val mediaItem = MediaItem.fromUri(Uri.parse(videoUrl))

val extendMediaItem = MediaItem.Builder().apply { 
    setUri(Uri.parse(url))
    setMediaId("video-01")
    setTag("TAG_01")
}.build()

// 비디오 URL
val url = "https://www.learningcontainer.com/wp-content/uploads/2020/05/sample-mp4-file.mp4"

// MediaItem을 만들고
val mediaItem = MediaItem.fromUri(Uri.parse(url))

// MediaSource를 만들고
val userAgent = Util.getUserAgent(this, this.applicationInfo.name)
val factory = DefaultDataSourceFactory(this, userAgent)
val progressiveMediaSource = ProgressiveMediaSource.Factory(factory).createMediaSource(mediaItem)

// 비디오 URL
val url = "https://www.learningcontainer.com/wp-content/uploads/2020/05/sample-mp4-file.mp4"

// MediaItem을 만들고
val mediaItem = MediaItem.fromUri(Uri.parse(url))

// MediaSource를 만들고
val userAgent = Util.getUserAgent(this, this.applicationInfo.name)
val factory = DefaultHttpDataSourceFactory(userAgent)
val dashMediaSource = DashMediaSource.Factory(factory).createMediaSource(mediaItem)

// 비디오 URL
val url = "https://www.learningcontainer.com/wp-content/uploads/2020/05/sample-mp4-file.mp4"

// MediaItem을 만들고
val mediaItem = MediaItem.fromUri(Uri.parse(url))

// MediaSource를 만들고
val userAgent = Util.getUserAgent(this, this.applicationInfo.name)
val factory = DefaultHttpDataSourceFactory(userAgent)
val ssMediaSource = SsMediaSource.Factory(factory).createMediaSource(mediaItem)

// 비디오 URL
val url = "https://www.learningcontainer.com/wp-content/uploads/2020/05/sample-mp4-file.mp4"

// MediaItem을 만들고
val mediaItem = MediaItem.fromUri(Uri.parse(url))

// MediaSource를 만들고
val userAgent = Util.getUserAgent(this, this.applicationInfo.name)
val factory = DefaultHttpDataSourceFactory(userAgent)
val hlsMediaSource = HlsMediaSource.Factory(factory).createMediaSource(mediaItem)

val trackSelector = DefaultTrackSelector(this)
trackSelector.setParameters(
trackSelector.buildUponParameters()
    .setMaxVideoSizeSd() // 비디오 트랙 선택을 SD로 제한
    .setMaxAudioBitrate(1000) // 최대 오디오 bitrate를 1000으로 설정
)

val player = SimpleExoPlayer.Builder(this).apply {
setTrackSelector(trackSelector)
}.build()

SimpleExoPlayer.Builder(context).build().apply {
    this.addListener(object : Player.EventListener {
        override fun onPlayerStateChanged(playWhenReady: Boolean, playbackState: Int) {
            super.onPlayerStateChanged(playWhenReady, playbackState)
            
            when (playbackState) {
                Player.STATE_IDLE -> {
                    // 초기 상태, 플레이어가 중지 된 상태, 재생이 실패한 상태입니다.
                }
                Player.STATE_BUFFERING -> {
                    // 플레이어는 현재 위치에서 즉시 플레이 할 수 없습니다. 이것은 더 많은 데이터를로드해야하기 때문에 주로 발생합니다.
                }
                Player.STATE_READY -> {
                    // 플레이어는 현재 위치에서 즉시 플레이 할 수 있습니다.
                }
                Player.STATE_ENDED -> {
                   // 플레이어가 모든 미디어 재생을 마쳤습니다.
                }
            }
        }
    })
}

