gecko-dev/dom/media/AudioConverter.cpp

393 строки
13 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 "AudioConverter.h"
#include <string.h>
#include <speex/speex_resampler.h>
#include <cmath>
/*
* Parts derived from MythTV AudioConvert Class
* Created by Jean-Yves Avenard.
*
* Copyright (C) Bubblestuff Pty Ltd 2013
* Copyright (C) foobum@gmail.com 2010
*/
namespace mozilla {
AudioConverter::AudioConverter(const AudioConfig& aIn, const AudioConfig& aOut)
: mIn(aIn)
, mOut(aOut)
, mResampler(nullptr)
{
MOZ_DIAGNOSTIC_ASSERT(aIn.Format() == aOut.Format() &&
aIn.Interleaved() == aOut.Interleaved(),
"No format or rate conversion is supported at this stage");
MOZ_DIAGNOSTIC_ASSERT(aOut.Channels() <= 2 ||
aIn.Channels() == aOut.Channels(),
"Only down/upmixing to mono or stereo is supported at this stage");
MOZ_DIAGNOSTIC_ASSERT(aOut.Interleaved(), "planar audio format not supported");
mIn.Layout().MappingTable(mOut.Layout(), mChannelOrderMap);
if (aIn.Rate() != aOut.Rate()) {
RecreateResampler();
}
}
AudioConverter::~AudioConverter()
{
if (mResampler) {
speex_resampler_destroy(mResampler);
mResampler = nullptr;
}
}
bool
AudioConverter::CanWorkInPlace() const
{
bool needDownmix = mIn.Channels() > mOut.Channels();
bool needUpmix = mIn.Channels() < mOut.Channels();
bool canDownmixInPlace =
mIn.Channels() * AudioConfig::SampleSize(mIn.Format()) >=
mOut.Channels() * AudioConfig::SampleSize(mOut.Format());
bool needResample = mIn.Rate() != mOut.Rate();
bool canResampleInPlace = mIn.Rate() >= mOut.Rate();
// We should be able to work in place if 1s of audio input takes less space
// than 1s of audio output. However, as we downmix before resampling we can't
// perform any upsampling in place (e.g. if incoming rate >= outgoing rate)
return !needUpmix && (!needDownmix || canDownmixInPlace) &&
(!needResample || canResampleInPlace);
}
size_t
AudioConverter::ProcessInternal(void* aOut, const void* aIn, size_t aFrames)
{
if (mIn.Channels() > mOut.Channels()) {
return DownmixAudio(aOut, aIn, aFrames);
} else if (mIn.Channels() < mOut.Channels()) {
return UpmixAudio(aOut, aIn, aFrames);
} else if (mIn.Layout() != mOut.Layout() && CanReorderAudio()) {
ReOrderInterleavedChannels(aOut, aIn, aFrames);
} else if (aIn != aOut) {
memmove(aOut, aIn, FramesOutToBytes(aFrames));
}
return aFrames;
}
// Reorder interleaved channels.
// Can work in place (e.g aOut == aIn).
template <class AudioDataType>
void
_ReOrderInterleavedChannels(AudioDataType* aOut, const AudioDataType* aIn,
uint32_t aFrames, uint32_t aChannels,
const uint8_t* aChannelOrderMap)
{
MOZ_DIAGNOSTIC_ASSERT(aChannels <= MAX_AUDIO_CHANNELS);
AudioDataType val[MAX_AUDIO_CHANNELS];
for (uint32_t i = 0; i < aFrames; i++) {
for (uint32_t j = 0; j < aChannels; j++) {
val[j] = aIn[aChannelOrderMap[j]];
}
for (uint32_t j = 0; j < aChannels; j++) {
aOut[j] = val[j];
}
aOut += aChannels;
aIn += aChannels;
}
}
void
AudioConverter::ReOrderInterleavedChannels(void* aOut, const void* aIn,
size_t aFrames) const
{
MOZ_DIAGNOSTIC_ASSERT(mIn.Channels() == mOut.Channels());
if (mOut.Channels() == 1 || mOut.Layout() == mIn.Layout()) {
// If channel count is 1, planar and non-planar formats are the same and
// there's nothing to reorder.
if (aOut != aIn) {
memmove(aOut, aIn, FramesOutToBytes(aFrames));
}
return;
}
uint32_t bits = AudioConfig::FormatToBits(mOut.Format());
switch (bits) {
case 8:
_ReOrderInterleavedChannels((uint8_t*)aOut, (const uint8_t*)aIn,
aFrames, mIn.Channels(), mChannelOrderMap);
break;
case 16:
_ReOrderInterleavedChannels((int16_t*)aOut,(const int16_t*)aIn,
aFrames, mIn.Channels(), mChannelOrderMap);
break;
default:
MOZ_DIAGNOSTIC_ASSERT(AudioConfig::SampleSize(mOut.Format()) == 4);
_ReOrderInterleavedChannels((int32_t*)aOut,(const int32_t*)aIn,
aFrames, mIn.Channels(), mChannelOrderMap);
break;
}
}
static inline int16_t clipTo15(int32_t aX)
{
return aX < -32768 ? -32768 : aX <= 32767 ? aX : 32767;
}
size_t
AudioConverter::DownmixAudio(void* aOut, const void* aIn, size_t aFrames) const
{
MOZ_ASSERT(mIn.Format() == AudioConfig::FORMAT_S16 ||
mIn.Format() == AudioConfig::FORMAT_FLT);
MOZ_ASSERT(mIn.Channels() >= mOut.Channels());
MOZ_ASSERT(mIn.Layout() == AudioConfig::ChannelLayout(mIn.Channels()),
"Can only downmix input data in SMPTE layout");
MOZ_ASSERT(mOut.Layout() == AudioConfig::ChannelLayout(2) ||
mOut.Layout() == AudioConfig::ChannelLayout(1));
uint32_t channels = mIn.Channels();
if (channels == 1 && mOut.Channels() == 1) {
if (aOut != aIn) {
memmove(aOut, aIn, FramesOutToBytes(aFrames));
}
return aFrames;
}
if (channels > 2) {
if (mIn.Format() == AudioConfig::FORMAT_FLT) {
// Downmix matrix. Per-row normalization 1 for rows 3,4 and 2 for rows 5-8.
static const float dmatrix[6][8][2]= {
/*3*/{{0.5858f,0},{0,0.5858f},{0.4142f,0.4142f}},
/*4*/{{0.4226f,0},{0,0.4226f},{0.366f, 0.2114f},{0.2114f,0.366f}},
/*5*/{{0.6510f,0},{0,0.6510f},{0.4600f,0.4600f},{0.5636f,0.3254f},{0.3254f,0.5636f}},
/*6*/{{0.5290f,0},{0,0.5290f},{0.3741f,0.3741f},{0.3741f,0.3741f},{0.4582f,0.2645f},{0.2645f,0.4582f}},
/*7*/{{0.4553f,0},{0,0.4553f},{0.3220f,0.3220f},{0.3220f,0.3220f},{0.2788f,0.2788f},{0.3943f,0.2277f},{0.2277f,0.3943f}},
/*8*/{{0.3886f,0},{0,0.3886f},{0.2748f,0.2748f},{0.2748f,0.2748f},{0.3366f,0.1943f},{0.1943f,0.3366f},{0.3366f,0.1943f},{0.1943f,0.3366f}},
};
// Re-write the buffer with downmixed data
const float* in = static_cast<const float*>(aIn);
float* out = static_cast<float*>(aOut);
for (uint32_t i = 0; i < aFrames; i++) {
float sampL = 0.0;
float sampR = 0.0;
for (uint32_t j = 0; j < channels; j++) {
sampL += in[i*mIn.Channels()+j]*dmatrix[mIn.Channels()-3][j][0];
sampR += in[i*mIn.Channels()+j]*dmatrix[mIn.Channels()-3][j][1];
}
*out++ = sampL;
*out++ = sampR;
}
} else if (mIn.Format() == AudioConfig::FORMAT_S16) {
// Downmix matrix. Per-row normalization 1 for rows 3,4 and 2 for rows 5-8.
// Coefficients in Q14.
static const int16_t dmatrix[6][8][2]= {
/*3*/{{9598, 0},{0, 9598},{6786,6786}},
/*4*/{{6925, 0},{0, 6925},{5997,3462},{3462,5997}},
/*5*/{{10663,0},{0, 10663},{7540,7540},{9234,5331},{5331,9234}},
/*6*/{{8668, 0},{0, 8668},{6129,6129},{6129,6129},{7507,4335},{4335,7507}},
/*7*/{{7459, 0},{0, 7459},{5275,5275},{5275,5275},{4568,4568},{6460,3731},{3731,6460}},
/*8*/{{6368, 0},{0, 6368},{4502,4502},{4502,4502},{5514,3184},{3184,5514},{5514,3184},{3184,5514}}
};
// Re-write the buffer with downmixed data
const int16_t* in = static_cast<const int16_t*>(aIn);
int16_t* out = static_cast<int16_t*>(aOut);
for (uint32_t i = 0; i < aFrames; i++) {
int32_t sampL = 0;
int32_t sampR = 0;
for (uint32_t j = 0; j < channels; j++) {
sampL+=in[i*channels+j]*dmatrix[channels-3][j][0];
sampR+=in[i*channels+j]*dmatrix[channels-3][j][1];
}
*out++ = clipTo15((sampL + 8192)>>14);
*out++ = clipTo15((sampR + 8192)>>14);
}
} else {
MOZ_DIAGNOSTIC_ASSERT(false, "Unsupported data type");
}
// If we are to continue downmixing to mono, start working on the output
// buffer.
aIn = aOut;
channels = 2;
}
if (mOut.Channels() == 1) {
if (mIn.Format() == AudioConfig::FORMAT_FLT) {
const float* in = static_cast<const float*>(aIn);
float* out = static_cast<float*>(aOut);
for (size_t fIdx = 0; fIdx < aFrames; ++fIdx) {
float sample = 0.0;
// The sample of the buffer would be interleaved.
sample = (in[fIdx*channels] + in[fIdx*channels + 1]) * 0.5;
*out++ = sample;
}
} else if (mIn.Format() == AudioConfig::FORMAT_S16) {
const int16_t* in = static_cast<const int16_t*>(aIn);
int16_t* out = static_cast<int16_t*>(aOut);
for (size_t fIdx = 0; fIdx < aFrames; ++fIdx) {
int32_t sample = 0.0;
// The sample of the buffer would be interleaved.
sample = (in[fIdx*channels] + in[fIdx*channels + 1]) * 0.5;
*out++ = sample;
}
} else {
MOZ_DIAGNOSTIC_ASSERT(false, "Unsupported data type");
}
}
return aFrames;
}
size_t
AudioConverter::ResampleAudio(void* aOut, const void* aIn, size_t aFrames)
{
if (!mResampler) {
return 0;
}
uint32_t outframes = ResampleRecipientFrames(aFrames);
uint32_t inframes = aFrames;
int error;
if (mOut.Format() == AudioConfig::FORMAT_FLT) {
const float* in = reinterpret_cast<const float*>(aIn);
float* out = reinterpret_cast<float*>(aOut);
error =
speex_resampler_process_interleaved_float(mResampler, in, &inframes,
out, &outframes);
} else if (mOut.Format() == AudioConfig::FORMAT_S16) {
const int16_t* in = reinterpret_cast<const int16_t*>(aIn);
int16_t* out = reinterpret_cast<int16_t*>(aOut);
error =
speex_resampler_process_interleaved_int(mResampler, in, &inframes,
out, &outframes);
} else {
MOZ_DIAGNOSTIC_ASSERT(false, "Unsupported data type");
}
MOZ_ASSERT(error == RESAMPLER_ERR_SUCCESS);
if (error != RESAMPLER_ERR_SUCCESS) {
speex_resampler_destroy(mResampler);
mResampler = nullptr;
return 0;
}
MOZ_ASSERT(inframes == aFrames, "Some frames will be dropped");
