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Rework OPUS comment header parsing

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Simplify how the comment header is parsed and eliminate a few possible
bugs in the process, such as:
- Metadata being overwritten directly by the comments header.
- The packet being rewound to 0 if it cannot find a comment header,
which might result in the cursor being moved to a bad position.
This commit is contained in:
OxygenCobalt 2022-01-17 09:09:01 -07:00
parent 84c9d290bb
commit b9191615ee
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GPG key ID: 37DBE3621FE9AD47
1 changed files with 48 additions and 33 deletions
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81
library/extractor/src/main/java/com/google/android/exoplayer2/extractor/ogg/OpusReader.java
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@ -20,9 +20,11 @@ import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
import androidx.annotation.Nullable;
import com.google.android.exoplayer2.Format;
import com.google.android.exoplayer2.ParserException;
import com.google.android.exoplayer2.audio.OpusUtil;
import com.google.android.exoplayer2.extractor.VorbisUtil;
import com.google.android.exoplayer2.metadata.Metadata;
import com.google.android.exoplayer2.util.Log;
import com.google.android.exoplayer2.util.MimeTypes;
import com.google.android.exoplayer2.util.ParsableByteArray;
@ -34,18 +36,20 @@ import org.checkerframework.checker.nullness.qual.EnsuresNonNullIf;
/** {@link StreamReader} to extract Opus data out of Ogg byte stream. */
/* package */ final class OpusReader extends StreamReader {
private static final byte[] OPUS_ID_SIGNATURE = {'O', 'p', 'u', 's', 'H', 'e', 'a', 'd'};
private static final byte[] OPUS_TAG_SIGNATURE = {'O', 'p', 'u', 's', 'T', 'a', 'g', 's'};
private static final byte[] OPUS_ID_HEADER_SIGNATURE =
{'O', 'p', 'u', 's', 'H', 'e', 'a', 'd'};
private static final byte[] OPUS_COMMENT_HEADER_SIGNATURE =
{'O', 'p', 'u', 's', 'T', 'a', 'g', 's'};
private boolean headerRead;
public static boolean verifyBitstreamType(ParsableByteArray data) {
if (data.bytesLeft() < OPUS_ID_SIGNATURE.length) {
if (data.bytesLeft() < OPUS_ID_HEADER_SIGNATURE.length) {
return false;
}
byte[] header = new byte[OPUS_ID_SIGNATURE.length];
data.readBytes(header, 0, OPUS_ID_SIGNATURE.length);
return Arrays.equals(header, OPUS_ID_SIGNATURE);
byte[] header = new byte[OPUS_ID_HEADER_SIGNATURE.length];
data.readBytes(header, 0, OPUS_ID_HEADER_SIGNATURE.length);
return Arrays.equals(header, OPUS_ID_HEADER_SIGNATURE);
}
@Override
@ -80,40 +84,51 @@ import org.checkerframework.checker.nullness.qual.EnsuresNonNullIf;
headerRead = true;
return true;
} else {
checkNotNull(setupData.format); // Has been set when the header was read.
checkNotNull(setupData.format); // Has been set when the header was read
// Handle the comments frame if we are working with one.
boolean isComment;
int startPosition = packet.getPosition();
if (packet.bytesLeft() < OPUS_TAG_SIGNATURE.length) {
isComment = false;
} else {
byte[] header = new byte[OPUS_TAG_SIGNATURE.length];
packet.readBytes(header, 0, OPUS_TAG_SIGNATURE.length);
isComment = Arrays.equals(header, OPUS_TAG_SIGNATURE);
}
if (isComment) {
VorbisUtil.CommentHeader commentHeader = VorbisUtil.readVorbisCommentHeader(
packet, false, false);
@Nullable Metadata vorbisMetadata = VorbisUtil.buildMetadata(
Arrays.asList(commentHeader.comments)
);
setupData.format = setupData.format
.buildUpon()
.setMetadata(vorbisMetadata)
.build();
return true;
} else {
packet.setPosition(0);
if (!validateCommentHeaderSignature(packet)) {
packet.setPosition(startPosition);
return false;
}
VorbisUtil.CommentHeader commentHeader = VorbisUtil.readVorbisCommentHeader(
packet, false, false);
@Nullable Metadata vorbisMetadata = VorbisUtil.buildMetadata(
Arrays.asList(commentHeader.comments)
);
setupData.format = setupData.format
.buildUpon()
.setMetadata(
setupData.format.metadata != null
? setupData.format.metadata.copyWithAppendedEntriesFrom(vorbisMetadata)
: vorbisMetadata)
.build();
return true;
}
}
/**
* Validates that the given scratch signifies a comment header.
*
* @param scratch The packet data
* @return True if the packet signifies a comment header, false if not
*/
private boolean validateCommentHeaderSignature(ParsableByteArray scratch) {
if (scratch.bytesLeft() < OPUS_COMMENT_HEADER_SIGNATURE.length) {
return false;
}
byte[] header = new byte[OPUS_COMMENT_HEADER_SIGNATURE.length];
scratch.readBytes(header, 0, OPUS_COMMENT_HEADER_SIGNATURE.length);
return Arrays.equals(header, OPUS_COMMENT_HEADER_SIGNATURE);
}
/**
* Returns the duration of the given audio packet.
*