import android.content.Context
import com.google.android.exoplayer2.database.ExoDatabaseProvider
import com.google.android.exoplayer2.upstream.DataSource
import com.google.android.exoplayer2.upstream.DefaultDataSource
import com.google.android.exoplayer2.upstream.DefaultDataSourceFactory
import com.google.android.exoplayer2.upstream.FileDataSource
import com.google.android.exoplayer2.upstream.cache.CacheDataSink
import com.google.android.exoplayer2.upstream.cache.CacheDataSource
import com.google.android.exoplayer2.upstream.cache.LeastRecentlyUsedCacheEvictor
import com.google.android.exoplayer2.upstream.cache.SimpleCache
import com.google.android.exoplayer2.util.Util
import java.io.File

class CacheDataSourceFactory(
    val context: Context,
    maxCacheSize: Long,
    maxFileSize: Long
) : DataSource.Factory {

    private val simpleCache = SimpleCache(
        File(context.cacheDir, "media"), // 1번 설명
        LeastRecentlyUsedCacheEvictor(maxCacheSize), // 2번 설명
        ExoDatabaseProvider(context) // 3번 설명
    )

    private val cacheDataSink = CacheDataSink(simpleCache, maxFileSize) // 4번 설명

    override fun createDataSource(): DataSource {
        // 5번 설명
        return CacheDataSource(
            simpleCache,
            getDefaultDataSource(),
            FileDataSource(),
            cacheDataSink,
            CacheDataSource.FLAG_BLOCK_ON_CACHE or CacheDataSource.FLAG_IGNORE_CACHE_ON_ERROR,
            null
        )
    }

    private fun getDefaultDataSource(): DefaultDataSource {
        val userAgent = Util.getUserAgent(context, context.applicationInfo.name)
        return DefaultDataSourceFactory(context, userAgent).createDataSource()
    }
}

private val cacheDataSourceFactory = CacheDataSourceFactory(
    context = context,
    maxCacheSize = 50.MB(), // 이 부분은 직접 계산해야합니다.
    maxFileSize = 100.MB()  // 이 부분은 직접 계산해야합니다.
)

val videoUrl = "https://www.learningcontainer.com/wp-content/uploads/2020/05/sample-mp4-file.mp4"
val uri = Uri.parse(videoUrl)
val mediaItem = MediaItem.fromUri(uri)
val mediaSource = ProgressiveMediaSource.Factory(cacheDataSourceFactory).createMediaSource(mediaItem) // <- 이 부분
val simpleExoPlayer = SimpleExoPlayer.Builder(context).build()

simpleExoPlayer.setMediaSource(currentItem?.source!!)
simpleExoPlayer.prepare()
simpleExoPlayer.play()

package com.global.exoplayer

import android.net.Uri
import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import com.google.android.exoplayer2.MediaItem
import com.google.android.exoplayer2.SimpleExoPlayer
import com.google.android.exoplayer2.source.ProgressiveMediaSource
import com.google.android.exoplayer2.ui.PlayerView
import com.google.android.exoplayer2.upstream.DefaultDataSourceFactory
import com.google.android.exoplayer2.util.Util


class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val playerView: PlayerView = findViewById(R.id.player_view)

        // SimpleExoPlayer 인스턴스
        val simpleExoPlayer = SimpleExoPlayer.Builder(this).build()
        playerView.player = simpleExoPlayer // PlayerView에 만들어진 SimpleExoPlayer 인스턴스 바인딩

        // 비디오 URL
        val url = "https://www.learningcontainer.com/wp-content/uploads/2020/05/sample-mp4-file.mp4"

        // MediaItem을 만들고
        val mediaItem = MediaItem.fromUri(Uri.parse(url))

        // MediaSource를 만들고
        val userAgent = Util.getUserAgent(this, this.applicationInfo.name)
        val factory = DefaultDataSourceFactory(this, userAgent)
        val progressiveMediaSource = ProgressiveMediaSource.Factory(factory).createMediaSource(mediaItem)

        // 만들어진 MediaSource를 연결
        simpleExoPlayer.setMediaSource(progressiveMediaSource)

        // Player 준비
        simpleExoPlayer.prepare()

        // Player 재생
        simpleExoPlayer.play()
    }
}

PlayerView.switchTargetView(player 인스턴스, 바꾸기 전 PlayerView, 바꿀 PlayerView)
or
simpleExoPlayer.release()