), IMA_ADPCM_DecodeBlockHeader(), WaveChunk::length, NULL, SafeMult(), WaveFile::sampleframes, WaveFormat::samplesperblock, SDL_calloc, SDL_free, SDL_malloc, SDL_MAX_UINT32, SDL_OutOfMemory, SDL_SetError, SDL_zero, WaveChunk::size, SIZE_MAX, state, TruncDropFrame, WaveFile::trunchint, TruncStrict, and TruncVeryStrict.

Referenced by WaveLoad().

IMA_ADPCM_DecodeBlockData()

static int IMA_ADPCM_DecodeBlockData ( ADPCM_DecoderState *  state )

static

Definition at line 966 of file SDL_wave.c.

{
    size_t i;
    int retval = 0;
    const Uint32 channels = state->channels;
    const size_t subblockframesize = channels * 4;
    Uint64 bytesrequired;
    Uint32 c;
 
    size_t blockpos = state->block.pos;
    size_t blocksize = state->block.size;
    size_t blockleft = blocksize - blockpos;
 
    size_t outpos = state->output.pos;
 
    Sint64 blockframesleft = state->samplesperblock - 1;
    if (blockframesleft > state->framesleft) {
        blockframesleft = state->framesleft;
    }
 
    bytesrequired = (blockframesleft + 7) / 8 * subblockframesize;
    if (blockleft < bytesrequired) {
        /* Data truncated. Calculate how many samples we can get out if it. */
        const size_t guaranteedframes = blockleft / subblockframesize;
        const size_t remainingbytes = blockleft % subblockframesize;
        blockframesleft = guaranteedframes;
        if (remainingbytes > subblockframesize - 4) {
            blockframesleft += (remainingbytes % 4) * 2;
        }
        /* Signal the truncation. */
        retval = -1;
    }
 
    /* Each channel has their nibbles packed into 32-bit blocks. These blocks
     * are interleaved and make up the data part of the ADPCM block. This loop
     * decodes the samples as they come from the input data and puts them at
     * the appropriate places in the output data.
     */
    while (blockframesleft > 0) {
        const size_t subblocksamples = blockframesleft < 8 ? (size_t)blockframesleft : 8;
 
        for (c = 0; c < channels; c++) {
            Uint8 nybble = 0;
            /* Load previous sample which may come from the block header. */
            Sint16 sample = state->output.data[outpos + c - channels];
 
            for (i = 0; i < subblocksamples; i++) {
                if (i & 1) {
                    nybble >>= 4;
                } else {
                    nybble = state->block.data[blockpos++];
                }
 
                sample = IMA_ADPCM_ProcessNibble((Sint8 *)state->cstate + c, sample, nybble & 0x0f);
                state->output.data[outpos + c + i * channels] = sample;
            }
        }
 
        outpos += channels * subblocksamples;
        state->framesleft -= subblocksamples;
        blockframesleft -= subblocksamples;
    }
 
    state->block.pos = blockpos;
    state->output.pos = outpos;
 
    return retval;
}

References i, IMA_ADPCM_ProcessNibble(), retval, and state.

Referenced by IMA_ADPCM_Decode().

IMA_ADPCM_DecodeBlockHeader()

static int IMA_ADPCM_DecodeBlockHeader ( ADPCM_DecoderState *  state )

static

Definition at line 926 of file SDL_wave.c.

{
    Sint16 step;
    Uint32 c;
    Uint8 *cstate = (Uint8 *) state->cstate;
 
    for (c = 0; c < state->channels; c++) {
        size_t o = state->block.pos + c * 4;
 
        /* Extract the sample from the header. */
        Sint32 sample = state->block.data[o] | ((Sint32)state->block.data[o + 1] << 8);
        if (sample >= 0x8000) {
            sample -= 0x10000;
        }
        state->output.data[state->output.pos++] = (Sint16)sample;
 
        /* Channel step index. */
        step = (Sint16)state->block.data[o + 2];
        cstate[c] = (Sint8)(step > 0x80 ? step - 0x100 : step);
 
        /* Reserved byte in block header, should be 0. */
        if (state->block.data[o + 3] != 0) {
            /* Uh oh, corrupt data?  Buggy code? */ ;
        }
    }
 
    state->block.pos += state->blockheadersize;
 
    /* Header provided one sample frame. */
    state->framesleft--;
 
    return 0;
}

References state.

Referenced by IMA_ADPCM_Decode().

IMA_ADPCM_Init()

static int IMA_ADPCM_Init ( WaveFile *  file, size_t  datalength  )

static

Definition at line 794 of file SDL_wave.c.

{
    WaveFormat *format = &file->format;
    WaveChunk *chunk = &file->chunk;
    const size_t blockheadersize = (size_t)format->channels * 4;
    const size_t blockdatasize = (size_t)format->blockalign - blockheadersize;
    const size_t blockframebitsize = (size_t)format->bitspersample * format->channels;
    const size_t blockdatasamples = (blockdatasize * 8) / blockframebitsize;
 
    /* Sanity checks. */
 
    /* IMA ADPCM can also have 3-bit samples, but it's not supported by SDL at this time. */
    if (format->bitspersample == 3) {
        return SDL_SetError("3-bit IMA ADPCM currently not supported");
    } else if (format->bitspersample != 4) {
        return SDL_SetError("Invalid IMA ADPCM bits per sample of %u", (unsigned int)format->bitspersample);
    }
 
    /* The block size is required to be a multiple of 4 and it must be able to
     * hold a block header.
     */
    if (format->blockalign < blockheadersize || format->blockalign % 4) {
        return SDL_SetError("Invalid IMA ADPCM block size (nBlockAlign)");
    }
 
    if (format->formattag == EXTENSIBLE_CODE) {
        /* There's no specification for this, but it's basically the same
         * format because the extensible header has wSampePerBlocks too.
         */
    } else  {
        /* The Standards Update says there 'should' be 2 bytes for wSamplesPerBlock. */
        if (chunk->size >= 20 && format->extsize >= 2) {
            format->samplesperblock = chunk->data[18] | ((Uint16)chunk->data[19] << 8);
        }
    }
 
    if (format->samplesperblock == 0) {
        /* Field zero? No problem. We just assume the encoder packed the block.
         * The specification calculates it this way:
         *
         *   x = Block size (in bits) minus header size (in bits)
         *   y = Bit depth multiplied by channel count
         *   z = Number of samples per channel in header
         *   wSamplesPerBlock = x / y + z
         */
        format->samplesperblock = (Uint32)blockdatasamples + 1;
    }
 
    /* nBlockAlign can be in conflict with wSamplesPerBlock. For example, if
     * the number of samples doesn't fit into the block. The Standards Update
     * also describes wSamplesPerBlock with a formula that makes it necessary
     * to always fill the block with the maximum amount of samples, but this is
     * not enforced here as there are no compatibility issues.
     */
    if (blockdatasamples < format->samplesperblock - 1) {
        return SDL_SetError("Invalid number of samples per IMA ADPCM block (wSamplesPerBlock)");
    }
 
    if (IMA_ADPCM_CalculateSampleFrames(file, datalength) < 0) {
        return -1;
    }
 
    return 0;
}

References WaveFile::chunk, WaveChunk::data, EXTENSIBLE_CODE, WaveFile::format, IMA_ADPCM_CalculateSampleFrames(), SDL_SetError, and WaveChunk::size.

Referenced by WaveCheckFormat().

IMA_ADPCM_ProcessNibble()

static Sint16 IMA_ADPCM_ProcessNibble ( Sint8 *  cindex, Sint16  lastsample, Uint8  nybble  )

static

Definition at line 860 of file SDL_wave.c.

{
    const Sint32 max_audioval = 32767;
    const Sint32 min_audioval = -32768;
    const Sint8 index_table_4b[16] = {
        -1, -1, -1, -1,
        2, 4, 6, 8,
        -1, -1, -1, -1,
        2, 4, 6, 8
    };
    const Uint16 step_table[89] = {
        7, 8, 9, 10, 11, 12, 13, 14, 16, 17, 19, 21, 23, 25, 28, 31,
        34, 37, 41, 45, 50, 55, 60, 66, 73, 80, 88, 97, 107, 118, 130,
        143, 157, 173, 190, 209, 230, 253, 279, 307, 337, 371, 408,
        449, 494, 544, 598, 658, 724, 796, 876, 963, 1060, 1166, 1282,
        1411, 1552, 1707, 1878, 2066, 2272, 2499, 2749, 3024, 3327,
        3660, 4026, 4428, 4871, 5358, 5894, 6484, 7132, 7845, 8630,
        9493, 10442, 11487, 12635, 13899, 15289, 16818, 18500, 20350,
        22385, 24623, 27086, 29794, 32767
    };
    Uint32 step;
    Sint32 sample, delta;
    Sint8 index = *cindex;
 
    /* Clamp index into valid range. */
    if (index > 88) {
        index = 88;
    } else if (index < 0) {
        index = 0;
    }
 
    /* explicit cast to avoid gcc warning about using 'char' as array index */
    step = step_table[(size_t)index];
 
    /* Update index value */
    *cindex = index + index_table_4b[nybble];
 
    /* This calculation uses shifts and additions because multiplications were
     * much slower back then. Sadly, this can't just be replaced with an actual
     * multiplication now as the old algorithm drops some bits. The closest
     * approximation I could find is something like this:
     * (nybble & 0x8 ? -1 : 1) * ((nybble & 0x7) * step / 4 + step / 8)
     */
    delta = step >> 3;
    if (nybble & 0x04)
        delta += step;
    if (nybble & 0x02)
        delta += step >> 1;
    if (nybble & 0x01)
        delta += step >> 2;
    if (nybble & 0x08)
        delta = -delta;
 
    sample = lastsample + delta;
 
    /* Clamp output sample */
    if (sample > max_audioval) {
        sample = max_audioval;
    } else if (sample < min_audioval) {
        sample = min_audioval;
    }
 
    return (Sint16)sample;
}

Referenced by IMA_ADPCM_DecodeBlockData().

