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// Copyright (c) 2012 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.
#ifndef MEDIA_BASE_AUDIO_BUS_H_
#define MEDIA_BASE_AUDIO_BUS_H_
#include <stdint.h>
#include <memory>
#include <vector>
#include "base/callback.h"
#include "base/macros.h"
#include "base/memory/aligned_memory.h"
#include "media/base/audio_sample_types.h"
#include "media/base/media_shmem_export.h"
namespace media {
class AudioParameters;
// Represents a sequence of audio frames containing frames() audio samples for
// each of channels() channels. The data is stored as a set of contiguous
// float arrays with one array per channel. The memory for the arrays is either
// allocated and owned by the AudioBus or it is provided to one of the factory
// methods. AudioBus guarantees that it allocates memory such that float array
// for each channel is aligned by AudioBus::kChannelAlignment bytes and it
// requires the same for memory passed to its Wrap...() factory methods.
class MEDIA_SHMEM_EXPORT AudioBus {
public:
// Guaranteed alignment of each channel's data; use 16-byte alignment for easy
// SSE optimizations.
enum { kChannelAlignment = 16 };
// Creates a new AudioBus and allocates |channels| of length |frames|. Uses
// channels() and frames_per_buffer() from AudioParameters if given.
static std::unique_ptr<AudioBus> Create(int channels, int frames);
static std::unique_ptr<AudioBus> Create(const AudioParameters& params);
// Creates a new AudioBus with the given number of channels, but zero length.
// Clients are expected to subsequently call SetChannelData() and set_frames()
// to wrap externally allocated memory.
static std::unique_ptr<AudioBus> CreateWrapper(int channels);
// Creates a new AudioBus from an existing channel vector. Does not transfer
// ownership of |channel_data| to AudioBus; i.e., |channel_data| must outlive
// the returned AudioBus. Each channel must be aligned by kChannelAlignment.
static std::unique_ptr<AudioBus> WrapVector(
int frames,
const std::vector<float*>& channel_data);
// Creates a new AudioBus by wrapping an existing block of memory. Block must
// be at least CalculateMemorySize() bytes in size. |data| must outlive the
// returned AudioBus. |data| must be aligned by kChannelAlignment.
static std::unique_ptr<AudioBus> WrapMemory(int channels,
int frames,
void* data);
static std::unique_ptr<AudioBus> WrapMemory(const AudioParameters& params,
void* data);
static std::unique_ptr<const AudioBus> WrapReadOnlyMemory(int channels,
int frames,
const void* data);
static std::unique_ptr<const AudioBus> WrapReadOnlyMemory(
const AudioParameters& params,
const void* data);
// Based on the given number of channels and frames, calculates the minimum
// required size in bytes of a contiguous block of memory to be passed to
// AudioBus for storage of the audio data.
// Uses channels() and frames_per_buffer() from AudioParameters if given.
static int CalculateMemorySize(int channels, int frames);
static int CalculateMemorySize(const AudioParameters& params);
// Methods that are expected to be called after AudioBus::CreateWrapper() in
// order to wrap externally allocated memory. Note: It is illegal to call
// these methods when using a factory method other than CreateWrapper().
void SetChannelData(int channel, float* data);
void set_frames(int frames);
// Method optionally called after AudioBus::CreateWrapper().
// Runs |deleter| when on |this|' destruction, freeing external data
// referenced by SetChannelData().
// Note: It is illegal to call this method when using a factory method other
// than CreateWrapper().
void SetWrappedDataDeleter(base::OnceClosure deleter);
// Methods for compressed bitstream formats. The data size may not be equal to
// the capacity of the AudioBus. Also, the frame count may not be equal to the
// capacity of the AudioBus. Thus, we need extra methods to access the real
// data size and frame count for bitstream formats.
bool is_bitstream_format() const { return is_bitstream_format_; }
void set_is_bitstream_format(bool is_bitstream_format) {
is_bitstream_format_ = is_bitstream_format;
}
size_t GetBitstreamDataSize() const;
void SetBitstreamDataSize(size_t data_size);
int GetBitstreamFrames() const;
void SetBitstreamFrames(int frames);
// Overwrites the sample values stored in this AudioBus instance with values
// from a given interleaved |source_buffer| with expected layout
// [ch0, ch1, ..., chN, ch0, ch1, ...] and sample values in the format
// corresponding to the given SourceSampleTypeTraits.
