NekoX/TMessagesProj/src/main/java/com/google/android/exoplayer2/Renderer.java

307 lines
12 KiB
Java

/*
* 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 androidx.annotation.IntDef;
import androidx.annotation.Nullable;
import com.google.android.exoplayer2.source.SampleStream;
import com.google.android.exoplayer2.util.MediaClock;
import java.io.IOException;
import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
/**
* Renders media read from a {@link SampleStream}.
*
* <p>Internally, a renderer's lifecycle is managed by the owning {@link ExoPlayer}. The renderer is
* transitioned through various states as the overall playback state and enabled tracks change. The
* valid state transitions are shown below, annotated with the methods that are called during each
* transition.
*
* <p style="align:center"><img src="doc-files/renderer-states.svg" alt="Renderer state
* transitions">
*/
public interface Renderer extends PlayerMessage.Target {
/**
* The renderer states. One of {@link #STATE_DISABLED}, {@link #STATE_ENABLED} or {@link
* #STATE_STARTED}.
*/
@Documented
@Retention(RetentionPolicy.SOURCE)
@IntDef({STATE_DISABLED, STATE_ENABLED, STATE_STARTED})
@interface State {}
/**
* The renderer is disabled. A renderer in this state may hold resources that it requires for
* rendering (e.g. media decoders), for use if it's subsequently enabled. {@link #reset()} can be
* called to force the renderer to release these resources.
*/
int STATE_DISABLED = 0;
/**
* The renderer is enabled but not started. A renderer in this state may render media at the
* current position (e.g. an initial video frame), but the position will not advance. A renderer
* in this state will typically hold resources that it requires for rendering (e.g. media
* decoders).
*/
int STATE_ENABLED = 1;
/**
* The renderer is started. Calls to {@link #render(long, long)} will cause media to be rendered.
*/
int STATE_STARTED = 2;
/**
* Returns the track type that the {@link Renderer} handles. For example, a video renderer will
* return {@link C#TRACK_TYPE_VIDEO}, an audio renderer will return {@link C#TRACK_TYPE_AUDIO}, a
* text renderer will return {@link C#TRACK_TYPE_TEXT}, and so on.
*
* @return One of the {@code TRACK_TYPE_*} constants defined in {@link C}.
*/
int getTrackType();
/**
* Returns the capabilities of the renderer.
*
* @return The capabilities of the renderer.
*/
RendererCapabilities getCapabilities();
/**
* Sets the index of this renderer within the player.
*
* @param index The renderer index.
*/
void setIndex(int index);
/**
* If the renderer advances its own playback position then this method returns a corresponding
* {@link MediaClock}. If provided, the player will use the returned {@link MediaClock} as its
* source of time during playback. A player may have at most one renderer that returns a {@link
* MediaClock} from this method.
*
* @return The {@link MediaClock} tracking the playback position of the renderer, or null.
*/
@Nullable
MediaClock getMediaClock();
/**
* Returns the current state of the renderer.
*
* @return The current state. One of {@link #STATE_DISABLED}, {@link #STATE_ENABLED} and {@link
* #STATE_STARTED}.
*/
@State
int getState();
/**
* Enables the renderer to consume from the specified {@link SampleStream}.
* <p>
* This method may be called when the renderer is in the following states:
* {@link #STATE_DISABLED}.
*
* @param configuration The renderer configuration.
* @param formats The enabled formats.
* @param stream The {@link SampleStream} from which the renderer should consume.
* @param positionUs The player's current position.
* @param joining Whether this renderer is being enabled to join an ongoing playback.
* @param offsetUs The offset to be added to timestamps of buffers read from {@code stream}
* before they are rendered.
* @throws ExoPlaybackException If an error occurs.
*/
void enable(RendererConfiguration configuration, Format[] formats, SampleStream stream,
long positionUs, boolean joining, long offsetUs) throws ExoPlaybackException;
/**
* Starts the renderer, meaning that calls to {@link #render(long, long)} will cause media to be
* rendered.
* <p>
* This method may be called when the renderer is in the following states:
* {@link #STATE_ENABLED}.
*
* @throws ExoPlaybackException If an error occurs.
*/
void start() throws ExoPlaybackException;
/**
* Replaces the {@link SampleStream} from which samples will be consumed.
* <p>
* This method may be called when the renderer is in the following states:
* {@link #STATE_ENABLED}, {@link #STATE_STARTED}.
*
* @param formats The enabled formats.
* @param stream The {@link SampleStream} from which the renderer should consume.
* @param offsetUs The offset to be added to timestamps of buffers read from {@code stream} before
* they are rendered.
* @throws ExoPlaybackException If an error occurs.
*/
void replaceStream(Format[] formats, SampleStream stream, long offsetUs)
throws ExoPlaybackException;
/** Returns the {@link SampleStream} being consumed, or null if the renderer is disabled. */
@Nullable
SampleStream getStream();
/**
* Returns whether the renderer has read the current {@link SampleStream} to the end.
* <p>
* This method may be called when the renderer is in the following states:
* {@link #STATE_ENABLED}, {@link #STATE_STARTED}.
