diff options
| -rw-r--r-- | sound/adpcm.cpp | 17 | ||||
| -rw-r--r-- | sound/adpcm.h | 11 |
2 files changed, 16 insertions, 12 deletions
diff --git a/sound/adpcm.cpp b/sound/adpcm.cpp index d1e54de2af..1ca3f845cb 100644 --- a/sound/adpcm.cpp +++ b/sound/adpcm.cpp @@ -265,10 +265,10 @@ int16 ADPCMInputStream::decodeMS(ADPCMChannelStatus *c, byte code) { predictor = (((c->sample1) * (c->coeff1)) + ((c->sample2) * (c->coeff2))) / 256; predictor += (signed)((code & 0x08) ? (code - 0x10) : (code)) * c->delta; - if (predictor < -0x8000) - predictor = -0x8000; - else if (predictor > 0x7fff) - predictor = 0x7fff; + if (predictor < -32768) + predictor = -32768; + else if (predictor > 32767) + predictor = 32767; c->sample2 = c->sample1; c->sample1 = predictor; @@ -345,13 +345,12 @@ int16 ADPCMInputStream::decodeMSIMA(byte code) { diff = (code & 0x08) ? -E : E; samp = _status.last + diff; - if (samp < -0x8000) - samp = -0x8000; - else if (samp > 0x7fff) - samp = 0x7fff; + if (samp < -32768) + samp = -32768; + else if (samp > 32767) + samp = 32767; _status.last = samp; - _status.stepIndex += stepAdjust(code); if (_status.stepIndex < 0) _status.stepIndex = 0; diff --git a/sound/adpcm.h b/sound/adpcm.h index db008609ec..43296e617c 100644 --- a/sound/adpcm.h +++ b/sound/adpcm.h @@ -34,10 +34,15 @@ namespace Audio { class AudioStream; +// There are several types of ADPCM encoding, only some are supported here +// For all the different encodings, refer to: +// http://wiki.multimedia.cx/index.php?title=Category:ADPCM_Audio_Codecs +// Usually, if the audio stream we're trying to play has the FourCC header +// string intact, it's easy to discern which encoding is used enum typesADPCM { - kADPCMOki, - kADPCMMSIma, - kADPCMMS + kADPCMOki, // Dialogic/Oki ADPCM (aka VOX) + kADPCMMSIma, // Microsoft IMA ADPCM + kADPCMMS // Microsoft ADPCM }; /** |