Merge pull request #5807 from zsmatyas:dev-v2

PiperOrigin-RevId: 246132620

RELEASENOTES.md

@@ -2,8 +2,11 @@
 
 ### dev-v2 (not yet released) ###
 
-* Decoders: prefer codecs that advertise format support over ones that do not,
- even if they are listed lower in the `MediaCodecList`.
+* Decoders:
+ * Prefer codecs that advertise format support over ones that do not, even if
+ they are listed lower in the `MediaCodecList`.
+ * CEA-608: Handle XDS and TEXT modes
+ ([5807](https:/google/ExoPlayer/pull/5807)).
 * Audio: fix an issue where not all audio was played out when the configuration
  for the underlying track was changing (e.g., at some period transitions).
 * UI: Change playback controls toggle from touch down to touch up events

library/core/src/main/java/com/google/android/exoplayer2/text/cea/Cea608Decoder.java

@@ -80,6 +80,11 @@ public final class Cea608Decoder extends CeaDecoder {
  * at which point the non-displayed memory becomes the displayed memory (and vice versa).
  */
  private static final byte CTRL_RESUME_CAPTION_LOADING = 0x20;
+
+ private static final byte CTRL_BACKSPACE = 0x21;
+
+ private static final byte CTRL_DELETE_TO_END_OF_ROW = 0x24;
+
  /**
  * Command initiating roll-up style captioning, with the maximum of 2 rows displayed
  * simultaneously.
@@ -95,25 +100,31 @@ public final class Cea608Decoder extends CeaDecoder {
  * simultaneously.
  */
  private static final byte CTRL_ROLL_UP_CAPTIONS_4_ROWS = 0x27;
+
  /**
  * Command initiating paint-on style captioning. Subsequent data should be addressed immediately
  * to displayed memory without need for the {@link #CTRL_RESUME_CAPTION_LOADING} command.
  */
  private static final byte CTRL_RESUME_DIRECT_CAPTIONING = 0x29;
  /**
- * Command indicating the end of a pop-on style caption. At this point the caption loaded in
- * non-displayed memory should be swapped with the one in displayed memory. If no
- * {@link #CTRL_RESUME_CAPTION_LOADING} command has been received, this command forces the
- * receiver into pop-on style.
+ * TEXT commands are switching to TEXT service. All consecutive incoming data must be filtered out
+ * until a command is received that switches back to the CAPTION service.
  */
- private static final byte CTRL_END_OF_CAPTION = 0x2F;
+ private static final byte CTRL_TEXT_RESTART = 0x2A;
+
+ private static final byte CTRL_RESUME_TEXT_DISPLAY = 0x2B;
 
  private static final byte CTRL_ERASE_DISPLAYED_MEMORY = 0x2C;
  private static final byte CTRL_CARRIAGE_RETURN = 0x2D;
  private static final byte CTRL_ERASE_NON_DISPLAYED_MEMORY = 0x2E;
- private static final byte CTRL_DELETE_TO_END_OF_ROW = 0x24;
 
- private static final byte CTRL_BACKSPACE = 0x21;
+ /**
+ * Command indicating the end of a pop-on style caption. At this point the caption loaded in
+ * non-displayed memory should be swapped with the one in displayed memory. If no {@link
+ * #CTRL_RESUME_CAPTION_LOADING} command has been received, this command forces the receiver into
+ * pop-on style.
+ */
+ private static final byte CTRL_END_OF_CAPTION = 0x2F;
 
  // Basic North American 608 CC char set, mostly ASCII. Indexed by (char-0x20).
  private static final int[] BASIC_CHARACTER_SET = new int[] {
@@ -237,6 +248,11 @@ public final class Cea608Decoder extends CeaDecoder {
  private byte repeatableControlCc2;
  private int currentChannel;
 
+ // The incoming characters may belong to 3 different services based on the last received control
+ // codes. The 3 services are Captioning, Text and XDS. The decoder only processes Captioning
+ // service bytes and drops the rest.
+ private boolean isInCaptionService;
+
  public Cea608Decoder(String mimeType, int accessibilityChannel) {
  ccData = new ParsableByteArray();
  cueBuilders = new ArrayList<>();
@@ -268,6 +284,7 @@ public Cea608Decoder(String mimeType, int accessibilityChannel) {
 
  setCaptionMode(CC_MODE_UNKNOWN);
  resetCueBuilders();
+ isInCaptionService = true;
  }
 
  @Override
@@ -288,6 +305,7 @@ public void flush() {
  repeatableControlCc1 = 0;
  repeatableControlCc2 = 0;
  currentChannel = NTSC_CC_CHANNEL_1;
+ isInCaptionService = true;
  }
 
  @Override
@@ -363,6 +381,12 @@ protected void decode(SubtitleInputBuffer inputBuffer) {
  continue;
  }
 
+ maybeUpdateIsInCaptionService(ccData1, ccData2);
+ if (!isInCaptionService) {
+ // Only the Captioning service is supported. Drop all other bytes.
+ continue;
+ }
+
  // Special North American character set.
  // ccData1 - 0|0|0|1|C|0|0|1
  // ccData2 - 0|0|1|1|X|X|X|X
@@ -629,6 +653,29 @@ private void resetCueBuilders() {
  cueBuilders.add(currentCueBuilder);
  }
 
+ private void maybeUpdateIsInCaptionService(byte cc1, byte cc2) {
+ if (isXdsControlCode(cc1)) {
+ isInCaptionService = false;
+ } else if (isServiceSwitchCommand(cc1)) {
+ switch (cc2) {
+ case CTRL_TEXT_RESTART:
+ case CTRL_RESUME_TEXT_DISPLAY:
+ isInCaptionService = false;
+ break;
+ case CTRL_END_OF_CAPTION:
+ case CTRL_RESUME_CAPTION_LOADING:
+ case CTRL_RESUME_DIRECT_CAPTIONING:
+ case CTRL_ROLL_UP_CAPTIONS_2_ROWS:
+ case CTRL_ROLL_UP_CAPTIONS_3_ROWS:
+ case CTRL_ROLL_UP_CAPTIONS_4_ROWS:
+ isInCaptionService = true;
+ break;
+ default:
+ // No update.
+ }
+ }
+ }
+
  private static char getChar(byte ccData) {
  int index = (ccData & 0x7F) - 0x20;
  return (char) BASIC_CHARACTER_SET[index];
@@ -683,6 +730,15 @@ private static boolean isRepeatable(byte cc1) {
  return (cc1 & 0xF0) == 0x10;
  }
 
+ private static boolean isXdsControlCode(byte cc1) {
+ return 0x01 <= cc1 && cc1 <= 0x0F;
+ }
+
+ private static boolean isServiceSwitchCommand(byte cc1) {
+ // cc1 - 0|0|0|1|C|1|0|0
+ return (cc1 & 0xF7) == 0x14;
+ }
+
  private static class CueBuilder {
 
  // 608 captions define a 15 row by 32 column screen grid. These constants convert from 608