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MediaFile

API MIT license Android Weekly #378 Android Weekly #396

Overview

The library reads basic information about video and audio files.

For video streams:

  • Video codec name
  • Bit rate
  • Frame rate and size

For audio streams:

  • Audio codec name
  • Bit rate
  • Number of channels
  • Channel layout
  • Sample rate and format

For subtitle streams: title and language from stream’s metadata.

An incubating feature allows reading N equidistant frames from a video stream.

Supported ABIs are: armeabi-v7a, arm64-v8a, x86 and x86_64.

How it works

Under the hood this library uses FFmpeg. Android-specific binaries of FFmpeg are produced with ffmpeg-android-maker.

Extensive description can be found in this article, though the article was written at the time this library wasn't extracted as a separate repository.

FFmpeg's C API is accessed directly. Native part is connected to JVM part via JNI layer.

APIs

MediaFileFactory class represents the entry point for MediaFile instances retrieval.

FFmpeg supports various types of input. MediaFile uses only a subset, that covers local content accessing:

  • MediaSource.File(). Despite the restrictions Android OS imposes on raw file paths usage, they are still valid if you want to use the files in your app's directories. Backed by file protocol.

  • MediaSource.FileDescriptor(). A ParcelFileDescriptor and AssetFileDescriptor are covered with this MediaSource type. Backed by fd protocol.

  • MediaSource.Content(). Regular Uris with content:// scheme can also be read by FFmpeg directly. Backed by android_content protocol.

MediaFile and FrameLoader implement AutoClosable, so they can be used in try-with-resources ( Java) or with use() function (Kotlin).

Logs from FFmpeg can be redirected to LogCat, which is controlled by MediaFileFactory#setMinLogLevel() method.

Download

The library is available via Maven Central, so you are able to use it as a dependency:

dependencies {
    implementation 'io.github.javernaut:mediafile:2.0.0'
}

repositories {
    mavenCentral()
}

Build on your own

It is possible to have a different set of modules for the underlying FFmpeg's binaries. For that you need to rebuild them yourself. In order to do that you have to get ffmpeg-android-maker source code and compile it. It is already added as a submodule. So the first thing to do is to load it:

git submodule update --init

Then you need to setup and execute the ffmpeg-android-maker's script. The command used to generate the artifacts for Maven Central looks like this:

./ffmpeg-android-maker.sh -dav1d

More details about how to setup your environment for FFmpeg compilation can be found in ffmpeg-android-maker repository.

License

MediaFile library's source code is available under the MIT license. See the LICENSE.txt file for more details.