Eliminate buffers, conversions, and unused code
This commit is contained in:
parent
3d8dceee57
commit
83e1979f26
4 changed files with 26 additions and 1062 deletions
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@ -333,8 +333,7 @@ int __Sound_strcasecmp(const char *x, const char *y)
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* Allocate a Sound_Sample, and fill in most of its fields. Those that need
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* to be filled in later, by a decoder, will be initialized to zero.
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*/
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static Sound_Sample *alloc_sample(SDL_RWops *rw, Sound_AudioInfo *desired,
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Uint32 bufferSize)
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static Sound_Sample *alloc_sample(SDL_RWops *rw, Sound_AudioInfo *desired)
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{
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/*
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* !!! FIXME: We're going to need to pool samples, since the mixer
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@ -356,18 +355,6 @@ static Sound_Sample *alloc_sample(SDL_RWops *rw, Sound_AudioInfo *desired,
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memset(retval, '\0', sizeof (Sound_Sample));
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memset(internal, '\0', sizeof (Sound_SampleInternal));
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assert(bufferSize > 0);
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retval->buffer = malloc(bufferSize); /* pure ugly. */
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if (!retval->buffer)
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{
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__Sound_SetError(ERR_OUT_OF_MEMORY);
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free(internal);
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free(retval);
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return(NULL);
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} /* if */
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memset(retval->buffer, '\0', bufferSize);
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retval->buffer_size = bufferSize;
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if (desired != NULL)
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memcpy(&retval->desired, desired, sizeof (Sound_AudioInfo));
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@ -426,8 +413,6 @@ static int init_sample(const Sound_DecoderFunctions *funcs,
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/* success; we've got a decoder! */
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/* Now we need to set up the conversion buffer... */
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memcpy(&desired, (_desired != NULL) ? _desired : &sample->actual,
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sizeof (Sound_AudioInfo));
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@ -438,40 +423,9 @@ static int init_sample(const Sound_DecoderFunctions *funcs,
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if (desired.rate == 0)
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desired.rate = sample->actual.rate;
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if (Sound_BuildAudioCVT(&internal->sdlcvt,
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sample->actual.format,
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sample->actual.channels,
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sample->actual.rate,
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desired.format,
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desired.channels,
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desired.rate,
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sample->buffer_size) == -1)
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{
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__Sound_SetError(SDL_GetError());
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funcs->close(sample);
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SDL_RWseek(internal->rw, pos, SEEK_SET); /* set for next try... */
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return(0);
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} /* if */
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if (internal->sdlcvt.len_mult > 1)
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{
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void *rc = realloc(sample->buffer,
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sample->buffer_size * internal->sdlcvt.len_mult);
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if (rc == NULL)
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{
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funcs->close(sample);
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SDL_RWseek(internal->rw, pos, SEEK_SET); /* set for next try... */
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return(0);
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} /* if */
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sample->buffer = rc;
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} /* if */
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/* these pointers are all one and the same. */
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memcpy(&sample->desired, &desired, sizeof (Sound_AudioInfo));
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internal->sdlcvt.buf = internal->buffer = sample->buffer;
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internal->buffer_size = sample->buffer_size / internal->sdlcvt.len_mult;
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internal->sdlcvt.len = internal->buffer_size;
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/* Prepend our new Sound_Sample to the sample_list... */
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SDL_LockMutex(samplelist_mutex);
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@ -490,16 +444,12 @@ static int init_sample(const Sound_DecoderFunctions *funcs,
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fmt_to_str(sample->actual.format),
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sample->actual.rate,
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sample->actual.channels));
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SNDDBG(("On-the-fly conversion: %s.\n",
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internal->sdlcvt.needed ? "ENABLED" : "DISABLED"));
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return(1);
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} /* init_sample */
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Sound_Sample *Sound_NewSample(SDL_RWops *rw, const char *ext,
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Sound_AudioInfo *desired, Uint32 bSize)
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Sound_AudioInfo *desired)
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{
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Sound_Sample *retval;
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decoder_element *decoder;
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@ -508,7 +458,7 @@ Sound_Sample *Sound_NewSample(SDL_RWops *rw, const char *ext,
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BAIL_IF_MACRO(!initialized, ERR_NOT_INITIALIZED, NULL);
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BAIL_IF_MACRO(rw == NULL, ERR_INVALID_ARGUMENT, NULL);
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retval = alloc_sample(rw, desired, bSize);
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retval = alloc_sample(rw, desired);
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if (!retval)
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return(NULL); /* alloc_sample() sets error message... */
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@ -562,8 +512,6 @@ Sound_Sample *Sound_NewSample(SDL_RWops *rw, const char *ext,
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/* nothing could handle the sound data... */
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free(retval->opaque);
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if (retval->buffer != NULL)
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free(retval->buffer);
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free(retval);
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SDL_RWclose(rw);
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__Sound_SetError(ERR_UNSUPPORTED_FORMAT);
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@ -572,8 +520,7 @@ Sound_Sample *Sound_NewSample(SDL_RWops *rw, const char *ext,
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Sound_Sample *Sound_NewSampleFromFile(const char *filename,
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Sound_AudioInfo *desired,
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Uint32 bufferSize)
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Sound_AudioInfo *desired)
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{
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const char *ext;
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SDL_RWops *rw;
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@ -593,30 +540,9 @@ Sound_Sample *Sound_NewSampleFromFile(const char *filename,
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if (ext != NULL)
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ext++;
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return(Sound_NewSample(rw, ext, desired, bufferSize));
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return(Sound_NewSample(rw, ext, desired));
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} /* Sound_NewSampleFromFile */
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Sound_Sample *Sound_NewSampleFromMem(const Uint8 *data,
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Uint32 size,
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const char *ext,
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Sound_AudioInfo *desired,
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Uint32 bufferSize)
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{
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SDL_RWops *rw;
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BAIL_IF_MACRO(!initialized, ERR_NOT_INITIALIZED, NULL);
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BAIL_IF_MACRO(data == NULL, ERR_INVALID_ARGUMENT, NULL);
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BAIL_IF_MACRO(size == 0, ERR_INVALID_ARGUMENT, NULL);
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rw = SDL_RWFromConstMem(data, size);
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/* !!! FIXME: rw = RWops_FromMem(data, size);*/
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BAIL_IF_MACRO(rw == NULL, SDL_GetError(), NULL);
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return(Sound_NewSample(rw, ext, desired, bufferSize));
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} /* Sound_NewSampleFromMem */
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void Sound_FreeSample(Sound_Sample *sample)
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{
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Sound_SampleInternal *internal;
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@ -665,42 +591,13 @@ void Sound_FreeSample(Sound_Sample *sample)
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if (internal->rw != NULL) /* this condition is a "just in case" thing. */
