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;
  
  import android.support.annotation.Nullable;
  import com.google.android.exoplayer2.decoder.DecoderInputBuffer;
  import com.google.android.exoplayer2.drm.DrmInitData;
  import com.google.android.exoplayer2.drm.DrmSessionManager;
  import com.google.android.exoplayer2.source.SampleStream;
  import com.google.android.exoplayer2.util.Assertions;
  import com.google.android.exoplayer2.util.MediaClock;
  import java.io.IOException;
  
  /**
   * An abstract base class suitable for most {@link Renderer} implementations.
   */
  public abstract class BaseRenderer implements Renderer, RendererCapabilities {
  
    private final int trackType;
  
    private RendererConfiguration configuration;
    private int index;
    private int state;
    private SampleStream stream;
    private long streamOffsetUs;
    private boolean readEndOfStream;
    private boolean streamIsFinal;
  
    /**
     * @param trackType The track type that the renderer handles. One of the {@link C}
     * {@code TRACK_TYPE_*} constants.
     */
    public BaseRenderer(int trackType) {
      this.trackType = trackType;
      readEndOfStream = true;
    }
  
    @Override
    public final int getTrackType() {
      return trackType;
    }
  
    @Override
    public final RendererCapabilities getCapabilities() {
      return this;
    }
  
    @Override
    public final void setIndex(int index) {
      this.index = index;
    }
  
    @Override
    public MediaClock getMediaClock() {
      return null;
    }
  
    @Override
    public final int getState() {
      return state;
    }
  
    @Override
    public final void enable(RendererConfiguration configuration, Format[] formats,
        SampleStream stream, long positionUs, boolean joining, long offsetUs)
        throws ExoPlaybackException {
      Assertions.checkState(state == STATE_DISABLED);
      this.configuration = configuration;
      state = STATE_ENABLED;
      onEnabled(joining);
      replaceStream(formats, stream, offsetUs);
      onPositionReset(positionUs, joining);
    }
  
    @Override
    public final void start() throws ExoPlaybackException {
      Assertions.checkState(state == STATE_ENABLED);
      state = STATE_STARTED;
      onStarted();
    }
  
    @Override
    public final void replaceStream(Format[] formats, SampleStream stream, long offsetUs)
        throws ExoPlaybackException {
      Assertions.checkState(!streamIsFinal);
      this.stream = stream;
      readEndOfStream = false;
      streamOffsetUs = offsetUs;
      onStreamChanged(formats, offsetUs);
    }
  
    @Override
    public final SampleStream getStream() {
      return stream;
    }
  
    @Override
    public final boolean hasReadStreamToEnd() {
      return readEndOfStream;
    }
  
    @Override
    public final void setCurrentStreamFinal() {
      streamIsFinal = true;
    }
  
    @Override
    public final boolean isCurrentStreamFinal() {
      return streamIsFinal;
    }
  
    @Override
    public final void maybeThrowStreamError() throws IOException {
      stream.maybeThrowError();
    }
  
    @Override
    public final void resetPosition(long positionUs) throws ExoPlaybackException {
      streamIsFinal = false;
      readEndOfStream = false;
      onPositionReset(positionUs, false);
    }
  
    @Override
    public final void stop() throws ExoPlaybackException {
      Assertions.checkState(state == STATE_STARTED);
      state = STATE_ENABLED;
      onStopped();
    }
  
    @Override
    public final void disable() {
      Assertions.checkState(state == STATE_ENABLED);
      state = STATE_DISABLED;
      stream = null;
      streamIsFinal = false;
      onDisabled();
    }
  
    // RendererCapabilities implementation.
  
    @Override
    public int supportsMixedMimeTypeAdaptation() throws ExoPlaybackException {
      return ADAPTIVE_NOT_SUPPORTED;
    }
  
    // PlayerMessage.Target implementation.
  
    @Override
    public void handleMessage(int what, Object object) throws ExoPlaybackException {
      // Do nothing.
    }
  
    // Methods to be overridden by subclasses.
  
    /**
     * Called when the renderer is enabled.
     * <p>
     * The default implementation is a no-op.
     *
     * @param joining Whether this renderer is being enabled to join an ongoing playback.
     * @throws ExoPlaybackException If an error occurs.
     */
    protected void onEnabled(boolean joining) throws ExoPlaybackException {
      // Do nothing.
    }
  
    /**
     * Called when the renderer's stream has changed. This occurs when the renderer is enabled after
     * {@link #onEnabled(boolean)} has been called, and also when the stream has been replaced whilst
     * the renderer is enabled or started.
     * <p>
     * The default implementation is a no-op.
     *
     * @param formats The enabled formats.
     * @param offsetUs The offset that will be added to the timestamps of buffers read via
     *     {@link #readSource(FormatHolder, DecoderInputBuffer, boolean)} so that decoder input
     *     buffers have monotonically increasing timestamps.
     * @throws ExoPlaybackException If an error occurs.
     */
    protected void onStreamChanged(Format[] formats, long offsetUs) throws ExoPlaybackException {
      // Do nothing.
    }
  