return outframes;
}
void
AudioConverter::RecreateResampler()
{
if (mResampler) {
speex_resampler_destroy(mResampler);
}
int error;
mResampler = speex_resampler_init(mOut.Channels(),
mIn.Rate(),
mOut.Rate(),
SPEEX_RESAMPLER_QUALITY_DEFAULT,
&error);
if (error == RESAMPLER_ERR_SUCCESS) {
speex_resampler_skip_zeros(mResampler);
} else {
NS_WARNING("Failed to initialize resampler.");
mResampler = nullptr;
}
}
size_t
AudioConverter::DrainResampler(void* aOut)
{
if (!mResampler) {
return 0;
}
int frames = speex_resampler_get_input_latency(mResampler);
AlignedByteBuffer buffer(FramesOutToBytes(frames));
if (!buffer) {
// OOM
return 0;
}
frames = ResampleAudio(aOut, buffer.Data(), frames);
// Tore down the resampler as it's easier than handling follow-up.
RecreateResampler();
return frames;
}
size_t
AudioConverter::UpmixAudio(void* aOut, const void* aIn, size_t aFrames) const
{
MOZ_ASSERT(mIn.Format() == AudioConfig::FORMAT_S16 ||
mIn.Format() == AudioConfig::FORMAT_FLT);
MOZ_ASSERT(mIn.Channels() < mOut.Channels());
MOZ_ASSERT(mIn.Channels() == 1, "Can only upmix mono for now");
MOZ_ASSERT(mOut.Channels() == 2, "Can only upmix to stereo for now");
if (mOut.Channels() != 2) {
return 0;
}
// Upmix mono to stereo.
// This is a very dumb mono to stereo upmixing, power levels are preserved
// following the calculation: left = right = -3dB*mono.
if (mIn.Format() == AudioConfig::FORMAT_FLT) {
const float m3db = std::sqrt(0.5); // -3dB = sqrt(1/2)
const float* in = static_cast<const float*>(aIn);
float* out = static_cast<float*>(aOut);
for (size_t fIdx = 0; fIdx < aFrames; ++fIdx) {
float sample = in[fIdx] * m3db;
// The samples of the buffer would be interleaved.
*out++ = sample;
*out++ = sample;
}
} else if (mIn.Format() == AudioConfig::FORMAT_S16) {
const int16_t* in = static_cast<const int16_t*>(aIn);
int16_t* out = static_cast<int16_t*>(aOut);
for (size_t fIdx = 0; fIdx < aFrames; ++fIdx) {
int16_t sample = ((int32_t)in[fIdx] * 11585) >> 14; // close enough to i*sqrt(0.5)
// The samples of the buffer would be interleaved.
*out++ = sample;
*out++ = sample;
}
} else {
MOZ_DIAGNOSTIC_ASSERT(false, "Unsupported data type");
}
return aFrames;
}
size_t
AudioConverter::ResampleRecipientFrames(size_t aFrames) const
{
if (!aFrames && mIn.Rate() != mOut.Rate()) {
// The resampler will be drained, account for frames currently buffered
// in the resampler.
if (!mResampler) {
return 0;
}
return speex_resampler_get_output_latency(mResampler);
} else {
return (uint64_t)aFrames * mOut.Rate() / mIn.Rate() + 1;
}
}
size_t
AudioConverter::FramesOutToSamples(size_t aFrames) const
{
return aFrames * mOut.Channels();
}
size_t
AudioConverter::SamplesInToFrames(size_t aSamples) const
{
return aSamples / mIn.Channels();
}
size_t
AudioConverter::FramesOutToBytes(size_t aFrames) const
{
return FramesOutToSamples(aFrames) * AudioConfig::SampleSize(mOut.Format());
}
} // namespace mozilla