gecko/content/media/encoder/OpusTrackEncoder.h

87 lines
2.4 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 OpusTrackEncoder_h_
#define OpusTrackEncoder_h_
#include <stdint.h>
#include <speex/speex_resampler.h>
#include "TrackEncoder.h"
struct OpusEncoder;
namespace mozilla {
// Opus meta data structure
class OpusMetadata : public TrackMetadataBase
{
public:
// The ID Header of OggOpus. refer to http://wiki.xiph.org/OggOpus.
nsTArray<uint8_t> mIdHeader;
// The Comment Header of OggOpus.
nsTArray<uint8_t> mCommentHeader;
MetadataKind GetKind() const MOZ_OVERRIDE { return METADATA_OPUS; }
};
class OpusTrackEncoder : public AudioTrackEncoder
{
public:
OpusTrackEncoder();
virtual ~OpusTrackEncoder();
already_AddRefed<TrackMetadataBase> GetMetadata() MOZ_OVERRIDE;
nsresult GetEncodedTrack(EncodedFrameContainer& aData) MOZ_OVERRIDE;
protected:
int GetPacketDuration();
nsresult Init(int aChannels, int aSamplingRate) MOZ_OVERRIDE;
/**
* Get the samplerate of the data to be fed to the Opus encoder. This might be
* different from the input samplerate if resampling occurs.
*/
int GetOutputSampleRate();
private:
/**
* The Opus encoder from libopus.
*/
OpusEncoder* mEncoder;
/**
* A local segment queue which takes the raw data out from mRawSegment in the
* call of GetEncodedTrack(). Opus encoder only accepts GetPacketDuration()
* samples from mSourceSegment every encoding cycle, thus it needs to be
* global in order to store the leftover segments taken from mRawSegment.
*/
AudioSegment mSourceSegment;
/**
* Total samples of delay added by codec, can be queried by the encoder. From
* the perspective of decoding, real data begins this many samples late, so
* the encoder needs to append this many null samples to the end of stream,
* in order to align the time of input and output.
*/
int mLookahead;
/**
* If the input sample rate does not divide 48kHz evenly, the input data are
* resampled.
*/
SpeexResamplerState* mResampler;
/**
* Store the resampled frames that don't fit into an Opus packet duration.
* They will be prepended to the resampled frames next encoding cycle.
*/
nsTArray<AudioDataValue> mResampledLeftover;
};
}
#endif