gecko-dev/content/media/AudioSegment.h
2014-04-25 15:15:21 +02:00

290 lines
9.9 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/. */
#ifndef MOZILLA_AUDIOSEGMENT_H_
#define MOZILLA_AUDIOSEGMENT_H_
#include "MediaSegment.h"
#include "AudioSampleFormat.h"
#include "SharedBuffer.h"
#include "WebAudioUtils.h"
#ifdef MOZILLA_INTERNAL_API
#include "mozilla/TimeStamp.h"
#endif
namespace mozilla {
template<typename T>
class SharedChannelArrayBuffer : public ThreadSharedObject {
public:
SharedChannelArrayBuffer(nsTArray<nsTArray<T> >* aBuffers)
{
mBuffers.SwapElements(*aBuffers);
}
virtual size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const MOZ_OVERRIDE
{
size_t amount = 0;
amount += mBuffers.SizeOfExcludingThis(aMallocSizeOf);
for (size_t i = 0; i < mBuffers.Length(); i++) {
amount += mBuffers[i].SizeOfExcludingThis(aMallocSizeOf);
}
return amount;
}
virtual size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const MOZ_OVERRIDE
{
return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
}
nsTArray<nsTArray<T> > mBuffers;
};
class AudioStream;
class AudioMixer;
/**
* For auto-arrays etc, guess this as the common number of channels.
*/
const int GUESS_AUDIO_CHANNELS = 2;
// We ensure that the graph advances in steps that are multiples of the Web
// Audio block size
const uint32_t WEBAUDIO_BLOCK_SIZE_BITS = 7;
const uint32_t WEBAUDIO_BLOCK_SIZE = 1 << WEBAUDIO_BLOCK_SIZE_BITS;
void InterleaveAndConvertBuffer(const void** aSourceChannels,
AudioSampleFormat aSourceFormat,
int32_t aLength, float aVolume,
int32_t aChannels,
AudioDataValue* aOutput);
/**
* Given an array of input channels (aChannelData), downmix to aOutputChannels,
* interleave the channel data. A total of aOutputChannels*aDuration
* interleaved samples will be copied to a channel buffer in aOutput.
*/
void DownmixAndInterleave(const nsTArray<const void*>& aChannelData,
AudioSampleFormat aSourceFormat, int32_t aDuration,
float aVolume, uint32_t aOutputChannels,
AudioDataValue* aOutput);
/**
* An AudioChunk represents a multi-channel buffer of audio samples.
* It references an underlying ThreadSharedObject which manages the lifetime
* of the buffer. An AudioChunk maintains its own duration and channel data
* pointers so it can represent a subinterval of a buffer without copying.
* An AudioChunk can store its individual channels anywhere; it maintains
* separate pointers to each channel's buffer.
*/
struct AudioChunk {
typedef mozilla::AudioSampleFormat SampleFormat;
// Generic methods
void SliceTo(TrackTicks aStart, TrackTicks aEnd)
{
NS_ASSERTION(aStart >= 0 && aStart < aEnd && aEnd <= mDuration,
"Slice out of bounds");
if (mBuffer) {
MOZ_ASSERT(aStart < INT32_MAX, "Can't slice beyond 32-bit sample lengths");
for (uint32_t channel = 0; channel < mChannelData.Length(); ++channel) {
mChannelData[channel] = AddAudioSampleOffset(mChannelData[channel],
mBufferFormat, int32_t(aStart));
}
}
mDuration = aEnd - aStart;
}
TrackTicks GetDuration() const { return mDuration; }
bool CanCombineWithFollowing(const AudioChunk& aOther) const
{
if (aOther.mBuffer != mBuffer) {
return false;
}
if (mBuffer) {
NS_ASSERTION(aOther.mBufferFormat == mBufferFormat,
"Wrong metadata about buffer");
NS_ASSERTION(aOther.mChannelData.Length() == mChannelData.Length(),
"Mismatched channel count");
if (mDuration > INT32_MAX) {
return false;
}
for (uint32_t channel = 0; channel < mChannelData.Length(); ++channel) {
if (aOther.mChannelData[channel] != AddAudioSampleOffset(mChannelData[channel],
mBufferFormat, int32_t(mDuration))) {
return false;
}
}
}
return true;
}
bool IsNull() const { return mBuffer == nullptr; }
void SetNull(TrackTicks aDuration)
{
mBuffer = nullptr;
mChannelData.Clear();
mDuration = aDuration;
mVolume = 1.0f;
mBufferFormat = AUDIO_FORMAT_SILENCE;
}
int ChannelCount() const { return mChannelData.Length(); }
size_t SizeOfExcludingThisIfUnshared(MallocSizeOf aMallocSizeOf) const
{
return SizeOfExcludingThis(aMallocSizeOf, true);
}
size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf, bool aUnshared) const
{
size_t amount = 0;
// Possibly owned:
// - mBuffer - Can hold data that is also in the decoded audio queue. If it
// is not shared, or unshared == false it gets counted.
if (mBuffer && (!aUnshared || !mBuffer->IsShared())) {
amount += mBuffer->SizeOfIncludingThis(aMallocSizeOf);
}
// Memory in the array is owned by mBuffer.
amount += mChannelData.SizeOfExcludingThis(aMallocSizeOf);
return amount;
}
TrackTicks mDuration; // in frames within the buffer
nsRefPtr<ThreadSharedObject> mBuffer; // the buffer object whose lifetime is managed; null means data is all zeroes
nsTArray<const void*> mChannelData; // one pointer per channel; empty if and only if mBuffer is null
float mVolume; // volume multiplier to apply (1.0f if mBuffer is nonnull)
SampleFormat mBufferFormat; // format of frames in mBuffer (only meaningful if mBuffer is nonnull)
#ifdef MOZILLA_INTERNAL_API
mozilla::TimeStamp mTimeStamp; // time at which this has been fetched from the MediaEngine
#endif
};
/**
* A list of audio samples consisting of a sequence of slices of SharedBuffers.
