diff options
Diffstat (limited to 'audio/decoders')
| -rw-r--r-- | audio/decoders/adpcm.cpp | 16 | ||||
| -rw-r--r-- | audio/decoders/adpcm_intern.h | 4 |
2 files changed, 15 insertions, 5 deletions
diff --git a/audio/decoders/adpcm.cpp b/audio/decoders/adpcm.cpp index 5c96d5245a..e7297423f6 100644 --- a/audio/decoders/adpcm.cpp +++ b/audio/decoders/adpcm.cpp @@ -71,13 +71,19 @@ int Oki_ADPCMStream::readBuffer(int16 *buffer, const int numSamples) { int samples; byte data; - assert(numSamples % 2 == 0); + for (samples = 0; samples < numSamples && !_stream->eos() && (_stream->pos() < _endpos); samples++) { + if (_decodedSampleCount == 0) { + data = _stream->readByte(); + _decodedSamples[0] = decodeOKI((data >> 4) & 0x0f); + _decodedSamples[1] = decodeOKI((data >> 0) & 0x0f); + _decodedSampleCount = 2; + } - for (samples = 0; samples < numSamples && !_stream->eos() && _stream->pos() < _endpos; samples += 2) { - data = _stream->readByte(); - buffer[samples] = decodeOKI((data >> 4) & 0x0f); - buffer[samples + 1] = decodeOKI(data & 0x0f); + // (1 - (count - 1)) ensures that _decodedSamples acts as a FIFO of depth 2 + buffer[samples] = _decodedSamples[1 - (_decodedSampleCount - 1)]; + _decodedSampleCount--; } + return samples; } diff --git a/audio/decoders/adpcm_intern.h b/audio/decoders/adpcm_intern.h index 537ae023ef..423c4af267 100644 --- a/audio/decoders/adpcm_intern.h +++ b/audio/decoders/adpcm_intern.h @@ -89,6 +89,10 @@ public: protected: int16 decodeOKI(byte); + +private: + uint8 _decodedSampleCount; + int16 _decodedSamples[2]; }; class Ima_ADPCMStream : public ADPCMStream { |