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SDL_RWclose(internal->rw);
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if ((internal->buffer != NULL) && (internal->buffer != sample->buffer))
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free(internal->buffer);
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free(internal);
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if (sample->buffer != NULL)
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free(sample->buffer);
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free(sample);
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} /* Sound_FreeSample */
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int Sound_SetBufferSize(Sound_Sample *sample, Uint32 newSize)
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{
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void *newBuf = NULL;
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Sound_SampleInternal *internal = NULL;
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BAIL_IF_MACRO(!initialized, ERR_NOT_INITIALIZED, 0);
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BAIL_IF_MACRO(sample == NULL, ERR_INVALID_ARGUMENT, 0);
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internal = ((Sound_SampleInternal *) sample->opaque);
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newBuf = realloc(sample->buffer, newSize * internal->sdlcvt.len_mult);
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BAIL_IF_MACRO(newBuf == NULL, ERR_OUT_OF_MEMORY, 0);
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internal->sdlcvt.buf = internal->buffer = sample->buffer = newBuf;
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sample->buffer_size = newSize;
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internal->buffer_size = newSize / internal->sdlcvt.len_mult;
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internal->sdlcvt.len = internal->buffer_size;
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return(1);
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} /* Sound_SetBufferSize */
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Uint32 Sound_Decode(Sound_Sample *sample)
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Uint32 Sound_Decode_Direct(Sound_Sample *sample, void* buffer, Uint32 desired_frames)
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{
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Sound_SampleInternal *internal = NULL;
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Uint32 retval = 0;
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/* a boatload of sanity checks... */
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BAIL_IF_MACRO(!initialized, ERR_NOT_INITIALIZED, 0);
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@ -710,73 +607,12 @@ Uint32 Sound_Decode(Sound_Sample *sample)
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internal = (Sound_SampleInternal *) sample->opaque;
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assert(sample->buffer != NULL);
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assert(sample->buffer_size > 0);
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assert(internal->buffer != NULL);
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assert(internal->buffer_size > 0);
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/* reset EAGAIN. Decoder can flip it back on if it needs to. */
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sample->flags &= ~SOUND_SAMPLEFLAG_EAGAIN;
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retval = internal->funcs->read(sample);
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if (retval > 0 && internal->sdlcvt.needed)
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{
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internal->sdlcvt.len = retval;
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Sound_ConvertAudio(&internal->sdlcvt);
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retval = internal->sdlcvt.len_cvt;
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} /* if */
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return(retval);
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return internal->funcs->read(sample, buffer, desired_frames);
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} /* Sound_Decode */
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Uint32 Sound_DecodeAll(Sound_Sample *sample)
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{
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Sound_SampleInternal *internal = NULL;
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void *buf = NULL;
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Uint32 newBufSize = 0;
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BAIL_IF_MACRO(!initialized, ERR_NOT_INITIALIZED, 0);
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BAIL_IF_MACRO(sample->flags & SOUND_SAMPLEFLAG_EOF, ERR_PREV_EOF, 0);
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BAIL_IF_MACRO(sample->flags & SOUND_SAMPLEFLAG_ERROR, ERR_PREV_ERROR, 0);
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internal = (Sound_SampleInternal *) sample->opaque;
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while ( ((sample->flags & SOUND_SAMPLEFLAG_EOF) == 0) &&
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((sample->flags & SOUND_SAMPLEFLAG_ERROR) == 0) )
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{
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Uint32 br = Sound_Decode(sample);
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void *ptr = realloc(buf, newBufSize + br);
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if (ptr == NULL)
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{
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sample->flags |= SOUND_SAMPLEFLAG_ERROR;
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__Sound_SetError(ERR_OUT_OF_MEMORY);
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} /* if */
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else
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{
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buf = ptr;
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memcpy( ((char *) buf) + newBufSize, sample->buffer, br );
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newBufSize += br;
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} /* else */
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} /* while */
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if (buf == NULL) /* ...in case first call to realloc() fails... */
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return(sample->buffer_size);
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if (internal->buffer != sample->buffer)
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free(internal->buffer);
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free(sample->buffer);
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internal->sdlcvt.buf = internal->buffer = sample->buffer = buf;
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sample->buffer_size = newBufSize;
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internal->buffer_size = newBufSize / internal->sdlcvt.len_mult;
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internal->sdlcvt.len = internal->buffer_size;
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return(newBufSize);
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} /* Sound_DecodeAll */
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int Sound_Rewind(Sound_Sample *sample)
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{
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Sound_SampleInternal *internal;
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@ -825,4 +661,3 @@ Sint32 Sound_GetDuration(Sound_Sample *sample)
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} /* Sound_GetDuration */
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/* end of SDL_sound.c ... */
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@ -94,7 +94,6 @@ extern "C" {
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* \sa Sound_SampleNew
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* \sa Sound_SampleNewFromFile
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* \sa Sound_SampleDecode
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* \sa Sound_SampleDecodeAll
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* \sa Sound_SampleSeek
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*/
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typedef enum
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@ -174,8 +173,6 @@ typedef struct
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const Sound_DecoderInfo *decoder; /**< Decoder used for this sample. */
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Sound_AudioInfo desired; /**< Desired audio format for conversion. */
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Sound_AudioInfo actual; /**< Actual audio format of sample. */
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void *buffer; /**< Decoded sound data lands in here. */
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Uint32 buffer_size; /**< Current size of (buffer), in bytes (Uint8). */
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Uint32 flags; /**< Flags relating to this sample. */
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} Sound_Sample;
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@ -440,41 +437,7 @@ SNDDECLSPEC void SDLCALL Sound_ClearError(void);
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*/
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SNDDECLSPEC Sound_Sample * SDLCALL Sound_NewSample(SDL_RWops *rw,
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const char *ext,
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Sound_AudioInfo *desired,
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Uint32 bufferSize);
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/**
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* \fn Sound_Sample *Sound_NewSampleFromMem(const Uint8 *data, Sound_AudioInfo *desired, Uint32 bufferSize)
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* \brief Start decoding a new sound sample from a file on disk.
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*
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* This is identical to Sound_NewSample(), but it creates an SDL_RWops for you
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* from the (size) bytes of memory referenced by (data).
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*
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* This can pool RWops structures, so it may fragment the heap less over time
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* than using SDL_RWFromMem().
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*
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* \param filename file containing sound data.
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* \param desired Format to convert sound data into. Can usually be NULL,
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* if you don't need conversion.
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* \param bufferSize size, in bytes, of initial read buffer.
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* \return Sound_Sample pointer, which is used as a handle to several other
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* SDL_sound APIs. NULL on error. If error, use
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* Sound_GetError() to see what went wrong.