// The sample values are converted to float values by means of the method
// convert_to_float32() provided by the SourceSampleTypeTraits. For a list of
// ready-to-use SampleTypeTraits, see file audio_sample_types.h.
// If |num_frames_to_write| is less than frames(), the remaining frames are
// zeroed out. If |num_frames_to_write| is more than frames(), this results in
// undefined behavior.
template <class SourceSampleTypeTraits>
void FromInterleaved(
const typename SourceSampleTypeTraits::ValueType* source_buffer,
int num_frames_to_write);
// Similar to FromInterleaved...(), but overwrites the frames starting at a
// given offset |write_offset_in_frames| and does not zero out frames that are
// not overwritten.
template <class SourceSampleTypeTraits>
void FromInterleavedPartial(
const typename SourceSampleTypeTraits::ValueType* source_buffer,
int write_offset_in_frames,
int num_frames_to_write);
// Reads the sample values stored in this AudioBus instance and places them
// into the given |dest_buffer| in interleaved format using the sample format
// specified by TargetSampleTypeTraits. For a list of ready-to-use
// SampleTypeTraits, see file audio_sample_types.h. If |num_frames_to_read| is
// larger than frames(), this results in undefined behavior.
template <class TargetSampleTypeTraits>
void ToInterleaved(
int num_frames_to_read,
typename TargetSampleTypeTraits::ValueType* dest_buffer) const;
// Similar to ToInterleaved(), but reads the frames starting at a given
// offset |read_offset_in_frames|.
template <class TargetSampleTypeTraits>
void ToInterleavedPartial(
int read_offset_in_frames,
int num_frames_to_read,
typename TargetSampleTypeTraits::ValueType* dest_buffer) const;
// Helper method for copying channel data from one AudioBus to another. Both
// AudioBus object must have the same frames() and channels().
void CopyTo(AudioBus* dest) const;
// Similar to above, but clips values to [-1, 1] during the copy process.
void CopyAndClipTo(AudioBus* dest) const;
// Helper method to copy frames from one AudioBus to another. Both AudioBus
// objects must have the same number of channels(). |source_start_frame| is
// the starting offset. |dest_start_frame| is the starting offset in |dest|.
// |frame_count| is the number of frames to copy.
void CopyPartialFramesTo(int source_start_frame,
int frame_count,
int dest_start_frame,
AudioBus* dest) const;
// Returns a raw pointer to the requested channel. Pointer is guaranteed to
// have a 16-byte alignment. Warning: Do not rely on having sane (i.e. not
// inf, nan, or between [-1.0, 1.0]) values in the channel data.
float* channel(int channel) { return channel_data_[channel]; }
const float* channel(int channel) const { return channel_data_[channel]; }
// Returns the number of channels.
int channels() const { return static_cast<int>(channel_data_.size()); }
// Returns the number of frames.
int frames() const { return frames_; }
// Helper method for zeroing out all channels of audio data.
void Zero();
void ZeroFrames(int frames);
void ZeroFramesPartial(int start_frame, int frames);
// Checks if all frames are zero.
bool AreFramesZero() const;
// Scale internal channel values by |volume| >= 0. If an invalid value
// is provided, no adjustment is done.
void Scale(float volume);
// Swaps channels identified by |a| and |b|. The caller needs to make sure
// the channels are valid.
void SwapChannels(int a, int b);
AudioBus(const AudioBus&) = delete;
AudioBus& operator=(const AudioBus&) = delete;
virtual ~AudioBus();
protected:
AudioBus(int channels, int frames);
AudioBus(int channels, int frames, float* data);
AudioBus(int frames, const std::vector<float*>& channel_data);
explicit AudioBus(int channels);
private:
// Helper method for building |channel_data_| from a block of memory. |data|
// must be at least CalculateMemorySize(...) bytes in size.
void BuildChannelData(int channels, int aligned_frame, float* data);
static void CheckOverflow(int start_frame, int frames, int total_frames);
template <class SourceSampleTypeTraits>
static void CopyConvertFromInterleavedSourceToAudioBus(
const typename SourceSampleTypeTraits::ValueType* source_buffer,
int write_offset_in_frames,
int num_frames_to_write,
AudioBus* dest);
template <class TargetSampleTypeTraits>
static void CopyConvertFromAudioBusToInterleavedTarget(
const AudioBus* source,
int read_offset_in_frames,
int num_frames_to_read,
typename TargetSampleTypeTraits::ValueType* dest_buffer);
// Contiguous block of channel memory.
