正在下载缺少的编解码器？

Question

I am facing an issue where i am unable to download codec for some random media files. i was hoping there was a way i could tell the android OS to download the respected codec inorder to play the file ? right now i am using https://github.com/brianwernick/ExoMedia player which is some kind of fork of exoPlayer for android. and i it does not support a codec and will only play audio or nothing. how can i get it (or even the OS) to download the missing codec ?

here is the mp4 file codec info that will not play on many devices that i wish to solve:

the code itself is trivial:

 class MediaPlayerActivity : AppCompatActivity(), OnPreparedListener {

    private var uri: String = ""

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_media_player)
        uri = intent.getStringExtra("uri")

        setupVideoView(uri)
    }

    private fun setupVideoView(uri: String) {
        videoView.setOnPreparedListener(this)
        videoView.setVideoURI(Uri.parse(uri))
    }

    override fun onPrepared() {
        //Starts the video playback as soon as it is ready
        videoView.start()
    }

}

and respectively the xml file:

<?xml version="1.0" encoding="utf-8"?>


<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/black">

    <com.devbrackets.android.exomedia.ui.widget.VideoView
        android:id="@+id/videoView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:useDefaultControls="true" />

</RelativeLayout>

i also installed mx player on the android device and mx player did not offer to install a codec. instead it played just hte audio, no visual. also if i open the mp4 in chrome it plays fine.

Answer 1

You are trying to play a UHD (2160x3840) video encoded in H.264 on a variety of devices. This is a bad idea as each device has a upper limit of what it can decode reasonably even with hardware decode. This would explain why you can hear audio but not see anything.

The general solution is to deliver an appropriated encoded video for the target client. By implication it means that you aren't delivering a larger than necessary file/stream should the end user be on a metered data connection.

The Android site has size/format recommendations:

https://developer.android.com/guide/topics/media/media-formats

but real details are listed in the Android Compatibility Definition Document (CDD)

You should transcode your video into a set of files of the appropriate codecs & bitrates for the customers you are expecting and deliver according. For example if the file is for high end devices with UHD screens, as determined by Display.getSupportedModes() then you should be encoding the video in either H.265 or VP9 at 20 Mbps.