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// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "media/base/audio_buffer.h"
#include <cmath>
#include "base/logging.h"
#include "media/base/audio_bus.h"
#include "media/base/limits.h"
#include "media/base/timestamp_constants.h"
namespace media {
static base::TimeDelta CalculateDuration(int frames, double sample_rate) {
DCHECK_GT(sample_rate, 0);
return base::TimeDelta::FromMicroseconds(
frames * base::Time::kMicrosecondsPerSecond / sample_rate);
}
AudioBuffer::AudioBuffer(SampleFormat sample_format,
ChannelLayout channel_layout,
int channel_count,
int sample_rate,
int frame_count,
bool create_buffer,
const uint8_t* const* data,
const base::TimeDelta timestamp)
: sample_format_(sample_format),
channel_layout_(channel_layout),
channel_count_(channel_count),
sample_rate_(sample_rate),
adjusted_frame_count_(frame_count),
end_of_stream_(!create_buffer && data == NULL && frame_count == 0),
timestamp_(timestamp),
duration_(end_of_stream_
? base::TimeDelta()
: CalculateDuration(adjusted_frame_count_, sample_rate_)),
data_size_(0) {
CHECK_GE(channel_count_, 0);
CHECK_LE(channel_count_, limits::kMaxChannels);
CHECK_GE(frame_count, 0);
DCHECK(channel_layout == CHANNEL_LAYOUT_DISCRETE ||
ChannelLayoutToChannelCount(channel_layout) == channel_count);
int bytes_per_channel = SampleFormatToBytesPerChannel(sample_format);
DCHECK_LE(bytes_per_channel, kChannelAlignment);
// Empty buffer?
if (!create_buffer)
return;
int data_size_per_channel = frame_count * bytes_per_channel;
if (IsPlanar(sample_format)) {
// Planar data, so need to allocate buffer for each channel.
// Determine per channel data size, taking into account alignment.
int block_size_per_channel =
(data_size_per_channel + kChannelAlignment - 1) &
~(kChannelAlignment - 1);
DCHECK_GE(block_size_per_channel, data_size_per_channel);
// Allocate a contiguous buffer for all the channel data.
data_size_ = channel_count_ * block_size_per_channel;
data_.reset(static_cast<uint8_t*>(
base::AlignedAlloc(data_size_, kChannelAlignment)));
channel_data_.reserve(channel_count_);
// Copy each channel's data into the appropriate spot.
for (int i = 0; i < channel_count_; ++i) {
channel_data_.push_back(data_.get() + i * block_size_per_channel);
if (data)
memcpy(channel_data_[i], data[i], data_size_per_channel);
}
return;
}
// Remaining formats are interleaved data.
DCHECK(IsInterleaved(sample_format)) << sample_format_;
// Allocate our own buffer and copy the supplied data into it. Buffer must
// contain the data for all channels.
data_size_ = data_size_per_channel * channel_count_;
data_.reset(
static_cast<uint8_t*>(base::AlignedAlloc(data_size_, kChannelAlignment)));
channel_data_.reserve(1);
channel_data_.push_back(data_.get());
if (data)
memcpy(data_.get(), data[0], data_size_);
}
AudioBuffer::~AudioBuffer() {}
// static
scoped_refptr<AudioBuffer> AudioBuffer::CopyFrom(
SampleFormat sample_format,
ChannelLayout channel_layout,
int channel_count,
int sample_rate,
int frame_count,
const uint8_t* const* data,
const base::TimeDelta timestamp) {
// If you hit this CHECK you likely have a bug in a demuxer. Go fix it.
CHECK_GT(frame_count, 0); // Otherwise looks like an EOF buffer.
CHECK(data[0]);
return make_scoped_refptr(new AudioBuffer(sample_format,
channel_layout,
channel_count,
sample_rate,
frame_count,
true,
data,
timestamp));
}
// static
scoped_refptr<AudioBuffer> AudioBuffer::CreateBuffer(
SampleFormat sample_format,
ChannelLayout channel_layout,
int channel_count,
int sample_rate,
int frame_count) {
CHECK_GT(frame_count, 0); // Otherwise looks like an EOF buffer.
return make_scoped_refptr(
new AudioBuffer(sample_format, channel_layout, channel_count, sample_rate,
frame_count, true, NULL, kNoTimestamp));
}
// static
scoped_refptr<AudioBuffer> AudioBuffer::CreateEmptyBuffer(
ChannelLayout channel_layout,
int channel_count,
int sample_rate,
int frame_count,
const base::TimeDelta timestamp) {
CHECK_GT(frame_count, 0); // Otherwise looks like an EOF buffer.
// Since data == NULL, format doesn't matter.
return make_scoped_refptr(new AudioBuffer(kSampleFormatF32,
channel_layout,
channel_count,
sample_rate,
frame_count,
false,
NULL,
timestamp));
}
// static
scoped_refptr<AudioBuffer> AudioBuffer::CreateEOSBuffer() {
return make_scoped_refptr(new AudioBuffer(kUnknownSampleFormat,
CHANNEL_LAYOUT_NONE, 0, 0, 0, false,
NULL, kNoTimestamp));
}
// Convert int16_t values in the range [INT16_MIN, INT16_MAX] to [-1.0, 1.0].
inline float ConvertSample(int16_t value) {
return value * (value < 0 ? -1.0f / std::numeric_limits<int16_t>::min()
: 1.0f / std::numeric_limits<int16_t>::max());
}
void AudioBuffer::AdjustSampleRate(int sample_rate) {
DCHECK(!end_of_stream_);
sample_rate_ = sample_rate;
duration_ = CalculateDuration(adjusted_frame_count_, sample_rate_);
}
void AudioBuffer::ReadFrames(int frames_to_copy,
int source_frame_offset,
int dest_frame_offset,
AudioBus* dest) {
// Deinterleave each channel (if necessary) and convert to 32bit
// floating-point with nominal range -1.0 -> +1.0 (if necessary).
