1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/content/media/MediaDecoderReader.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,181 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* vim: set ts=8 sts=2 et sw=2 tw=80: */
1.6 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +#if !defined(MediaDecoderReader_h_)
1.10 +#define MediaDecoderReader_h_
1.11 +
1.12 +#include "AbstractMediaDecoder.h"
1.13 +#include "MediaInfo.h"
1.14 +#include "MediaData.h"
1.15 +#include "MediaQueue.h"
1.16 +#include "AudioCompactor.h"
1.17 +
1.18 +namespace mozilla {
1.19 +
1.20 +namespace dom {
1.21 +class TimeRanges;
1.22 +}
1.23 +
1.24 +// Encapsulates the decoding and reading of media data. Reading can only be
1.25 +// done on the decode thread. Never hold the decoder monitor when
1.26 +// calling into this class. Unless otherwise specified, methods and fields of
1.27 +// this class can only be accessed on the decode thread.
1.28 +class MediaDecoderReader {
1.29 +public:
1.30 + MediaDecoderReader(AbstractMediaDecoder* aDecoder);
1.31 + virtual ~MediaDecoderReader();
1.32 +
1.33 + // Initializes the reader, returns NS_OK on success, or NS_ERROR_FAILURE
1.34 + // on failure.
1.35 + virtual nsresult Init(MediaDecoderReader* aCloneDonor) = 0;
1.36 +
1.37 + // True if this reader is waiting media resource allocation
1.38 + virtual bool IsWaitingMediaResources() { return false; }
1.39 + // True when this reader need to become dormant state
1.40 + virtual bool IsDormantNeeded() { return false; }
1.41 + // Release media resources they should be released in dormant state
1.42 + virtual void ReleaseMediaResources() {};
1.43 + // Release the decoder during shutdown
1.44 + virtual void ReleaseDecoder() {};
1.45 +
1.46 + // Resets all state related to decoding, emptying all buffers etc.
1.47 + virtual nsresult ResetDecode();
1.48 +
1.49 + // Decodes an unspecified amount of audio data, enqueuing the audio data
1.50 + // in mAudioQueue. Returns true when there's more audio to decode,
1.51 + // false if the audio is finished, end of file has been reached,
1.52 + // or an un-recoverable read error has occured.
1.53 + virtual bool DecodeAudioData() = 0;
1.54 +
1.55 + // Reads and decodes one video frame. Packets with a timestamp less
1.56 + // than aTimeThreshold will be decoded (unless they're not keyframes
1.57 + // and aKeyframeSkip is true), but will not be added to the queue.
1.58 + virtual bool DecodeVideoFrame(bool &aKeyframeSkip,
1.59 + int64_t aTimeThreshold) = 0;
1.60 +
1.61 + virtual bool HasAudio() = 0;
1.62 + virtual bool HasVideo() = 0;
1.63 +
1.64 + // Read header data for all bitstreams in the file. Fills aInfo with
1.65 + // the data required to present the media, and optionally fills *aTags
1.66 + // with tag metadata from the file.
1.67 + // Returns NS_OK on success, or NS_ERROR_FAILURE on failure.
1.68 + virtual nsresult ReadMetadata(MediaInfo* aInfo,
1.69 + MetadataTags** aTags) = 0;
1.70 +
1.71 + // Stores the presentation time of the first frame we'd be able to play if
1.72 + // we started playback at the current position. Returns the first video
1.73 + // frame, if we have video.
1.74 + virtual VideoData* FindStartTime(int64_t& aOutStartTime);
1.75 +
1.76 + // Moves the decode head to aTime microseconds. aStartTime and aEndTime
1.77 + // denote the start and end times of the media in usecs, and aCurrentTime
1.78 + // is the current playback position in microseconds.
1.79 + virtual nsresult Seek(int64_t aTime,
1.80 + int64_t aStartTime,
1.81 + int64_t aEndTime,
1.82 + int64_t aCurrentTime) = 0;
1.83 +
1.84 + // Called to move the reader into idle/active state. When the reader is
1.85 + // created it is assumed to be active (i.e. not idle). When the media
1.86 + // element is paused and we don't need to decode any more data, the state
1.87 + // machine calls SetIdle() to inform the reader that its decoder won't be
1.88 + // needed for a while. When we need to decode data again, the state machine
1.89 + // calls SetActive() to activate the decoder. The reader can use these
1.90 + // notifications to enter/exit a low power state when the decoder isn't
1.91 + // needed, if desired. This is most useful on mobile.
