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Fix playback within Sample (#7100)

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This revisits two main aspects of playback from `Sample`: copying frames into a temporary playback buffer before resampling, and advancing the state's frame index.  Both operations were improperly done, causing distorted audio to be heard when resampling from within the `Sample::play` function.

To fix this, playback into the temporary playback buffer is now done using the `playRaw` function, which copies the frame one by one in a loop, moving through the buffer correctly as determined by the loop mode. In addition, advancement of the playback index is done using the `advance` function, which advances the index by the given amount and handles an out of bounds index for the loop modes as necessary using the modulo operator.
This commit is contained in:
saker
2024-02-16 16:31:44 -05:00
committed by GitHub
parent c87ff4194f
commit a81ad74e3a
4 changed files with 108 additions and 96 deletions
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21
include/Sample.h
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@@ -33,9 +33,6 @@
#include "SampleBuffer.h"
#include "lmms_export.h"
class QPainter;
class QRect;
namespace lmms {
class LMMS_EXPORT Sample
{
@@ -63,17 +60,17 @@ public:
}
auto resampler() -> AudioResampler& { return m_resampler; }
auto frameIndex() const -> f_cnt_t { return m_frameIndex; }
auto frameIndex() const -> int { return m_frameIndex; }
auto varyingPitch() const -> bool { return m_varyingPitch; }
auto backwards() const -> bool { return m_backwards; }
void setFrameIndex(f_cnt_t frameIndex) { m_frameIndex = frameIndex; }
void setFrameIndex(int frameIndex) { m_frameIndex = frameIndex; }
void setVaryingPitch(bool varyingPitch) { m_varyingPitch = varyingPitch; }
void setBackwards(bool backwards) { m_backwards = backwards; }
private:
AudioResampler m_resampler;
f_cnt_t m_frameIndex = 0;
int m_frameIndex = 0;
bool m_varyingPitch = false;
bool m_backwards = false;
friend class Sample;
@@ -81,7 +78,7 @@ public:
Sample() = default;
Sample(const QByteArray& base64, int sampleRate = Engine::audioEngine()->processingSampleRate());
Sample(const sampleFrame* data, int numFrames, int sampleRate = Engine::audioEngine()->processingSampleRate());
Sample(const sampleFrame* data, size_t numFrames, int sampleRate = Engine::audioEngine()->processingSampleRate());
Sample(const Sample& other);
Sample(Sample&& other);
explicit Sample(const QString& audioFile);
@@ -90,8 +87,8 @@ public:
auto operator=(const Sample&) -> Sample&;
auto operator=(Sample&&) -> Sample&;
auto play(sampleFrame* dst, PlaybackState* state, int numFrames, float desiredFrequency = DefaultBaseFreq,
Loop loopMode = Loop::Off) -> bool;
auto play(sampleFrame* dst, PlaybackState* state, size_t numFrames, float desiredFrequency = DefaultBaseFreq,
Loop loopMode = Loop::Off) const -> bool;
auto sampleDuration() const -> std::chrono::milliseconds;
auto sampleFile() const -> const QString& { return m_buffer->audioFile(); }
@@ -120,10 +117,8 @@ public:
void setReversed(bool reversed) { m_reversed.store(reversed, std::memory_order_relaxed); }
private:
void playSampleRange(PlaybackState* state, sampleFrame* dst, size_t numFrames) const;
void amplifySampleRange(sampleFrame* src, int numFrames) const;
void copyBufferForward(sampleFrame* dst, int initialPosition, int advanceAmount) const;
void copyBufferBackward(sampleFrame* dst, int initialPosition, int advanceAmount) const;
void playRaw(sampleFrame* dst, size_t numFrames, const PlaybackState* state, Loop loopMode) const;
void advance(PlaybackState* state, size_t advanceAmount, Loop loopMode) const;
private:
std::shared_ptr<const SampleBuffer> m_buffer = SampleBuffer::emptyBuffer();

2
include/SampleBuffer.h
View File

@@ -56,7 +56,7 @@ public:
SampleBuffer(const QString& base64, int sampleRate);
SampleBuffer(std::vector<sampleFrame> data, int sampleRate);
SampleBuffer(
const sampleFrame* data, int numFrames, int sampleRate = Engine::audioEngine()->processingSampleRate());
const sampleFrame* data, size_t numFrames, int sampleRate = Engine::audioEngine()->processingSampleRate());
friend void swap(SampleBuffer& first, SampleBuffer& second) noexcept;
auto toBase64() const -> QString;