android-transcoder
Hardware accelerated transcoder for Android, written in pure Java.
Why?
Android does not offer straight forward way to transcode video.
FFmpeg is the most famous solution for transcoding. But using FFmpeg binary on Android can cause GPL and/or patent issues. Also using native code for Android development can be troublesome because of cross-compiling, architecture compatibility, build time and binary size.
To transcode without any hassle written above, I created this library to provide hardware accelerated transcoding of H.264 (mp4) video without ffmpeg by using MediaCodec.
Requirements
API Level 18 (Android 4.3, JELLY_BEAN_MR2) or later. If your app targets older Android, you should add below line to AndroidManifest.xml:
<!-- Only supports API >= 18 -->
<uses-sdk tools:overrideLibrary="net.ypresto.androidtranscoder" />
Please ensure checking Build.VERSION by your self.
Usage
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
ParcelFileDescriptor parcelFileDescriptor = resolver.openFileDescriptor(data.getData(), "r");
FileDescriptor fileDescriptor = parcelFileDescriptor.getFileDescriptor();
MediaTranscoder.Listener listener = new MediaTranscoder.Listener() {
@Override
public void onTranscodeProgress(double progress) {
...
}
@Override
public void onTranscodeCompleted() {
startActivity(new Intent(Intent.ACTION_VIEW).setDataAndType(Uri.fromFile(file), "video/mp4"));
...
}
@Override
public void onTranscodeFailed(Exception exception) {
...
}
};
MediaTranscoder.getInstance().transcodeVideo(fileDescriptor, file.getAbsolutePath(),
MediaFormatStrategyPresets.createAndroid720pStrategy(), listener); // or createAndroid720pStrategy([your bitrate here])
}
See TranscoderActivity.java
in example directory for ready-made transcoder app.
Quick Setup
Gradle
compile 'com.klinkerapps:android-transcoder:1.0.2'
Note (PLEASE READ FIRST)
- This library raises
RuntimeException
s (likeIlleagalStateException
) in various situations. Please catch it and provide alternate logics. I know this is bad design according to Effective Java; just is TODO. - Currently this library does not generate streaming-aware mp4 file. Use qtfaststart-java to place moov atom at beginning of file.
- Android does not gurantees that all devices have bug-free codecs/accelerators for your codec parameters (especially, resolution). Refer supported media formats for parameters guaranteed by CTS.
- This library does not support video files recorded by other device like digital cameras, iOS (mov files, including non-baseline profile h.264), etc.
More information about internals
There is a blog post about this library written in Japanese. http://qiita.com/yuya_presto/items/d48e29c89109b746d000
While it is Japanese, diagrams would be useful for understanding internals of this library.
References for Android Low-Level Media APIs
- http://bigflake.com/mediacodec/
- https://github.com/google/grafika
- https://android.googlesource.com/platform/frameworks/av/+/lollipop-release/media/libstagefright
License
Copyright (C) 2014-2016 Yuya Tanaka
Licensed 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.