    /**
     * Called when the position is reset. This occurs when the renderer is enabled after
     * {@link #onStreamChanged(Format[], long)} has been called, and also when a position
     * discontinuity is encountered.
     * <p>
     * After a position reset, the renderer's {@link SampleStream} is guaranteed to provide samples
     * starting from a key frame.
     * <p>
     * The default implementation is a no-op.
     *
     * @param positionUs The new playback position in microseconds.
     * @param joining Whether this renderer is being enabled to join an ongoing playback.
     * @throws ExoPlaybackException If an error occurs.
     */
    protected void onPositionReset(long positionUs, boolean joining) throws ExoPlaybackException {
      // Do nothing.
    }
  
    /**
     * Called when the renderer is started.
     * <p>
     * The default implementation is a no-op.
     *
     * @throws ExoPlaybackException If an error occurs.
     */
    protected void onStarted() throws ExoPlaybackException {
      // Do nothing.
    }
  
    /**
     * Called when the renderer is stopped.
     * <p>
     * The default implementation is a no-op.
     *
     * @throws ExoPlaybackException If an error occurs.
     */
    protected void onStopped() throws ExoPlaybackException {
      // Do nothing.
    }
  
    /**
     * Called when the renderer is disabled.
     * <p>
     * The default implementation is a no-op.
     */
    protected void onDisabled() {
      // Do nothing.
    }
  
    // Methods to be called by subclasses.
  
    /**
     * Returns the configuration set when the renderer was most recently enabled.
     */
    protected final RendererConfiguration getConfiguration() {
      return configuration;
    }
  
    /**
     * Returns the index of the renderer within the player.
     */
    protected final int getIndex() {
      return index;
    }
  
    /**
     * Reads from the enabled upstream source. If the upstream source has been read to the end then
     * {@link C#RESULT_BUFFER_READ} is only returned if {@link #setCurrentStreamFinal()} has been
     * called. {@link C#RESULT_NOTHING_READ} is returned otherwise.
     *
     * @param formatHolder A {@link FormatHolder} to populate in the case of reading a format.
     * @param buffer A {@link DecoderInputBuffer} to populate in the case of reading a sample or the
     *     end of the stream. If the end of the stream has been reached, the
     *     {@link C#BUFFER_FLAG_END_OF_STREAM} flag will be set on the buffer.
     * @param formatRequired Whether the caller requires that the format of the stream be read even if
     *     it's not changing. A sample will never be read if set to true, however it is still possible
     *     for the end of stream or nothing to be read.
     * @return The result, which can be {@link C#RESULT_NOTHING_READ}, {@link C#RESULT_FORMAT_READ} or
     *     {@link C#RESULT_BUFFER_READ}.
     */
    protected final int readSource(FormatHolder formatHolder, DecoderInputBuffer buffer,
        boolean formatRequired) {
      int result = stream.readData(formatHolder, buffer, formatRequired);
      if (result == C.RESULT_BUFFER_READ) {
        if (buffer.isEndOfStream()) {
          readEndOfStream = true;
          return streamIsFinal ? C.RESULT_BUFFER_READ : C.RESULT_NOTHING_READ;
        }
        buffer.timeUs += streamOffsetUs;
      } else if (result == C.RESULT_FORMAT_READ) {
        Format format = formatHolder.format;
        if (format.subsampleOffsetUs != Format.OFFSET_SAMPLE_RELATIVE) {
          format = format.copyWithSubsampleOffsetUs(format.subsampleOffsetUs + streamOffsetUs);
          formatHolder.format = format;
        }
      }
      return result;
    }
  
    /**
     * Attempts to skip to the keyframe before the specified position, or to the end of the stream if
     * {@code positionUs} is beyond it.
     *
     * @param positionUs The position in microseconds.
     * @return The number of samples that were skipped.
     */
    protected int skipSource(long positionUs) {
      return stream.skipData(positionUs - streamOffsetUs);
    }
  
    /**
     * Returns whether the upstream source is ready.
     */
    protected final boolean isSourceReady() {
      return readEndOfStream ? streamIsFinal : stream.isReady();
    }
  
    /**
     * Returns whether {@code drmSessionManager} supports the specified {@code drmInitData}, or true
     * if {@code drmInitData} is null.
     *
     * @param drmSessionManager The drm session manager.
     * @param drmInitData {@link DrmInitData} of the format to check for support.
     * @return Whether {@code drmSessionManager} supports the specified {@code drmInitData}, or
     *     true if {@code drmInitData} is null.
     */
    protected static boolean supportsFormatDrm(@Nullable DrmSessionManager<?> drmSessionManager,
        @Nullable DrmInitData drmInitData) {
      if (drmInitData == null) {
        // Content is unencrypted.
        return true;
      } else if (drmSessionManager == null) {
        // Content is encrypted, but no drm session manager is available.
        return false;
      }
      return drmSessionManager.canAcquireSession(drmInitData);
    }
  
  }
  