LAW_Decode()

static int LAW_Decode ( WaveFile *  file, Uint8 **  audio_buf, Uint32 *  audio_len  )

static

Definition at line 1169 of file SDL_wave.c.

{
#ifdef SDL_WAVE_LAW_LUT
    const Sint16 alaw_lut[256] = {
        -5504, -5248, -6016, -5760, -4480, -4224, -4992, -4736, -7552, -7296, -8064, -7808, -6528, -6272, -7040, -6784, -2752,
        -2624, -3008, -2880, -2240, -2112, -2496, -2368, -3776, -3648, -4032, -3904, -3264, -3136, -3520, -3392, -22016,
        -20992, -24064, -23040, -17920, -16896, -19968, -18944, -30208, -29184, -32256, -31232, -26112, -25088, -28160, -27136, -11008,
        -10496, -12032, -11520, -8960, -8448, -9984, -9472, -15104, -14592, -16128, -15616, -13056, -12544, -14080, -13568, -344,
        -328, -376, -360, -280, -264, -312, -296, -472, -456, -504, -488, -408, -392, -440, -424, -88,
        -72, -120, -104, -24, -8, -56, -40, -216, -200, -248, -232, -152, -136, -184, -168, -1376,
        -1312, -1504, -1440, -1120, -1056, -1248, -1184, -1888, -1824, -2016, -1952, -1632, -1568, -1760, -1696, -688,
        -656, -752, -720, -560, -528, -624, -592, -944, -912, -1008, -976, -816, -784, -880, -848, 5504,
        5248, 6016, 5760, 4480, 4224, 4992, 4736, 7552, 7296, 8064, 7808, 6528, 6272, 7040, 6784, 2752,
        2624, 3008, 2880, 2240, 2112, 2496, 2368, 3776, 3648, 4032, 3904, 3264, 3136, 3520, 3392, 22016,
        20992, 24064, 23040, 17920, 16896, 19968, 18944, 30208, 29184, 32256, 31232, 26112, 25088, 28160, 27136, 11008,
        10496, 12032, 11520, 8960, 8448, 9984, 9472, 15104, 14592, 16128, 15616, 13056, 12544, 14080, 13568, 344,
        328, 376, 360, 280, 264, 312, 296, 472, 456, 504, 488, 408, 392, 440, 424, 88,
        72, 120, 104, 24, 8, 56, 40, 216, 200, 248, 232, 152, 136, 184, 168, 1376,
        1312, 1504, 1440, 1120, 1056, 1248, 1184, 1888, 1824, 2016, 1952, 1632, 1568, 1760, 1696, 688,
        656, 752, 720, 560, 528, 624, 592, 944, 912, 1008, 976, 816, 784, 880, 848
    };
    const Sint16 mulaw_lut[256] = {
        -32124, -31100, -30076, -29052, -28028, -27004, -25980, -24956, -23932, -22908, -21884, -20860, -19836, -18812, -17788, -16764, -15996,
        -15484, -14972, -14460, -13948, -13436, -12924, -12412, -11900, -11388, -10876, -10364, -9852, -9340, -8828, -8316, -7932,
        -7676, -7420, -7164, -6908, -6652, -6396, -6140, -5884, -5628, -5372, -5116, -4860, -4604, -4348, -4092, -3900,
        -3772, -3644, -3516, -3388, -3260, -3132, -3004, -2876, -2748, -2620, -2492, -2364, -2236, -2108, -1980, -1884,
        -1820, -1756, -1692, -1628, -1564, -1500, -1436, -1372, -1308, -1244, -1180, -1116, -1052, -988, -924, -876,
        -844, -812, -780, -748, -716, -684, -652, -620, -588, -556, -524, -492, -460, -428, -396, -372,
        -356, -340, -324, -308, -292, -276, -260, -244, -228, -212, -196, -180, -164, -148, -132, -120,
        -112, -104, -96, -88, -80, -72, -64, -56, -48, -40, -32, -24, -16, -8, 0, 32124,
        31100, 30076, 29052, 28028, 27004, 25980, 24956, 23932, 22908, 21884, 20860, 19836, 18812, 17788, 16764, 15996,
        15484, 14972, 14460, 13948, 13436, 12924, 12412, 11900, 11388, 10876, 10364, 9852, 9340, 8828, 8316, 7932,
        7676, 7420, 7164, 6908, 6652, 6396, 6140, 5884, 5628, 5372, 5116, 4860, 4604, 4348, 4092, 3900,
        3772, 3644, 3516, 3388, 3260, 3132, 3004, 2876, 2748, 2620, 2492, 2364, 2236, 2108, 1980, 1884,
        1820, 1756, 1692, 1628, 1564, 1500, 1436, 1372, 1308, 1244, 1180, 1116, 1052, 988, 924, 876,
        844, 812, 780, 748, 716, 684, 652, 620, 588, 556, 524, 492, 460, 428, 396, 372,
        356, 340, 324, 308, 292, 276, 260, 244, 228, 212, 196, 180, 164, 148, 132, 120,
        112, 104, 96, 88, 80, 72, 64, 56, 48, 40, 32, 24, 16, 8, 0
    };
#endif
 
    WaveFormat *format = &file->format;
    WaveChunk *chunk = &file->chunk;
    size_t i, sample_count, expanded_len;
    Uint8 *src;
    Sint16 *dst;
 
    if (chunk->length != chunk->size) {
        file->sampleframes = WaveAdjustToFactValue(file, chunk->size / format->blockalign);
        if (file->sampleframes < 0) {
            return -1;
        }
    }
 
    /* Nothing to decode, nothing to return. */
    if (file->sampleframes == 0) {
        *audio_buf = NULL;
        *audio_len = 0;
        return 0;
    }
 
    sample_count = (size_t)file->sampleframes;
    if (SafeMult(&sample_count, format->channels)) {
        return SDL_OutOfMemory();
    }
 
    expanded_len = sample_count;
    if (SafeMult(&expanded_len, sizeof(Sint16))) {
        return SDL_OutOfMemory();
    } else if (expanded_len > SDL_MAX_UINT32 || file->sampleframes > SIZE_MAX) {
        return SDL_SetError("WAVE file too big");
    }
 
    /* 1 to avoid allocating zero bytes, to keep static analysis happy. */
    src = (Uint8 *)SDL_realloc(chunk->data, expanded_len ? expanded_len : 1);
    if (src == NULL) {
        return SDL_OutOfMemory();
    }
    chunk->data = NULL;
    chunk->size = 0;
 
    dst = (Sint16 *)src;
 
    /* Work backwards, since we're expanding in-place. SDL_AudioSpec.format will
     * inform the caller about the byte order.
     */
    i = sample_count;
    switch (file->format.encoding) {
#ifdef SDL_WAVE_LAW_LUT
    case ALAW_CODE:
        while (i--) {
            dst[i] = alaw_lut[src[i]];
        }
        break;
    case MULAW_CODE:
        while (i--) {
            dst[i] = mulaw_lut[src[i]];
        }
        break;
#else
    case ALAW_CODE:
        while (i--) {
            Uint8 nibble = src[i];
            Uint8 exponent = (nibble & 0x7f) ^ 0x55;
            Sint16 mantissa = exponent & 0xf;
 
            exponent >>= 4;
            if (exponent > 0) {
                mantissa |= 0x10;
            }
            mantissa = (mantissa << 4) | 0x8;
            if (exponent > 1) {
                mantissa <<= exponent - 1;
            }
 
            dst[i] = nibble & 0x80 ? mantissa : -mantissa;
        }
        break;
    case MULAW_CODE:
        while (i--) {
            Uint8 nibble = ~src[i];
            Sint16 mantissa = nibble & 0xf;
            Uint8 exponent = (nibble >> 4) & 0x7;
            Sint16 step = 4 << (exponent + 1);
 
            mantissa = (0x80 << exponent) + step * mantissa + step / 2 - 132;
 
            dst[i] = nibble & 0x80 ? -mantissa : mantissa;
        }
        break;
#endif
    default:
        SDL_free(src);
        return SDL_SetError("Unknown companded encoding");
    }
 
    *audio_buf = src;
    *audio_len = (Uint32)expanded_len;
 
    return 0;
}

References ALAW_CODE, WaveFile::chunk, WaveChunk::data, WaveFormat::encoding, WaveFile::format, i, if, WaveChunk::length, MULAW_CODE, nibble(), NULL, SafeMult(), WaveFile::sampleframes, SDL_free, SDL_MAX_UINT32, SDL_OutOfMemory, SDL_realloc, SDL_SetError, WaveChunk::size, SIZE_MAX, and WaveAdjustToFactValue().

Referenced by WaveLoad().

LAW_Init()

static int LAW_Init ( WaveFile *  file, size_t  datalength  )

static

Definition at line 1140 of file SDL_wave.c.

{
    WaveFormat *format = &file->format;
 
    /* Standards Update requires this to be 8. */
    if (format->bitspersample != 8) {
        return SDL_SetError("Invalid companded bits per sample of %u", (unsigned int)format->bitspersample);
    }
 
    /* Not going to bother with weird padding. */
    if (format->blockalign != format->channels) {
        return SDL_SetError("Unsupported block alignment");
    }
 
    if ((file->trunchint == TruncVeryStrict || file->trunchint == TruncStrict)) {
        if (format->blockalign > 1 && datalength % format->blockalign) {
            return SDL_SetError("Truncated data chunk in WAVE file");
        }
    }
 
    file->sampleframes = WaveAdjustToFactValue(file, datalength / format->blockalign);
    if (file->sampleframes < 0) {
        return -1;
    }
 
    return 0;
}

References WaveFile::format, WaveFile::sampleframes, SDL_SetError, WaveFile::trunchint, TruncStrict, TruncVeryStrict, and WaveAdjustToFactValue().

Referenced by WaveCheckFormat().

MS_ADPCM_CalculateSampleFrames()

static int MS_ADPCM_CalculateSampleFrames ( WaveFile *  file, size_t  datalength  )

static

Definition at line 335 of file SDL_wave.c.

{
    WaveFormat *format = &file->format;
    const size_t blockheadersize = (size_t)file->format.channels * 7;
    const size_t availableblocks = datalength / file->format.blockalign;
    const size_t blockframebitsize = (size_t)file->format.bitspersample * file->format.channels;
    const size_t trailingdata = datalength % file->format.blockalign;
 
    if (file->trunchint == TruncVeryStrict || file->trunchint == TruncStrict) {
        /* The size of the data chunk must be a multiple of the block size. */
        if (datalength < blockheadersize || trailingdata > 0) {
            return SDL_SetError("Truncated MS ADPCM block");
        }
    }
 
    /* Calculate number of sample frames that will be decoded. */
    file->sampleframes = (Sint64)availableblocks * format->samplesperblock;
    if (trailingdata > 0) {
        /* The last block is truncated. Check if we can get any samples out of it. */
        if (file->trunchint == TruncDropFrame) {
            /* Drop incomplete sample frame. */
            if (trailingdata >= blockheadersize) {
                size_t trailingsamples = 2 + (trailingdata - blockheadersize) * 8 / blockframebitsize;
                if (trailingsamples > format->samplesperblock) {
                    trailingsamples = format->samplesperblock;
                }
                file->sampleframes += trailingsamples;
            }
        }
    }
 
    file->sampleframes = WaveAdjustToFactValue(file, file->sampleframes);
    if (file->sampleframes < 0) {
        return -1;
    }
 
    return 0;
}

References WaveFormat::bitspersample, WaveFormat::blockalign, WaveFormat::channels, WaveFile::format, if, WaveFile::sampleframes, SDL_SetError, TruncDropFrame, WaveFile::trunchint, TruncStrict, TruncVeryStrict, and WaveAdjustToFactValue().

Referenced by MS_ADPCM_Decode(), and MS_ADPCM_Init().

MS_ADPCM_Decode()

static int MS_ADPCM_Decode ( WaveFile *  file, Uint8 **  audio_buf, Uint32 *  audio_len  )

static

Definition at line 640 of file SDL_wave.c.

{
    int result;
    size_t bytesleft, outputsize;
    WaveChunk *chunk = &file->chunk;
    ADPCM_DecoderState state;
    MS_ADPCM_ChannelState cstate[2];
 
    SDL_zero(state);
    SDL_zeroa(cstate);
 
    if (chunk->size != chunk->length) {
        /* Could not read everything. Recalculate number of sample frames. */
        if (MS_ADPCM_CalculateSampleFrames(file, chunk->size) < 0) {
            return -1;
        }
    }
 
    /* Nothing to decode, nothing to return. */
    if (file->sampleframes == 0) {
        *audio_buf = NULL;
        *audio_len = 0;
        return 0;
    }
 
    state.blocksize = file->format.blockalign;
    state.channels = file->format.channels;
    state.blockheadersize = (size_t)state.channels * 7;
    state.samplesperblock = file->format.samplesperblock;
    state.framesize = state.channels * sizeof(Sint16);
    state.ddata = file->decoderdata;
    state.framestotal = file->sampleframes;
    state.framesleft = state.framestotal;
 
    state.input.data = chunk->data;
    state.input.size = chunk->size;
    state.input.pos = 0;
 
    /* The output size in bytes. May get modified if data is truncated. */
    outputsize = (size_t)state.framestotal;
    if (SafeMult(&outputsize, state.framesize)) {
        return SDL_OutOfMemory();
    } else if (outputsize > SDL_MAX_UINT32 || state.framestotal > SIZE_MAX) {
        return SDL_SetError("WAVE file too big");
    }
 
    state.output.pos = 0;
    state.output.size = outputsize / sizeof(Sint16);
    state.output.data = (Sint16 *)SDL_malloc(outputsize);
    if (state.output.data == NULL) {
        return SDL_OutOfMemory();
    }
 
    state.cstate = cstate;
 
    /* Decode block by block. A truncated block will stop the decoding. */
    bytesleft = state.input.size - state.input.pos;
    while (state.framesleft > 0 && bytesleft >= state.blockheadersize) {
        state.block.data = state.input.data + state.input.pos;
        state.block.size = bytesleft < state.blocksize ? bytesleft : state.blocksize;
        state.block.pos = 0;
 
        if (state.output.size - state.output.pos < (Uint64)state.framesleft * state.channels) {
            /* Somehow didn't allocate enough space for the output. */
            SDL_free(state.output.data);
            return SDL_SetError("Unexpected overflow in MS ADPCM decoder");
        }
 
        /* Initialize decoder with the values from the block header. */
        result = MS_ADPCM_DecodeBlockHeader(&state);
        if (result == -1) {
            SDL_free(state.output.data);
            return -1;
        }
 
        /* Decode the block data. It stores the samples directly in the output. */
        result = MS_ADPCM_DecodeBlockData(&state);
        if (result == -1) {
            /* Unexpected end. Stop decoding and return partial data if necessary. */
            if (file->trunchint == TruncVeryStrict || file->trunchint == TruncStrict) {
                SDL_free(state.output.data);
                return SDL_SetError("Truncated data chunk");
            } else if (file->trunchint != TruncDropFrame) {
                state.output.pos -= state.output.pos % (state.samplesperblock * state.channels);
            }
            outputsize = state.output.pos * sizeof(Sint16); /* Can't overflow, is always smaller. */
            break;
        }
 
        state.input.pos += state.block.size;
        bytesleft = state.input.size - state.input.pos;
    }
 
    *audio_buf = (Uint8 *)state.output.data;
    *audio_len = (Uint32)outputsize;
 
    return 0;
}

References WaveFormat::blockalign, WaveFormat::channels, WaveFile::chunk, WaveChunk::data, WaveFile::decoderdata, WaveFile::format, if, WaveChunk::length, MS_ADPCM_CalculateSampleFrames(), MS_ADPCM_DecodeBlockData(), MS_ADPCM_DecodeBlockHeader(), NULL, SafeMult(), WaveFile::sampleframes, WaveFormat::samplesperblock, SDL_free, SDL_malloc, SDL_MAX_UINT32, SDL_OutOfMemory, SDL_SetError, SDL_zero, SDL_zeroa, WaveChunk::size, SIZE_MAX, state, TruncDropFrame, WaveFile::trunchint, TruncStrict, and TruncVeryStrict.

Referenced by WaveLoad().

MS_ADPCM_DecodeBlockData()

static int MS_ADPCM_DecodeBlockData ( ADPCM_DecoderState *  state )

static

Definition at line 592 of file SDL_wave.c.

{
    Uint16 nybble = 0;
    Sint16 sample1, sample2;
    const Uint32 channels = state->channels;
    Uint32 c;
    MS_ADPCM_ChannelState *cstate = (MS_ADPCM_ChannelState *)state->cstate;
 
    size_t blockpos = state->block.pos;
    size_t blocksize = state->block.size;
 
    size_t outpos = state->output.pos;
 
    Sint64 blockframesleft = state->samplesperblock - 2;
    if (blockframesleft > state->framesleft) {
        blockframesleft = state->framesleft;
    }
 
    while (blockframesleft > 0) {
        for (c = 0; c < channels; c++) {
            if (nybble & 0x4000) {
                nybble <<= 4;
            } else if (blockpos < blocksize) {
                nybble = state->block.data[blockpos++] | 0x4000;
            } else {
                /* Out of input data. Drop the incomplete frame and return. */
                state->output.pos = outpos - c;
                return -1;
            }
 
            /* Load previous samples which may come from the block header. */
            sample1 = state->output.data[outpos - channels];
            sample2 = state->output.data[outpos - channels * 2];
 
            sample1 = MS_ADPCM_ProcessNibble(cstate + c, sample1, sample2, (nybble >> 4) & 0x0f);
            state->output.data[outpos++] = sample1;
        }
 
        state->framesleft--;
        blockframesleft--;
    }
 
    state->output.pos = outpos;
 
    return 0;
}

References if, MS_ADPCM_ProcessNibble(), and state.

Referenced by MS_ADPCM_Decode().

MS_ADPCM_DecodeBlockHeader()

static int MS_ADPCM_DecodeBlockHeader ( ADPCM_DecoderState *  state )

static

Definition at line 531 of file SDL_wave.c.

{
    Uint8 coeffindex;
    const Uint32 channels = state->channels;
    Sint32 sample;
    Uint32 c;
    MS_ADPCM_ChannelState *cstate = (MS_ADPCM_ChannelState *)state->cstate;
    MS_ADPCM_CoeffData *ddata = (MS_ADPCM_CoeffData *)state->ddata;
 
    for (c = 0; c < channels; c++) {
        size_t o = c;
 
        /* Load the coefficient pair into the channel state. */
        coeffindex = state->block.data[o];
        if (coeffindex > ddata->coeffcount) {
            return SDL_SetError("Invalid MS ADPCM coefficient index in block header");
        }
        cstate[c].coeff1 = ddata->coeff[coeffindex * 2];
        cstate[c].coeff2 = ddata->coeff[coeffindex * 2 + 1];
 
        /* Initial delta value. */
        o = channels + c * 2;
        cstate[c].delta = state->block.data[o] | ((Uint16)state->block.data[o + 1] << 8);
 
        /* Load the samples from the header. Interestingly, the sample later in
         * the output stream comes first.
         */
        o = channels * 3 + c * 2;
        sample = state->block.data[o] | ((Sint32)state->block.data[o + 1] << 8);
        if (sample >= 0x8000) {
            sample -= 0x10000;
        }
        state->output.data[state->output.pos + channels] = (Sint16)sample;
 
        o = channels * 5 + c * 2;
        sample = state->block.data[o] | ((Sint32)state->block.data[o + 1] << 8);
        if (sample >= 0x8000) {
            sample -= 0x10000;
        }
        state->output.data[state->output.pos] = (Sint16)sample;
 
        state->output.pos++;
    }
 
    state->block.pos += state->blockheadersize;
 
    /* Skip second sample frame that came from the header. */
    state->output.pos += state->channels;
 
    /* Header provided two sample frames. */
    state->framesleft -= 2;
 
    return 0;
}

References MS_ADPCM_ChannelState::coeff1, MS_ADPCM_ChannelState::coeff2, MS_ADPCM_ChannelState::delta, SDL_SetError, and state.