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*
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* \sa Sound_NewSample
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* \sa Sound_SetBufferSize
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* \sa Sound_Decode
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* \sa Sound_DecodeAll
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* \sa Sound_Seek
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* \sa Sound_Rewind
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* \sa Sound_FreeSample
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*/
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SNDDECLSPEC Sound_Sample * SDLCALL Sound_NewSampleFromMem(const Uint8 *data,
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Uint32 size,
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const char *ext,
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Sound_AudioInfo *desired,
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Uint32 bufferSize);
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Sound_AudioInfo *desired);
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/**
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* \fn Sound_Sample *Sound_NewSampleFromFile(const char *filename, Sound_AudioInfo *desired, Uint32 bufferSize)
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@ -507,8 +470,7 @@ SNDDECLSPEC Sound_Sample * SDLCALL Sound_NewSampleFromMem(const Uint8 *data,
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* \sa Sound_FreeSample
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*/
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SNDDECLSPEC Sound_Sample * SDLCALL Sound_NewSampleFromFile(const char *fname,
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Sound_AudioInfo *desired,
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Uint32 bufferSize);
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Sound_AudioInfo *desired);
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/**
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* \fn void Sound_FreeSample(Sound_Sample *sample)
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@ -551,93 +513,27 @@ SNDDECLSPEC void SDLCALL Sound_FreeSample(Sound_Sample *sample);
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*/
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SNDDECLSPEC Sint32 SDLCALL Sound_GetDuration(Sound_Sample *sample);
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/**
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* \fn int Sound_SetBufferSize(Sound_Sample *sample, Uint32 new_size)
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* \brief Change the current buffer size for a sample.
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* \fn Uint32 Sound_Decode_Direct(Sound_Sample *sample)
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* \brief Decode more of the sound data in a Sound_Sample directly into
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* the supplied buffer.
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*
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* If the buffer size could be changed, then the sample->buffer and
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* sample->buffer_size fields will reflect that. If they could not be
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* changed, then your original sample state is preserved. If the buffer is
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* shrinking, the data at the end of buffer is truncated. If the buffer is
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* growing, the contents of the new space at the end is undefined until you
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* decode more into it or initialize it yourself.
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*
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* The buffer size specified must be a multiple of the size of a single
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* sample point. So, if you want 16-bit, stereo samples, then your sample
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* point size is (2 channels * 16 bits), or 32 bits per sample, which is four
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* bytes. In such a case, you could specify 128 or 132 bytes for a buffer,
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* but not 129, 130, or 131 (although in reality, you'll want to specify a
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* MUCH larger buffer).
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*
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* \param sample The Sound_Sample whose buffer to modify.
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* \param new_size The desired size, in bytes, of the new buffer.
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* \return non-zero if buffer size changed, zero on failure.
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*
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* \sa Sound_Decode
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* \sa Sound_DecodeAll
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*/
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SNDDECLSPEC int SDLCALL Sound_SetBufferSize(Sound_Sample *sample,
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Uint32 new_size);
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/**
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* \fn Uint32 Sound_Decode(Sound_Sample *sample)
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* \brief Decode more of the sound data in a Sound_Sample.
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*
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* It will decode at most sample->buffer_size bytes into sample->buffer in the
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* desired format, and return the number of decoded bytes.
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* If sample->buffer_size bytes could not be decoded, then please refer to
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* It will decode at most desired_frames into buffer, and return the number
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* frames decoded.
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* If the number of desired_frames could not be decoded, then please refer to
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* sample->flags to determine if this was an end-of-stream or error condition.
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*
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* \param sample Do more decoding to this Sound_Sample.
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* \return number of bytes decoded into sample->buffer. If it is less than
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* sample->buffer_size, then you should check sample->flags to see
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* \param buffer PCM frames into this buffer.
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* \param desired_frames indicates how many PCM should be decoded.
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* \return number of frames decoded into buffer. If it is less than
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* desired_frames, then you should check sample->flags to see
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* what the current state of the sample is (EOF, error, read again).
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*
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* \sa Sound_DecodeAll
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* \sa Sound_SetBufferSize
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* \sa Sound_Seek
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* \sa Sound_Rewind
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*/
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SNDDECLSPEC Uint32 SDLCALL Sound_Decode(Sound_Sample *sample);
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/**
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* \fn Uint32 Sound_DecodeAll(Sound_Sample *sample)
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* \brief Decode the remainder of the sound data in a Sound_Sample.
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*
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* This will dynamically allocate memory for the ENTIRE remaining sample.
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* sample->buffer_size and sample->buffer will be updated to reflect the
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* new buffer. Please refer to sample->flags to determine if the decoding
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* finished due to an End-of-stream or error condition.
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*
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* Be aware that sound data can take a large amount of memory, and that
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* this function may block for quite awhile while processing. Also note
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* that a streaming source (for example, from a SDL_RWops that is getting
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* fed from an Internet radio feed that doesn't end) may fill all available
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* memory before giving up...be sure to use this on finite sound sources
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* only!
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*
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* When decoding the sample in its entirety, the work is done one buffer at a
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* time. That is, sound is decoded in sample->buffer_size blocks, and
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* appended to a continually-growing buffer until the decoding completes.
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* That means that this function will need enough RAM to hold approximately
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* sample->buffer_size bytes plus the complete decoded sample at most. The
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* larger your buffer size, the less overhead this function needs, but beware
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* the possibility of paging to disk. Best to make this user-configurable if
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* the sample isn't specific and small.
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*
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* \param sample Do all decoding for this Sound_Sample.
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* \return number of bytes decoded into sample->buffer. You should check
|
||||
* sample->flags to see what the current state of the sample is
|
||||
* (EOF, error, read again).
