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rtphone/src/engine/audio/Audio_Resampler.cpp
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/* Copyright(C) 2007-2018 VoIP objects (voipobjects.com)
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "../engine_config.h"
#include "Audio_Resampler.h"
#include <stdlib.h>
#include <assert.h>
#include <memory.h>
#include <algorithm>
#include "speex/speex_resampler.h"
#define IS_FRACTIONAL_RATE(X) (((X) % 8000) != 0)
namespace Audio
{
SpeexResampler::SpeexResampler() {}
void SpeexResampler::start(int channels, int sourceRate, int destRate)
{
if (mSourceRate == sourceRate && mDestRate == destRate && mContext)
return;
if (mContext)
stop();
mSourceRate = sourceRate;
mDestRate = destRate;
mChannels = channels;
if (sourceRate != destRate)
{
// Defer context creation until first request
// mContext = speex_resampler_init(channels, sourceRate, destRate, AUDIO_RESAMPLER_QUALITY, &mErrorCode);
// assert(mContext != NULL);
}
}
void SpeexResampler::stop()
{
if (mContext)
{
speex_resampler_destroy((SpeexResamplerState*)mContext);
mContext = NULL;
}
}
bool SpeexResampler::isOpened() const
{
return mContext != nullptr;
}
SpeexResampler::~SpeexResampler()
{
stop();
}
size_t SpeexResampler::processBuffer(const void* src, size_t sourceLength, size_t& sourceProcessed, void* dest,
size_t destCapacity)
{
assert(mSourceRate != 0 && mDestRate != 0);
if (mDestRate == mSourceRate)
{
// Pass-through, but never write past the caller's buffer: clamp to its
// capacity instead of trusting sourceLength (which is caller/file driven).
assert(destCapacity >= sourceLength);
size_t copied = std::min(sourceLength, destCapacity);
memcpy(dest, src, copied);
sourceProcessed = copied;
return copied;
}
if (!mContext)
{
mContext = speex_resampler_init(mChannels, mSourceRate, mDestRate, AUDIO_RESAMPLER_QUALITY, &mErrorCode);
if (!mContext)
return 0;
}
// Check if there is zero samples passed
if (sourceLength / (sizeof(short) * mChannels) == 0)
{
// Consume all data
sourceProcessed = sourceLength;
// But no output
return 0;
}
size_t outLen = getDestLength(sourceLength);
if (outLen > destCapacity)
return 0; // Skip resampling if not enough space
assert(destCapacity >= outLen);
// Calculate number of samples - input length is in bytes
unsigned inLen = sourceLength / (sizeof(short) * mChannels);
outLen /= sizeof(short) * mChannels;
assert(mContext != NULL);
spx_uint32_t in_len = static_cast<spx_uint32_t>(inLen), out_len = static_cast<spx_uint32_t>(outLen);
int speexCode = speex_resampler_process_interleaved_int((SpeexResamplerState*)mContext, (spx_int16_t*)src, &in_len,
(spx_int16_t*)dest, &out_len);
assert(speexCode == RESAMPLER_ERR_SUCCESS);
inLen = static_cast<size_t>(in_len);
outLen = static_cast<size_t>(out_len);
// Return results in bytes
sourceProcessed = inLen * sizeof(short) * mChannels;
return outLen * sizeof(short) * mChannels;
}
int SpeexResampler::sourceRate() const
{
return mSourceRate;
}
int SpeexResampler::destRate() const
{
return mDestRate;
}
size_t SpeexResampler::getDestLength(size_t sourceLen) const
{
return size_t(sourceLen * (float(mDestRate) / mSourceRate) + 0.5f);
}
size_t SpeexResampler::getSourceLength(size_t destLen) const
{
// Here we want to get 'destLen' number of samples
return size_t(destLen * (float(mSourceRate) / mDestRate) + 0.5f);
}
// Returns instance + speex resampler size in bytes
size_t SpeexResampler::getSize() const
{
return sizeof(*this) + 200; // 200 is approximate size of speex resample structure
}
// -------------------------- ChannelConverter --------------------
int ChannelConverter::stereoToMono(const void* source, int sourceLength, void* dest, int destLength)
{
assert(destLength == sourceLength / 2);