Referenced by MS_ADPCM_Decode().

MS_ADPCM_Init()

static int MS_ADPCM_Init ( WaveFile *  file, size_t  datalength  )

static

Definition at line 375 of file SDL_wave.c.

{
    WaveFormat *format = &file->format;
    WaveChunk *chunk = &file->chunk;
    const size_t blockheadersize = (size_t)format->channels * 7;
    const size_t blockdatasize = (size_t)format->blockalign - blockheadersize;
    const size_t blockframebitsize = (size_t)format->bitspersample * format->channels;
    const size_t blockdatasamples = (blockdatasize * 8) / blockframebitsize;
    const Sint16 presetcoeffs[14] = {256, 0, 512, -256, 0, 0, 192, 64, 240, 0, 460, -208, 392, -232};
    size_t i, coeffcount;
    MS_ADPCM_CoeffData *coeffdata;
 
    /* Sanity checks. */
 
    /* While it's clear how IMA ADPCM handles more than two channels, the nibble
     * order of MS ADPCM makes it awkward. The Standards Update does not talk
     * about supporting more than stereo anyway.
     */
    if (format->channels > 2) {
        return SDL_SetError("Invalid number of channels");
    }
 
    if (format->bitspersample != 4) {
        return SDL_SetError("Invalid MS ADPCM bits per sample of %u", (unsigned int)format->bitspersample);
    }
 
    /* The block size must be big enough to contain the block header. */
    if (format->blockalign < blockheadersize) {
        return SDL_SetError("Invalid MS ADPCM block size (nBlockAlign)");
    }
 
    if (format->formattag == EXTENSIBLE_CODE) {
        /* Does have a GUID (like all format tags), but there's no specification
         * for how the data is packed into the extensible header. Making
         * assumptions here could lead to new formats nobody wants to support.
         */
        return SDL_SetError("MS ADPCM with the extensible header is not supported");
    }
 
    /* There are wSamplesPerBlock, wNumCoef, and at least 7 coefficient pairs in
     * the extended part of the header.
     */
    if (chunk->size < 22) {
        return SDL_SetError("Could not read MS ADPCM format header");
    }
 
    format->samplesperblock = chunk->data[18] | ((Uint16)chunk->data[19] << 8);
    /* Number of coefficient pairs. A pair has two 16-bit integers. */
    coeffcount = chunk->data[20] | ((size_t)chunk->data[21] << 8);
    /* bPredictor, the integer offset into the coefficients array, is only
     * 8 bits. It can only address the first 256 coefficients. Let's limit
     * the count number here.
     */
    if (coeffcount > 256) {
        coeffcount = 256;
    }
 
    if (chunk->size < 22 + coeffcount * 4) {
        return SDL_SetError("Could not read custom coefficients in MS ADPCM format header");
    } else if (format->extsize < 4 + coeffcount * 4) {
        return SDL_SetError("Invalid MS ADPCM format header (too small)");
    } else if (coeffcount < 7) {
        return SDL_SetError("Missing required coefficients in MS ADPCM format header");
    }
 
    coeffdata = (MS_ADPCM_CoeffData *)SDL_malloc(sizeof(MS_ADPCM_CoeffData) + coeffcount * 4);
    file->decoderdata = coeffdata; /* Freed in cleanup. */
    if (coeffdata == NULL) {
        return SDL_OutOfMemory();
    }
    coeffdata->coeff = &coeffdata->aligndummy;
    coeffdata->coeffcount = (Uint16)coeffcount;
 
    /* Copy the 16-bit pairs. */
    for (i = 0; i < coeffcount * 2; i++) {
        Sint32 c = chunk->data[22 + i * 2] | ((Sint32)chunk->data[23 + i * 2] << 8);
        if (c >= 0x8000) {
            c -= 0x10000;
        }
        if (i < 14 && c != presetcoeffs[i]) {
            return SDL_SetError("Wrong preset coefficients in MS ADPCM format header");
        }
        coeffdata->coeff[i] = (Sint16)c;
    }
 
    /* Technically, wSamplesPerBlock is required, but we have all the
     * information in the other fields to calculate it, if it's zero.
     */
    if (format->samplesperblock == 0) {
        /* Let's be nice to the encoders that didn't know how to fill this.
         * The Standards Update calculates it this way:
         *
         *   x = Block size (in bits) minus header size (in bits)
         *   y = Bit depth multiplied by channel count
         *   z = Number of samples per channel in block header
         *   wSamplesPerBlock = x / y + z
         */
        format->samplesperblock = (Uint32)blockdatasamples + 2;
    }
 
    /* nBlockAlign can be in conflict with wSamplesPerBlock. For example, if
     * the number of samples doesn't fit into the block. The Standards Update
     * also describes wSamplesPerBlock with a formula that makes it necessary to
     * always fill the block with the maximum amount of samples, but this is not
     * enforced here as there are no compatibility issues.
     * A truncated block header with just one sample is not supported.
     */
    if (format->samplesperblock == 1 || blockdatasamples < format->samplesperblock - 2) {
        return SDL_SetError("Invalid number of samples per MS ADPCM block (wSamplesPerBlock)");
    }
 
    if (MS_ADPCM_CalculateSampleFrames(file, datalength) < 0) {
        return -1;
    }
 
    return 0;
}

References MS_ADPCM_CoeffData::aligndummy, WaveFile::chunk, MS_ADPCM_CoeffData::coeff, MS_ADPCM_CoeffData::coeffcount, WaveChunk::data, WaveFile::decoderdata, EXTENSIBLE_CODE, WaveFile::format, i, MS_ADPCM_CalculateSampleFrames(), NULL, SDL_malloc, SDL_OutOfMemory, SDL_SetError, and WaveChunk::size.

Referenced by WaveCheckFormat().

MS_ADPCM_ProcessNibble()

static Sint16 MS_ADPCM_ProcessNibble ( MS_ADPCM_ChannelState *  cstate, Sint32  sample1, Sint32  sample2, Uint8  nybble  )

static

Definition at line 494 of file SDL_wave.c.

{
    const Sint32 max_audioval = 32767;
    const Sint32 min_audioval = -32768;
    const Uint16 max_deltaval = 65535;
    const Uint16 adaptive[] = {
        230, 230, 230, 230, 307, 409, 512, 614,
        768, 614, 512, 409, 307, 230, 230, 230
    };
    Sint32 new_sample;
    Sint32 errordelta;
    Uint32 delta = cstate->delta;
 
    new_sample = (sample1 * cstate->coeff1 + sample2 * cstate->coeff2) / 256;
    /* The nibble is a signed 4-bit error delta. */
    errordelta = (Sint32)nybble - (nybble >= 0x08 ? 0x10 : 0);
    new_sample += (Sint32)delta * errordelta;
    if (new_sample < min_audioval) {
        new_sample = min_audioval;
    } else if (new_sample > max_audioval) {
        new_sample = max_audioval;
    }
    delta = (delta * adaptive[nybble]) / 256;
    if (delta < 16) {
        delta = 16;
    } else if (delta > max_deltaval) {
        /* This issue is not described in the Standards Update and therefore
         * undefined. It seems sensible to prevent overflows with a limit.
         */
        delta = max_deltaval;
    }
 
    cstate->delta = (Uint16)delta;
    return (Sint16)new_sample;
}

References MS_ADPCM_ChannelState::coeff1, MS_ADPCM_ChannelState::coeff2, and MS_ADPCM_ChannelState::delta.

Referenced by MS_ADPCM_DecodeBlockData().

PCM_ConvertSint24ToSint32()

static int PCM_ConvertSint24ToSint32 ( WaveFile *  file, Uint8 **  audio_buf, Uint32 *  audio_len  )

static

Definition at line 1356 of file SDL_wave.c.

{
    WaveFormat *format = &file->format;
    WaveChunk *chunk = &file->chunk;
    size_t i, expanded_len, sample_count;
    Uint8 *ptr;
 
    sample_count = (size_t)file->sampleframes;
    if (SafeMult(&sample_count, format->channels)) {
        return SDL_OutOfMemory();
    }
 
    expanded_len = sample_count;
    if (SafeMult(&expanded_len, sizeof(Sint32))) {
        return SDL_OutOfMemory();
    } else if (expanded_len > SDL_MAX_UINT32 || file->sampleframes > SIZE_MAX) {
        return SDL_SetError("WAVE file too big");
    }
 
    /* 1 to avoid allocating zero bytes, to keep static analysis happy. */
    ptr = (Uint8 *)SDL_realloc(chunk->data, expanded_len ? expanded_len : 1);
    if (ptr == NULL) {
        return SDL_OutOfMemory();
    }
 
    /* This pointer is now invalid. */
    chunk->data = NULL;
    chunk->size = 0;
 
    *audio_buf = ptr;
    *audio_len = (Uint32)expanded_len;
 
    /* work from end to start, since we're expanding in-place. */
    for (i = sample_count; i > 0; i--) {
        const size_t o = i - 1;
        uint8_t b[4];
 
        b[0] = 0;
        b[1] = ptr[o * 3];
        b[2] = ptr[o * 3 + 1];
        b[3] = ptr[o * 3 + 2];
 
        ptr[o * 4 + 0] = b[0];
        ptr[o * 4 + 1] = b[1];
        ptr[o * 4 + 2] = b[2];
        ptr[o * 4 + 3] = b[3];
    }
 
    return 0;
}

References WaveFile::chunk, WaveChunk::data, WaveFile::format, i, if, NULL, ptr, SafeMult(), WaveFile::sampleframes, SDL_MAX_UINT32, SDL_OutOfMemory, SDL_realloc, SDL_SetError, WaveChunk::size, and SIZE_MAX.

