xref: /developers/build/prebuilts/gradle/BasicMediaDecoder

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.

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 v21
- Android Build Tools v21.1.1
- 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
---------------

This sample uses the Gradle build system. To build this project, use the
"gradlew build" command or use "Import Project" in Android Studio.

Support
-------

- Google+ Community: https://plus.google.com/communities/105153134372062985968
- Stack Overflow: http://stackoverflow.com/questions/tagged/android

If you've found an error in this sample, please file an issue:
https://github.com/googlesamples/android-BasicMediaDecoder

Patches are encouraged, and may be submitted by forking this project and
submitting a pull request through GitHub. Please see CONTRIBUTING.md for more details.

License
-------

Copyright 2014 The Android Open Source Project, Inc.

Licensed to the Apache Software Foundation (ASF) under one or more contributor
license agreements.  See the NOTICE file distributed with this work for
additional information regarding copyright ownership.  The ASF licenses this
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

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
License for the specific language governing permissions and limitations under
the License.