std::unique_ptr<float, base::AlignedFreeDeleter> data_;
// Whether the data is compressed bitstream or not.
bool is_bitstream_format_ = false;
// The data size for a compressed bitstream.
size_t bitstream_data_size_ = 0;
// The PCM frame count for a compressed bitstream.
int bitstream_frames_ = 0;
// One float pointer per channel pointing to a contiguous block of memory for
// that channel. If the memory is owned by this instance, this will
// point to the memory in |data_|. Otherwise, it may point to memory provided
// by the client.
std::vector<float*> channel_data_;
int frames_;
// Protect SetChannelData(), set_frames() and SetWrappedDataDeleter() for use
// by CreateWrapper().
bool is_wrapper_;
// Run on destruction. Frees memory to the data set via SetChannelData().
// Only used with CreateWrapper().
base::OnceClosure wrapped_data_deleter_cb_;
};
// Delegates to FromInterleavedPartial()
template <class SourceSampleTypeTraits>
void AudioBus::FromInterleaved(
const typename SourceSampleTypeTraits::ValueType* source_buffer,
int num_frames_to_write) {
FromInterleavedPartial<SourceSampleTypeTraits>(source_buffer, 0,
num_frames_to_write);
// Zero any remaining frames.
ZeroFramesPartial(num_frames_to_write, frames_ - num_frames_to_write);
}
template <class SourceSampleTypeTraits>
void AudioBus::FromInterleavedPartial(
const typename SourceSampleTypeTraits::ValueType* source_buffer,
int write_offset_in_frames,
int num_frames_to_write) {
CheckOverflow(write_offset_in_frames, num_frames_to_write, frames_);
CopyConvertFromInterleavedSourceToAudioBus<SourceSampleTypeTraits>(
source_buffer, write_offset_in_frames, num_frames_to_write, this);
}
// Delegates to ToInterleavedPartial()
template <class TargetSampleTypeTraits>
void AudioBus::ToInterleaved(
int num_frames_to_read,
typename TargetSampleTypeTraits::ValueType* dest_buffer) const {
ToInterleavedPartial<TargetSampleTypeTraits>(0, num_frames_to_read,
dest_buffer);
}
template <class TargetSampleTypeTraits>
void AudioBus::ToInterleavedPartial(
int read_offset_in_frames,
int num_frames_to_read,
typename TargetSampleTypeTraits::ValueType* dest) const {
CheckOverflow(read_offset_in_frames, num_frames_to_read, frames_);
CopyConvertFromAudioBusToInterleavedTarget<TargetSampleTypeTraits>(
this, read_offset_in_frames, num_frames_to_read, dest);
}
// TODO(chfremer): Consider using vector instructions to speed this up,
// https://crbug.com/619628
template <class SourceSampleTypeTraits>
void AudioBus::CopyConvertFromInterleavedSourceToAudioBus(
const typename SourceSampleTypeTraits::ValueType* source_buffer,
int write_offset_in_frames,
int num_frames_to_write,
AudioBus* dest) {
const int channels = dest->channels();
for (int ch = 0; ch < channels; ++ch) {
float* channel_data = dest->channel(ch);
for (int target_frame_index = write_offset_in_frames,
read_pos_in_source = ch;
target_frame_index < write_offset_in_frames + num_frames_to_write;
++target_frame_index, read_pos_in_source += channels) {
auto source_value = source_buffer[read_pos_in_source];
channel_data[target_frame_index] =
SourceSampleTypeTraits::ToFloat(source_value);
}
}
}
// TODO(chfremer): Consider using vector instructions to speed this up,
// https://crbug.com/619628
template <class TargetSampleTypeTraits>
void AudioBus::CopyConvertFromAudioBusToInterleavedTarget(
const AudioBus* source,
int read_offset_in_frames,
int num_frames_to_read,
typename TargetSampleTypeTraits::ValueType* dest_buffer) {
const int channels = source->channels();
for (int ch = 0; ch < channels; ++ch) {
const float* channel_data = source->channel(ch);
for (int source_frame_index = read_offset_in_frames, write_pos_in_dest = ch;
source_frame_index < read_offset_in_frames + num_frames_to_read;
++source_frame_index, write_pos_in_dest += channels) {
float sourceSampleValue = channel_data[source_frame_index];
dest_buffer[write_pos_in_dest] =
TargetSampleTypeTraits::FromFloat(sourceSampleValue);
}
}
}
} // namespace media
#endif // MEDIA_BASE_AUDIO_BUS_H_