diff options
Diffstat (limited to 'OpenAL32')
| -rw-r--r-- | OpenAL32/alBuffer.c | 66 |
1 files changed, 47 insertions, 19 deletions
diff --git a/OpenAL32/alBuffer.c b/OpenAL32/alBuffer.c index eeeb9315..7230fe29 100644 --- a/OpenAL32/alBuffer.c +++ b/OpenAL32/alBuffer.c @@ -1362,31 +1362,43 @@ static void DecodeMSADPCMBlock(ALshort *dst, const ALmsadpcm *src, ALint numchan } } -/* FIXME: Stubbed. Just inserts silence. */ -static void EncodeMSADPCMBlock(ALmsadpcm *dst, const ALshort* UNUSED(src), ALint* UNUSED(sample), ALint* UNUSED(index), ALint numchans, ALsizei align) +/* NOTE: This encoder is pretty dumb/simplistic. Some kind of pre-processing + * that tries to find the optimal block predictors would be nice, at least. A + * multi-pass method that can generate better deltas would be good, too. */ +static void EncodeMSADPCMBlock(ALmsadpcm *dst, const ALshort *src, ALint *sample, ALint numchans, ALsizei align) { + ALubyte blockpred[MAX_INPUT_CHANNELS]; + ALint delta[MAX_INPUT_CHANNELS]; + ALshort samples[MAX_INPUT_CHANNELS][2]; ALint i, j; /* Block predictor */ for(i = 0;i < numchans;i++) - *(dst++) = 2; + { + /* FIXME: Calculate something better. */ + blockpred[i] = 0; + *(dst++) = blockpred[i]; + } /* Initial delta */ for(i = 0;i < numchans;i++) { - *(dst++) = 16; - *(dst++) = 0; + delta[i] = 16; + *(dst++) = (delta[i] ) & 0xff; + *(dst++) = (delta[i]>>8) & 0xff; } /* Initial sample 1 */ for(i = 0;i < numchans;i++) { - *(dst++) = 0; - *(dst++) = 0; + samples[i][0] = src[1*numchans + i]; + *(dst++) = (samples[i][0] ) & 0xff; + *(dst++) = (samples[i][0]>>8) & 0xff; } /* Initial sample 2 */ for(i = 0;i < numchans;i++) { - *(dst++) = 0; - *(dst++) = 0; + samples[i][1] = src[i]; + *(dst++) = (samples[i][1] ) & 0xff; + *(dst++) = (samples[i][1]>>8) & 0xff; } for(j = 2;j < align;j++) @@ -1394,7 +1406,29 @@ static void EncodeMSADPCMBlock(ALmsadpcm *dst, const ALshort* UNUSED(src), ALint for(i = 0;i < numchans;i++) { const ALint num = (j*numchans) + i; - ALubyte nibble = 0; + ALint nibble = 0; + ALint bias; + + sample[i] = (samples[i][0]*MSADPCMAdaptionCoeff[blockpred[i]][0] + + samples[i][1]*MSADPCMAdaptionCoeff[blockpred[i]][1]) / 256; + + nibble = src[num] - sample[i]; + if(nibble >= 0) + bias = delta[i] / 2; + else + bias = -delta[i] / 2; + + nibble = (nibble + bias) / delta[i]; + nibble = clampi(nibble, -8, 7)&0x0f; + + sample[i] += ((nibble^0x08)-0x08) * delta[i]; + sample[i] = clampi(sample[i], -32768, 32767); + + samples[i][1] = samples[i][0]; + samples[i][0] = sample[i]; + + delta[i] = (MSADPCMAdaption[nibble] * delta[i]) / 256; + delta[i] = maxi(16, delta[i]); if(!(num&1)) *dst = nibble << 4; @@ -1980,13 +2014,10 @@ static void Convert_ALmsadpcm_##T(ALmsadpcm *dst, const T *src, \ ALuint numchans, ALuint len, ALuint align) \ { \ ALint sample[MaxChannels] = {0,0,0,0,0,0,0,0}; \ - ALint index[MaxChannels] = {0,0,0,0,0,0,0,0}; \ ALsizei byte_align = ((align-2)/2 + 7) * numchans; \ ALuint i, j, k; \ ALshort *tmp; \ \ - ERR("MSADPCM encoding not currently supported!\n"); \ - \ tmp = alloca(align*numchans*sizeof(*tmp)); \ for(i = 0;i < len;i += align) \ { \ @@ -1995,7 +2026,7 @@ static void Convert_ALmsadpcm_##T(ALmsadpcm *dst, const T *src, \ for(k = 0;k < numchans;k++) \ tmp[j*numchans + k] = Conv_ALshort_##T(*(src++)); \ } \ - EncodeMSADPCMBlock(dst, tmp, sample, index, numchans, align); \ + EncodeMSADPCMBlock(dst, tmp, sample, numchans, align); \ dst += byte_align; \ } \ } @@ -2003,18 +2034,15 @@ static void Convert_ALmsadpcm_##T(ALmsadpcm *dst, const T *src, \ DECL_TEMPLATE(ALbyte) DECL_TEMPLATE(ALubyte) static void Convert_ALmsadpcm_ALshort(ALmsadpcm *dst, const ALshort *src, - ALuint numchans, ALuint len, ALuint align) + ALuint numchans, ALuint len, ALuint align) { ALint sample[MaxChannels] = {0,0,0,0,0,0,0,0}; - ALint index[MaxChannels] = {0,0,0,0,0,0,0,0}; ALsizei byte_align = ((align-2)/2 + 7) * numchans; ALuint i; - ERR("MSADPCM encoding not currently supported!\n"); - for(i = 0;i < len;i += align) { - EncodeMSADPCMBlock(dst, src, sample, index, numchans, align); + EncodeMSADPCMBlock(dst, src, sample, numchans, align); src += align*numchans; dst += byte_align; } |