Referenced by PCM_Decode().

PCM_Decode()

static int PCM_Decode ( WaveFile *  file, Uint8 **  audio_buf, Uint32 *  audio_len  )

static

Definition at line 1408 of file SDL_wave.c.

{
    WaveFormat *format = &file->format;
    WaveChunk *chunk = &file->chunk;
    size_t outputsize;
 
    if (chunk->length != chunk->size) {
        file->sampleframes = WaveAdjustToFactValue(file, chunk->size / format->blockalign);
        if (file->sampleframes < 0) {
            return -1;
        }
    }
 
    /* Nothing to decode, nothing to return. */
    if (file->sampleframes == 0) {
        *audio_buf = NULL;
        *audio_len = 0;
        return 0;
    }
 
    /* 24-bit samples get shifted to 32 bits. */
    if (format->encoding == PCM_CODE && format->bitspersample == 24) {
        return PCM_ConvertSint24ToSint32(file, audio_buf, audio_len);
    }
 
    outputsize = (size_t)file->sampleframes;
    if (SafeMult(&outputsize, format->blockalign)) {
        return SDL_OutOfMemory();
    } else if (outputsize > SDL_MAX_UINT32 || file->sampleframes > SIZE_MAX) {
        return SDL_SetError("WAVE file too big");
    }
 
    *audio_buf = chunk->data;
    *audio_len = (Uint32)outputsize;
 
    /* This pointer is going to be returned to the caller. Prevent free in cleanup. */
    chunk->data = NULL;
    chunk->size = 0;
 
    return 0;
}

References WaveFile::chunk, WaveChunk::data, WaveFile::format, if, WaveChunk::length, NULL, PCM_CODE, PCM_ConvertSint24ToSint32(), SafeMult(), WaveFile::sampleframes, SDL_MAX_UINT32, SDL_OutOfMemory, SDL_SetError, WaveChunk::size, SIZE_MAX, and WaveAdjustToFactValue().

Referenced by WaveLoad().

PCM_Init()

static int PCM_Init ( WaveFile *  file, size_t  datalength  )

static

Definition at line 1312 of file SDL_wave.c.

{
    WaveFormat *format = &file->format;
 
    if (format->encoding == PCM_CODE) {
        switch (format->bitspersample) {
        case 8:
        case 16:
        case 24:
        case 32:
            /* These are supported. */
            break;
        default:
            return SDL_SetError("%u-bit PCM format not supported", (unsigned int)format->bitspersample);
        }
    } else if (format->encoding == IEEE_FLOAT_CODE) {
        if (format->bitspersample != 32) {
            return SDL_SetError("%u-bit IEEE floating-point format not supported", (unsigned int)format->bitspersample);
        }
    }
 
    /* It wouldn't be that hard to support more exotic block sizes, but
     * the most common formats should do for now.
     */
    /* Make sure we're a multiple of the blockalign, at least. */
    if ((format->channels * format->bitspersample) % (format->blockalign * 8)) {
        return SDL_SetError("Unsupported block alignment");
    }
 
    if ((file->trunchint == TruncVeryStrict || file->trunchint == TruncStrict)) {
        if (format->blockalign > 1 && datalength % format->blockalign) {
            return SDL_SetError("Truncated data chunk in WAVE file");
        }
    }
 
    file->sampleframes = WaveAdjustToFactValue(file, datalength / format->blockalign);
    if (file->sampleframes < 0) {
        return -1;
    }
 
    return 0;
}

References WaveFile::format, IEEE_FLOAT_CODE, PCM_CODE, WaveFile::sampleframes, SDL_SetError, WaveFile::trunchint, TruncStrict, TruncVeryStrict, and WaveAdjustToFactValue().

Referenced by WaveCheckFormat().

SafeMult()

static int SafeMult ( size_t *  f1, size_t  f2  )

static

Definition at line 47 of file SDL_wave.c.

{
    if (*f1 > 0 && SIZE_MAX / *f1 <= f2) {
        return -1;
    }
    *f1 *= f2;
    return 0;
}

References SIZE_MAX.

Referenced by IMA_ADPCM_Decode(), LAW_Decode(), MS_ADPCM_Decode(), PCM_ConvertSint24ToSint32(), and PCM_Decode().

SDL_FreeWAV()

void SDL_FreeWAV

(

Uint8 *

audio_buf

)

This function frees data previously allocated with SDL_LoadWAV_RW()

Definition at line 2150 of file SDL_wave.c.

{
    SDL_free(audio_buf);
}

References SDL_free.

SDL_LoadWAV_RW()

SDL_AudioSpec* SDL_LoadWAV_RW	(	SDL_RWops *	src,
		int	freesrc,
		SDL_AudioSpec *	spec,
		Uint8 **	audio_buf,
		Uint32 *	audio_len
	)

Load the audio data of a WAVE file into memory.

Loading a WAVE file requires src, spec, audio_buf and audio_len to be valid pointers. The entire data portion of the file is then loaded into memory and decoded if necessary.

If freesrc is non-zero, the data source gets automatically closed and freed before the function returns.

Supported are RIFF WAVE files with the formats PCM (8, 16, 24, and 32 bits), IEEE Float (32 bits), Microsoft ADPCM and IMA ADPCM (4 bits), and A-law and µ-law (8 bits). Other formats are currently unsupported and cause an error.

If this function succeeds, the pointer returned by it is equal to spec and the pointer to the audio data allocated by the function is written to audio_buf and its length in bytes to audio_len. The SDL_AudioSpec members freq, channels, and format are set to the values of the audio data in the buffer. The samples member is set to a sane default and all others are set to zero.

It's necessary to use SDL_FreeWAV() to free the audio data returned in audio_buf when it is no longer used.

Because of the underspecification of the Waveform format, there are many problematic files in the wild that cause issues with strict decoders. To provide compatibility with these files, this decoder is lenient in regards to the truncation of the file, the fact chunk, and the size of the RIFF chunk. The hints SDL_HINT_WAVE_RIFF_CHUNK_SIZE, SDL_HINT_WAVE_TRUNCATION, and SDL_HINT_WAVE_FACT_CHUNK can be used to tune the behavior of the loading process.

Any file that is invalid (due to truncation, corruption, or wrong values in the headers), too big, or unsupported causes an error. Additionally, any critical I/O error from the data source will terminate the loading process with an error. The function returns NULL on error and in all cases (with the exception of src being NULL), an appropriate error message will be set.

It is required that the data source supports seeking.

Example:

SDL_LoadWAV_RW(SDL_RWFromFile("sample.wav", "rb"), 1, ...);

Parameters

src	The data source with the WAVE data
freesrc	A integer value that makes the function close the data source if non-zero
spec	A pointer filled with the audio format of the audio data
audio_buf	A pointer filled with the audio data allocated by the function
audio_len	A pointer filled with the length of the audio data buffer in bytes

Returns

NULL on error, or non-NULL on success.

Definition at line 2097 of file SDL_wave.c.

{
    int result;
    WaveFile file;
 
    SDL_zero(file);
 
    /* Make sure we are passed a valid data source */
    if (src == NULL) {
        /* Error may come from RWops. */
        return NULL;
    } else if (spec == NULL) {
        SDL_InvalidParamError("spec");
        return NULL;
    } else if (audio_buf == NULL) {
        SDL_InvalidParamError("audio_buf");
        return NULL;
    } else if (audio_len == NULL) {
        SDL_InvalidParamError("audio_len");
        return NULL;
    }
 
    *audio_buf = NULL;
    *audio_len = 0;
 
    file.riffhint = WaveGetRiffSizeHint();
    file.trunchint = WaveGetTruncationHint();
    file.facthint = WaveGetFactChunkHint();
 
    result = WaveLoad(src, &file, spec, audio_buf, audio_len);
    if (result < 0) {
        SDL_free(*audio_buf);
        spec = NULL;
        audio_buf = NULL;
        audio_len = 0;
    }
 
    /* Cleanup */
    if (freesrc) {
        SDL_RWclose(src);
    } else {
        SDL_RWseek(src, file.chunk.position, RW_SEEK_SET);
    }
    WaveFreeChunkData(&file.chunk);
    SDL_free(file.decoderdata);
 
    return spec;
}

References WaveFile::chunk, WaveFile::decoderdata, WaveFile::facthint, NULL, WaveChunk::position, WaveFile::riffhint, RW_SEEK_SET, SDL_free, SDL_InvalidParamError, SDL_RWclose, SDL_RWseek, SDL_zero, spec, WaveFile::trunchint, WaveFreeChunkData(), WaveGetFactChunkHint(), WaveGetRiffSizeHint(), WaveGetTruncationHint(), and WaveLoad().

WaveAdjustToFactValue()

static Sint64 WaveAdjustToFactValue ( WaveFile *  file, Sint64  sampleframes  )

static

Definition at line 321 of file SDL_wave.c.

{
    if (file->fact.status == 2) {
        if (file->facthint == FactStrict && sampleframes < file->fact.samplelength) {
            return SDL_SetError("Invalid number of sample frames in WAVE fact chunk (too many)");
        } else if (sampleframes > file->fact.samplelength) {
            return file->fact.samplelength;
        }
    }
 
    return sampleframes;
}

References WaveFile::fact, WaveFile::facthint, FactStrict, WaveFact::samplelength, SDL_SetError, and WaveFact::status.