*/
boolean hasReadStreamToEnd();
/**
* Returns the playback position up to which the renderer has read samples from the current {@link
* SampleStream}, in microseconds, or {@link C#TIME_END_OF_SOURCE} if the renderer has read the
* current {@link SampleStream} to the end.
*
* <p>This method may be called when the renderer is in the following states: {@link
* #STATE_ENABLED}, {@link #STATE_STARTED}.
*/
long getReadingPositionUs();
/**
* Signals to the renderer that the current {@link SampleStream} will be the final one supplied
* before it is next disabled or reset.
* <p>
* This method may be called when the renderer is in the following states:
* {@link #STATE_ENABLED}, {@link #STATE_STARTED}.
*/
void setCurrentStreamFinal();
/**
* Returns whether the current {@link SampleStream} will be the final one supplied before the
* renderer is next disabled or reset.
*/
boolean isCurrentStreamFinal();
/**
* Throws an error that's preventing the renderer from reading from its {@link SampleStream}. Does
* nothing if no such error exists.
* <p>
* This method may be called when the renderer is in the following states:
* {@link #STATE_ENABLED}, {@link #STATE_STARTED}.
*
* @throws IOException An error that's preventing the renderer from making progress or buffering
* more data.
*/
void maybeThrowStreamError() throws IOException;
/**
* Signals to the renderer that a position discontinuity has occurred.
* <p>
* After a position discontinuity, the renderer's {@link SampleStream} is guaranteed to provide
* samples starting from a key frame.
* <p>
* This method may be called when the renderer is in the following states:
* {@link #STATE_ENABLED}, {@link #STATE_STARTED}.
*
* @param positionUs The new playback position in microseconds.
* @throws ExoPlaybackException If an error occurs handling the reset.
*/
void resetPosition(long positionUs) throws ExoPlaybackException;
/**
* Sets the operating rate of this renderer, where 1 is the default rate, 2 is twice the default
* rate, 0.5 is half the default rate and so on. The operating rate is a hint to the renderer of
* the speed at which playback will proceed, and may be used for resource planning.
*
* <p>The default implementation is a no-op.
*
* @param operatingRate The operating rate.
* @throws ExoPlaybackException If an error occurs handling the operating rate.
*/
default void setOperatingRate(float operatingRate) throws ExoPlaybackException {}
/**
* Incrementally renders the {@link SampleStream}.
* <p>
* If the renderer is in the {@link #STATE_ENABLED} state then each call to this method will do
* work toward being ready to render the {@link SampleStream} when the renderer is started. It may
* also render the very start of the media, for example the first frame of a video stream. If the
* renderer is in the {@link #STATE_STARTED} state then calls to this method will render the
* {@link SampleStream} in sync with the specified media positions.
* <p>
* This method should return quickly, and should not block if the renderer is unable to make
* useful progress.
* <p>
* This method may be called when the renderer is in the following states:
* {@link #STATE_ENABLED}, {@link #STATE_STARTED}.
*
* @param positionUs The current media time in microseconds, measured at the start of the
* current iteration of the rendering loop.
* @param elapsedRealtimeUs {@link android.os.SystemClock#elapsedRealtime()} in microseconds,
* measured at the start of the current iteration of the rendering loop.
* @throws ExoPlaybackException If an error occurs.
*/
void render(long positionUs, long elapsedRealtimeUs) throws ExoPlaybackException;
/**
* Whether the renderer is able to immediately render media from the current position.
* <p>
* If the renderer is in the {@link #STATE_STARTED} state then returning true indicates that the
* renderer has everything that it needs to continue playback. Returning false indicates that
* the player should pause until the renderer is ready.
* <p>
* If the renderer is in the {@link #STATE_ENABLED} state then returning true indicates that the
* renderer is ready for playback to be started. Returning false indicates that it is not.
* <p>
* This method may be called when the renderer is in the following states:
* {@link #STATE_ENABLED}, {@link #STATE_STARTED}.
*
* @return Whether the renderer is ready to render media.
*/
boolean isReady();
/**
* Whether the renderer is ready for the {@link ExoPlayer} instance to transition to
* {@link Player#STATE_ENDED}. The player will make this transition as soon as {@code true} is
* returned by all of its {@link Renderer}s.
* <p>
* This method may be called when the renderer is in the following states:
* {@link #STATE_ENABLED}, {@link #STATE_STARTED}.
*
* @return Whether the renderer is ready for the player to transition to the ended state.
*/
boolean isEnded();
/**
* Stops the renderer, transitioning it to the {@link #STATE_ENABLED} state.
* <p>
* This method may be called when the renderer is in the following states:
* {@link #STATE_STARTED}.
*
* @throws ExoPlaybackException If an error occurs.
*/
void stop() throws ExoPlaybackException;
/**
* Disable the renderer, transitioning it to the {@link #STATE_DISABLED} state.
* <p>
* This method may be called when the renderer is in the following states:
* {@link #STATE_ENABLED}.
*/
void disable();
/**
* Forces the renderer to give up any resources (e.g. media decoders) that it may be holding. If
* the renderer is not holding any resources, the call is a no-op.
*
* <p>This method may be called when the renderer is in the following states: {@link
* #STATE_DISABLED}.
*/
void reset();
}