diff --git a/RELEASENOTES.md b/RELEASENOTES.md index b87e86decf..38ef32bd10 100644 --- a/RELEASENOTES.md +++ b/RELEASENOTES.md @@ -93,6 +93,10 @@ that contained Binder objects` error when using `DefaultExtractorsFactory.setTextTrackTranscodingEnabled` ([#836](https://github.com/androidx/media/issues/836)). + * CEA-708: Ignore `rowLock` value. The CEA-708-E S-2023 spec states that + `rowLock` and `columnLock` should both be assumed to be true, regardless + of the values present in the stream (`columnLock` support is not + implemented, so it's effectively assumed to always be false). * Metadata: * Fix bug where `MediaMetadata` was only populated from Vorbis comments with upper-case keys diff --git a/libraries/extractor/src/main/java/androidx/media3/extractor/text/cea/Cea708Parser.java b/libraries/extractor/src/main/java/androidx/media3/extractor/text/cea/Cea708Parser.java index f11b176e5b..dc7b43b670 100644 --- a/libraries/extractor/src/main/java/androidx/media3/extractor/text/cea/Cea708Parser.java +++ b/libraries/extractor/src/main/java/androidx/media3/extractor/text/cea/Cea708Parser.java @@ -786,8 +786,11 @@ public final class Cea708Parser implements SubtitleParser { // first byte captionChannelPacketData.skipBits(2); // null padding boolean visible = captionChannelPacketData.readBit(); - boolean rowLock = captionChannelPacketData.readBit(); - boolean columnLock = captionChannelPacketData.readBit(); + + // ANSI/CTA-708-E S-2023 spec (Section 8.4.7) indicates that rowLock and columnLock values in + // the media should be ignored and assumed to be true. + captionChannelPacketData.skipBits(2); + int priority = captionChannelPacketData.readBits(3); // second byte boolean relativePositioning = captionChannelPacketData.readBit(); @@ -799,7 +802,8 @@ public final class Cea708Parser implements SubtitleParser { int rowCount = captionChannelPacketData.readBits(4); // fifth byte captionChannelPacketData.skipBits(2); // null padding - int columnCount = captionChannelPacketData.readBits(6); + // TODO: Add support for column count. + captionChannelPacketData.skipBits(6); // column count // sixth byte captionChannelPacketData.skipBits(2); // null padding int windowStyle = captionChannelPacketData.readBits(3); @@ -807,14 +811,11 @@ public final class Cea708Parser implements SubtitleParser { cueInfoBuilder.defineWindow( visible, - rowLock, - columnLock, priority, relativePositioning, verticalAnchor, horizontalAnchor, rowCount, - columnCount, anchorId, windowStyle, penStyle); @@ -975,7 +976,6 @@ public final class Cea708Parser implements SubtitleParser { private int horizontalAnchor; private int anchorId; private int rowCount; - private boolean rowLock; private int justification; private int windowStyleId; private int penStyleId; @@ -1011,7 +1011,6 @@ public final class Cea708Parser implements SubtitleParser { horizontalAnchor = 0; anchorId = 0; rowCount = MAXIMUM_ROW_COUNT; - rowLock = true; justification = JUSTIFICATION_LEFT; windowStyleId = 0; penStyleId = 0; @@ -1045,20 +1044,16 @@ public final class Cea708Parser implements SubtitleParser { public void defineWindow( boolean visible, - boolean rowLock, - boolean columnLock, int priority, boolean relativePositioning, int verticalAnchor, int horizontalAnchor, int rowCount, - int columnCount, int anchorId, int windowStyleId, int penStyleId) { this.defined = true; this.visible = visible; - this.rowLock = rowLock; this.priority = priority; this.relativePositioning = relativePositioning; this.verticalAnchor = verticalAnchor; @@ -1070,14 +1065,12 @@ public final class Cea708Parser implements SubtitleParser { this.rowCount = rowCount + 1; // Trim any rolled up captions that are no longer valid, if applicable. - while ((rowLock && (rolledUpCaptions.size() >= this.rowCount)) + while ((rolledUpCaptions.size() >= this.rowCount) || (rolledUpCaptions.size() >= MAXIMUM_ROW_COUNT)) { rolledUpCaptions.remove(0); } } - // TODO: Add support for column lock and count. - if (windowStyleId != 0 && this.windowStyleId != windowStyleId) { this.windowStyleId = windowStyleId; // windowStyleId is 1-based. @@ -1239,7 +1232,7 @@ public final class Cea708Parser implements SubtitleParser { backgroundColorStartPosition = 0; } - while ((rowLock && (rolledUpCaptions.size() >= rowCount)) + while ((rolledUpCaptions.size() >= rowCount) || (rolledUpCaptions.size() >= MAXIMUM_ROW_COUNT)) { rolledUpCaptions.remove(0); } diff --git a/libraries/extractor/src/test/java/androidx/media3/extractor/text/cea/Cea708ParserTest.java b/libraries/extractor/src/test/java/androidx/media3/extractor/text/cea/Cea708ParserTest.java index 3910fa0093..802d41cba0 100644 --- a/libraries/extractor/src/test/java/androidx/media3/extractor/text/cea/Cea708ParserTest.java +++ b/libraries/extractor/src/test/java/androidx/media3/extractor/text/cea/Cea708ParserTest.java @@ -115,6 +115,40 @@ public class Cea708ParserTest { .isEqualTo("test subtitle"); } + @Test + public void singleServiceAndWindowDefinition_ignoreRowLock() throws Exception { + Cea708Parser cea708Parser = + new Cea708Parser( + /* accessibilityChannel= */ Format.NO_VALUE, /* initializationData= */ null); + byte[] windowDefinition = + TestUtil.createByteArray( + 0x98, // DF0 command (define window 0) + 0b0010_0000, // visible=true, row lock and column lock disabled, priority=0 + 0xF0 | 50, // relative positioning, anchor vertical + 50, // anchor horizontal + 1, // anchor point = 0, row count = 1 + 30, // column count = 30 + 0b0000_1001); // window style = 1, pen style = 1 + byte[] setCurrentWindow = TestUtil.createByteArray(0x80); // CW0 (set current window to 0) + byte[] subtitleData = + encodePacketIntoBytePairs( + createPacket( + /* sequenceNumber= */ 0, + createServiceBlock( + Bytes.concat( + windowDefinition, + setCurrentWindow, + "row1\r\nrow2\r\nrow3\r\nrow4".getBytes(Charsets.UTF_8))))); + + List result = new ArrayList<>(); + cea708Parser.parse(subtitleData, SubtitleParser.OutputOptions.allCues(), result::add); + + // Row count is 1 (which means 2 rows should be kept). Row lock is disabled in the media, + // but this is ignored and the result is still truncated to only the last two rows. + assertThat(Iterables.getOnlyElement(Iterables.getOnlyElement(result).cues).text.toString()) + .isEqualTo("row3\nrow4"); + } + /** See section 4.4.1 of the CEA-708-B spec. */ private static byte[] encodePacketIntoBytePairs(byte[] packet) { checkState(packet.length % 2 == 0);