Referenced by IMA_ADPCM_CalculateSampleFrames(), LAW_Decode(), LAW_Init(), MS_ADPCM_CalculateSampleFrames(), PCM_Decode(), and PCM_Init().

WaveCheckFormat()

static int WaveCheckFormat ( WaveFile *  file, size_t  datalength  )

static

Definition at line 1679 of file SDL_wave.c.

{
    WaveFormat *format = &file->format;
 
    /* Check for some obvious issues. */
 
    if (format->channels == 0) {
        return SDL_SetError("Invalid number of channels");
    } else if (format->channels > 255) {
        /* Limit given by SDL_AudioSpec.channels. */
        return SDL_SetError("Number of channels exceeds limit of 255");
    }
 
    if (format->frequency == 0) {
        return SDL_SetError("Invalid sample rate");
    } else if (format->frequency > INT_MAX) {
        /* Limit given by SDL_AudioSpec.freq. */
        return SDL_SetError("Sample rate exceeds limit of %d", INT_MAX);
    }
 
    /* Reject invalid fact chunks in strict mode. */
    if (file->facthint == FactStrict && file->fact.status == -1) {
        return SDL_SetError("Invalid fact chunk in WAVE file");
    }
 
    /* Check for issues common to all encodings. Some unsupported formats set
     * the bits per sample to zero. These fall through to the 'unsupported
     * format' error.
     */
    switch (format->encoding) {
    case IEEE_FLOAT_CODE:
    case ALAW_CODE:
    case MULAW_CODE:
    case MS_ADPCM_CODE:
    case IMA_ADPCM_CODE:
        /* These formats require a fact chunk. */
        if (file->facthint == FactStrict && file->fact.status <= 0) {
            return SDL_SetError("Missing fact chunk in WAVE file");
        }
        /* fallthrough */
    case PCM_CODE:
        /* All supported formats require a non-zero bit depth. */
        if (file->chunk.size < 16) {
            return SDL_SetError("Missing wBitsPerSample field in WAVE fmt chunk");
        } else if (format->bitspersample == 0) {
            return SDL_SetError("Invalid bits per sample");
        }
 
        /* All supported formats must have a proper block size. */
        if (format->blockalign == 0) {
            return SDL_SetError("Invalid block alignment");
        }
 
        /* If the fact chunk is valid and the appropriate hint is set, the
         * decoders will use the number of sample frames from the fact chunk.
         */
        if (file->fact.status == 1) {
            WaveFactChunkHint hint = file->facthint;
            Uint32 samples = file->fact.samplelength;
            if (hint == FactTruncate || hint == FactStrict || (hint == FactIgnoreZero && samples > 0)) {
                file->fact.status = 2;
            }
        }
    }
 
    /* Check the format for encoding specific issues and initialize decoders. */
    switch (format->encoding) {
    case PCM_CODE:
    case IEEE_FLOAT_CODE:
        if (PCM_Init(file, datalength) < 0) {
            return -1;
        }
        break;
    case ALAW_CODE:
    case MULAW_CODE:
        if (LAW_Init(file, datalength) < 0) {
            return -1;
        }
        break;
    case MS_ADPCM_CODE:
        if (MS_ADPCM_Init(file, datalength) < 0) {
            return -1;
        }
        break;
    case IMA_ADPCM_CODE:
        if (IMA_ADPCM_Init(file, datalength) < 0) {
            return -1;
        }
        break;
    case MPEG_CODE:
    case MPEGLAYER3_CODE:
        return SDL_SetError("MPEG formats not supported");
    default:
        if (format->formattag == EXTENSIBLE_CODE) {
            const char *errstr = "Unknown WAVE format GUID: %08x-%04x-%04x-%02x%02x%02x%02x%02x%02x%02x%02x";
            const Uint8 *g = format->subformat;
            const Uint32 g1 = g[0] | ((Uint32)g[1] << 8) | ((Uint32)g[2] << 16) | ((Uint32)g[3] << 24);
            const Uint32 g2 = g[4] | ((Uint32)g[5] << 8);
            const Uint32 g3 = g[6] | ((Uint32)g[7] << 8);
            return SDL_SetError(errstr, g1, g2, g3, g[8], g[9], g[10], g[11], g[12], g[13], g[14], g[15]);
        }
        return SDL_SetError("Unknown WAVE format tag: 0x%04x", (unsigned int)format->encoding);
    }
 
    return 0;
}

References ALAW_CODE, WaveFile::chunk, EXTENSIBLE_CODE, WaveFile::fact, WaveFile::facthint, FactIgnoreZero, FactStrict, FactTruncate, WaveFile::format, IEEE_FLOAT_CODE, IMA_ADPCM_CODE, IMA_ADPCM_Init(), INT_MAX, LAW_Init(), MPEG_CODE, MPEGLAYER3_CODE, MS_ADPCM_CODE, MS_ADPCM_Init(), MULAW_CODE, PCM_CODE, PCM_Init(), WaveFact::samplelength, SDL_SetError, WaveChunk::size, and WaveFact::status.

Referenced by WaveLoad().

WaveFreeChunkData()

static void WaveFreeChunkData ( WaveChunk *  chunk )

static

Definition at line 1511 of file SDL_wave.c.

{
    if (chunk->data != NULL) {
        SDL_free(chunk->data);
        chunk->data = NULL;
    }
    chunk->size = 0;
}

References WaveChunk::data, NULL, SDL_free, and WaveChunk::size.

Referenced by SDL_LoadWAV_RW(), WaveLoad(), WaveNextChunk(), and WaveReadPartialChunkData().

WaveGetFactChunkHint()

static WaveFactChunkHint WaveGetFactChunkHint ( )

static

Definition at line 1491 of file SDL_wave.c.

{
    const char *hint = SDL_GetHint(SDL_HINT_WAVE_FACT_CHUNK);
 
    if (hint != NULL) {
        if (SDL_strcmp(hint, "truncate") == 0) {
            return FactTruncate;
        } else if (SDL_strcmp(hint, "strict") == 0) {
            return FactStrict;
        } else if (SDL_strcmp(hint, "ignorezero") == 0) {
            return FactIgnoreZero;
        } else if (SDL_strcmp(hint, "ignore") == 0) {
            return FactIgnore;
        }
    }
 
    return FactNoHint;
}

References FactIgnore, FactIgnoreZero, FactNoHint, FactStrict, FactTruncate, NULL, SDL_GetHint, SDL_HINT_WAVE_FACT_CHUNK, and SDL_strcmp.

Referenced by SDL_LoadWAV_RW().

WaveGetFormatGUIDEncoding()

static Uint16 WaveGetFormatGUIDEncoding ( WaveFormat *  format )

static

Definition at line 1605 of file SDL_wave.c.

{
    size_t i;
    for (i = 0; i < SDL_arraysize(extensible_guids); i++) {
        if (SDL_memcmp(format->subformat, extensible_guids[i].guid, 16) == 0) {
            return extensible_guids[i].encoding;
        }
    }
    return UNKNOWN_CODE;
}

References WaveExtensibleGUID::encoding, extensible_guids, WaveExtensibleGUID::guid, i, SDL_arraysize, SDL_memcmp, and UNKNOWN_CODE.

Referenced by WaveReadFormat().

WaveGetRiffSizeHint()

static WaveRiffSizeHint WaveGetRiffSizeHint ( )

static

Definition at line 1451 of file SDL_wave.c.

{
    const char *hint = SDL_GetHint(SDL_HINT_WAVE_RIFF_CHUNK_SIZE);
 
    if (hint != NULL) {
        if (SDL_strcmp(hint, "force") == 0) {
            return RiffSizeForce;
        } else if (SDL_strcmp(hint, "ignore") == 0) {
            return RiffSizeIgnore;
        } else if (SDL_strcmp(hint, "ignorezero") == 0) {
            return RiffSizeIgnoreZero;
        } else if (SDL_strcmp(hint, "maximum") == 0) {
            return RiffSizeMaximum;
        }
    }
 
    return RiffSizeNoHint;
}

References NULL, RiffSizeForce, RiffSizeIgnore, RiffSizeIgnoreZero, RiffSizeMaximum, RiffSizeNoHint, SDL_GetHint, SDL_HINT_WAVE_RIFF_CHUNK_SIZE, and SDL_strcmp.

Referenced by SDL_LoadWAV_RW().

WaveGetTruncationHint()

static WaveTruncationHint WaveGetTruncationHint ( )

static

Definition at line 1471 of file SDL_wave.c.

{
    const char *hint = SDL_GetHint(SDL_HINT_WAVE_TRUNCATION);
 
    if (hint != NULL) {
        if (SDL_strcmp(hint, "verystrict") == 0) {
            return TruncVeryStrict;
        } else if (SDL_strcmp(hint, "strict") == 0) {
            return TruncStrict;
        } else if (SDL_strcmp(hint, "dropframe") == 0) {
            return TruncDropFrame;
        } else if (SDL_strcmp(hint, "dropblock") == 0) {
            return TruncDropBlock;
        }
    }
 
    return TruncNoHint;
}

References NULL, SDL_GetHint, SDL_HINT_WAVE_TRUNCATION, SDL_strcmp, TruncDropBlock, TruncDropFrame, TruncNoHint, TruncStrict, and TruncVeryStrict.

Referenced by SDL_LoadWAV_RW().

WaveLoad()

static int WaveLoad ( SDL_RWops *  src, WaveFile *  file, SDL_AudioSpec *  spec, Uint8 **  audio_buf, Uint32 *  audio_len  )

static

Definition at line 1787 of file SDL_wave.c.

