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miniaudio
Commit 966aeb07 authored by David Reid's avatar David Reid
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Update linear resampler expected output frame count calculations. 

This updates ma_linear_resampler_get_expected_output_frame_count() to
calculate the expected output frame count in constant time rather than
linear time. This should improve performances of anything using
ma_calculate_frame_count_after_resampling() which includes
ma_decoder_get_length_in_pcm_frames().
parent c92c7764
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Showing with 44 additions and 60 deletions
miniaudio.h
View file @ 966aeb07
......@@ -35867,13 +35867,9 @@ static ma_result ma_linear_resampler_process_pcm_frames_s16_downsample(ma_linear
framesProcessedIn = 0;
framesProcessedOut = 0;
for (;;) {
if (framesProcessedOut >= frameCountOut) {
break;
}
while (framesProcessedOut < frameCountOut) {
/* Before interpolating we need to load the buffers. When doing this we need to ensure we run every input sample through the filter. */
while (pResampler->inTimeInt > 0 && frameCountIn > 0) {
while (pResampler->inTimeInt > 0 && frameCountIn > framesProcessedIn) {
ma_uint32 iChannel;
if (pFramesInS16 != NULL) {
......@@ -35892,7 +35888,6 @@ static ma_result ma_linear_resampler_process_pcm_frames_s16_downsample(ma_linear
/* Filter. */
ma_lpf_process_pcm_frame_s16(&pResampler->lpf, pResampler->x1.s16, pResampler->x1.s16);
frameCountIn -= 1;
framesProcessedIn += 1;
pResampler->inTimeInt -= 1;
}
......@@ -35946,13 +35941,9 @@ static ma_result ma_linear_resampler_process_pcm_frames_s16_upsample(ma_linear_r
framesProcessedIn = 0;
framesProcessedOut = 0;
for (;;) {
if (framesProcessedOut >= frameCountOut) {
break;
}
while (framesProcessedOut < frameCountOut) {
/* Before interpolating we need to load the buffers. */
while (pResampler->inTimeInt > 0 && frameCountIn > 0) {
while (pResampler->inTimeInt > 0 && frameCountIn > framesProcessedIn) {
ma_uint32 iChannel;
if (pFramesInS16 != NULL) {
......@@ -35968,7 +35959,6 @@ static ma_result ma_linear_resampler_process_pcm_frames_s16_upsample(ma_linear_r
}
}
frameCountIn -= 1;
framesProcessedIn += 1;
pResampler->inTimeInt -= 1;
}
......@@ -36037,13 +36027,9 @@ static ma_result ma_linear_resampler_process_pcm_frames_f32_downsample(ma_linear
framesProcessedIn = 0;
framesProcessedOut = 0;
for (;;) {
if (framesProcessedOut >= frameCountOut) {
break;
}
while (framesProcessedOut < frameCountOut) {
/* Before interpolating we need to load the buffers. When doing this we need to ensure we run every input sample through the filter. */
while (pResampler->inTimeInt > 0 && frameCountIn > 0) {
while (pResampler->inTimeInt > 0 && frameCountIn > framesProcessedIn) {
ma_uint32 iChannel;
if (pFramesInF32 != NULL) {
......@@ -36062,7 +36048,6 @@ static ma_result ma_linear_resampler_process_pcm_frames_f32_downsample(ma_linear
/* Filter. */
ma_lpf_process_pcm_frame_f32(&pResampler->lpf, pResampler->x1.f32, pResampler->x1.f32);
frameCountIn -= 1;
framesProcessedIn += 1;
pResampler->inTimeInt -= 1;
}
......@@ -36116,13 +36101,9 @@ static ma_result ma_linear_resampler_process_pcm_frames_f32_upsample(ma_linear_r
framesProcessedIn = 0;
framesProcessedOut = 0;
for (;;) {
if (framesProcessedOut >= frameCountOut) {
break;
}
while (framesProcessedOut < frameCountOut) {
/* Before interpolating we need to load the buffers. */
while (pResampler->inTimeInt > 0 && frameCountIn > 0) {
while (pResampler->inTimeInt > 0 && frameCountIn > framesProcessedIn) {
ma_uint32 iChannel;
if (pFramesInF32 != NULL) {
......@@ -36138,7 +36119,6 @@ static ma_result ma_linear_resampler_process_pcm_frames_f32_upsample(ma_linear_r
}
}
frameCountIn -= 1;
framesProcessedIn += 1;
pResampler->inTimeInt -= 1;
}
......@@ -36230,7 +36210,7 @@ MA_API ma_result ma_linear_resampler_set_rate_ratio(ma_linear_resampler* pResamp
MA_API ma_uint64 ma_linear_resampler_get_required_input_frame_count(ma_linear_resampler* pResampler, ma_uint64 outputFrameCount)
{
ma_uint64 count;
ma_uint64 inputFrameCount;
