content: /*
   * Copyright (C) 2016 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package com.google.android.exoplayer2.ext.ffmpeg;
  
  import static com.google.android.exoplayer2.audio.AudioSink.SINK_FORMAT_SUPPORTED_DIRECTLY;
  import static com.google.android.exoplayer2.audio.AudioSink.SINK_FORMAT_SUPPORTED_WITH_TRANSCODING;
  import static com.google.android.exoplayer2.audio.AudioSink.SINK_FORMAT_UNSUPPORTED;
  
  import android.os.Handler;
  import androidx.annotation.Nullable;
  import com.google.android.exoplayer2.C;
  import com.google.android.exoplayer2.Format;
  import com.google.android.exoplayer2.audio.AudioProcessor;
  import com.google.android.exoplayer2.audio.AudioRendererEventListener;
  import com.google.android.exoplayer2.audio.AudioSink;
  import com.google.android.exoplayer2.audio.AudioSink.SinkFormatSupport;
  import com.google.android.exoplayer2.audio.DecoderAudioRenderer;
  import com.google.android.exoplayer2.audio.DefaultAudioSink;
  import com.google.android.exoplayer2.decoder.CryptoConfig;
  import com.google.android.exoplayer2.util.Assertions;
  import com.google.android.exoplayer2.util.MimeTypes;
  import com.google.android.exoplayer2.util.TraceUtil;
  import com.google.android.exoplayer2.util.Util;
  
  /** Decodes and renders audio using FFmpeg. */
  public final class FfmpegAudioRenderer extends DecoderAudioRenderer<FfmpegAudioDecoder> {
  
    private static final String TAG = "FfmpegAudioRenderer";
  
    /** The number of input and output buffers. */
    private static final int NUM_BUFFERS = 16;
    /** The default input buffer size. */
    private static final int DEFAULT_INPUT_BUFFER_SIZE = 960 * 6;
  
    public FfmpegAudioRenderer() {
      this(/* eventHandler= */ null, /* eventListener= */ null);
    }
  
    /**
     * Creates a new instance.
     *
     * @param eventHandler A handler to use when delivering events to {@code eventListener}. May be
     *     null if delivery of events is not required.
     * @param eventListener A listener of events. May be null if delivery of events is not required.
     * @param audioProcessors Optional {@link AudioProcessor}s that will process audio before output.
     */
    public FfmpegAudioRenderer(
        @Nullable Handler eventHandler,
        @Nullable AudioRendererEventListener eventListener,
        AudioProcessor... audioProcessors) {
      this(
          eventHandler,
          eventListener,
          new DefaultAudioSink.Builder().setAudioProcessors(audioProcessors).build());
    }
  
    /**
     * Creates a new instance.
     *
     * @param eventHandler A handler to use when delivering events to {@code eventListener}. May be
     *     null if delivery of events is not required.
     * @param eventListener A listener of events. May be null if delivery of events is not required.
     * @param audioSink The sink to which audio will be output.
     */
    public FfmpegAudioRenderer(
        @Nullable Handler eventHandler,
        @Nullable AudioRendererEventListener eventListener,
        AudioSink audioSink) {
      super(eventHandler, eventListener, audioSink);
    }
  
    @Override
    public String getName() {
      return TAG;
    }
  
    @Override
    protected @C.FormatSupport int supportsFormatInternal(Format format) {
      String mimeType = Assertions.checkNotNull(format.sampleMimeType);
      if (!FfmpegLibrary.isAvailable() || !MimeTypes.isAudio(mimeType)) {
        return C.FORMAT_UNSUPPORTED_TYPE;
      } else if (!FfmpegLibrary.supportsFormat(mimeType)
          || (!sinkSupportsFormat(format, C.ENCODING_PCM_16BIT)
              && !sinkSupportsFormat(format, C.ENCODING_PCM_FLOAT))) {
        return C.FORMAT_UNSUPPORTED_SUBTYPE;
      } else if (format.cryptoType != C.CRYPTO_TYPE_NONE) {
        return C.FORMAT_UNSUPPORTED_DRM;
      } else {
        return C.FORMAT_HANDLED;
      }
    }
  
    @Override
    public @AdaptiveSupport int supportsMixedMimeTypeAdaptation() {
      return ADAPTIVE_NOT_SEAMLESS;
    }
  
    /** {@inheritDoc} */
    @Override
    protected FfmpegAudioDecoder createDecoder(Format format, @Nullable CryptoConfig cryptoConfig)
        throws FfmpegDecoderException {
      TraceUtil.beginSection("createFfmpegAudioDecoder");
      int initialInputBufferSize =
          format.maxInputSize != Format.NO_VALUE ? format.maxInputSize : DEFAULT_INPUT_BUFFER_SIZE;
      FfmpegAudioDecoder decoder =
          new FfmpegAudioDecoder(
              format, NUM_BUFFERS, NUM_BUFFERS, initialInputBufferSize, shouldOutputFloat(format));
      TraceUtil.endSection();
      return decoder;
    }
  
    /** {@inheritDoc} */
    @Override
    protected Format getOutputFormat(FfmpegAudioDecoder decoder) {
      Assertions.checkNotNull(decoder);
      return new Format.Builder()
          .setSampleMimeType(MimeTypes.AUDIO_RAW)
          .setChannelCount(decoder.getChannelCount())
          .setSampleRate(decoder.getSampleRate())
          .setPcmEncoding(decoder.getEncoding())
          .build();
    }
  
    /**
     * Returns whether the renderer's {@link AudioSink} supports the PCM format that will be output
     * from the decoder for the given input format and requested output encoding.
     */
    private boolean sinkSupportsFormat(Format inputFormat, @C.PcmEncoding int pcmEncoding) {
      return sinkSupportsFormat(
          Util.getPcmFormat(pcmEncoding, inputFormat.channelCount, inputFormat.sampleRate));
    }
  
    private boolean shouldOutputFloat(Format inputFormat) {
      if (!sinkSupportsFormat(inputFormat, C.ENCODING_PCM_16BIT)) {
        // We have no choice because the sink doesn't support 16-bit integer PCM.
        return true;
      }
  
      @SinkFormatSupport
      int formatSupport =
          getSinkFormatSupport(
              Util.getPcmFormat(
                  C.ENCODING_PCM_FLOAT, inputFormat.channelCount, inputFormat.sampleRate));
      switch (formatSupport) {
        case SINK_FORMAT_SUPPORTED_DIRECTLY:
          // AC-3 is always 16-bit, so there's no point using floating point. Assume that it's worth
          // using for all other formats.
          return !MimeTypes.AUDIO_AC3.equals(inputFormat.sampleMimeType);
        case SINK_FORMAT_UNSUPPORTED:
        case SINK_FORMAT_SUPPORTED_WITH_TRANSCODING:
        default:
          // Always prefer 16-bit PCM if the sink does not provide direct support for floating point.
          return false;
      }
    }
  }
  