{
    int result;
    Uint32 chunkcount = 0;
    Uint32 chunkcountlimit = 10000;
    char *envchunkcountlimit;
    Sint64 RIFFstart, RIFFend, lastchunkpos;
    SDL_bool RIFFlengthknown = SDL_FALSE;
    WaveFormat *format = &file->format;
    WaveChunk *chunk = &file->chunk;
    WaveChunk RIFFchunk;
    WaveChunk fmtchunk;
    WaveChunk datachunk;
 
    SDL_zero(RIFFchunk);
    SDL_zero(fmtchunk);
    SDL_zero(datachunk);
 
    envchunkcountlimit = SDL_getenv("SDL_WAVE_CHUNK_LIMIT");
    if (envchunkcountlimit != NULL) {
        unsigned int count;
        if (SDL_sscanf(envchunkcountlimit, "%u", &count) == 1) {
            chunkcountlimit = count <= SDL_MAX_UINT32 ? count : SDL_MAX_UINT32;
        }
    }
 
    RIFFstart = SDL_RWtell(src);
    if (RIFFstart < 0) {
        return SDL_SetError("Could not seek in file");
    }
 
    RIFFchunk.position = RIFFstart;
    if (WaveNextChunk(src, &RIFFchunk) < 0) {
        return SDL_SetError("Could not read RIFF header");
    }
 
    /* Check main WAVE file identifiers. */
    if (RIFFchunk.fourcc == RIFF) {
        Uint32 formtype;
        /* Read the form type. "WAVE" expected. */
        if (SDL_RWread(src, &formtype, sizeof(Uint32), 1) != 1) {
            return SDL_SetError("Could not read RIFF form type");
        } else if (SDL_SwapLE32(formtype) != WAVE) {
            return SDL_SetError("RIFF form type is not WAVE (not a Waveform file)");
        }
    } else if (RIFFchunk.fourcc == WAVE) {
        /* RIFF chunk missing or skipped. Length unknown. */
        RIFFchunk.position = 0;
        RIFFchunk.length = 0;
    } else {
        return SDL_SetError("Could not find RIFF or WAVE identifiers (not a Waveform file)");
    }
 
    /* The 4-byte form type is immediately followed by the first chunk.*/
    chunk->position = RIFFchunk.position + 4;
 
    /* Use the RIFF chunk size to limit the search for the chunks. This is not
     * always reliable and the hint can be used to tune the behavior. By
     * default, it will never search past 4 GiB.
     */
    switch (file->riffhint) {
    case RiffSizeIgnore:
        RIFFend = RIFFchunk.position + SDL_MAX_UINT32;
        break;
    default:
    case RiffSizeIgnoreZero:
        if (RIFFchunk.length == 0) {
            RIFFend = RIFFchunk.position + SDL_MAX_UINT32;
            break;
        }
        /* fallthrough */
    case RiffSizeForce:
        RIFFend = RIFFchunk.position + RIFFchunk.length;
        RIFFlengthknown = SDL_TRUE;
        break;
    case RiffSizeMaximum:
        RIFFend = SDL_MAX_SINT64;
        break;
    }
 
    /* Step through all chunks and save information on the fmt, data, and fact
     * chunks. Ignore the chunks we don't know as per specification. This
     * currently also ignores cue, list, and slnt chunks.
     */
    while ((Uint64)RIFFend > (Uint64)chunk->position + chunk->length + (chunk->length & 1)) {
        /* Abort after too many chunks or else corrupt files may waste time. */
        if (chunkcount++ >= chunkcountlimit) {
            return SDL_SetError("Chunk count in WAVE file exceeds limit of %u", chunkcountlimit);
        }
 
        result = WaveNextChunk(src, chunk);
        if (result == -1) {
            /* Unexpected EOF. Corrupt file or I/O issues. */
            if (file->trunchint == TruncVeryStrict) {
                return SDL_SetError("Unexpected end of WAVE file");
            }
            /* Let the checks after this loop sort this issue out. */
            break;
        } else if (result == -2) {
            return SDL_SetError("Could not seek to WAVE chunk header");
        }
 
        if (chunk->fourcc == FMT) {
            if (fmtchunk.fourcc == FMT) {
                /* Multiple fmt chunks. Ignore or error? */
            } else {
                /* The fmt chunk must occur before the data chunk. */
                if (datachunk.fourcc == DATA) {
                    return SDL_SetError("fmt chunk after data chunk in WAVE file");
                }
                fmtchunk = *chunk;
            }
        } else if (chunk->fourcc == DATA) {
            /* Only use the first data chunk. Handling the wavl list madness
             * may require a different approach.
             */
            if (datachunk.fourcc != DATA) {
                datachunk = *chunk;
            }
        } else if (chunk->fourcc == FACT) {
            /* The fact chunk data must be at least 4 bytes for the
             * dwSampleLength field. Ignore all fact chunks after the first one.
             */
            if (file->fact.status == 0) {
                if (chunk->length < 4) {
                    file->fact.status = -1;
                } else {
                    /* Let's use src directly, it's just too convenient. */
                    Sint64 position = SDL_RWseek(src, chunk->position, RW_SEEK_SET);
                    Uint32 samplelength;
                    if (position == chunk->position && SDL_RWread(src, &samplelength, sizeof(Uint32), 1) == 1) {
                        file->fact.status = 1;
                        file->fact.samplelength = SDL_SwapLE32(samplelength);
                    } else {
                        file->fact.status = -1;
                    }
                }
            }
        }
 
        /* Go through all chunks in verystrict mode or stop the search early if
         * all required chunks were found.
         */
        if (file->trunchint == TruncVeryStrict) {
            if ((Uint64)RIFFend < (Uint64)chunk->position + chunk->length) {
                return SDL_SetError("RIFF size truncates chunk");
            }
        } else if (fmtchunk.fourcc == FMT && datachunk.fourcc == DATA) {
            if (file->fact.status == 1 || file->facthint == FactIgnore || file->facthint == FactNoHint) {
                break;
            }
        }
    }
 
    /* Save the position after the last chunk. This position will be used if the
     * RIFF length is unknown.
     */
    lastchunkpos = chunk->position + chunk->length;
 
    /* The fmt chunk is mandatory. */
    if (fmtchunk.fourcc != FMT) {
        return SDL_SetError("Missing fmt chunk in WAVE file");
    }
    /* A data chunk must be present. */
    if (datachunk.fourcc != DATA) {
        return SDL_SetError("Missing data chunk in WAVE file");
    }
    /* Check if the last chunk has all of its data in verystrict mode. */
    if (file->trunchint == TruncVeryStrict) {
        /* data chunk is handled later. */
        if (chunk->fourcc != DATA && chunk->length > 0) {
            Uint8 tmp;
            Uint64 position = (Uint64)chunk->position + chunk->length - 1;
            if (position > SDL_MAX_SINT64 || SDL_RWseek(src, (Sint64)position, RW_SEEK_SET) != (Sint64)position) {
                return SDL_SetError("Could not seek to WAVE chunk data");
            } else if (SDL_RWread(src, &tmp, 1, 1) != 1) {
                return SDL_SetError("RIFF size truncates chunk");
            }
        }
    }
 
    /* Process fmt chunk. */
    *chunk = fmtchunk;
 
    /* No need to read more than 1046 bytes of the fmt chunk data with the
     * formats that are currently supported. (1046 because of MS ADPCM coefficients)
     */
    if (WaveReadPartialChunkData(src, chunk, 1046) < 0) {
        return SDL_SetError("Could not read data of WAVE fmt chunk");
    }
 
    /* The fmt chunk data must be at least 14 bytes to include all common fields.
     * It usually is 16 and larger depending on the header and encoding.
     */
    if (chunk->length < 14) {
        return SDL_SetError("Invalid WAVE fmt chunk length (too small)");
    } else if (chunk->size < 14) {
        return SDL_SetError("Could not read data of WAVE fmt chunk");
    } else if (WaveReadFormat(file) < 0) {
        return -1;
    } else if (WaveCheckFormat(file, (size_t)datachunk.length) < 0) {
        return -1;
    }
 
#ifdef SDL_WAVE_DEBUG_LOG_FORMAT
    WaveDebugLogFormat(file);
#endif
#ifdef SDL_WAVE_DEBUG_DUMP_FORMAT
    WaveDebugDumpFormat(file, RIFFchunk.length, fmtchunk.length, datachunk.length);
#endif
 
    WaveFreeChunkData(chunk);
 
    /* Process data chunk. */
    *chunk = datachunk;
 
    if (chunk->length > 0) {
        result = WaveReadChunkData(src, chunk);
        if (result == -1) {
            return -1;
        } else if (result == -2) {
            return SDL_SetError("Could not seek data of WAVE data chunk");
        }
    }
 
    if (chunk->length != chunk->size) {
        /* I/O issues or corrupt file. */
        if (file->trunchint == TruncVeryStrict || file->trunchint == TruncStrict) {
            return SDL_SetError("Could not read data of WAVE data chunk");
        }
        /* The decoders handle this truncation. */
    }
 
    /* Decode or convert the data if necessary. */
    switch (format->encoding) {
    case PCM_CODE:
    case IEEE_FLOAT_CODE:
        if (PCM_Decode(file, audio_buf, audio_len) < 0) {
            return -1;
        }
        break;
    case ALAW_CODE:
    case MULAW_CODE:
        if (LAW_Decode(file, audio_buf, audio_len) < 0) {
            return -1;
        }
        break;
    case MS_ADPCM_CODE:
        if (MS_ADPCM_Decode(file, audio_buf, audio_len) < 0) {
            return -1;
        }
        break;
    case IMA_ADPCM_CODE:
        if (IMA_ADPCM_Decode(file, audio_buf, audio_len) < 0) {
            return -1;
        }
        break;
    }
 
