此页面由 Cloud Translation API 翻译。

图像

ExoPlayer 支持以下图片格式。请参阅图片加载库如何集成外部库，这些库可能为不同的格式

映像格式	支持	备注
BMP	是
GIF	否	不支持提取器
JPEG	是
JPEG 动态照片	是	支持静态图片和视频
JPEG Ultra HDR	是	在 Android 14 或以下版本之前回退到 SDR 非 HDR 显示屏
PNG	是
WebP	是
HEIF/HEIC	是
HEIC 动态照片	部分解决/回答	仅支持静态图片*
AVIF（基准）	是	仅在 Android 14 及更高版本中解码

* HEIC 动态照片的视频部分可通过 MetadataRetriever 并作为独立文件播放

使用 MediaItem

如需播放播放列表中的图片，请使用图片 URI 创建 MediaItem 并将其传递给播放器。MediaItem 必须具有 imageDurationMs 才能用于指定图片的显示时长。

Kotlin

// Create a player instance.
val player = ExoPlayer.Builder(context).build()
// Set the media item to be played with the desired duration.
player.setMediaItem(
    MediaItem.Builder().setUri(imageUri).setImageDurationMs(2000).build())
// Prepare the player.
player.prepare()

Java

// Create a player instance.
ExoPlayer player = new ExoPlayer.Builder(context).build();
// Set the media item to be played with the desired duration.
player.setMediaItem(
    new MediaItem.Builder().setUri(imageUri).setImageDurationMs(2000).build());
// Prepare the player.
player.prepare();

动态照片

动态照片是指将静态图片和短视频合并在一起的文件。

如果使用 setImageDuration 定义图片时长，则动态照片为在声明的时长内以静态图片的形式显示。
如果未定义图片时长，则动态照片将作为视频播放。

使用 ProgressiveMediaSource

如需更多自定义选项，您可以创建 ProgressiveMediaSource 并而是直接将其传递给播放器，而不是 MediaItem。

Kotlin

// Create a data source factory.
val dataSourceFactory = DefaultHttpDataSource.Factory()
// Create a media item with the image URI and the desired duration.
val mediaItem =
    MediaItem.Builder().setUri(imageUri).setImageDurationMs(2000).build()
// Create a progressive media source for this media item.
val mediaSource =
    ProgressiveMediaSource.Factory(dataSourceFactory)
        .createMediaSource(mediaItem)
// Create a player instance.
val player = ExoPlayer.Builder(context).build()
// Set the media source to be played.
player.setMediaSource(mediaSource)
// Prepare the player.
player.prepare()

Java

// Create a data source factory.
DataSource.Factory dataSourceFactory = new DefaultHttpDataSource.Factory();
// Create a media item with the image URI and the desired duration.
MediaItem mediaItem =
    new MediaItem.Builder().setUri(imageUri).setImageDurationMs(2000).build();
// Create a progressive media source for this media item.
MediaSource mediaSource =
    new ProgressiveMediaSource.Factory(dataSourceFactory)
        .createMediaSource(mediaItem);
// Create a player instance.
ExoPlayer player = new ExoPlayer.Builder(context).build();
// Set the media source to be played.
player.setMediaSource(mediaSource);
// Prepare the player.
player.prepare();

自定义播放

ExoPlayer 提供了多种方法，让您可以根据自己的需求量身打造播放体验。应用需求。有关示例，请参阅“自定义”页面。

图片加载库

图片通常由外部图片加载库管理，例如 Glide 或 Coil。

将这些库集成到播放流水线中需要 3 个步骤：

使用 APPLICATION_EXTERNALLY_LOADED_IMAGE MIME 类型定义 MediaItem。
提供图片解码器，以便从图片加载中检索 Bitmap 库。
提供外部加载器以触发缓存和预加载。

具有外部加载的图片 MIME 类型的 MediaItem

添加到 Player 的 MediaItem 必须定义显式使用 APPLICATION_EXTERNALLY_LOADED_IMAGE MIME 类型加载库代码路径：

Kotlin

val mediaItem =
  MediaItem.Builder()
    .setUri(imageUri)
    .setMimeType(MimeTypes.APPLICATION_EXTERNALLY_LOADED_IMAGE)
    .build()

Java

MediaItem mediaItem =
    new MediaItem.Builder()
        .setUri(imageUri)
        .setMimeType(MimeTypes.APPLICATION_EXTERNALLY_LOADED_IMAGE)
        .build();

