Code changes suggested by tonihei

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

@@ -83,12 +83,6 @@ public final class Cea608Decoder extends CeaDecoder {
 
  private static final byte CTRL_BACKSPACE = 0x21;
 
- @SuppressWarnings("unused")
- private static final byte CTRL_ALARM_OFF= 0x22; // not supported any more
-
- @SuppressWarnings("unused")
- private static final byte CTRL_ALARM_ON= 0x23; // not supported any more
-
  private static final byte CTRL_DELETE_TO_END_OF_ROW = 0x24;
 
  /**
@@ -258,7 +252,7 @@ public final class Cea608Decoder extends CeaDecoder {
  // The incoming characters may belong to 3 different services based on the last received control
  // codes. The 3 services are Captioning, Text and XDS. In this decoder we only intend to process
  // bytes belonging to the Captioning service.
- private boolean isInCaptionMode = true;
+ private boolean isInCaptionMode;
 
  public Cea608Decoder(String mimeType, int accessibilityChannel) {
  ccData = new ParsableByteArray();
@@ -291,6 +285,7 @@ public Cea608Decoder(String mimeType, int accessibilityChannel) {
 
  setCaptionMode(CC_MODE_UNKNOWN);
  resetCueBuilders();
+ isInCaptionMode = true;
  }
 
  @Override
@@ -330,23 +325,28 @@ protected Subtitle createSubtitle() {
  return new CeaSubtitle(cues);
  }
 
- private boolean isCodeForUnsupportedMode(byte cc1, byte cc2) {
+ private static boolean isCodeForUnsupportedMode(byte cc1, byte cc2) {
  // Control codes from 0x01 to 0x0F indicate the beginning of XDS Data
  if (0x01 <= cc1 && cc1 <= 0x0F) {
  return true;
  }
 
  // 2 commands switch to TEXT mode.
- if (((cc1 & 0xF7) == 0x14) // first byte must be 0x14 or 0x1C based on channel
+ if ((isModeSwitchCommand(cc1))
  && (cc2 == CTRL_TEXT_RESTART || cc2 == CTRL_RESUME_TEXT_DISPLAY)) {
  return true;
  }
 
  return false;
  }
 
+ // first byte of these commands must be 0x14 or 0x1C based on channel
+ private static boolean isModeSwitchCommand(byte cc1) {
+ return (cc1 & 0xF7) == 0x14;
+ }
+
  private static boolean isControlCodeSwitchingToCaptionMode(byte cc1, byte cc2) {
- if ((cc1 & 0xF7) != 0x14) { // Matching commands must have the CC1 value: 0|0|0|1|CH|1|0|0 where CH is the channel bit
+ if (!isModeSwitchCommand(cc1)) {
  return false;
  }