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Fix Ac3 extractor sniffing for E-AC-3 frames

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-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=213443047
This commit is contained in:
aquilescanta 2018-09-18 07:02:47 -07:00 committed by Oliver Woodman
parent a92344ac9e
commit bca2f5c3a0
2 changed files with 20 additions and 10 deletions
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26
library/core/src/main/java/com/google/android/exoplayer2/audio/Ac3Util.java
View File

@ -27,7 +27,10 @@ import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.nio.ByteBuffer;
/** Utility methods for parsing Dolby TrueHD and (E-)AC3 syncframes. */
/**
* Utility methods for parsing Dolby TrueHD and (E-)AC-3 syncframes. (E-)AC-3 parsing follows the
* definition in ETSI TS 102 366 V1.2.1.
*/
public final class Ac3Util {
/** Holds sample format information as presented by a syncframe header. */
@ -237,7 +240,7 @@ public final class Ac3Util {
public static SyncFrameInfo parseAc3SyncframeInfo(ParsableBitArray data) {
int initialPosition = data.getPosition();
data.skipBits(40);
boolean isEac3 = data.readBits(5) == 16;
boolean isEac3 = data.readBits(5) == 16; // See bsid in subsection E.1.3.1.6.
data.setPosition(initialPosition);
String mimeType;
@StreamType int streamType = SyncFrameInfo.STREAM_TYPE_UNDEFINED;
@ -265,7 +268,7 @@ public final class Ac3Util {
break;
}
data.skipBits(3); // substreamid
frameSize = (data.readBits(11) + 1) * 2;
frameSize = (data.readBits(11) + 1) * 2; // See frmsiz in subsection E.1.3.1.3.
int fscod = data.readBits(2);
int audioBlocks;
int numblkscod;
@ -451,18 +454,25 @@ public final class Ac3Util {
}
/**
* Returns the size in bytes of the given AC-3 syncframe.
* Returns the size in bytes of the given (E-)AC-3 syncframe.
*
* @param data The syncframe to parse.
* @return The syncframe size in bytes. {@link C#LENGTH_UNSET} if the input is invalid.
*/
public static int parseAc3SyncframeSize(byte[] data) {
if (data.length < 5) {
if (data.length < 6) {
return C.LENGTH_UNSET;
}
int fscod = (data[4] & 0xC0) >> 6;
int frmsizecod = data[4] & 0x3F;
return getAc3SyncframeSize(fscod, frmsizecod);
boolean isEac3 = ((data[5] & 0xFF) >> 3) == 16; // See bsid in subsection E.1.3.1.6.
if (isEac3) {
int frmsiz = (data[2] & 0x07) << 8; // Most significant 3 bits.
frmsiz |= data[3] & 0xFF; // Least significant 8 bits.
return (frmsiz + 1) * 2; // See frmsiz in subsection E.1.3.1.3.
} else {
int fscod = (data[4] & 0xC0) >> 6;
int frmsizecod = data[4] & 0x3F;
return getAc3SyncframeSize(fscod, frmsizecod);
}
}
/**

4
library/core/src/main/java/com/google/android/exoplayer2/extractor/ts/Ac3Extractor.java
View File

@ -85,7 +85,7 @@ public final class Ac3Extractor implements Extractor {
int headerPosition = startPosition;
int validFramesCount = 0;
while (true) {
input.peekFully(scratch.data, 0, 5);
input.peekFully(scratch.data, 0, 6);
scratch.setPosition(0);
int syncBytes = scratch.readUnsignedShort();
if (syncBytes != AC3_SYNC_WORD) {
@ -103,7 +103,7 @@ public final class Ac3Extractor implements Extractor {
if (frameSize == C.LENGTH_UNSET) {
return false;
}
input.advancePeekPosition(frameSize - 5);
input.advancePeekPosition(frameSize - 6);
}
}
}