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Diffstat (limited to 'src/audio_core/time_stretch.h')
-rw-r--r-- | src/audio_core/time_stretch.h | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/src/audio_core/time_stretch.h b/src/audio_core/time_stretch.h new file mode 100644 index 000000000..1fde3f72a --- /dev/null +++ b/src/audio_core/time_stretch.h @@ -0,0 +1,57 @@ +// Copyright 2016 Citra Emulator Project +// Licensed under GPLv2 or any later version +// Refer to the license.txt file included. + +#include <cstddef> +#include <memory> +#include <vector> + +#include "common/common_types.h" + +namespace AudioCore { + +class TimeStretcher final { +public: + TimeStretcher(); + ~TimeStretcher(); + + /** + * Set sample rate for the samples that Process returns. + * @param sample_rate The sample rate. + */ + void SetOutputSampleRate(unsigned int sample_rate); + + /** + * Add samples to be processed. + * @param sample_buffer Buffer of samples in interleaved stereo PCM16 format. + * @param num_sample Number of samples. + */ + void AddSamples(const s16* sample_buffer, size_t num_samples); + + /// Flush audio remaining in internal buffers. + void Flush(); + + /// Resets internal state and clears buffers. + void Reset(); + + /** + * Does audio stretching and produces the time-stretched samples. + * Timer calculations use sample_delay to determine how much of a margin we have. + * @param sample_delay How many samples are buffered downstream of this module and haven't been played yet. + * @return Samples to play in interleaved stereo PCM16 format. + */ + std::vector<s16> Process(size_t sample_delay); + +private: + struct Impl; + std::unique_ptr<Impl> impl; + + /// INTERNAL: ratio = wallclock time / emulated time + double CalculateCurrentRatio(); + /// INTERNAL: If we have too many or too few samples downstream, nudge ratio in the appropriate direction. + double CorrectForUnderAndOverflow(double ratio, size_t sample_delay) const; + /// INTERNAL: Gets the time-stretched samples from SoundTouch. + std::vector<s16> GetSamples(); +}; + +} // namespace AudioCore |