The Tor Browser: content/media/encoder/OpusTrackEncoder.h@6474c204b198

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

     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/. */

     6 #ifndef OpusTrackEncoder_h_

     7 #define OpusTrackEncoder_h_

     9 #include <stdint.h>

    10 #include <speex/speex_resampler.h>

    11 #include "TrackEncoder.h"

    13 struct OpusEncoder;

    15 namespace mozilla {

    17 // Opus meta data structure

    18 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;

    26   MetadataKind GetKind() const MOZ_OVERRIDE { return METADATA_OPUS; }

    27 };

    29 class OpusTrackEncoder : public AudioTrackEncoder

    30 {

    31 public:

    32   OpusTrackEncoder();

    33   virtual ~OpusTrackEncoder();

    35   already_AddRefed<TrackMetadataBase> GetMetadata() MOZ_OVERRIDE;

    37   nsresult GetEncodedTrack(EncodedFrameContainer& aData) MOZ_OVERRIDE;

    39 protected:

    40   int GetPacketDuration();

    42   nsresult Init(int aChannels, int aSamplingRate) MOZ_OVERRIDE;

    44   /**

    45    * Get the samplerate of the data to be fed to the Opus encoder. This might be

    46    * different from the input samplerate if resampling occurs.

    47    */

    48   int GetOutputSampleRate();

    50 private:

    51   /**

    52    * The Opus encoder from libopus.

    53    */

    54   OpusEncoder* mEncoder;

    56   /**

    57    * A local segment queue which takes the raw data out from mRawSegment in the

    58    * call of GetEncodedTrack(). Opus encoder only accepts GetPacketDuration()

    59    * samples from mSourceSegment every encoding cycle, thus it needs to be

    60    * global in order to store the leftover segments taken from mRawSegment.

    61    */

    62   AudioSegment mSourceSegment;

    64   /**

    65    * Total samples of delay added by codec, can be queried by the encoder. From

    66    * the perspective of decoding, real data begins this many samples late, so

    67    * the encoder needs to append this many null samples to the end of stream,

    68    * in order to align the time of input and output.

    69    */

    70   int mLookahead;

    72   /**

    73    * If the input sample rate does not divide 48kHz evenly, the input data are

    74    * resampled.

    75    */

    76   SpeexResamplerState* mResampler;

    78   /**

    79    * Store the resampled frames that don't fit into an Opus packet duration.

    80    * They will be prepended to the resampled frames next encoding cycle.

    81    */

    82   nsTArray<AudioDataValue> mResampledLeftover;

    83 };

    85 }

    86 #endif

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