tenfourfox/dom/media/encoder/VP8TrackEncoder.h

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2017-04-19 07:56:45 +00:00
/* -*- 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 VP8TrackEncoder_h_
#define VP8TrackEncoder_h_
#include "TrackEncoder.h"
#include "vpx/vpx_codec.h"
namespace mozilla {
typedef struct vpx_codec_ctx vpx_codec_ctx_t;
typedef struct vpx_codec_enc_cfg vpx_codec_enc_cfg_t;
typedef struct vpx_image vpx_image_t;
/**
* VP8TrackEncoder implements VideoTrackEncoder by using libvpx library.
* We implement a realtime and fixed FPS encoder. In order to achieve that,
* there is a pick target frame and drop frame encoding policy implemented in
* GetEncodedTrack.
*/
class VP8TrackEncoder : public VideoTrackEncoder
{
enum EncodeOperation {
ENCODE_NORMAL_FRAME, // VP8 track encoder works normally.
ENCODE_I_FRAME, // The next frame will be encoded as I-Frame.
SKIP_FRAME, // Skip the next frame.
};
public:
VP8TrackEncoder();
virtual ~VP8TrackEncoder();
already_AddRefed<TrackMetadataBase> GetMetadata() final override;
nsresult GetEncodedTrack(EncodedFrameContainer& aData) final override;
protected:
nsresult Init(int32_t aWidth, int32_t aHeight,
int32_t aDisplayWidth, int32_t aDisplayHeight,
TrackRate aTrackRate) final override;
private:
// Calculate the target frame's encoded duration.
StreamTime CalculateEncodedDuration(StreamTime aDurationCopied);
// Calculate the mRemainingTicks for next target frame.
StreamTime CalculateRemainingTicks(StreamTime aDurationCopied,
StreamTime aEncodedDuration);
// Get the EncodeOperation for next target frame.
EncodeOperation GetNextEncodeOperation(TimeDuration aTimeElapsed,
StreamTime aProcessedDuration);
// Get the encoded data from encoder to aData.
nsresult GetEncodedPartitions(EncodedFrameContainer& aData);
// Prepare the input data to the mVPXImageWrapper for encoding.
nsresult PrepareRawFrame(VideoChunk &aChunk);
// Output frame rate.
uint32_t mEncodedFrameRate;
// Duration for the output frame, reciprocal to mEncodedFrameRate.
StreamTime mEncodedFrameDuration;
// Encoded timestamp.
StreamTime mEncodedTimestamp;
// Duration to the next encode frame.
StreamTime mRemainingTicks;
// Muted frame, we only create it once.
RefPtr<layers::Image> mMuteFrame;
// I420 frame, for converting to I420.
nsTArray<uint8_t> mI420Frame;
/**
* A local segment queue which takes the raw data out from mRawSegment in the
* call of GetEncodedTrack(). Since we implement the fixed FPS encoding
* policy, it needs to be global in order to store the leftover segments
* taken from mRawSegment.
*/
VideoSegment mSourceSegment;
// VP8 relative members.
// Codec context structure.
nsAutoPtr<vpx_codec_ctx_t> mVPXContext;
// Image Descriptor.
nsAutoPtr<vpx_image_t> mVPXImageWrapper;
};
} // namespace mozilla
#endif