|
||||
*
|
||||
* \sa Sound_Decode
|
||||
* \sa Sound_SetBufferSize
|
||||
*/
|
||||
SNDDECLSPEC Uint32 SDLCALL Sound_DecodeAll(Sound_Sample *sample);
|
||||
|
||||
SNDDECLSPEC Uint32 SDLCALL Sound_Decode_Direct(Sound_Sample *sample, void* buffer, Uint32 desired_frames);
|
||||
|
||||
/**
|
||||
* \fn int Sound_Rewind(Sound_Sample *sample)
|
||||
|
|
|
@ -126,9 +126,6 @@ typedef struct __SOUND_DECODERFUNCTIONS__
|
|||
* Sound_Sample *prev; (offlimits)
|
||||
* SDL_RWops *rw; (can use, but do NOT close it)
|
||||
* const Sound_DecoderFunctions *funcs; (that's this structure)
|
||||
* Sound_AudioCVT sdlcvt; (offlimits)
|
||||
* void *buffer; (offlimits until read() method)
|
||||
* Uint32 buffer_size; (offlimits until read() method)
|
||||
* void *decoder_private; (read and write access)
|
||||
*
|
||||
* in rest of Sound_Sample:
|
||||
|
@ -136,8 +133,6 @@ typedef struct __SOUND_DECODERFUNCTIONS__
|
|||
* const Sound_DecoderInfo *decoder; (read only)
|
||||
* Sound_AudioInfo desired; (read only, usually not needed here)
|
||||
* Sound_AudioInfo actual; (please fill this in)
|
||||
* void *buffer; (offlimits)
|
||||
* Uint32 buffer_size; (offlimits)
|
||||
* Sound_SampleFlags flags; (set appropriately)
|
||||
*/
|
||||
int (*open)(Sound_Sample *sample, const char *ext);
|
||||
|
@ -157,15 +152,12 @@ typedef struct __SOUND_DECODERFUNCTIONS__
|
|||
* Sound_SampleInternal *internal;
|
||||
* internal = (Sound_SampleInternal *) sample->opaque;
|
||||
*
|
||||
* ...and then start decoding. Fill in up to internal->buffer_size
|
||||
* bytes of decoded sound in the space pointed to by
|
||||
* internal->buffer. The encoded data is read in from internal->rw.
|
||||
* Data should be decoded in the format specified during the
|
||||
* decoder's open() method in the sample->actual field. The
|
||||
* conversion to the desired format is done at a higher level.
|
||||
* ...and then start decoding. Fill in up to desired_frames
|
||||
* PCM frames of decoded sound into the space pointed to by
|
||||
* buffer. The encoded data is read in from internal->rw.
|
||||
*
|
||||
* The return value is the number of bytes decoded into
|
||||
* internal->buffer, which can be no more than internal->buffer_size,
|
||||
* The return value is the number of frames decoded into
|
||||
* buffer, which can be no more than desired_frames,
|
||||
* but can be less. If it is less, you should set a state flag:
|
||||
*
|
||||
* If there's just no more data (end of file, etc), then do:
|
||||
|
@ -186,7 +178,7 @@ typedef struct __SOUND_DECODERFUNCTIONS__
|
|||
* SOUND_SAMPLEFLAG_EAGAIN flag is reset before each call to this
|
||||
* method.
|
||||
*/
|
||||
Uint32 (*read)(Sound_Sample *sample);
|
||||
Uint32 (*read)(Sound_Sample *sample, void* buffer, Uint32 desired_frames);
|
||||
|
||||
/*
|
||||
* Reset the decoding to the beginning of the stream. Nonzero on
|
||||
|
@ -223,31 +215,6 @@ typedef struct __SOUND_DECODERFUNCTIONS__
|
|||
int (*seek)(Sound_Sample *sample, Uint32 ms);
|
||||
} Sound_DecoderFunctions;
|
||||
|
||||
|
||||
/* A structure to hold a set of audio conversion filters and buffers */
|
||||
typedef struct Sound_AudioCVT
|
||||
{
|
||||
int needed; /* Set to 1 if conversion possible */
|
||||
Uint16 src_format; /* Source audio format */
|
||||
Uint16 dst_format; /* Target audio format */
|
||||
double rate_incr; /* Rate conversion increment */
|
||||
Uint8 *buf; /* Buffer to hold entire audio data */
|
||||
int len; /* Length of original audio buffer */
|
||||
int len_cvt; /* Length of converted audio buffer */
|
||||
int len_mult; /* buffer must be len*len_mult big */
|
||||
double len_ratio; /* Given len, final size is len*len_ratio */
|
||||
void (*filters[20])(struct Sound_AudioCVT *cvt, Uint16 *format);
|
||||
int filter_index; /* Current audio conversion function */
|
||||
} Sound_AudioCVT;
|
||||
|
||||
extern SNDDECLSPEC int Sound_BuildAudioCVT(Sound_AudioCVT *cvt,
|
||||
Uint16 src_format, Uint8 src_channels, Uint32 src_rate,
|
||||
Uint16 dst_format, Uint8 dst_channels, Uint32 dst_rate,
|
||||
Uint32 dst_size);
|
||||
|
||||
extern SNDDECLSPEC int Sound_ConvertAudio(Sound_AudioCVT *cvt);
|
||||
|
||||
|
||||
typedef void (*MixFunc)(float *dst, void *src, Uint32 frames, float *gains);
|
||||
|
||||
typedef struct __SOUND_SAMPLEINTERNAL__
|
||||
|
@ -256,7 +223,6 @@ typedef struct __SOUND_SAMPLEINTERNAL__
|
|||
Sound_Sample *prev;
|
||||
SDL_RWops *rw;
|
||||
const Sound_DecoderFunctions *funcs;
|
||||
Sound_AudioCVT sdlcvt;
|
||||
void *buffer;
|
||||
Uint32 buffer_size;
|
||||
void *decoder_private;
|
||||
|
|
|
@ -1,733 +0,0 @@
|
|||
/*
|
||||
SDL - Simple DirectMedia Layer
|
||||
Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga
|
||||
|
||||
This library is free software; you can redistribute it and/or
|
||||
modify it under the terms of the GNU Library General Public
|
||||
License as published by the Free Software Foundation; either
|
||||
version 2 of the License, or (at your option) any later version.
|
||||
|
||||
This library is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||||
Library General Public License for more details.
|
||||
|
||||
You should have received a copy of the GNU Library General Public
|
||||
License along with this library; if not, write to the Free
|
||||
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
||||
|
||||
Sam Lantinga
|
||||
slouken@devolution.com
|
||||
*/
|
||||
|
||||
/*
|
||||
* This file was derived from SDL's SDL_audiocvt.c and is an attempt to
|
||||
* address the shortcomings of it.
|
||||
*
|
||||
* Perhaps we can adapt some good filters from SoX?
|
||||
*/
|
||||
|
||||
#if HAVE_CONFIG_H
|
||||
# include <config.h>
|
||||
#endif
|
||||
|
||||
#include "SDL_sound.h"
|
||||
#define __SDL_SOUND_INTERNAL__
|
||||
#include "SDL_sound_internal.h"
|
||||
|
||||
/* Functions for audio drivers to perform runtime conversion of audio format */
|
||||
|
||||
|
||||
/*
|
||||
* Toggle endianness. This filter is, of course, only applied to 16-bit
|
||||
* audio data.