const short* input = (const short*)source;
short* output = (short*)dest;
for (int sampleIndex = 0; sampleIndex < destLength / 2; sampleIndex++)
{
output[sampleIndex] = (input[sampleIndex * 2] + input[sampleIndex * 2 + 1]) >> 1;
}
return sourceLength / 2;
}
int ChannelConverter::monoToStereo(const void* source, int sourceLength, void* dest, int destLength)
{
assert(destLength == sourceLength * 2);
const short* input = (const short*)source;
short* output = (short*)dest;
// Convert starting from the end of buffer to allow inplace conversion
for (int sampleIndex = sourceLength / 2 - 1; sampleIndex >= 0; sampleIndex--)
{
output[2 * sampleIndex] = output[2 * sampleIndex + 1] = input[sampleIndex];
}
return sourceLength * 2;
}
#if defined(USE_WEBRTC_RESAMPLER)
Resampler48kTo16k::Resampler48kTo16k()
{
WebRtcSpl_ResetResample48khzTo16khz(&mContext);
}
Resampler48kTo16k::~Resampler48kTo16k()
{
WebRtcSpl_ResetResample48khzTo16khz(&mContext);
}
int Resampler48kTo16k::process(const void* source, int sourceLen, void* dest, int destLen)
{
const short* input = (const short*)source;
int inputLen = sourceLen / 2;
short* output = (short*)dest; // int outputCapacity = destLen / 2;
assert(inputLen % 480 == 0);
int frames = inputLen / 480;
for (int i = 0; i < frames; i++)
WebRtcSpl_Resample48khzTo16khz(input + i * 480, output + i * 160, &mContext, mTemp);
return sourceLen / 3;
}
Resampler16kto48k::Resampler16kto48k()
{
WebRtcSpl_ResetResample16khzTo48khz(&mContext);
}
Resampler16kto48k::~Resampler16kto48k()
{
WebRtcSpl_ResetResample16khzTo48khz(&mContext);
}
int Resampler16kto48k::process(const void* source, int sourceLen, void* dest, int destLen)
{
const WebRtc_Word16* input = (const WebRtc_Word16*)source;
int inputLen = sourceLen / 2;
WebRtc_Word16* output = (WebRtc_Word16*)dest; // int outputCapacity = destLen / 2;
assert(inputLen % 160 == 0);
int frames = inputLen / 160;
for (int i = 0; i < frames; i++)
WebRtcSpl_Resample16khzTo48khz(input + i * 160, output + i * 480, &mContext, mTemp);
return sourceLen * 3;
}
#endif
// ---------------- UniversalResampler -------------------
UniversalResampler::UniversalResampler() {}
UniversalResampler::~UniversalResampler() {}
size_t UniversalResampler::resample(int sourceRate, const void* sourceBuffer, size_t sourceLength,
size_t& sourceProcessed, int destRate, void* destBuffer, size_t destCapacity)
{
assert(destBuffer && sourceBuffer);
size_t result;
if (sourceRate == destRate)
{
assert(destCapacity >= sourceLength);
memcpy(destBuffer, sourceBuffer, sourceLength);
sourceProcessed = sourceLength;
result = sourceLength;
}
else
{
PResampler r = findResampler(sourceRate, destRate);
result = r->processBuffer(sourceBuffer, sourceLength, sourceProcessed, destBuffer, destCapacity);
}
return result;
}
void UniversalResampler::preload() {}
size_t UniversalResampler::getDestLength(int sourceRate, int destRate, size_t sourceLength)
{
if (sourceRate == destRate)
return sourceLength;
else
return findResampler(sourceRate, destRate)->getDestLength(sourceLength);
}
size_t UniversalResampler::getSourceLength(int sourceRate, int destRate, size_t destLength)
{
if (sourceRate == destRate)
return destLength;
else
return findResampler(sourceRate, destRate)->getSourceLength(destLength);
}
PResampler UniversalResampler::findResampler(int sourceRate, int destRate)
{
assert(sourceRate != destRate);
ResamplerMap::iterator resamplerIter = mResamplerMap.find(RatePair(sourceRate, destRate));
PResampler r;
if (resamplerIter == mResamplerMap.end())
{
r = std::make_shared<Resampler>();
r->start(AUDIO_CHANNELS, sourceRate, destRate);
mResamplerMap[RatePair(sourceRate, destRate)] = r;
}
else
r = resamplerIter->second;
return r;
}
} // namespace Audio