/*
* Copyright 2020 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 androidx.media3.transformer;
import static androidx.media3.common.util.Assertions.checkState;
import static androidx.media3.common.util.Util.maxValue;
import static androidx.media3.common.util.Util.minValue;
import android.util.SparseIntArray;
import android.util.SparseLongArray;
import androidx.annotation.Nullable;
import androidx.media3.common.C;
import androidx.media3.common.Format;
import androidx.media3.common.MimeTypes;
import androidx.media3.common.util.Util;
import com.google.common.collect.ImmutableList;
import java.nio.ByteBuffer;
/**
* A wrapper around a media muxer.
*
* <p>This wrapper can contain at most one video track and one audio track.
*/
/* package */ final class MuxerWrapper {
/**
* The maximum difference between the track positions, in microseconds.
*
* <p>The value of this constant has been chosen based on the interleaving observed in a few media
* files, where continuous chunks of the same track were about 0.5 seconds long.
*/
private static final long MAX_TRACK_WRITE_AHEAD_US = Util.msToUs(500);
private final Muxer muxer;
private final Muxer.Factory muxerFactory;
private final SparseIntArray trackTypeToIndex;
private final SparseIntArray trackTypeToSampleCount;
private final SparseLongArray trackTypeToTimeUs;
private final SparseLongArray trackTypeToBytesWritten;
private final String containerMimeType;
private int trackCount;
private int trackFormatCount;
private boolean isReady;
private @C.TrackType int previousTrackType;
private long minTrackTimeUs;
public MuxerWrapper(Muxer muxer, Muxer.Factory muxerFactory, String containerMimeType) {
this.muxer = muxer;
this.muxerFactory = muxerFactory;
this.containerMimeType = containerMimeType;
trackTypeToIndex = new SparseIntArray();
trackTypeToSampleCount = new SparseIntArray();
trackTypeToTimeUs = new SparseLongArray();
trackTypeToBytesWritten = new SparseLongArray();
previousTrackType = C.TRACK_TYPE_NONE;
}
/**
* Registers an output track.
*
* <p>All tracks must be registered before any track format is {@linkplain #addTrackFormat(Format)
* added}.
*
* @throws IllegalStateException If a track format was {@linkplain #addTrackFormat(Format) added}
* before calling this method.
*/
public void registerTrack() {
checkState(
trackFormatCount == 0, "Tracks cannot be registered after track formats have been added.");
trackCount++;
}
/** Returns whether the sample {@linkplain MimeTypes MIME type} is supported. */
public boolean supportsSampleMimeType(@Nullable String mimeType) {
return muxerFactory.supportsSampleMimeType(mimeType, containerMimeType);
}
/**
* Returns the supported {@linkplain MimeTypes MIME types} for the given {@linkplain C.TrackType
* track type}.
*/
public ImmutableList<String> getSupportedSampleMimeTypes(@C.TrackType int trackType) {
return muxerFactory.getSupportedSampleMimeTypes(trackType, containerMimeType);
}
/**
* Adds a track format to the muxer.
*
* <p>The tracks must all be {@linkplain #registerTrack() registered} before any format is added
* and all the formats must be added before samples are {@linkplain #writeSample(int, ByteBuffer,
* boolean, long) written}.
*
* @param format The {@link Format} to be added.
* @throws IllegalStateException If the format is unsupported or if there is already a track
* format of the same type (audio or video).
* @throws Muxer.MuxerException If the underlying muxer encounters a problem while adding the
* track.
*/
public void addTrackFormat(Format format) throws Muxer.MuxerException {
checkState(trackCount > 0, "All tracks should be registered before the formats are added.");
checkState(trackFormatCount < trackCount, "All track formats have already been added.");
@Nullable String sampleMimeType = format.sampleMimeType;
boolean isAudio = MimeTypes.isAudio(sampleMimeType);
boolean isVideo = MimeTypes.isVideo(sampleMimeType);
checkState(isAudio || isVideo, "Unsupported track format: " + sampleMimeType);
@C.TrackType int trackType = MimeTypes.getTrackType(sampleMimeType);
checkState(
trackTypeToIndex.get(trackType, /* valueIfKeyNotFound= */ C.INDEX_UNSET) == C.INDEX_UNSET,
"There is already a track of type " + trackType);
int trackIndex = muxer.addTrack(format);
trackTypeToIndex.put(trackType, trackIndex);
trackTypeToSampleCount.put(trackType, 0);
trackTypeToTimeUs.put(trackType, 0L);
trackTypeToBytesWritten.put(trackType, 0L);
trackFormatCount++;
if (trackFormatCount == trackCount) {
isReady = true;
}
}
/**
* Attempts to write a sample to the muxer.
*
* @param trackType The {@linkplain C.TrackType track type} of the sample.
* @param data The sample to write.
* @param isKeyFrame Whether the sample is a key frame.