使用图片加载库的图片解码器

ImageRenderer 使用 ImageDecoder 实例来检索Bitmap 图片 URI。可以将此解码器编写为使用外部图片加载库，如以下示例中的 Glide 所示：

Kotlin

val glideImageDecoder: ImageDecoder =
  object : ImageDecoder {
    private val inputBuffer =
      DecoderInputBuffer(DecoderInputBuffer.BUFFER_REPLACEMENT_MODE_NORMAL)
    private val outputBuffer: ImageOutputBuffer =
      object : ImageOutputBuffer() {
        override fun release() {
          clear()
          bitmap = null
        }
      }
    private var pendingDecode: AtomicBoolean? = null
    private var decodeError: ImageDecoderException? = null

    override fun dequeueInputBuffer(): DecoderInputBuffer? {
      return if (pendingDecode == null) inputBuffer else null
    }

    override fun queueInputBuffer(inputBuffer: DecoderInputBuffer) {
      if (inputBuffer.isEndOfStream) {
        outputBuffer.addFlag(C.BUFFER_FLAG_END_OF_STREAM)
        inputBuffer.clear()
        return
      }
      val currentDecode = AtomicBoolean(true)
      pendingDecode = currentDecode
      val imageUri =
        Uri.parse(
          String(
            inputBuffer.data!!.array(),
            inputBuffer.data!!.position(),
            inputBuffer.data!!.limit() - inputBuffer.data!!.position(),
            Charsets.UTF_8,
          )
        )
      val imageTimeUs = inputBuffer.timeUs
      Glide.with(context)
        .asBitmap()
        .load(imageUri)
        .into(
          object : CustomTarget<Bitmap?>() {
            override fun onResourceReady(
              resource: Bitmap,
              transition: Transition<in Bitmap?>?,
            ) {
              if (currentDecode.get()) {
                outputBuffer.timeUs = imageTimeUs
                outputBuffer.bitmap = resource
                pendingDecode = null
              }
            }

            override fun onLoadFailed(errorDrawable: Drawable?) {
              if (currentDecode.get()) {
                decodeError = ImageDecoderException("Glide load failed")
              }
            }

            override fun onLoadCleared(placeholder: Drawable?) {}
          }
        )
      inputBuffer.clear()
    }

    @Throws(ImageDecoderException::class)
    override fun dequeueOutputBuffer(): ImageOutputBuffer? {
      if (decodeError != null) {
        throw decodeError as ImageDecoderException
      }
      val hasOutput =
        (pendingDecode == null
          && (outputBuffer.bitmap != null || outputBuffer.isEndOfStream))
      return if (hasOutput) outputBuffer else null
    }

    override fun getName(): String {
      return "glideDecoder"
    }

    override fun setOutputStartTimeUs(outputStartTimeUs: Long) {}

    override fun flush() {
      if (pendingDecode != null) {
        pendingDecode!!.set(false)
        pendingDecode = null
      }
      decodeError = null
      inputBuffer.clear()
      outputBuffer.release()
    }

    override fun release() {
      flush()
    }
}
val glideImageDecoderFactory: ImageDecoder.Factory =
  object : ImageDecoder.Factory {
    override fun supportsFormat(format: Format):
        @RendererCapabilities.Capabilities Int {
      val isExternalImageUrl =
        format.sampleMimeType != null &&
          format.sampleMimeType == MimeTypes.APPLICATION_EXTERNALLY_LOADED_IMAGE
      return RendererCapabilities.create(
        if (isExternalImageUrl) C.FORMAT_HANDLED else C.FORMAT_UNSUPPORTED_TYPE
      )
    }

    override fun createImageDecoder(): ImageDecoder {
      return glideImageDecoder
    }
  }
val player: Player =
  ExoPlayer.Builder(context)
    .setRenderersFactory(
      object : DefaultRenderersFactory(context) {
        override fun buildImageRenderers(out: ArrayList<Renderer>) {
          out.add(
            ImageRenderer(glideImageDecoderFactory, /* imageOutput= */ null))
        }
      }
    )
  .build()

Java

ImageDecoder glideImageDecoder =
    new ImageDecoder() {
      private final DecoderInputBuffer inputBuffer =
          new DecoderInputBuffer(BUFFER_REPLACEMENT_MODE_NORMAL);
      private final ImageOutputBuffer outputBuffer =
          new ImageOutputBuffer() {
            @Override
            public void release() {
              clear();
              bitmap = null;
            }
          };
      @Nullable private AtomicBoolean pendingDecode;
      @Nullable private ImageDecoderException decodeError;

