1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/content/media/encoder/OpusTrackEncoder.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,86 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this file,
1.7 + * You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef OpusTrackEncoder_h_
1.10 +#define OpusTrackEncoder_h_
1.11 +
1.12 +#include <stdint.h>
1.13 +#include <speex/speex_resampler.h>
1.14 +#include "TrackEncoder.h"
1.15 +
1.16 +struct OpusEncoder;
1.17 +
1.18 +namespace mozilla {
1.19 +
1.20 +// Opus meta data structure
1.21 +class OpusMetadata : public TrackMetadataBase
1.22 +{
1.23 +public:
1.24 + // The ID Header of OggOpus. refer to http://wiki.xiph.org/OggOpus.
1.25 + nsTArray<uint8_t> mIdHeader;
1.26 + // The Comment Header of OggOpus.
1.27 + nsTArray<uint8_t> mCommentHeader;
1.28 +
1.29 + MetadataKind GetKind() const MOZ_OVERRIDE { return METADATA_OPUS; }
1.30 +};
1.31 +
1.32 +class OpusTrackEncoder : public AudioTrackEncoder
1.33 +{
1.34 +public:
1.35 + OpusTrackEncoder();
1.36 + virtual ~OpusTrackEncoder();
1.37 +
1.38 + already_AddRefed<TrackMetadataBase> GetMetadata() MOZ_OVERRIDE;
1.39 +
1.40 + nsresult GetEncodedTrack(EncodedFrameContainer& aData) MOZ_OVERRIDE;
1.41 +
1.42 +protected:
1.43 + int GetPacketDuration();
1.44 +
1.45 + nsresult Init(int aChannels, int aSamplingRate) MOZ_OVERRIDE;
1.46 +
1.47 + /**
1.48 + * Get the samplerate of the data to be fed to the Opus encoder. This might be
1.49 + * different from the input samplerate if resampling occurs.
1.50 + */
1.51 + int GetOutputSampleRate();
1.52 +
1.53 +private:
1.54 + /**
1.55 + * The Opus encoder from libopus.
1.56 + */
1.57 + OpusEncoder* mEncoder;
1.58 +
1.59 + /**
1.60 + * A local segment queue which takes the raw data out from mRawSegment in the
1.61 + * call of GetEncodedTrack(). Opus encoder only accepts GetPacketDuration()
1.62 + * samples from mSourceSegment every encoding cycle, thus it needs to be
1.63 + * global in order to store the leftover segments taken from mRawSegment.
1.64 + */
1.65 + AudioSegment mSourceSegment;
1.66 +
1.67 + /**
1.68 + * Total samples of delay added by codec, can be queried by the encoder. From
1.69 + * the perspective of decoding, real data begins this many samples late, so
1.70 + * the encoder needs to append this many null samples to the end of stream,
1.71 + * in order to align the time of input and output.
1.72 + */
1.73 + int mLookahead;
1.74 +
1.75 + /**
1.76 + * If the input sample rate does not divide 48kHz evenly, the input data are
1.77 + * resampled.
1.78 + */
1.79 + SpeexResamplerState* mResampler;
1.80 +
1.81 + /**
1.82 + * Store the resampled frames that don't fit into an Opus packet duration.
1.83 + * They will be prepended to the resampled frames next encoding cycle.
1.84 + */
1.85 + nsTArray<AudioDataValue> mResampledLeftover;
1.86 +};
1.87 +
1.88 +}
1.89 +#endif
