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       1             : /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
       2             : /* This Source Code Form is subject to the terms of the Mozilla Public
       3             :  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
       4             :  * You can obtain one at http://mozilla.org/MPL/2.0/. */
       5             : 
       6             : #ifndef OpusTrackEncoder_h_
       7             : #define OpusTrackEncoder_h_
       8             : 
       9             : #include <stdint.h>
      10             : #include <speex/speex_resampler.h>
      11             : #include "TrackEncoder.h"
      12             : 
      13             : struct OpusEncoder;
      14             : 
      15             : namespace mozilla {
      16             : 
      17             : // Opus meta data structure
      18           0 : class OpusMetadata : public TrackMetadataBase
      19             : {
      20             : public:
      21             :   // The ID Header of OggOpus. refer to http://wiki.xiph.org/OggOpus.
      22             :   nsTArray<uint8_t> mIdHeader;
      23             :   // The Comment Header of OggOpus.
      24             :   nsTArray<uint8_t> mCommentHeader;
      25             :   int32_t mChannels;
      26             :   float mSamplingFrequency;
      27           0 :   MetadataKind GetKind() const override { return METADATA_OPUS; }
      28             : };
      29             : 
      30             : class OpusTrackEncoder : public AudioTrackEncoder
      31             : {
      32             : public:
      33             :   OpusTrackEncoder();
      34             :   virtual ~OpusTrackEncoder();
      35             : 
      36             :   already_AddRefed<TrackMetadataBase> GetMetadata() override;
      37             : 
      38             :   nsresult GetEncodedTrack(EncodedFrameContainer& aData) override;
      39             : 
      40             : protected:
      41             :   int GetPacketDuration() override;
      42             : 
      43             :   nsresult Init(int aChannels, int aSamplingRate) override;
      44             : 
      45             :   /**
      46             :    * Get the samplerate of the data to be fed to the Opus encoder. This might be
      47             :    * different from the input samplerate if resampling occurs.
      48             :    */
      49             :   int GetOutputSampleRate();
      50             : 
      51             : private:
      52             :   /**
      53             :    * The Opus encoder from libopus.
      54             :    */
      55             :   OpusEncoder* mEncoder;
      56             : 
      57             :   /**
      58             :    * A local segment queue which takes the raw data out from mRawSegment in the
      59             :    * call of GetEncodedTrack(). Opus encoder only accepts GetPacketDuration()
      60             :    * samples from mSourceSegment every encoding cycle, thus it needs to be
      61             :    * global in order to store the leftover segments taken from mRawSegment.
      62             :    */
      63             :   AudioSegment mSourceSegment;
      64             : 
      65             :   /**
      66             :    * Total samples of delay added by codec, can be queried by the encoder. From
      67             :    * the perspective of decoding, real data begins this many samples late, so
      68             :    * the encoder needs to append this many null samples to the end of stream,
      69             :    * in order to align the time of input and output.
      70             :    */
      71             :   int mLookahead;
      72             : 
      73             :   /**
      74             :    * If the input sample rate does not divide 48kHz evenly, the input data are
      75             :    * resampled.
      76             :    */
      77             :   SpeexResamplerState* mResampler;
      78             : 
      79             :   /**
      80             :    * Store the resampled frames that don't fit into an Opus packet duration.
      81             :    * They will be prepended to the resampled frames next encoding cycle.
      82             :    */
      83             :   nsTArray<AudioDataValue> mResampledLeftover;
      84             : 
      85             :   // TimeStamp in microseconds.
      86             :   uint64_t mOutputTimeStamp;
      87             : };
      88             : 
      89             : } // namespace mozilla
      90             : 
      91             : #endif