|
||||
*/
|
||||
|
||||
static void Sound_ConvertEndian(Sound_AudioCVT *cvt, Uint16 *format)
|
||||
{
|
||||
int i;
|
||||
Uint8 *data, tmp;
|
||||
|
||||
/* SNDDBG(("Converting audio endianness\n")); */
|
||||
|
||||
data = cvt->buf;
|
||||
|
||||
for (i = cvt->len_cvt / 2; i; --i)
|
||||
{
|
||||
tmp = data[0];
|
||||
data[0] = data[1];
|
||||
data[1] = tmp;
|
||||
data += 2;
|
||||
} /* for */
|
||||
|
||||
*format = (*format ^ 0x1000);
|
||||
} /* Sound_ConvertEndian */
|
||||
|
||||
|
||||
/*
|
||||
* Toggle signed/unsigned. Apparently this is done by toggling the most
|
||||
* significant bit of each sample.
|
||||
*/
|
||||
|
||||
static void Sound_ConvertSign(Sound_AudioCVT *cvt, Uint16 *format)
|
||||
{
|
||||
int i;
|
||||
Uint8 *data;
|
||||
|
||||
/* SNDDBG(("Converting audio signedness\n")); */
|
||||
|
||||
data = cvt->buf;
|
||||
|
||||
/* 16-bit sound? */
|
||||
if ((*format & 0xFF) == 16)
|
||||
{
|
||||
/* Little-endian? */
|
||||
if ((*format & 0x1000) != 0x1000)
|
||||
++data;
|
||||
|
||||
for (i = cvt->len_cvt / 2; i; --i)
|
||||
{
|
||||
*data ^= 0x80;
|
||||
data += 2;
|
||||
} /* for */
|
||||
} /* if */
|
||||
else
|
||||
{
|
||||
for (i = cvt->len_cvt; i; --i)
|
||||
*data++ ^= 0x80;
|
||||
} /* else */
|
||||
|
||||
*format = (*format ^ 0x8000);
|
||||
} /* Sound_ConvertSign */
|
||||
|
||||
|
||||
/*
|
||||
* Convert 16-bit to 8-bit. This is done by taking the most significant byte
|
||||
* of each 16-bit sample.
|
||||
*/
|
||||
|
||||
static void Sound_Convert8(Sound_AudioCVT *cvt, Uint16 *format)
|
||||
{
|
||||
int i;
|
||||
Uint8 *src, *dst;
|
||||
|
||||
/* SNDDBG(("Converting to 8-bit\n")); */
|
||||
|
||||
src = cvt->buf;
|
||||
dst = cvt->buf;
|
||||
|
||||
/* Little-endian? */
|
||||
if ((*format & 0x1000) != 0x1000)
|
||||
++src;
|
||||
|
||||
for (i = cvt->len_cvt / 2; i; --i)
|
||||
{
|
||||
*dst = *src;
|
||||
src += 2;
|
||||
dst += 1;
|
||||
} /* for */
|
||||
|
||||
*format = ((*format & ~0x9010) | AUDIO_U8);
|
||||
cvt->len_cvt /= 2;
|
||||
} /* Sound_Convert8 */
|
||||
|
||||
|
||||
/* Convert 8-bit to 16-bit - LSB */
|
||||
|
||||
static void Sound_Convert16LSB(Sound_AudioCVT *cvt, Uint16 *format)
|
||||
{
|
||||
int i;
|
||||
Uint8 *src, *dst;
|
||||
|
||||
/* SNDDBG(("Converting to 16-bit LSB\n")); */
|
||||
|
||||
src = cvt->buf + cvt->len_cvt;
|
||||
dst = cvt->buf + cvt->len_cvt * 2;
|
||||
|
||||
for (i = cvt->len_cvt; i; --i)
|
||||
{
|
||||
src -= 1;
|
||||
dst -= 2;
|
||||
dst[1] = *src;
|
||||
dst[0] = 0;
|
||||
} /* for */
|
||||
|
||||
*format = ((*format & ~0x0008) | AUDIO_U16LSB);
|
||||
cvt->len_cvt *= 2;
|
||||
} /* Sound_Convert16LSB */
|
||||
|
||||
|
||||
/* Convert 8-bit to 16-bit - MSB */
|
||||
|
||||
static void Sound_Convert16MSB(Sound_AudioCVT *cvt, Uint16 *format)
|
||||
{
|
||||
int i;
|
||||
Uint8 *src, *dst;
|
||||
|
||||
/* SNDDBG(("Converting to 16-bit MSB\n")); */
|
||||
|
||||
src = cvt->buf + cvt->len_cvt;
|
||||
dst = cvt->buf + cvt->len_cvt * 2;
|
||||
|
||||
for (i = cvt->len_cvt; i; --i)
|
||||
{
|
||||
src -= 1;
|
||||
dst -= 2;
|
||||
dst[0] = *src;
|
||||
dst[1] = 0;
|
||||
} /* for */
|
||||
|
||||
*format = ((*format & ~0x0008) | AUDIO_U16MSB);
|
||||
cvt->len_cvt *= 2;
|
||||
} /* Sound_Convert16MSB */
|
||||
|
||||
|
||||
/* Duplicate a mono channel to both stereo channels */
|
||||
|
||||
static void Sound_ConvertStereo(Sound_AudioCVT *cvt, Uint16 *format)
|
||||
{
|
||||
int i;
|
||||
|
||||
/* SNDDBG(("Converting to stereo\n")); */
|
||||
|
||||
/* 16-bit sound? */
|
||||
if ((*format & 0xFF) == 16)
|
||||
{
|
||||
Uint16 *src, *dst;
|
||||
|
||||
src = (Uint16 *) (cvt->buf + cvt->len_cvt);
|
||||
dst = (Uint16 *) (cvt->buf + cvt->len_cvt * 2);
|
||||
|
||||
for (i = cvt->len_cvt/2; i; --i)
|
||||
{
|
||||
dst -= 2;
|
||||
src -= 1;
|
||||
dst[0] = src[0];
|
||||
dst[1] = src[0];
|
||||
} /* for */
|
||||
} /* if */
|
||||
else
|
||||
{
|
||||
Uint8 *src, *dst;
|
||||
|
||||
src = cvt->buf + cvt->len_cvt;
|
||||
dst = cvt->buf + cvt->len_cvt * 2;
|
||||
|
||||
for (i = cvt->len_cvt; i; --i)
|
||||
{
|
||||
dst -= 2;
|
||||
src -= 1;
|
||||