if (pResampler == NULL) {
return 0;
......@@ -36241,51 +36221,48 @@ MA_API ma_uint64 ma_linear_resampler_get_required_input_frame_count(ma_linear_re
}
/* Any whole input frames are consumed before the first output frame is generated. */
count = pResampler->inTimeInt;
inputFrameCount = pResampler->inTimeInt;
outputFrameCount -= 1;
/* The rest of the output frames can be calculated in constant time. */
count += outputFrameCount * pResampler->inAdvanceInt;
count += (pResampler->inTimeFrac + (outputFrameCount * pResampler->inAdvanceFrac)) / pResampler->config.sampleRateOut;
inputFrameCount += outputFrameCount * pResampler->inAdvanceInt;
inputFrameCount += (pResampler->inTimeFrac + (outputFrameCount * pResampler->inAdvanceFrac)) / pResampler->config.sampleRateOut;
return count;
return inputFrameCount;
}
MA_API ma_uint64 ma_linear_resampler_get_expected_output_frame_count(ma_linear_resampler* pResampler, ma_uint64 inputFrameCount)
{
ma_uint64 outputFrameCount;
ma_uint64 inTimeInt;
ma_uint64 inTimeFrac;
ma_uint64 preliminaryInputFrameCountFromFrac;
ma_uint64 preliminaryInputFrameCount;
if (pResampler == NULL) {
return 0;
}
/* TODO: Try making this run in constant time. */
outputFrameCount = 0;
inTimeInt = pResampler->inTimeInt;
inTimeFrac = pResampler->inTimeFrac;
for (;;) {
while (inTimeInt > 0 && inputFrameCount > 0) {
inputFrameCount -= 1;
inTimeInt -= 1;
}
/*
The first step is to get a preliminary output frame count. This will either be exactly equal to what we need, or less by 1. We need to
determine how many input frames will be consumed by this value. If it's greater than our original input frame count it means we won't
be able to generate an extra frame because we will have run out of input data. Otherwise we will have enough input for the generation
of an extra output frame. This add-by-one logic is necessary due to how the data loading logic works when processing frames.
*/
outputFrameCount = (inputFrameCount * pResampler->config.sampleRateOut) / pResampler->config.sampleRateIn;
if (inTimeInt > 0) {
break;
}
/*
We need to determine how many *whole* input frames will have been processed to generate our preliminary output frame count. This is
used in the logic below to determine whether or not we need to add an extra output frame.
*/
preliminaryInputFrameCountFromFrac = (pResampler->inTimeFrac + outputFrameCount*pResampler->inAdvanceFrac) / pResampler->config.sampleRateOut;
preliminaryInputFrameCount = (pResampler->inTimeInt + outputFrameCount*pResampler->inAdvanceInt ) + preliminaryInputFrameCountFromFrac;
/*
If the total number of *whole* input frames that would be required to generate our preliminary output frame count is greather than
the amount of whole input frames we have available as input we need to *not* add an extra output frame as there won't be enough data
to actually process. Otherwise we need to add the extra output frame.
*/
if (preliminaryInputFrameCount <= inputFrameCount) {
outputFrameCount += 1;
/* Advance time forward. */
inTimeInt += pResampler->inAdvanceInt;
inTimeFrac += pResampler->inAdvanceFrac;
if (inTimeFrac >= pResampler->config.sampleRateOut) {
inTimeFrac -= pResampler->config.sampleRateOut;
inTimeInt += 1;
}
}
return outputFrameCount;
......@@ -43682,11 +43659,18 @@ MA_API ma_uint64 ma_decoder_read_pcm_frames(ma_decoder* pDecoder, void* pFramesO
MA_API ma_result ma_decoder_seek_to_pcm_frame(ma_decoder* pDecoder, ma_uint64 frameIndex)
{
if (pDecoder == NULL) {
return 0;
return MA_INVALID_ARGS;
}
if (pDecoder->onSeekToPCMFrame) {
return pDecoder->onSeekToPCMFrame(pDecoder, frameIndex);
ma_uint64 internalFrameIndex;
if (pDecoder->internalSampleRate == pDecoder->outputSampleRate) {
internalFrameIndex = frameIndex;
} else {
internalFrameIndex = ma_calculate_frame_count_after_resampling(pDecoder->internalSampleRate, pDecoder->outputSampleRate, frameIndex);
}
return pDecoder->onSeekToPCMFrame(pDecoder, internalFrameIndex);
}
/* Should never get here, but if we do it means onSeekToPCMFrame was not set by the backend. */
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