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Userland+LibAudio: Make audio applications support dynamic sample rate

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All audio applications (aplay, Piano, Sound Player) respect the ability
of the system to have theoretically any sample rate. Therefore, they
resample their own audio into the system sample rate.

LibAudio previously had its loaders resample their own audio, even
though they expose their sample rate. This is now changed. The loaders
output audio data in their file's sample rate, which the user has to
query and resample appropriately. Resampling code from Buffer, WavLoader
and FlacLoader is removed.

Note that these applications only check the sample rate at startup,
which is reasonable (the user has to restart applications when changing
the sample rate). Fully dynamic adaptation could both lead to errors and
will require another IPC interface. This seems to be enough for now.
This commit is contained in:
kleines Filmröllchen 2021-08-19 00:13:26 +02:00 • committed by Ali Mohammad Pur
parent 9880a5c481
commit d049626f40
12 changed files with 56 additions and 41 deletions
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12
Userland/Libraries/LibAudio/Buffer.h
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@ -105,6 +105,9 @@ public:
void reset();
u32 source() const { return m_source; }
u32 target() const { return m_target; }
private:
const u32 m_source;
const u32 m_target;
@ -113,11 +116,11 @@ private:
SampleType m_last_sample_r;
};
// A buffer of audio samples, normalized to 44100hz.
// A buffer of audio samples.
class Buffer : public RefCounted<Buffer> {
public:
static RefPtr<Buffer> from_pcm_data(ReadonlyBytes data, ResampleHelper<double>& resampler, int num_channels, PcmSampleFormat sample_format);
static RefPtr<Buffer> from_pcm_stream(InputMemoryStream& stream, ResampleHelper<double>& resampler, int num_channels, PcmSampleFormat sample_format, int num_samples);
static RefPtr<Buffer> from_pcm_data(ReadonlyBytes data, int num_channels, PcmSampleFormat sample_format);
static RefPtr<Buffer> from_pcm_stream(InputMemoryStream& stream, int num_channels, PcmSampleFormat sample_format, int num_samples);
static NonnullRefPtr<Buffer> create_with_samples(Vector<Frame>&& samples)
{
return adopt_ref(*new Buffer(move(samples)));
@ -157,4 +160,7 @@ private:
const int m_sample_count;
};
// This only works for double resamplers, and therefore cannot be part of the class
NonnullRefPtr<Buffer> resample_buffer(ResampleHelper<double>& resampler, Buffer const& to_resample);
}