dst[0] = src[0];
|
||||
dst[1] = src[0];
|
||||
} /* for */
|
||||
} /* else */
|
||||
|
||||
cvt->len_cvt *= 2;
|
||||
} /* Sound_ConvertStereo */
|
||||
|
||||
|
||||
/* Effectively mix right and left channels into a single channel */
|
||||
|
||||
static void Sound_ConvertMono(Sound_AudioCVT *cvt, Uint16 *format)
|
||||
{
|
||||
int i;
|
||||
Sint32 sample;
|
||||
Uint8 *u_src, *u_dst;
|
||||
Sint8 *s_src, *s_dst;
|
||||
|
||||
/* SNDDBG(("Converting to mono\n")); */
|
||||
|
||||
switch (*format)
|
||||
{
|
||||
case AUDIO_U8:
|
||||
u_src = cvt->buf;
|
||||
u_dst = cvt->buf;
|
||||
|
||||
for (i = cvt->len_cvt / 2; i; --i)
|
||||
{
|
||||
sample = u_src[0] + u_src[1];
|
||||
*u_dst = (sample > 255) ? 255 : sample;
|
||||
u_src += 2;
|
||||
u_dst += 1;
|
||||
} /* for */
|
||||
break;
|
||||
|
||||
case AUDIO_S8:
|
||||
s_src = (Sint8 *) cvt->buf;
|
||||
s_dst = (Sint8 *) cvt->buf;
|
||||
|
||||
for (i = cvt->len_cvt / 2; i; --i)
|
||||
{
|
||||
sample = s_src[0] + s_src[1];
|
||||
if (sample > 127)
|
||||
*s_dst = 127;
|
||||
else if (sample < -128)
|
||||
*s_dst = -128;
|
||||
else
|
||||
*s_dst = sample;
|
||||
|
||||
s_src += 2;
|
||||
s_dst += 1;
|
||||
} /* for */
|
||||
break;
|
||||
|
||||
case AUDIO_U16MSB:
|
||||
u_src = cvt->buf;
|
||||
u_dst = cvt->buf;
|
||||
|
||||
for (i = cvt->len_cvt / 4; i; --i)
|
||||
{
|
||||
sample = (Uint16) ((u_src[0] << 8) | u_src[1])
|
||||
+ (Uint16) ((u_src[2] << 8) | u_src[3]);
|
||||
if (sample > 65535)
|
||||
{
|
||||
u_dst[0] = 0xFF;
|
||||
u_dst[1] = 0xFF;
|
||||
} /* if */
|
||||
else
|
||||
{
|
||||
u_dst[1] = (sample & 0xFF);
|
||||
sample >>= 8;
|
||||
u_dst[0] = (sample & 0xFF);
|
||||
} /* else */
|
||||
u_src += 4;
|
||||
u_dst += 2;
|
||||
} /* for */
|
||||
break;
|
||||
|
||||
case AUDIO_U16LSB:
|
||||
u_src = cvt->buf;
|
||||
u_dst = cvt->buf;
|
||||
|
||||
for (i = cvt->len_cvt / 4; i; --i)
|
||||
{
|
||||
sample = (Uint16) ((u_src[1] << 8) | u_src[0])
|
||||
+ (Uint16) ((u_src[3] << 8) | u_src[2]);
|
||||
if (sample > 65535)
|
||||
{
|
||||
u_dst[0] = 0xFF;
|
||||
u_dst[1] = 0xFF;
|
||||
} /* if */
|
||||
else
|
||||
{
|
||||
u_dst[0] = (sample & 0xFF);
|
||||
sample >>= 8;
|
||||
u_dst[1] = (sample & 0xFF);
|
||||
} /* else */
|
||||
u_src += 4;
|
||||
u_dst += 2;
|
||||
} /* for */
|
||||
break;
|
||||
|
||||
case AUDIO_S16MSB:
|
||||
u_src = cvt->buf;
|
||||
u_dst = cvt->buf;
|
||||
|
||||
for (i = cvt->len_cvt / 4; i; --i)
|
||||
{
|
||||
sample = (Sint16) ((u_src[0] << 8) | u_src[1])
|
||||
+ (Sint16) ((u_src[2] << 8) | u_src[3]);
|
||||
if (sample > 32767)
|
||||
{
|
||||
u_dst[0] = 0x7F;
|
||||
u_dst[1] = 0xFF;
|
||||
} /* if */
|
||||
else if (sample < -32768)
|
||||
{
|
||||
u_dst[0] = 0x80;
|
||||
u_dst[1] = 0x00;
|
||||
} /* else if */
|
||||
else
|
||||
{
|
||||
u_dst[1] = (sample & 0xFF);
|
||||
sample >>= 8;
|
||||
u_dst[0] = (sample & 0xFF);
|
||||
} /* else */
|
||||
u_src += 4;
|
||||
u_dst += 2;
|
||||
} /* for */
|
||||
break;
|
||||
|
||||
case AUDIO_S16LSB:
|
||||
u_src = cvt->buf;
|
||||
u_dst = cvt->buf;
|
||||
|
||||
for (i = cvt->len_cvt / 4; i; --i)
|
||||
{
|
||||
sample = (Sint16) ((u_src[1] << 8) | u_src[0])
|
||||
+ (Sint16) ((u_src[3] << 8) | u_src[2]);
|
||||
if (sample > 32767)
|
||||
{
|
||||
u_dst[1] = 0x7F;
|
||||
u_dst[0] = 0xFF;
|
||||
} /* if */
|
||||
else if (sample < -32768)
|
||||
{
|
||||
u_dst[1] = 0x80;
|
||||
u_dst[0] = 0x00;
|
||||
} /* else if */
|
||||
else
|
||||
{
|
||||
u_dst[0] = (sample & 0xFF);
|
||||
sample >>= 8;
|
||||
u_dst[1] = (sample & 0xFF);
|
||||
} /* else */
|
||||
u_src += 4;
|
||||
u_dst += 2;
|
||||
} /* for */
|
||||
break;
|
||||
} /* switch */
|
||||
|
||||
cvt->len_cvt /= 2;
|
||||
} /* Sound_ConvertMono */
|
||||
|
||||
|
||||
/* Convert rate up by multiple of 2 */
|
||||
|
||||
static void Sound_RateMUL2(Sound_AudioCVT *cvt, Uint16 *format)
|
||||
{
|
||||
int i;
|
||||
Uint8 *src, *dst;
|
||||
|
||||
/* SNDDBG(("Converting audio rate * 2\n")); */
|
||||
|
||||
src = cvt->buf + cvt->len_cvt;
|
||||
dst = cvt->buf + cvt->len_cvt*2;
|
||||
|
||||
/* 8- or 16-bit sound? */
|
||||
switch (*format & 0xFF)
