diff options
Diffstat (limited to 'Alc/mixer.c')
| -rw-r--r-- | Alc/mixer.c | 124 |
1 files changed, 32 insertions, 92 deletions
diff --git a/Alc/mixer.c b/Alc/mixer.c index 2f38ef3f..dd62ab73 100644 --- a/Alc/mixer.c +++ b/Alc/mixer.c @@ -57,16 +57,17 @@ enum Resampler { static enum Resampler DefaultResampler = LinearResampler; -/* Each entry is a pair, where the first is the number of samples needed before - * the current position, and the second is the number of samples needed after - * (not including) the current position, for the given resampler. +/* Specifies the number of samples needed after (not including) the current + * position, for the given resampler. */ -static const ALsizei ResamplerPadding[ResamplerMax][2] = { - {0, 0}, /* Point */ - {0, 1}, /* Linear */ - {1, 2}, /* FIR4 */ - {3, 4}, /* FIR8 */ +static const ALsizei ResamplerPadding[ResamplerMax] = { + 0, /* Point */ + 1, /* Linear */ + 2, /* FIR4 */ + 4, /* FIR8 */ }; +/* FIR8 requires 3 extra samples before the current position. */ +static_assert(MAX_PREVIOUS_SAMPLES >= 3, "MAX_PREVIOUS_SAMPLES must be at least 3!"); static HrtfMixerFunc MixHrtfSamples = MixHrtf_C; @@ -342,8 +343,7 @@ ALvoid MixSource(ALvoice *voice, ALsource *Source, ALCdevice *Device, ALuint Sam OutPos = 0; do { - const ALuint BufferPrePadding = ResamplerPadding[DefaultResampler][0]; - const ALuint BufferPadding = ResamplerPadding[DefaultResampler][1]; + const ALuint BufferPadding = ResamplerPadding[DefaultResampler]; ALuint SrcBufferSize, DstBufferSize; /* Figure out how many buffer samples will be needed */ @@ -351,13 +351,13 @@ ALvoid MixSource(ALvoice *voice, ALsource *Source, ALCdevice *Device, ALuint Sam DataSize64 *= increment; DataSize64 += DataPosFrac+FRACTIONMASK; DataSize64 >>= FRACTIONBITS; - DataSize64 += BufferPadding+BufferPrePadding; + DataSize64 += BufferPadding+MAX_PREVIOUS_SAMPLES; SrcBufferSize = (ALuint)mini64(DataSize64, BUFFERSIZE); /* Figure out how many samples we can actually mix from this. */ DataSize64 = SrcBufferSize; - DataSize64 -= BufferPadding+BufferPrePadding; + DataSize64 -= BufferPadding+MAX_PREVIOUS_SAMPLES; DataSize64 <<= FRACTIONBITS; DataSize64 -= DataPosFrac; @@ -373,7 +373,11 @@ ALvoid MixSource(ALvoice *voice, ALsource *Source, ALCdevice *Device, ALuint Sam { const ALfloat *ResampledData; ALfloat *SrcData = Device->SourceData; - ALuint SrcDataSize = 0; + ALuint SrcDataSize; + + /* Load the previous samples into the source data first. */ + memcpy(SrcData, voice->PrevSamples[chan], MAX_PREVIOUS_SAMPLES*sizeof(ALfloat)); + SrcDataSize = MAX_PREVIOUS_SAMPLES; if(Source->SourceType == AL_STATIC) { @@ -382,7 +386,7 @@ ALvoid MixSource(ALvoice *voice, ALsource *Source, ALCdevice *Device, ALuint Sam ALuint DataSize; ALuint pos; - /* Offset to current channel */ + /* Offset buffer data to current channel */ Data += chan*SampleSize; /* If current pos is beyond the loop range, do not loop */ @@ -390,21 +394,9 @@ ALvoid MixSource(ALvoice *voice, ALsource *Source, ALCdevice *Device, ALuint Sam { Looping = AL_FALSE; - if(DataPosInt >= BufferPrePadding) - pos = DataPosInt - BufferPrePadding; - else - { - DataSize = BufferPrePadding - DataPosInt; - DataSize = minu(SrcBufferSize - SrcDataSize, DataSize); - - SilenceSamples(&SrcData[SrcDataSize], DataSize); - SrcDataSize += DataSize; - - pos = 0; - } - - /* Copy what's left to play in the source buffer, and clear the - * rest of the temp buffer */ + /* Load what's left to play from the source buffer, and + * clear the rest of the temp buffer */ + pos = DataPosInt; DataSize = minu(SrcBufferSize - SrcDataSize, ALBuffer->SampleLen - pos); LoadSamples(&SrcData[SrcDataSize], &Data[pos * NumChannels*SampleSize], @@ -419,29 +411,9 @@ ALvoid MixSource(ALvoice *voice, ALsource *Source, ALCdevice *Device, ALuint Sam ALuint LoopStart = ALBuffer->LoopStart; ALuint LoopEnd = ALBuffer->LoopEnd; - if(DataPosInt >= LoopStart) - { - pos = DataPosInt-LoopStart; - while(pos < BufferPrePadding) - pos += LoopEnd-LoopStart; - pos -= BufferPrePadding; - pos += LoopStart; - } - else if(DataPosInt >= BufferPrePadding) - pos = DataPosInt - BufferPrePadding; - else - { - DataSize = BufferPrePadding - DataPosInt; - DataSize = minu(SrcBufferSize - SrcDataSize, DataSize); - - SilenceSamples(&SrcData[SrcDataSize], DataSize); - SrcDataSize += DataSize; - - pos = 0; - } - - /* Copy what's left of this loop iteration, then copy repeats - * of the loop section */ + /* Load what's left of this loop iteration, then load + * repeats of the loop section */ + pos = DataPosInt; DataSize = LoopEnd - pos; DataSize = minu(SrcBufferSize - SrcDataSize, DataSize); @@ -464,45 +436,7 @@ ALvoid MixSource(ALvoice *voice, ALsource *Source, ALCdevice *Device, ALuint Sam { /* Crawl the buffer queue to fill in the temp buffer */ ALbufferlistitem *tmpiter = BufferListItem; - ALuint pos; - - if(DataPosInt >= BufferPrePadding) - pos = DataPosInt - BufferPrePadding; - else - { - pos = BufferPrePadding - DataPosInt; - while(pos > 0) - { - ALbufferlistitem *prev; - if((prev=tmpiter->prev) != NULL) - tmpiter = prev; - else if(Looping) - { - while(tmpiter->next) - tmpiter = tmpiter->next; - } - else - { - ALuint DataSize = minu(SrcBufferSize - SrcDataSize, pos); - - SilenceSamples(&SrcData[SrcDataSize], DataSize); - SrcDataSize += DataSize; - - pos = 0; - break; - } - - if(tmpiter->buffer) - { - if((ALuint)tmpiter->buffer->SampleLen > pos) - { - pos = tmpiter->buffer->SampleLen - pos; - break; - } - pos -= tmpiter->buffer->SampleLen; - } - } - } + ALuint pos = DataPosInt; while(tmpiter && SrcBufferSize > SrcDataSize) { @@ -538,9 +472,15 @@ ALvoid MixSource(ALvoice *voice, ALsource *Source, ALCdevice *Device, ALuint Sam } } + /* Store the last source samples used for next time. */ + memcpy(voice->PrevSamples[chan], + &SrcData[(increment*DstBufferSize + DataPosFrac)>>FRACTIONBITS], + MAX_PREVIOUS_SAMPLES*sizeof(ALfloat) + ); + /* Now resample, then filter and mix to the appropriate outputs. */ ResampledData = Resample( - &SrcData[BufferPrePadding], DataPosFrac, increment, + &SrcData[MAX_PREVIOUS_SAMPLES], DataPosFrac, increment, Device->ResampledData, DstBufferSize ); { |