michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* vim:set ts=2 sw=2 sts=2 et cindent: */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #if !defined(DirectShowReader_h_)
michael@0: #define DirectShowReader_h_
michael@0: 
michael@0: #include "windows.h" // HRESULT, DWORD
michael@0: #include "MediaDecoderReader.h"
michael@0: #include "mozilla/RefPtr.h"
michael@0: #include "MP3FrameParser.h"
michael@0: 
michael@0: class IGraphBuilder;
michael@0: class IMediaControl;
michael@0: class IMediaSeeking;
michael@0: class IMediaEventEx;
michael@0: 
michael@0: namespace mozilla {
michael@0: 
michael@0: class AudioSinkFilter;
michael@0: class SourceFilter;
michael@0: 
michael@0: namespace dom {
michael@0: class TimeRanges;
michael@0: }
michael@0: 
michael@0: // Decoder backend for decoding MP3 using DirectShow. DirectShow operates as
michael@0: // a filter graph. The basic design of the DirectShowReader is that we have
michael@0: // a SourceFilter that wraps the MediaResource that connects to the
michael@0: // MP3 decoder filter. The MP3 decoder filter "pulls" data as it requires it
michael@0: // downstream on its own thread. When the MP3 decoder has produced a block of
michael@0: // decoded samples, its thread calls downstream into our AudioSinkFilter,
michael@0: // passing the decoded buffer in. The AudioSinkFilter inserts the samples into
michael@0: // a SampleSink object. The SampleSink blocks the MP3 decoder's thread until
michael@0: // the decode thread calls DecodeAudioData(), whereupon the SampleSink
michael@0: // releases the decoded samples to the decode thread, and unblocks the MP3
michael@0: // decoder's thread. The MP3 decoder can then request more data from the
michael@0: // SourceFilter, and decode more data. If the decode thread calls
michael@0: // DecodeAudioData() and there's no decoded samples waiting to be extracted
michael@0: // in the SampleSink, the SampleSink blocks the decode thread until the MP3
michael@0: // decoder produces a decoded sample.
michael@0: class DirectShowReader : public MediaDecoderReader
michael@0: {
michael@0: public:
michael@0:   DirectShowReader(AbstractMediaDecoder* aDecoder);
michael@0: 
michael@0:   virtual ~DirectShowReader();
michael@0: 
michael@0:   nsresult Init(MediaDecoderReader* aCloneDonor) MOZ_OVERRIDE;
michael@0: 
michael@0:   bool DecodeAudioData() MOZ_OVERRIDE;
michael@0:   bool DecodeVideoFrame(bool &aKeyframeSkip,
michael@0:                         int64_t aTimeThreshold) MOZ_OVERRIDE;
michael@0: 
michael@0:   bool HasAudio() MOZ_OVERRIDE;
michael@0:   bool HasVideo() MOZ_OVERRIDE;
michael@0: 
michael@0:   nsresult ReadMetadata(MediaInfo* aInfo,
michael@0:                         MetadataTags** aTags) MOZ_OVERRIDE;
michael@0: 
michael@0:   nsresult Seek(int64_t aTime,
michael@0:                 int64_t aStartTime,
michael@0:                 int64_t aEndTime,
michael@0:                 int64_t aCurrentTime) MOZ_OVERRIDE;
michael@0: 
michael@0:   void NotifyDataArrived(const char* aBuffer,
michael@0:                          uint32_t aLength,
michael@0:                          int64_t aOffset) MOZ_OVERRIDE;
michael@0: 
michael@0: private:
michael@0: 
michael@0:   // Notifies the filter graph that playback is complete. aStatus is
michael@0:   // the code to send to the filter graph. Always returns false, so
michael@0:   // that we can just "return Finish()" from DecodeAudioData().
michael@0:   bool Finish(HRESULT aStatus);
michael@0: 
michael@0:   // DirectShow filter graph, and associated playback and seeking
michael@0:   // control interfaces.
michael@0:   RefPtr<IGraphBuilder> mGraph;
michael@0:   RefPtr<IMediaControl> mControl;
michael@0:   RefPtr<IMediaSeeking> mMediaSeeking;
michael@0: 
michael@0:   // Wraps the MediaResource, and feeds undecoded data into the filter graph.
michael@0:   RefPtr<SourceFilter> mSourceFilter;
michael@0: 
michael@0:   // Sits at the end of the graph, removing decoded samples from the graph.
michael@0:   // The graph will block while this is blocked, i.e. it will pause decoding.
michael@0:   RefPtr<AudioSinkFilter> mAudioSinkFilter;
michael@0: 
michael@0:   // Some MP3s are variable bitrate, so DirectShow's duration estimation
michael@0:   // can make its duration estimation based on the wrong bitrate. So we parse
michael@0:   // the MP3 frames to get a more accuate estimate of the duration.
michael@0:   MP3FrameParser mMP3FrameParser;
michael@0: 
michael@0: #ifdef DEBUG
michael@0:   // Used to add/remove the filter graph to the Running Object Table. You can
michael@0:   // connect GraphEdit/GraphStudio to the graph to observe and/or debug its
michael@0:   // topology and state.
michael@0:   DWORD mRotRegister;
michael@0: #endif
michael@0: 
michael@0:   // Number of channels in the audio stream.
michael@0:   uint32_t mNumChannels;
michael@0: 
michael@0:   // Samples per second in the audio stream.
michael@0:   uint32_t mAudioRate;
michael@0: 
michael@0:   // Number of bytes per sample. Can be either 1 or 2.
michael@0:   uint32_t mBytesPerSample;
michael@0: 
michael@0:   // Duration of the stream, in microseconds.
michael@0:   int64_t mDuration;
michael@0: };
michael@0: 
michael@0: } // namespace mozilla
michael@0: 
michael@0: #endif