|
||||
{
|
||||
case 8:
|
||||
for (i = cvt->len_cvt; i; --i)
|
||||
{
|
||||
src -= 1;
|
||||
dst -= 2;
|
||||
dst[0] = src[0];
|
||||
dst[1] = src[0];
|
||||
} /* for */
|
||||
break;
|
||||
|
||||
case 16:
|
||||
for (i = cvt->len_cvt / 2; i; --i)
|
||||
{
|
||||
src -= 2;
|
||||
dst -= 4;
|
||||
dst[0] = src[0];
|
||||
dst[1] = src[1];
|
||||
dst[2] = src[0];
|
||||
dst[3] = src[1];
|
||||
} /* for */
|
||||
break;
|
||||
} /* switch */
|
||||
|
||||
cvt->len_cvt *= 2;
|
||||
} /* Sound_RateMUL2 */
|
||||
|
||||
|
||||
/* Convert rate down by multiple of 2 */
|
||||
|
||||
static void Sound_RateDIV2(Sound_AudioCVT *cvt, Uint16 *format)
|
||||
{
|
||||
int i;
|
||||
Uint8 *src, *dst;
|
||||
|
||||
/* SNDDBG(("Converting audio rate / 2\n")); */
|
||||
|
||||
src = cvt->buf;
|
||||
dst = cvt->buf;
|
||||
|
||||
/* 8- or 16-bit sound? */
|
||||
switch (*format & 0xFF)
|
||||
{
|
||||
case 8:
|
||||
for (i = cvt->len_cvt / 2; i; --i)
|
||||
{
|
||||
dst[0] = src[0];
|
||||
src += 2;
|
||||
dst += 1;
|
||||
} /* for */
|
||||
break;
|
||||
|
||||
case 16:
|
||||
for (i = cvt->len_cvt / 4; i; --i)
|
||||
{
|
||||
dst[0] = src[0];
|
||||
dst[1] = src[1];
|
||||
src += 4;
|
||||
dst += 2;
|
||||
}
|
||||
break;
|
||||
} /* switch */
|
||||
|
||||
cvt->len_cvt /= 2;
|
||||
} /* Sound_RateDIV2 */
|
||||
|
||||
|
||||
/* Very slow rate conversion routine */
|
||||
|
||||
static void Sound_RateSLOW(Sound_AudioCVT *cvt, Uint16 *format)
|
||||
{
|
||||
double ipos;
|
||||
int i, clen;
|
||||
Uint8 *output8;
|
||||
Uint16 *output16;
|
||||
|
||||
/* SNDDBG(("Converting audio rate * %4.4f\n", 1.0/cvt->rate_incr)); */
|
||||
|
||||
clen = (int) ((double) cvt->len_cvt / cvt->rate_incr);
|
||||
|
||||
if (cvt->rate_incr > 1.0)
|
||||
{
|
||||
/* 8- or 16-bit sound? */
|
||||
switch (*format & 0xFF)
|
||||
{
|
||||
case 8:
|
||||
output8 = cvt->buf;
|
||||
|
||||
ipos = 0.0;
|
||||
for (i = clen; i; --i)
|
||||
{
|
||||
*output8 = cvt->buf[(int) ipos];
|
||||
ipos += cvt->rate_incr;
|
||||
output8 += 1;
|
||||
} /* for */
|
||||
break;
|
||||
|
||||
case 16:
|
||||
output16 = (Uint16 *) cvt->buf;
|
||||
|
||||
clen &= ~1;
|
||||
ipos = 0.0;
|
||||
for (i = clen / 2; i; --i)
|
||||
{
|
||||
*output16 = ((Uint16 *) cvt->buf)[(int) ipos];
|
||||
ipos += cvt->rate_incr;
|
||||
output16 += 1;
|
||||
} /* for */
|
||||
break;
|
||||
} /* switch */
|
||||
} /* if */
|
||||
else
|
||||
{
|
||||
/* 8- or 16-bit sound */
|
||||
switch (*format & 0xFF)
|
||||
{
|
||||
case 8:
|
||||
output8 = cvt->buf + clen;
|
||||
|
||||
ipos = (double) cvt->len_cvt;
|
||||
for (i = clen; i; --i)
|
||||
{
|
||||
ipos -= cvt->rate_incr;
|
||||
output8 -= 1;
|
||||
*output8 = cvt->buf[(int) ipos];
|
||||
} /* for */
|
||||
break;
|
||||
|
||||
case 16:
|
||||
clen &= ~1;
|
||||
output16 = (Uint16 *) (cvt->buf + clen);
|
||||
ipos = (double) cvt->len_cvt / 2;
|
||||
for (i = clen / 2; i; --i)
|
||||
{
|
||||
ipos -= cvt->rate_incr;
|
||||
output16 -= 1;
|
||||
*output16 = ((Uint16 *) cvt->buf)[(int) ipos];
|
||||
} /* for */
|
||||
break;
|
||||
} /* switch */
|
||||
} /* else */
|
||||
|
||||
cvt->len_cvt = clen;
|
||||
} /* Sound_RateSLOW */
|
||||
|
||||
|
||||
int Sound_ConvertAudio(Sound_AudioCVT *cvt)
|
||||
{
|
||||
Uint16 format;
|
||||
|
||||
/* Make sure there's data to convert */
|
||||
if (cvt->buf == NULL)
|
||||
{
|
||||
__Sound_SetError("No buffer allocated for conversion");
|
||||
return(-1);
|
||||
} /* if */
|
||||
|
||||
/* Return okay if no conversion is necessary */
|
||||
cvt->len_cvt = cvt->len;
|
||||
if (cvt->filters[0] == NULL)
|
||||
return(0);
|
||||
|
||||
/* Set up the conversion and go! */
|
||||
format = cvt->src_format;
|
||||
for (cvt->filter_index = 0; cvt->filters[cvt->filter_index];
|
||||
cvt->filter_index++)
|
||||
{
|
||||
cvt->filters[cvt->filter_index](cvt, &format);
|
||||
}
|
||||
return(0);
|
||||
} /* Sound_ConvertAudio */
|
||||
|
||||
|
||||
/*
|
||||
* Creates a set of audio filters to convert from one format to another.
|
||||
* Returns -1 if the format conversion is not supported, or 1 if the
|
||||
* audio filter is set up.