      @Nullable
      @Override
      public DecoderInputBuffer dequeueInputBuffer() {
        return pendingDecode == null ? inputBuffer : null;
      }

      @Override
      public void queueInputBuffer(DecoderInputBuffer inputBuffer) {
        if (inputBuffer.isEndOfStream()) {
          outputBuffer.addFlag(C.BUFFER_FLAG_END_OF_STREAM);
          inputBuffer.clear();
          return;
        }
        AtomicBoolean currentDecode = new AtomicBoolean(true);
        pendingDecode = currentDecode;
        Uri imageUri =
            Uri.parse(
                new String(
                    inputBuffer.data.array(),
                    inputBuffer.data.position(),
                    inputBuffer.data.limit() - inputBuffer.data.position(),
                    Charsets.UTF_8));
        long imageTimeUs = inputBuffer.timeUs;
        Glide.with(context)
            .asBitmap()
            .load(imageUri)
            .into(
                new CustomTarget<Bitmap>() {
                  @Override
                  public void onResourceReady(
                      Bitmap resource,
                      @Nullable Transition<? super Bitmap> transition) {
                    if (currentDecode.get()) {
                      outputBuffer.timeUs = imageTimeUs;
                      outputBuffer.bitmap = resource;
                      pendingDecode = null;
                    }
                  }

                  @Override
                  public void onLoadFailed(@Nullable Drawable errorDrawable) {
                    if (currentDecode.get()) {
                      decodeError =
                          new ImageDecoderException("Glide load failed");
                    }
                  }

                  @Override
                  public void onLoadCleared(@Nullable Drawable placeholder) {}
                });
        inputBuffer.clear();
      }

      @Nullable
      @Override
      public ImageOutputBuffer dequeueOutputBuffer()
            throws ImageDecoderException {
        if (decodeError != null) {
          throw decodeError;
        }
        boolean hasOutput =
            pendingDecode == null
              && (outputBuffer.bitmap != null || outputBuffer.isEndOfStream());
        return hasOutput ? outputBuffer : null;
      }

      @Override
      public String getName() {
        return "glideDecoder";
      }

      @Override
      public void setOutputStartTimeUs(long outputStartTimeUs) {}

      @Override
      public void flush() {
        if (pendingDecode != null) {
          pendingDecode.set(false);
          pendingDecode = null;
        }
        decodeError = null;
        inputBuffer.clear();
        outputBuffer.release();
      }

      @Override
      public void release() {
        flush();
      }
    };
ImageDecoder.Factory glideImageDecoderFactory =
    new ImageDecoder.Factory() {
      @Override
      public @RendererCapabilities.Capabilities int supportsFormat(
          Format format) {
        boolean isExternalImageUrl =
            format.sampleMimeType != null
                && format.sampleMimeType.equals(
                    MimeTypes.APPLICATION_EXTERNALLY_LOADED_IMAGE);
        return RendererCapabilities.create(
            isExternalImageUrl ? C.FORMAT_HANDLED : C.FORMAT_UNSUPPORTED_TYPE);
      }

      @Override
      public ImageDecoder createImageDecoder() {
        return glideImageDecoder;
      }
    };
Player player =
    new ExoPlayer.Builder(context)
        .setRenderersFactory(
            new DefaultRenderersFactory(context) {
              @Override
              protected void buildImageRenderers(ArrayList<Renderer> out) {
                out.add(
                    new ImageRenderer(
                        glideImageDecoderFactory, /* imageOutput= */ null));
              }
            })
        .build();

使用图片加载库预加载图片

在播放过程中，播放器会请求预加载下一张图片播放列表中的项已加载完毕。使用外部图片加载时库中，您必须指定 ExternalLoader 才能触发此预加载。如果拒绝可以或要求预加载，仍然需要提供此加载器，什么都做不到。

以下示例使用 Glide 来确保所请求的图片已预加载复制到磁盘：

Kotlin

val glidePreloader = ExternalLoader { request: LoadRequest ->
  GlideFutures.submit(
    Glide.with(context)
      .asFile()
      .apply(
        RequestOptions.diskCacheStrategyOf(DiskCacheStrategy.DATA)
          .priority(Priority.HIGH)
          .skipMemoryCache(true)
      )
      .load(request.uri)
  )
}

Java

ExternalLoader glidePreloader =
    request ->
        GlideFutures.submit(
            Glide.with(context)
                .asFile()
                .apply(
                    diskCacheStrategyOf(DiskCacheStrategy.DATA)
                        .priority(Priority.HIGH)
                        .skipMemoryCache(true))
                .load(request.uri));