    /* Setting up the SDL_AudioSpec. All unsupported formats were filtered out
     * by checks earlier in this function.
     */
    SDL_zerop(spec);
    spec->freq = format->frequency;
    spec->channels = (Uint8)format->channels;
    spec->samples = 4096;       /* Good default buffer size */
 
    switch (format->encoding) {
    case MS_ADPCM_CODE:
    case IMA_ADPCM_CODE:
    case ALAW_CODE:
    case MULAW_CODE:
        /* These can be easily stored in the byte order of the system. */
        spec->format = AUDIO_S16SYS;
        break;
    case IEEE_FLOAT_CODE:
        spec->format = AUDIO_F32LSB;
        break;
    case PCM_CODE:
        switch (format->bitspersample) {
        case 8:
            spec->format = AUDIO_U8;
            break;
        case 16:
            spec->format = AUDIO_S16LSB;
            break;
        case 24: /* Has been shifted to 32 bits. */
        case 32:
            spec->format = AUDIO_S32LSB;
            break;
        default:
            /* Just in case something unexpected happened in the checks. */
            return SDL_SetError("Unexpected %u-bit PCM data format", (unsigned int)format->bitspersample);
        }
        break;
    }
 
    spec->silence = SDL_SilenceValueForFormat(spec->format);
 
    /* Report the end position back to the cleanup code. */
    if (RIFFlengthknown) {
        chunk->position = RIFFend;
    } else {
        chunk->position = lastchunkpos;
    }
 
    return 0;
}

References ALAW_CODE, AUDIO_F32LSB, AUDIO_S16LSB, AUDIO_S16SYS, AUDIO_S32LSB, AUDIO_U8, SDL_AudioSpec::channels, WaveFile::chunk, DATA, FACT, WaveFile::fact, WaveFile::facthint, FactIgnore, FactNoHint, FMT, SDL_AudioSpec::format, WaveFile::format, WaveChunk::fourcc, SDL_AudioSpec::freq, IEEE_FLOAT_CODE, if, IMA_ADPCM_CODE, IMA_ADPCM_Decode(), LAW_Decode(), WaveChunk::length, MS_ADPCM_CODE, MS_ADPCM_Decode(), MULAW_CODE, NULL, PCM_CODE, PCM_Decode(), WaveChunk::position, RIFF, WaveFile::riffhint, RiffSizeForce, RiffSizeIgnore, RiffSizeIgnoreZero, RiffSizeMaximum, RW_SEEK_SET, WaveFact::samplelength, SDL_AudioSpec::samples, SDL_FALSE, SDL_getenv, SDL_MAX_SINT64, SDL_MAX_UINT32, SDL_RWread, SDL_RWseek, SDL_RWtell, SDL_SetError, SDL_SilenceValueForFormat(), SDL_sscanf, SDL_SwapLE32, SDL_TRUE, SDL_zero, SDL_zerop, SDL_AudioSpec::silence, WaveChunk::size, spec, WaveFact::status, WaveFile::trunchint, TruncStrict, TruncVeryStrict, WAVE, WaveCheckFormat(), WaveFreeChunkData(), WaveNextChunk(), WaveReadChunkData(), WaveReadFormat(), and WaveReadPartialChunkData().

Referenced by SDL_LoadWAV_RW().

WaveNextChunk()

static int WaveNextChunk ( SDL_RWops *  src, WaveChunk *  chunk  )

static

Definition at line 1521 of file SDL_wave.c.

{
    Uint32 chunkheader[2];
    Sint64 nextposition = chunk->position + chunk->length;
 
    /* Data is no longer valid after this function returns. */
    WaveFreeChunkData(chunk);
 
    /* Error on overflows. */
    if (SDL_MAX_SINT64 - chunk->length < chunk->position || SDL_MAX_SINT64 - 8 < nextposition) {
        return -1;
    }
 
    /* RIFF chunks have a 2-byte alignment. Skip padding byte. */
    if (chunk->length & 1) {
        nextposition++;
    }
 
    if (SDL_RWseek(src, nextposition, RW_SEEK_SET) != nextposition) {
        /* Not sure how we ended up here. Just abort. */
        return -2;
    } else if (SDL_RWread(src, chunkheader, 4, 2) != 2) {
        return -1;
    }
 
    chunk->fourcc = SDL_SwapLE32(chunkheader[0]);
    chunk->length = SDL_SwapLE32(chunkheader[1]);
    chunk->position = nextposition + 8;
 
    return 0;
}

References WaveChunk::fourcc, WaveChunk::length, WaveChunk::position, RW_SEEK_SET, SDL_MAX_SINT64, SDL_RWread, SDL_RWseek, SDL_SwapLE32, and WaveFreeChunkData().

Referenced by WaveLoad().

WaveReadChunkData()

static int WaveReadChunkData ( SDL_RWops *  src, WaveChunk *  chunk  )

static

Definition at line 1583 of file SDL_wave.c.

{
    return WaveReadPartialChunkData(src, chunk, chunk->length);
}

References WaveChunk::length, and WaveReadPartialChunkData().

Referenced by WaveLoad().

WaveReadFormat()

static int WaveReadFormat ( WaveFile *  file )

static

Definition at line 1617 of file SDL_wave.c.

{
    WaveChunk *chunk = &file->chunk;
    WaveFormat *format = &file->format;
    SDL_RWops *fmtsrc;
    size_t fmtlen = chunk->size;
 
    if (fmtlen > SDL_MAX_SINT32) {
        /* Limit given by SDL_RWFromConstMem. */
        return SDL_SetError("Data of WAVE fmt chunk too big");
    }
    fmtsrc = SDL_RWFromConstMem(chunk->data, (int)chunk->size);
    if (fmtsrc == NULL) {
        return SDL_OutOfMemory();
    }
 
    format->formattag = SDL_ReadLE16(fmtsrc);
    format->encoding = format->formattag;
    format->channels = SDL_ReadLE16(fmtsrc);
    format->frequency = SDL_ReadLE32(fmtsrc);
    format->byterate = SDL_ReadLE32(fmtsrc);
    format->blockalign = SDL_ReadLE16(fmtsrc);
 
    /* This is PCM specific in the first version of the specification. */
    if (fmtlen >= 16) {
        format->bitspersample = SDL_ReadLE16(fmtsrc);
    } else if (format->encoding == PCM_CODE) {
        SDL_RWclose(fmtsrc);
        return SDL_SetError("Missing wBitsPerSample field in WAVE fmt chunk");
    }
 
    /* The earlier versions also don't have this field. */
    if (fmtlen >= 18) {
        format->extsize = SDL_ReadLE16(fmtsrc);
    }
 
    if (format->formattag == EXTENSIBLE_CODE) {
        /* note that this ignores channel masks, smaller valid bit counts
         * inside a larger container, and most subtypes. This is just enough
         * to get things that didn't really _need_ WAVE_FORMAT_EXTENSIBLE
         * to be useful working when they use this format flag.
         */
 
        /* Extensible header must be at least 22 bytes. */
        if (fmtlen < 40 || format->extsize < 22) {
            SDL_RWclose(fmtsrc);
            return SDL_SetError("Extensible WAVE header too small");
        }
 
        format->validsamplebits = SDL_ReadLE16(fmtsrc);
        format->samplesperblock = format->validsamplebits;
        format->channelmask = SDL_ReadLE32(fmtsrc);
        SDL_RWread(fmtsrc, format->subformat, 1, 16);
        format->encoding = WaveGetFormatGUIDEncoding(format);
    }
 
    SDL_RWclose(fmtsrc);
 
    return 0;
}

References WaveFile::chunk, WaveChunk::data, EXTENSIBLE_CODE, WaveFile::format, NULL, PCM_CODE, SDL_MAX_SINT32, SDL_OutOfMemory, SDL_ReadLE16, SDL_ReadLE32, SDL_RWclose, SDL_RWFromConstMem, SDL_RWread, SDL_SetError, WaveChunk::size, and WaveGetFormatGUIDEncoding().

Referenced by WaveLoad().

WaveReadPartialChunkData()

static int WaveReadPartialChunkData ( SDL_RWops *  src, WaveChunk *  chunk, size_t  length  )

static

Definition at line 1554 of file SDL_wave.c.

{
    WaveFreeChunkData(chunk);
 
    if (length > chunk->length) {
        length = chunk->length;
    }
 
    if (length > 0) {
        chunk->data = (Uint8 *) SDL_malloc(length);
        if (chunk->data == NULL) {
            return SDL_OutOfMemory();
        }
 
        if (SDL_RWseek(src, chunk->position, RW_SEEK_SET) != chunk->position) {
            /* Not sure how we ended up here. Just abort. */
            return -2;
        }
 
        chunk->size = SDL_RWread(src, chunk->data, 1, length);
        if (chunk->size != length) {
            /* Expected to be handled by the caller. */
        }
    }
 
    return 0;
}

References WaveChunk::data, WaveChunk::length, NULL, WaveChunk::position, RW_SEEK_SET, SDL_malloc, SDL_OutOfMemory, SDL_RWread, SDL_RWseek, WaveChunk::size, and WaveFreeChunkData().

Referenced by WaveLoad(), and WaveReadChunkData().

Variable Documentation

extensible_guids

WaveExtensibleGUID extensible_guids[]

static

Initial value:

= {
    {PCM_CODE,        WAVE_FORMATTAG_GUID(PCM_CODE)},
    {MS_ADPCM_CODE,   WAVE_FORMATTAG_GUID(MS_ADPCM_CODE)},
    {IEEE_FLOAT_CODE, WAVE_FORMATTAG_GUID(IEEE_FLOAT_CODE)},
    {ALAW_CODE,       WAVE_FORMATTAG_GUID(ALAW_CODE)},
    {MULAW_CODE,      WAVE_FORMATTAG_GUID(MULAW_CODE)},
    {IMA_ADPCM_CODE,  WAVE_FORMATTAG_GUID(IMA_ADPCM_CODE)}
}

Definition at line 1595 of file SDL_wave.c.

Referenced by WaveGetFormatGUIDEncoding().