* The audio rate is determined by the track, not stored in this class.
*/
class AudioSegment : public MediaSegmentBase<AudioSegment, AudioChunk> {
public:
typedef mozilla::AudioSampleFormat SampleFormat;
AudioSegment() : MediaSegmentBase<AudioSegment, AudioChunk>(AUDIO) {}
// Resample the whole segment in place.
template<typename T>
void Resample(SpeexResamplerState* aResampler, uint32_t aInRate, uint32_t aOutRate)
{
mDuration = 0;
for (ChunkIterator ci(*this); !ci.IsEnded(); ci.Next()) {
nsAutoTArray<nsTArray<T>, GUESS_AUDIO_CHANNELS> output;
nsAutoTArray<const T*, GUESS_AUDIO_CHANNELS> bufferPtrs;
AudioChunk& c = *ci;
// If this chunk is null, don't bother resampling, just alter its duration
if (c.IsNull()) {
c.mDuration *= aOutRate / aInRate;
mDuration += c.mDuration;
continue;
}
uint32_t channels = c.mChannelData.Length();
output.SetLength(channels);
bufferPtrs.SetLength(channels);
uint32_t inFrames = c.mDuration,
outFrames = c.mDuration * aOutRate / aInRate;
for (uint32_t i = 0; i < channels; i++) {
const T* in = static_cast<const T*>(c.mChannelData[i]);
T* out = output[i].AppendElements(outFrames);
dom::WebAudioUtils::SpeexResamplerProcess(aResampler, i,
in, &inFrames,
out, &outFrames);
bufferPtrs[i] = out;
output[i].SetLength(outFrames);
}
c.mBuffer = new mozilla::SharedChannelArrayBuffer<T>(&output);
for (uint32_t i = 0; i < channels; i++) {
c.mChannelData[i] = bufferPtrs[i];
}
c.mDuration = outFrames;
mDuration += c.mDuration;
}
}
void ResampleChunks(SpeexResamplerState* aResampler);
void AppendFrames(already_AddRefed<ThreadSharedObject> aBuffer,
const nsTArray<const float*>& aChannelData,
int32_t aDuration)
{
AudioChunk* chunk = AppendChunk(aDuration);
chunk->mBuffer = aBuffer;
for (uint32_t channel = 0; channel < aChannelData.Length(); ++channel) {
chunk->mChannelData.AppendElement(aChannelData[channel]);
}
chunk->mVolume = 1.0f;
chunk->mBufferFormat = AUDIO_FORMAT_FLOAT32;
#ifdef MOZILLA_INTERNAL_API
chunk->mTimeStamp = TimeStamp::Now();
#endif
}
void AppendFrames(already_AddRefed<ThreadSharedObject> aBuffer,
const nsTArray<const int16_t*>& aChannelData,
int32_t aDuration)
{
AudioChunk* chunk = AppendChunk(aDuration);
chunk->mBuffer = aBuffer;
for (uint32_t channel = 0; channel < aChannelData.Length(); ++channel) {
chunk->mChannelData.AppendElement(aChannelData[channel]);
}
chunk->mVolume = 1.0f;
chunk->mBufferFormat = AUDIO_FORMAT_S16;
#ifdef MOZILLA_INTERNAL_API
chunk->mTimeStamp = TimeStamp::Now();
#endif
}
// Consumes aChunk, and returns a pointer to the persistent copy of aChunk
// in the segment.
AudioChunk* AppendAndConsumeChunk(AudioChunk* aChunk)
{
AudioChunk* chunk = AppendChunk(aChunk->mDuration);
chunk->mBuffer = aChunk->mBuffer.forget();
chunk->mChannelData.SwapElements(aChunk->mChannelData);
chunk->mVolume = aChunk->mVolume;
chunk->mBufferFormat = aChunk->mBufferFormat;
#ifdef MOZILLA_INTERNAL_API
chunk->mTimeStamp = TimeStamp::Now();
#endif
return chunk;
}
void ApplyVolume(float aVolume);
void WriteTo(uint64_t aID, AudioStream* aOutput, AudioMixer* aMixer = nullptr);
int ChannelCount() {
NS_WARN_IF_FALSE(!mChunks.IsEmpty(),
"Cannot query channel count on a AudioSegment with no chunks.");
// Find the first chunk that has non-zero channels. A chunk that hs zero
// channels is just silence and we can simply discard it.
for (ChunkIterator ci(*this); !ci.IsEnded(); ci.Next()) {
if (ci->ChannelCount()) {
return ci->ChannelCount();
}
}
return 0;
}
static Type StaticType() { return AUDIO; }
virtual size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const MOZ_OVERRIDE
{
return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
}
};
}
#endif /* MOZILLA_AUDIOSEGMENT_H_ */