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Add detection for DTS-HD audio tracks in MatroskaExtractor #2485

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Add detection for DTS-HD audio tracks in MatroskaExtractor #2485

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75 changes: 72 additions & 3 deletions libraries/extractor/src/main/java/androidx/media3/extractor/mkv/MatroskaExtractor.java
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Original file line number Diff line number Diff line change
Expand Up @@ -46,6 +46,7 @@
import androidx.media3.extractor.AacUtil;
import androidx.media3.extractor.AvcConfig;
import androidx.media3.extractor.ChunkIndex;
import androidx.media3.extractor.DtsUtil;
import androidx.media3.extractor.Extractor;
import androidx.media3.extractor.ExtractorInput;
import androidx.media3.extractor.ExtractorOutput;
Expand Down Expand Up @@ -444,6 +445,7 @@ public static ExtractorsFactory newFactory(SubtitleParser.Factory subtitleParser
private long durationTimecode = C.TIME_UNSET;
private long durationUs = C.TIME_UNSET;
private boolean isWebm;
private boolean pendingEndTracks = true;

// The track corresponding to the current TrackEntry element, or null.
@Nullable private Track currentTrack;
Expand Down Expand Up @@ -795,6 +797,23 @@ protected void startMasterElement(int id, long contentPosition, long contentSize
}
}

/**
* Ensures `extractorOutput.endTracks()` gets called only once, and only
* if we don't have any pending audio analysis.
*/
private void maybeEndTracks() {
if (!pendingEndTracks) {
return;
}
for (int i = 0; i < tracks.size(); i++) {
if (tracks.valueAt(i).waitingForDtsAnalysis) {
return;
}
}
extractorOutput.endTracks();
pendingEndTracks = false;
}

/**
* Called when the end of a master element is encountered.
*
Expand Down Expand Up @@ -905,7 +924,7 @@ protected void endMasterElement(int id) throws ParserException {
throw ParserException.createForMalformedContainer(
"No valid tracks were found", /* cause= */ null);
}
extractorOutput.endTracks();
maybeEndTracks();
break;
default:
break;
Expand Down Expand Up @@ -1564,6 +1583,53 @@ private int writeSampleData(ExtractorInput input, Track track, int size, boolean
return finishWriteSampleData();
}

if (track.waitingForDtsAnalysis) {
// The format for this DTS track as not been determined yet
long remaining = input.getLength() - input.getPosition();
// Limit the peek ahead to be up to the max frame size (16383) plus the
// sync word of the second frame
int scanLength = (int)Math.min(16383 + 95, remaining);
byte[] buf = new byte[scanLength];

input.advancePeekPosition(0);
input.peekFully(buf, 0, buf.length);
input.resetPeekPosition();

final ByteBuffer bb = ByteBuffer.wrap(buf);
for (int idx = 0; idx + 4 <= buf.length; idx += 4) {
int word = bb.getInt(idx);

if (DtsUtil.getFrameType(word) == DtsUtil.FRAME_TYPE_CORE) {
if (idx + 10 > buf.length) {
break;
}

bb.mark();
bb.position(idx);
byte[] header = new byte[10];
bb.get(header);
bb.reset();
int fsize = DtsUtil.getDtsFrameSize(header);
if (fsize <= 0 || idx + fsize + 4 > buf.length) {
break;
}

word = bb.getInt(idx + fsize);

if (DtsUtil.getFrameType(word) == DtsUtil.FRAME_TYPE_EXTENSION_SUBSTREAM) {
track.formatBuilder.setSampleMimeType(MimeTypes.AUDIO_DTS_HD);
track.output.format(track.formatBuilder.build());
}

// After finding a valid DTS core frame we can break the loop, there is no
// need to evaluate the rest of the buffer.
break;
}
}
track.waitingForDtsAnalysis = false;
maybeEndTracks();
}

TrackOutput output = track.output;
if (!sampleEncodingHandled) {
if (track.hasContentEncryption) {
Expand Down Expand Up @@ -2135,6 +2201,7 @@ protected static final class Track {
public long codecDelayNs = 0;
public long seekPreRollNs = 0;
public @MonotonicNonNull TrueHdSampleRechunker trueHdSampleRechunker;
public boolean waitingForDtsAnalysis = false;

// Text elements.
public boolean flagForced;
Expand All @@ -2143,6 +2210,7 @@ protected static final class Track {

// Set when the output is initialized. nalUnitLengthFieldLength is only set for H264/H265.
public @MonotonicNonNull TrackOutput output;
public Format.Builder formatBuilder;
public int nalUnitLengthFieldLength;

/** Initializes the track with an output. */
Expand Down Expand Up @@ -2246,7 +2314,8 @@ public void initializeOutput(ExtractorOutput output, int trackId) throws ParserE
break;
case CODEC_ID_DTS:
case CODEC_ID_DTS_EXPRESS:
mimeType = MimeTypes.AUDIO_DTS;
mimeType = MimeTypes.AUDIO_DTS; // temporary
waitingForDtsAnalysis = true;
break;
case CODEC_ID_DTS_LOSSLESS:
mimeType = MimeTypes.AUDIO_DTS_HD;
Expand Down Expand Up @@ -2369,7 +2438,7 @@ public void initializeOutput(ExtractorOutput output, int trackId) throws ParserE
selectionFlags |= flagForced ? C.SELECTION_FLAG_FORCED : 0;

int type;
Format.Builder formatBuilder = new Format.Builder();
formatBuilder = new Format.Builder();
// TODO: Consider reading the name elements of the tracks and, if present, incorporating them
// into the trackId passed when creating the formats.
if (MimeTypes.isAudio(mimeType)) {
Expand Down