Yesterday I was assigned to get metadata (width, height, frame rate and no of frames) of a video recorded by camera. I have gone through many articles and stackoverflow answers, but none of them have fully covered what I want. After playing with android framework I manged to complete my assignment. I will show you what I have learned.
What I need was either number of frames or frame rate. If I have one then I can calculate other because I have the video length.
First I tried to use MediaPlayer class. There were 2 promising methods in this class.
val mediaPlayer: MediaPlayer = MediaPlayer.create(context, uri)
val frames = mediaPlayer.metrics.get(MediaPlayer.MetricsConstants.FRAMES)
However this method requires api level 28. My minimum api level was 21 so this was not going to work. There was also another method call,
val frameRate = mediaPlayer.syncParams.frameRate
However this always returns null for me. I wasn't eager to chase this around because I had another promising class which named MediaMetadataRetriever.
val retriever = MediaMetadataRetriever()
val frameRate = retriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_CAPTURE_FRAMERATE)
However this method also requires android api level 23 and also it returns me null.
Finally I found MediaExtractor class which is compatible with android api level 16 and gives me what I want.
private fun getVideoMetaData(uri: Uri) : VideoMetaData{
val mediaExtractor = MediaExtractor()
mediaExtractor.setDataSource(uri.path)
val format = mediaExtractor.getTrackFormat(0)
mediaExtractor.release()
return if(format.containsKey(MediaFormat.KEY_FRAME_RATE)){
val frameRate = format.getInteger(MediaFormat.KEY_FRAME_RATE)
val frames = frameRate * (format.getLong(MediaFormat.KEY_DURATION)/ 1000000)
VideoMetaData(format.getInteger(MediaFormat.KEY_WIDTH).toString(),
format.getInteger(MediaFormat.KEY_HEIGHT).toString(),
frames.toString(),
frameRate.toString())
}else {
VideoMetaData(format.getInteger(MediaFormat.KEY_WIDTH).toString(), format.getInteger(MediaFormat.KEY_HEIGHT).toString())
}
}
** VideoMetaData is a simple data class
So that's it. Hope this will be a help for someone.
:-)
