diff options
| -rw-r--r-- | sound/mp3.cpp | 116 |
1 files changed, 62 insertions, 54 deletions
diff --git a/sound/mp3.cpp b/sound/mp3.cpp index f2a5f4ea8b..ff0e3d61dd 100644 --- a/sound/mp3.cpp +++ b/sound/mp3.cpp @@ -43,12 +43,18 @@ namespace Audio { class MP3InputStream : public AudioStream { protected: + enum State { + MP3_STATE_INIT, // Need to init the decoder + MP3_STATE_READY, // ready for processing data + MP3_STATE_EOS // end of data reached (may need to loop) + }; + Common::SeekableReadStream *_inStream; bool _disposeAfterUse; uint _numLoops; uint _posInFrame; - bool _eos; + State _state; const mad_timer_t _startTime; const mad_timer_t _endTime; @@ -75,14 +81,13 @@ public: int readBuffer(int16 *buffer, const int numSamples); - bool endOfData() const { return _eos; } + bool endOfData() const { return _state == MP3_STATE_EOS; } bool isStereo() const { return MAD_NCHANNELS(&_frame.header) == 2; } int getRate() const { return _frame.header.samplerate; } protected: - void rewind(); void decodeMP3Data(); - bool readMP3Data(); + void readMP3Data(); }; MP3InputStream::MP3InputStream(Common::SeekableReadStream *inStream, bool dispose, mad_timer_t start, mad_timer_t end, uint numLoops) : @@ -90,7 +95,7 @@ MP3InputStream::MP3InputStream(Common::SeekableReadStream *inStream, bool dispos _disposeAfterUse(dispose), _numLoops(numLoops), _posInFrame(0), - _eos(false), + _state(MP3_STATE_INIT), _startTime(start), _endTime(end), _totalTime(mad_timer_zero) { @@ -103,57 +108,52 @@ MP3InputStream::MP3InputStream(Common::SeekableReadStream *inStream, bool dispos // may read a few bytes beyond the end of the input buffer). memset(_buf + BUFFER_SIZE, 0, MAD_BUFFER_GUARD); - // Init MAD - mad_stream_init(&_stream); - mad_frame_init(&_frame); - mad_synth_init(&_synth); - - // Decode the first chunk of data. + // Decode the first chunk of data. This is necessary so that _frame + // is setup and isStereo() and getRate() return correct results. decodeMP3Data(); } MP3InputStream::~MP3InputStream() { - // Deinit MAD - mad_synth_finish(&_synth); - mad_frame_finish(&_frame); - mad_stream_finish(&_stream); + if (_state != MP3_STATE_INIT) { + // Deinit MAD + mad_synth_finish(&_synth); + mad_frame_finish(&_frame); + mad_stream_finish(&_stream); + } if (_disposeAfterUse) delete _inStream; } -void MP3InputStream::rewind() { - // Start over again: reset the decoders, seek back to the start of the file, etc. - - mad_synth_finish(&_synth); - mad_frame_finish(&_frame); - mad_stream_finish(&_stream); - - _inStream->seek(0, SEEK_SET); - _totalTime = mad_timer_zero; - _posInFrame = 0; - _eos = false; - - // Reinit MAD - mad_stream_init(&_stream); - mad_frame_init(&_frame); - mad_synth_init(&_synth); -} - void MP3InputStream::decodeMP3Data() { - if (_eos) - return; do { - // If necessary, load more data - if (_stream.buffer == NULL || _stream.error == MAD_ERROR_BUFLEN) { - if (!readMP3Data()) { - // We tried to read more data but failed -> end of stream reached - _eos = true; - } + if (_state == MP3_STATE_INIT) { + // Init MAD + mad_stream_init(&_stream); + mad_frame_init(&_frame); + mad_synth_init(&_synth); + + // Reset the stream data + _inStream->seek(0, SEEK_SET); + _totalTime = mad_timer_zero; + _posInFrame = 0; + + // Update state + _state = MP3_STATE_READY; + + // Read the first few sample bytes + readMP3Data(); } + + if (_state == MP3_STATE_EOS) + return; + + // If necessary, load more data into the stream decoder + if (_stream.error == MAD_ERROR_BUFLEN) + readMP3Data(); - while (!_eos) { + while (_state == MP3_STATE_READY) { _stream.error = MAD_ERROR_NONE; // Decode the next header. Note: mad_frame_decode would do this for us, too. @@ -180,7 +180,7 @@ void MP3InputStream::decodeMP3Data() { // If an end time is specified and we are past it, stop if (mad_timer_sign(_endTime) > 0 && mad_timer_compare(_totalTime, _endTime) >= 0) { - _eos = true; + _state = MP3_STATE_EOS; break; } @@ -206,25 +206,34 @@ void MP3InputStream::decodeMP3Data() { break; } - if (_eos && _numLoops != 1) { + if (_state == MP3_STATE_EOS && _numLoops != 1) { // If looping is on and there are loops left, rewind to the start if (_numLoops != 0) _numLoops--; - rewind(); + + // Deinit MAD + mad_synth_finish(&_synth); + mad_frame_finish(&_frame); + mad_stream_finish(&_stream); + + // Reset the decoder state to indicate we should start over + _state = MP3_STATE_INIT; } - } while (!_eos && _stream.error == MAD_ERROR_BUFLEN); + } while (_state != MP3_STATE_EOS && _stream.error == MAD_ERROR_BUFLEN); if (_stream.error != MAD_ERROR_NONE) - _eos = true; + _state = MP3_STATE_EOS; } -bool MP3InputStream::readMP3Data() { +void MP3InputStream::readMP3Data() { uint32 remaining = 0; // Give up immediately if we already used up all data in the stream - if (_inStream->eos()) - return false; + if (_inStream->eos()) { + _state = MP3_STATE_EOS; + return; + } if (_stream.next_frame) { // If there is still data in the MAD stream, we need to preserve it. @@ -238,14 +247,13 @@ bool MP3InputStream::readMP3Data() { // Try to read the next block uint32 size = _inStream->read(_buf + remaining, BUFFER_SIZE - remaining); if (size <= 0) { - return false; + _state = MP3_STATE_EOS; + return; } // Feed the data we just read into the stream decoder _stream.error = MAD_ERROR_NONE; mad_stream_buffer(&_stream, _buf, size + remaining); - - return true; } @@ -266,7 +274,7 @@ static inline int scale_sample(mad_fixed_t sample) { int MP3InputStream::readBuffer(int16 *buffer, const int numSamples) { int samples = 0; // Keep going as long as we have input available - while (samples < numSamples && !_eos) { + while (samples < numSamples && _state != MP3_STATE_EOS) { const int len = MIN(numSamples, samples + (int)(_synth.pcm.length - _posInFrame) * MAD_NCHANNELS(&_frame.header)); while (samples < len) { *buffer++ = (int16)scale_sample(_synth.pcm.samples[0][_posInFrame]); |