diff options
Diffstat (limited to 'audio/audiostream.cpp')
| -rw-r--r-- | audio/audiostream.cpp | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/audio/audiostream.cpp b/audio/audiostream.cpp index 1c5c435359..2d65d4afef 100644 --- a/audio/audiostream.cpp +++ b/audio/audiostream.cpp @@ -386,4 +386,42 @@ Timestamp convertTimeToStreamPos(const Timestamp &where, int rate, bool isStereo return Timestamp(result.secs(), result.numberOfFrames(), result.framerate()); } +/** + * An AudioStream wrapper that cuts off the amount of samples read after a + * given time length is reached. + */ +class LimitingAudioStream : public AudioStream { +public: + LimitingAudioStream(AudioStream *parentStream, const Audio::Timestamp &length, DisposeAfterUse::Flag disposeAfterUse) : + _parentStream(parentStream), _samplesRead(0), _disposeAfterUse(disposeAfterUse), + _totalSamples(length.convertToFramerate(getRate()).totalNumberOfFrames() * getChannels()) {} + + ~LimitingAudioStream() { + if (_disposeAfterUse == DisposeAfterUse::YES) + delete _parentStream; + } + + int readBuffer(int16 *buffer, const int numSamples) { + // Cap us off so we don't read past _totalSamples + int samplesRead = _parentStream->readBuffer(buffer, MIN<int>(numSamples, _totalSamples - _samplesRead)); + _samplesRead += samplesRead; + return samplesRead; + } + + bool endOfData() const { return _parentStream->endOfData() || _samplesRead >= _totalSamples; } + bool isStereo() const { return _parentStream->isStereo(); } + int getRate() const { return _parentStream->getRate(); } + +private: + int getChannels() const { return isStereo() ? 2 : 1; } + + AudioStream *_parentStream; + DisposeAfterUse::Flag _disposeAfterUse; + uint32 _totalSamples, _samplesRead; +}; + +AudioStream *makeLimitingAudioStream(AudioStream *parentStream, const Timestamp &length, DisposeAfterUse::Flag disposeAfterUse) { + return new LimitingAudioStream(parentStream, length, disposeAfterUse); +} + } // End of namespace Audio |