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/*
Copyright 2018 Google Inc. All Rights Reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS-IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
#ifndef RESONANCE_AUDIO_UTILS_VORBIS_STREAM_ENCODER_H_
#define RESONANCE_AUDIO_UTILS_VORBIS_STREAM_ENCODER_H_
#include <fstream>
#include <iostream>
#include "base/integral_types.h"
#include "ogg/ogg.h"
#include "vorbis/codec.h"
namespace vraudio {
class VorbisStreamEncoder {
public:
// Supported encoding modes.
enum class EncodingMode {
kUndefined,
// Variable bit rate mode (VBR).
kVariableBitRate,
// Average bit rate mode (ABR).
kAverageBitRate,
};
VorbisStreamEncoder();
// Initializes Vorbis encoding.
//
// @param filename Ogg vorbis output file. If it doesn't exist, it will be
// created. Existing files will be overwritten.
// @param num_channels Number of input channels.
// @param sample_rate Sample rate of input audio buffers.
// @param encoding_mode Selects variable (VBR) or average encoding (ABR).
// @param bitrate Target bitrate (only used when selecting ABR encoding).
// @param quality Target quality (only used when selecting VBR encoding). The
// usable range is -.1 (lowest quality, smallest file) to 1. (highest
// quality, largest file).
// @return False in case of file I/O errors or libvorbis initialization
// failures like non-supported channel/sample rate configuration.
bool InitializeForFile(const std::string& filename, size_t num_channels,
int sample_rate, EncodingMode encoding_mode,
int bitrate, float quality);
// Feeds input audio data into libvorbis encoder and triggers encoding.
//
// @param Array of pointers to planar channel data.
// @param num_channels Number of input channels.
// @param num_frames Number of input frames.
// @return False in case of file I/O errors or missing encoder initialization.
bool AddPlanarBuffer(const float* const* input_ptrs, size_t num_channels,
size_t num_frames);
// Flushes the remaining audio buffers and closes the output file.
//
// @return False in case of file I/O errors or missing encoder initialization.
bool FlushAndClose();
private:
// Copies input audio data into libvorbis encoder buffer.
//
// @param Array of pointers to planar channel data.
// @param num_channels Number of input channels.
// @param num_frames Number of input frames.
void PrepareVorbisBuffer(const float* const* input_ptrs, size_t num_channels,
size_t num_frames);
// Performs encoding of audio data prepared via |PrepareVorbisBuffer| or when
// the end of stream has been signaled.
//
// @return False in case of file I/O errors or missing encoder initialization.
bool PerformEncoding();
// Dumps data from |ogg_page_| struct to |output_file_stream_|.
//
// @return False in case of file I/O errors or missing encoder initialization.
bool WriteOggPage();
// Flag indicating if encoder has been successfully initialized.
bool init_;
// Output file stream.
std::ofstream output_file_stream_;
// libogg structs.
ogg_stream_state stream_state_;
ogg_page ogg_page_;
ogg_packet ogg_packet_;
// libvorbis structs.
vorbis_info vorbis_info_;
vorbis_comment vorbis_comment_;
vorbis_dsp_state vorbis_state_;
vorbis_block vorbis_block_;
};
} // namespace vraudio
#endif // RESONANCE_AUDIO_UTILS_VORBIS_STREAM_ENCODER_H_
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