|
||||
*/
|
||||
|
||||
int Sound_BuildAudioCVT(Sound_AudioCVT *cvt,
|
||||
Uint16 src_format, Uint8 src_channels, Uint32 src_rate,
|
||||
Uint16 dst_format, Uint8 dst_channels, Uint32 dst_rate,
|
||||
Uint32 dst_size)
|
||||
{
|
||||
/* Start off with no conversion necessary */
|
||||
cvt->needed = 0;
|
||||
cvt->filter_index = 0;
|
||||
cvt->filters[0] = NULL;
|
||||
cvt->len_mult = 1;
|
||||
cvt->len_ratio = 1.0;
|
||||
|
||||
/* First filter: Endian conversion from src to dst */
|
||||
if ((src_format & 0x1000) != (dst_format & 0x1000) &&
|
||||
((src_format & 0xff) != 8))
|
||||
{
|
||||
SNDDBG(("Adding filter: Sound_ConvertEndian\n"));
|
||||
cvt->filters[cvt->filter_index++] = Sound_ConvertEndian;
|
||||
} /* if */
|
||||
|
||||
/* Second filter: Sign conversion -- signed/unsigned */
|
||||
if ((src_format & 0x8000) != (dst_format & 0x8000))
|
||||
{
|
||||
SNDDBG(("Adding filter: Sound_ConvertSign\n"));
|
||||
cvt->filters[cvt->filter_index++] = Sound_ConvertSign;
|
||||
} /* if */
|
||||
|
||||
/* Next filter: Convert 16 bit <--> 8 bit PCM. */
|
||||
if ((src_format & 0xFF) != (dst_format & 0xFF))
|
||||
{
|
||||
switch (dst_format & 0x10FF)
|
||||
{
|
||||
case AUDIO_U8:
|
||||
SNDDBG(("Adding filter: Sound_Convert8\n"));
|
||||
cvt->filters[cvt->filter_index++] = Sound_Convert8;
|
||||
cvt->len_ratio /= 2;
|
||||
break;
|
||||
|
||||
case AUDIO_U16LSB:
|
||||
SNDDBG(("Adding filter: Sound_Convert16LSB\n"));
|
||||
cvt->filters[cvt->filter_index++] = Sound_Convert16LSB;
|
||||
cvt->len_mult *= 2;
|
||||
cvt->len_ratio *= 2;
|
||||
break;
|
||||
|
||||
case AUDIO_U16MSB:
|
||||
SNDDBG(("Adding filter: Sound_Convert16MSB\n"));
|
||||
cvt->filters[cvt->filter_index++] = Sound_Convert16MSB;
|
||||
cvt->len_mult *= 2;
|
||||
cvt->len_ratio *= 2;
|
||||
break;
|
||||
} /* switch */
|
||||
} /* if */
|
||||
|
||||
/* Next filter: Mono/Stereo conversion */
|
||||
if (src_channels != dst_channels)
|
||||
{
|
||||
while ((src_channels * 2) <= dst_channels)
|
||||
{
|
||||
SNDDBG(("Adding filter: Sound_ConvertStereo\n"));
|
||||
cvt->filters[cvt->filter_index++] = Sound_ConvertStereo;
|
||||
cvt->len_mult *= 2;
|
||||
src_channels *= 2;
|
||||
cvt->len_ratio *= 2;
|
||||
} /* while */
|
||||
|
||||
/* This assumes that 4 channel audio is in the format:
|
||||
* Left {front/back} + Right {front/back}
|
||||
* so converting to L/R stereo works properly.
|
||||
*/
|
||||
while (((src_channels % 2) == 0) &&
|
||||
((src_channels / 2) >= dst_channels))
|
||||
{
|
||||
SNDDBG(("Adding filter: Sound_ConvertMono\n"));
|
||||
cvt->filters[cvt->filter_index++] = Sound_ConvertMono;
|
||||
src_channels /= 2;
|
||||
cvt->len_ratio /= 2;
|
||||
} /* while */
|
||||
|
||||
if ( src_channels != dst_channels ) {
|
||||
/* Uh oh.. */;
|
||||
} /* if */
|
||||
} /* if */
|
||||
|
||||
/* Do rate conversion */
|
||||
cvt->rate_incr = 0.0;
|
||||
if ((src_rate / 100) != (dst_rate / 100))
|
||||
{
|
||||
Uint32 hi_rate, lo_rate;
|
||||
int len_mult;
|
||||
double len_ratio;
|
||||
void (*rate_cvt)(Sound_AudioCVT *cvt, Uint16 *format);
|
||||
|
||||
if (src_rate > dst_rate)
|
||||
{
|
||||
hi_rate = src_rate;
|
||||
lo_rate = dst_rate;
|
||||
SNDDBG(("Adding filter: Sound_RateDIV2\n"));
|
||||
rate_cvt = Sound_RateDIV2;
|
||||
len_mult = 1;
|
||||
len_ratio = 0.5;
|
||||
} /* if */
|
||||
else
|
||||
{
|
||||
hi_rate = dst_rate;
|
||||
lo_rate = src_rate;
|
||||
SNDDBG(("Adding filter: Sound_RateMUL2\n"));
|
||||
rate_cvt = Sound_RateMUL2;
|
||||
len_mult = 2;
|
||||
len_ratio = 2.0;
|
||||
} /* else */
|
||||
|
||||
/* If hi_rate = lo_rate*2^x then conversion is easy */
|
||||
while (((lo_rate * 2) / 100) <= (hi_rate / 100))
|
||||
{
|
||||
cvt->filters[cvt->filter_index++] = rate_cvt;
|
||||
cvt->len_mult *= len_mult;
|
||||
lo_rate *= 2;
|
||||
cvt->len_ratio *= len_ratio;
|
||||
} /* while */
|
||||
|
||||
/* We may need a slow conversion here to finish up */
|
||||
if ((lo_rate / 100) != (hi_rate / 100))
|
||||
{
|
||||
if (src_rate < dst_rate)
|
||||
{
|
||||
cvt->rate_incr = (double) lo_rate / hi_rate;
|
||||
cvt->len_mult *= 2;
|
||||
cvt->len_ratio /= cvt->rate_incr;
|
||||
} /* if */
|
||||
else
|
||||
{
|
||||
cvt->rate_incr = (double) hi_rate / lo_rate;
|
||||
cvt->len_ratio *= cvt->rate_incr;
|
||||
} /* else */
|
||||
SNDDBG(("Adding filter: Sound_RateSLOW\n"));
|
||||
cvt->filters[cvt->filter_index++] = Sound_RateSLOW;
|
||||
} /* if */
|
||||
} /* if */
|
||||
|
||||
/* Set up the filter information */
|
||||
if (cvt->filter_index != 0)
|
||||
{
|
||||
cvt->needed = 1;
|
||||
cvt->src_format = src_format;
|
||||
cvt->dst_format = dst_format;
|
||||
cvt->len = 0;
|
||||
cvt->buf = NULL;
|
||||
cvt->filters[cvt->filter_index] = NULL;
|
||||
} /* if */
|
||||
|
||||
return(cvt->needed);
|
||||
} /* Sound_BuildAudioCVT */
|
||||
|
||||
/* end of audio_convert.c ... */
|
||||
|
Loading…
Add table
Reference in a new issue