* @param presentationTimeUs The presentation time of the sample in microseconds.
* @return Whether the sample was successfully written. This is {@code false} if the muxer hasn't
* {@linkplain #addTrackFormat(Format) received a format} for every {@linkplain
* #registerTrack() registered track}, or if it should write samples of other track types
* first to ensure a good interleaving.
* @throws IllegalStateException If the muxer doesn't have any {@linkplain #endTrack(int)
* non-ended} track of the given track type.
* @throws Muxer.MuxerException If the underlying muxer fails to write the sample.
*/
public boolean writeSample(
@C.TrackType int trackType, ByteBuffer data, boolean isKeyFrame, long presentationTimeUs)
throws Muxer.MuxerException {
int trackIndex = trackTypeToIndex.get(trackType, /* valueIfKeyNotFound= */ C.INDEX_UNSET);
checkState(
trackIndex != C.INDEX_UNSET,
"Could not write sample because there is no track of type " + trackType);
if (!canWriteSampleOfType(trackType)) {
return false;
}
trackTypeToSampleCount.put(trackType, trackTypeToSampleCount.get(trackType) + 1);
trackTypeToBytesWritten.put(
trackType, trackTypeToBytesWritten.get(trackType) + data.remaining());
if (trackTypeToTimeUs.get(trackType) < presentationTimeUs) {
trackTypeToTimeUs.put(trackType, presentationTimeUs);
}
muxer.writeSampleData(trackIndex, data, isKeyFrame, presentationTimeUs);
previousTrackType = trackType;
return true;
}
/**
* Notifies the muxer that all the samples have been {@link #writeSample(int, ByteBuffer, boolean,
* long) written} for a given track.
*
* @param trackType The {@link C.TrackType track type}.
*/
public void endTrack(@C.TrackType int trackType) {
trackTypeToIndex.delete(trackType);
}
/**
* Releases any resources associated with muxing.
*
* <p>The muxer cannot be used anymore once this method has been called.
*
* @param forCancellation Whether the reason for releasing the resources is the transformation
* cancellation.
* @throws Muxer.MuxerException If the underlying muxer fails to stop and to release resources and
* {@code forCancellation} is false.
*/
public void release(boolean forCancellation) throws Muxer.MuxerException {
isReady = false;
muxer.release(forCancellation);
}
/** Returns the number of {@link #registerTrack() registered} tracks. */
public int getTrackCount() {
return trackCount;
}
/**
* Returns the average bitrate of data written to the track of the provided {@code trackType}, or
* {@link C#RATE_UNSET_INT} if there is no track data.
*/
public int getTrackAverageBitrate(@C.TrackType int trackType) {
long trackDurationUs = trackTypeToTimeUs.get(trackType, /* valueIfKeyNotFound= */ -1);
long trackBytes = trackTypeToBytesWritten.get(trackType, /* valueIfKeyNotFound= */ -1);
if (trackDurationUs <= 0 || trackBytes <= 0) {
return C.RATE_UNSET_INT;
}
// The number of bytes written is not a timestamp, however this utility method provides
// overflow-safe multiplication & division.
return (int)
Util.scaleLargeTimestamp(
/* timestamp= */ trackBytes,
/* multiplier= */ C.BITS_PER_BYTE * C.MICROS_PER_SECOND,
/* divisor= */ trackDurationUs);
}
/** Returns the number of samples written to the track of the provided {@code trackType}. */
public int getTrackSampleCount(@C.TrackType int trackType) {
return trackTypeToSampleCount.get(trackType, /* valueIfKeyNotFound= */ 0);
}
/** Returns the duration of the longest track in milliseconds. */
public long getDurationMs() {
return Util.usToMs(maxValue(trackTypeToTimeUs));
}
/**
* Returns whether the muxer can write a sample of the given track type.
*
* @param trackType The track type, defined by the {@code TRACK_TYPE_*} constants in {@link C}.
* @return Whether the muxer can write a sample of the given track type. This is {@code false} if
* the muxer hasn't {@link #addTrackFormat(Format) received a format} for every {@link
* #registerTrack() registered track}, or if it should write samples of other track types
* first to ensure a good interleaving.
* @throws IllegalStateException If the muxer doesn't have any {@link #endTrack(int) non-ended}
* track of the given track type.
*/
private boolean canWriteSampleOfType(int trackType) {
long trackTimeUs = trackTypeToTimeUs.get(trackType, /* valueIfKeyNotFound= */ C.TIME_UNSET);
checkState(trackTimeUs != C.TIME_UNSET);
if (!isReady) {
return false;
}
if (trackTypeToIndex.size() == 1) {
return true;
}
if (trackType != previousTrackType) {
minTrackTimeUs = minValue(trackTypeToTimeUs);
}
return trackTimeUs - minTrackTimeUs <= MAX_TRACK_WRITE_AHEAD_US;
}
}