// |dest| must have the same number of channels, and the number of frames
// specified must be in range.
DCHECK(!end_of_stream());
DCHECK_EQ(dest->channels(), channel_count_);
DCHECK_LE(source_frame_offset + frames_to_copy, adjusted_frame_count_);
DCHECK_LE(dest_frame_offset + frames_to_copy, dest->frames());
if (!data_) {
// Special case for an empty buffer.
dest->ZeroFramesPartial(dest_frame_offset, frames_to_copy);
return;
}
if (sample_format_ == kSampleFormatPlanarF32) {
// Format is planar float32. Copy the data from each channel as a block.
for (int ch = 0; ch < channel_count_; ++ch) {
const float* source_data =
reinterpret_cast<const float*>(channel_data_[ch]) +
source_frame_offset;
memcpy(dest->channel(ch) + dest_frame_offset,
source_data,
sizeof(float) * frames_to_copy);
}
return;
}
if (sample_format_ == kSampleFormatPlanarS16) {
// Format is planar signed16. Convert each value into float and insert into
// output channel data.
for (int ch = 0; ch < channel_count_; ++ch) {
const int16_t* source_data =
reinterpret_cast<const int16_t*>(channel_data_[ch]) +
source_frame_offset;
float* dest_data = dest->channel(ch) + dest_frame_offset;
for (int i = 0; i < frames_to_copy; ++i) {
dest_data[i] = ConvertSample(source_data[i]);
}
}
return;
}
if (sample_format_ == kSampleFormatF32) {
// Format is interleaved float32. Copy the data into each channel.
const float* source_data = reinterpret_cast<const float*>(data_.get()) +
source_frame_offset * channel_count_;
for (int ch = 0; ch < channel_count_; ++ch) {
float* dest_data = dest->channel(ch) + dest_frame_offset;
for (int i = 0, offset = ch; i < frames_to_copy;
++i, offset += channel_count_) {
dest_data[i] = source_data[offset];
}
}
return;
}
// Remaining formats are integer interleaved data. Use the deinterleaving code
// in AudioBus to copy the data.
DCHECK(
sample_format_ == kSampleFormatU8 || sample_format_ == kSampleFormatS16 ||
sample_format_ == kSampleFormatS24 || sample_format_ == kSampleFormatS32);
int bytes_per_channel = SampleFormatToBytesPerChannel(sample_format_);
int frame_size = channel_count_ * bytes_per_channel;
const uint8_t* source_data = data_.get() + source_frame_offset * frame_size;
dest->FromInterleavedPartial(
source_data, dest_frame_offset, frames_to_copy, bytes_per_channel);
}
void AudioBuffer::TrimStart(int frames_to_trim) {
CHECK_GE(frames_to_trim, 0);
CHECK_LE(frames_to_trim, adjusted_frame_count_);
TrimRange(0, frames_to_trim);
}
void AudioBuffer::TrimEnd(int frames_to_trim) {
CHECK_GE(frames_to_trim, 0);
CHECK_LE(frames_to_trim, adjusted_frame_count_);
// Adjust the number of frames and duration for this buffer.
adjusted_frame_count_ -= frames_to_trim;
duration_ = CalculateDuration(adjusted_frame_count_, sample_rate_);
}
void AudioBuffer::TrimRange(int start, int end) {
CHECK_GE(start, 0);
CHECK_LE(end, adjusted_frame_count_);
const int frames_to_trim = end - start;
CHECK_GE(frames_to_trim, 0);
CHECK_LE(frames_to_trim, adjusted_frame_count_);
const int bytes_per_channel = SampleFormatToBytesPerChannel(sample_format_);
const int frames_to_copy = adjusted_frame_count_ - end;
if (frames_to_copy > 0) {
switch (sample_format_) {
case kSampleFormatPlanarS16:
case kSampleFormatPlanarF32:
case kSampleFormatPlanarS32:
// Planar data must be shifted per channel.
for (int ch = 0; ch < channel_count_; ++ch) {
memmove(channel_data_[ch] + start * bytes_per_channel,
channel_data_[ch] + end * bytes_per_channel,
bytes_per_channel * frames_to_copy);
}
break;
case kSampleFormatU8:
case kSampleFormatS16:
case kSampleFormatS24:
case kSampleFormatS32:
case kSampleFormatF32: {
// Interleaved data can be shifted all at once.
const int frame_size = channel_count_ * bytes_per_channel;
memmove(channel_data_[0] + start * frame_size,
channel_data_[0] + end * frame_size,
frame_size * frames_to_copy);
break;
}
case kUnknownSampleFormat:
case kSampleFormatAc3:
case kSampleFormatEac3:
NOTREACHED() << "Invalid sample format!";
}
} else {
CHECK_EQ(frames_to_copy, 0);
}
// Trim the leftover data off the end of the buffer and update duration.
TrimEnd(frames_to_trim);
}
} // namespace media