1.92 + virtual void SetIdle() { }
1.93 + virtual void SetActive() { }
1.94 +
1.95 + // Tell the reader that the data decoded are not for direct playback, so it
1.96 + // can accept more files, in particular those which have more channels than
1.97 + // available in the audio output.
1.98 + void SetIgnoreAudioOutputFormat()
1.99 + {
1.100 + mIgnoreAudioOutputFormat = true;
1.101 + }
1.102 +
1.103 +protected:
1.104 + // Queue of audio frames. This queue is threadsafe, and is accessed from
1.105 + // the audio, decoder, state machine, and main threads.
1.106 + MediaQueue<AudioData> mAudioQueue;
1.107 +
1.108 + // Queue of video frames. This queue is threadsafe, and is accessed from
1.109 + // the decoder, state machine, and main threads.
1.110 + MediaQueue<VideoData> mVideoQueue;
1.111 +
1.112 + // An adapter to the audio queue which first copies data to buffers with
1.113 + // minimal allocation slop and then pushes them to the queue. This is
1.114 + // useful for decoders working with formats that give awkward numbers of
1.115 + // frames such as mp3.
1.116 + AudioCompactor mAudioCompactor;
1.117 +
1.118 +public:
1.119 + // Populates aBuffered with the time ranges which are buffered. aStartTime
1.120 + // must be the presentation time of the first frame in the media, e.g.
1.121 + // the media time corresponding to playback time/position 0. This function
1.122 + // is called on the main, decode, and state machine threads.
1.123 + //
1.124 + // This base implementation in MediaDecoderReader estimates the time ranges
1.125 + // buffered by interpolating the cached byte ranges with the duration
1.126 + // of the media. Reader subclasses should override this method if they
1.127 + // can quickly calculate the buffered ranges more accurately.
1.128 + //
1.129 + // The primary advantage of this implementation in the reader base class
1.130 + // is that it's a fast approximation, which does not perform any I/O.
1.131 + //
1.132 + // The OggReader relies on this base implementation not performing I/O,
1.133 + // since in FirefoxOS we can't do I/O on the main thread, where this is
1.134 + // called.
1.135 + virtual nsresult GetBuffered(dom::TimeRanges* aBuffered,
1.136 + int64_t aStartTime);
1.137 +
1.138 + // Returns the number of bytes of memory allocated by structures/frames in
1.139 + // the video queue.
1.140 + size_t SizeOfVideoQueueInBytes() const;
1.141 +
1.142 + // Returns the number of bytes of memory allocated by structures/frames in
1.143 + // the audio queue.
1.144 + size_t SizeOfAudioQueueInBytes() const;
1.145 +
1.146 + // Only used by WebMReader and MediaOmxReader for now, so stub here rather
1.147 + // than in every reader than inherits from MediaDecoderReader.
1.148 + virtual void NotifyDataArrived(const char* aBuffer, uint32_t aLength, int64_t aOffset) {}
1.149 +
1.150 + virtual MediaQueue<AudioData>& AudioQueue() { return mAudioQueue; }
1.151 + virtual MediaQueue<VideoData>& VideoQueue() { return mVideoQueue; }
1.152 +
1.153 + // Returns a pointer to the decoder.
1.154 + AbstractMediaDecoder* GetDecoder() {
1.155 + return mDecoder;
1.156 + }
1.157 +
1.158 + AudioData* DecodeToFirstAudioData();
1.159 + VideoData* DecodeToFirstVideoData();
1.160 +
1.161 + // Decodes samples until we reach frames required to play at time aTarget
1.162 + // (usecs). This also trims the samples to start exactly at aTarget,
1.163 + // by discarding audio samples and adjusting start times of video frames.
1.164 + nsresult DecodeToTarget(int64_t aTarget);
1.165 +
1.166 + MediaInfo GetMediaInfo() { return mInfo; }
1.167 +
1.168 +protected:
1.169 +
1.170 + // Reference to the owning decoder object.
1.171 + AbstractMediaDecoder* mDecoder;
1.172 +
1.173 + // Stores presentation info required for playback.
1.174 + MediaInfo mInfo;
1.175 +
1.176 + // Whether we should accept media that we know we can't play
1.177 + // directly, because they have a number of channel higher than
1.178 + // what we support.
1.179 + bool mIgnoreAudioOutputFormat;
1.180 +};
1.181 +
1.182 +} // namespace mozilla
1.183 +
1.184 +#endif
