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Diffstat (limited to 'media/BasicMediaDecoder/README.md')
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1 files changed, 58 insertions, 6 deletions
diff --git a/media/BasicMediaDecoder/README.md b/media/BasicMediaDecoder/README.md index 5663b3ca..d4cd1abd 100644 --- a/media/BasicMediaDecoder/README.md +++ b/media/BasicMediaDecoder/README.md @@ -1,16 +1,68 @@ + Android BasicMediaDecoder Sample -============================== +=================================== + +This sample shows how to use the MediaCoder to decode a video, +use a TimeAnimator to sync the rendering commands with the system +display frame rendering and finally render it to a TextureView. + +Introduction +------------ + +[MediaCodec][1] was introduced in API 16, and can be used for low level (decoding/encoding) operations. +In the same API was also introduced [TimeAnimator][2], which can be used to synchronise animation frames. +Finally, [MediaExtractor][3] provides a simple way to extract demuxed media data from a data source. -This activity uses a TextureView to render the frames of a video decoded using the -MediaCodec API. +The main steps are described below: + +1. Create a layout with a [TextureView][4] for your activity. +2. Initialise a MediaExtractor instance with `new MediaExtractor()` and a TimeAnimator instance with +`new TimeAnimator()`. +3. To start video playback, call `setDataSource(this, videoUri, null)` on your MediaExtractor instance, +where `videoUri` is the URI of your video source. +4. On your MediaExtractor instance, call `getTrackCount()` to know how many tracks you have in your streams. +They may not all be video tracks. Deselect all tracks by calling `unselectTrack(i)` where `i` is +the index of the track. +5. Get the mime type of a track by calling `getTrackFormat(i).getString(MediaFormat.KEY_MIME)` +on your MediaExtractor instance, where `i` is the index of your selected track. +If the mime type contains "video/", then this is a video track so you can select it, using `selectTrack(i)` +on your MediaExtractor instance. +6. Create a MediaCodec instance by calling `MediaCodec.createDecoderByType(mimeType)`. +7. Configure your MediaCodec instance with `configure(trackFormat, textureView, null, 0)`, +where `trackFormat` is obtained by calling `getTrackFormat(i)` on your MediaExtractor instance. +8. Set a TimeListener on your TimeAnimation instance, and override its `onTimeUpdate(final TimeAnimator animation, +final long totalTime, final long deltaTime)` method. +9. In `onTimeUpdate`, check if the media track has reached the end of stream, using `getSampleFlags()` +on your MediaExtractor instance and looking for `MediaCodec.BUFFER_FLAG_END_OF_STREAM` flag. +10. Still in `onTimeUpdate`, assuming this isn't the end of the sample, write the media sample to your +MediaDecoder instance, using `queueInputBuffer(index, 0, size, presentationTimeUs, flags)` method. +You will need to set up your buffers, refer to [MediaCodec][1] documentation for details. +11. After writing the media sample, you need to advance the sample, calling `advance()` on your +TimeExtractor instance (this is a blocking operation and should be done outside the main thread). +12. Finally, you can release and render the media sample by calling +`dequeueOutputBuffer(info, timeout)` and `releaseOutputBuffer(i, true)`, refer to [MediaCodec][1] +documentation for details. +13. In `onPause()` or if you have reached the end of the stream, call `end()` on your TimeAnimation instance, +then call `stop()` and `release()` on your MediaCodec instance, and finally, call `release()` on your +MediaExtractor instance. + +[1]: http://developer.android.com/reference/android/media/MediaCodec.html +[2]: http://developer.android.com/reference/android/animation/TimeAnimator.html +[3]: http://developer.android.com/reference/android/media/MediaExtractor.html +[4]: http://developer.android.com/reference/android/view/TextureView.html Pre-requisites -------------- -- Android SDK v20 -- Android Build Tools v20 +- Android SDK v23 +- Android Build Tools v22.0.1 - Android Support Repository +Screenshots +------------- + +<img src="screenshots/1-launch.png" height="400" alt="Screenshot"/> <img src="screenshots/2-play-video.png" height="400" alt="Screenshot"/> + Getting Started --------------- @@ -41,7 +93,7 @@ file to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at - http://www.apache.org/licenses/LICENSE-2.0 +http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |