Kotlin Extension Function to Generate Quality List

MediaExtension.kt

fun DefaultTrackSelector.generateQualityList(): ArrayList<Pair<String, TrackSelectionOverrides.Builder>> {
    //Render Track -> TRACK GROUPS (Track Array)(Video,Audio,Text)->Track
    val trackOverrideList = ArrayList<Pair<String, TrackSelectionOverrides.Builder>>()

    val renderTrack = this.currentMappedTrackInfo
    val renderCount = renderTrack?.rendererCount ?: 0
    for (rendererIndex in 0 until renderCount) {
        if (isSupportedFormat(renderTrack, rendererIndex)) {
            val trackGroupType = renderTrack?.getRendererType(rendererIndex)
            val trackGroups = renderTrack?.getTrackGroups(rendererIndex)
            val trackGroupsCount = trackGroups?.length!!
            if (trackGroupType == C.TRACK_TYPE_VIDEO) {
                for (groupIndex in 0 until trackGroupsCount) {
                    val videoQualityTrackCount = trackGroups[groupIndex].length
                    for (trackIndex in 0 until videoQualityTrackCount) {
                        val isTrackSupported = renderTrack.getTrackSupport(
                            rendererIndex,
                            groupIndex,
                            trackIndex
                        ) == C.FORMAT_HANDLED
                        if (isTrackSupported) {
                            val track = trackGroups[groupIndex]
                            val trackName =
                                "${track.getFormat(trackIndex).width} x ${track.getFormat(trackIndex).height}"
                            val trackBuilder =
                                TrackSelectionOverrides.Builder()
                                    .clearOverridesOfType(C.TRACK_TYPE_VIDEO)
                                    .addOverride(TrackSelectionOverrides.TrackSelectionOverride(track,
                                        listOf(trackIndex)))
                            trackOverrideList.add(Pair(trackName, trackBuilder))
                        }
                    }
                }
            }
        }
    }
    return trackOverrideList
}