1 /*
2  * Copyright (C) 2015 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.usbtuner.cc;
18 
19 import android.os.SystemClock;
20 import android.support.annotation.IntDef;
21 import android.util.Log;
22 import android.util.SparseIntArray;
23 
24 import com.android.usbtuner.data.Cea708Data;
25 import com.android.usbtuner.data.Cea708Data.CaptionColor;
26 import com.android.usbtuner.data.Cea708Data.CaptionEvent;
27 import com.android.usbtuner.data.Cea708Data.CaptionPenAttr;
28 import com.android.usbtuner.data.Cea708Data.CaptionPenColor;
29 import com.android.usbtuner.data.Cea708Data.CaptionPenLocation;
30 import com.android.usbtuner.data.Cea708Data.CaptionWindow;
31 import com.android.usbtuner.data.Cea708Data.CaptionWindowAttr;
32 import com.android.usbtuner.data.Cea708Data.CcPacket;
33 import com.android.usbtuner.util.ByteArrayBuffer;
34 
35 import java.io.UnsupportedEncodingException;
36 import java.lang.annotation.Retention;
37 import java.lang.annotation.RetentionPolicy;
38 import java.nio.ByteBuffer;
39 import java.nio.charset.StandardCharsets;
40 import java.util.Arrays;
41 import java.util.TreeSet;
42 
43 /**
44  * A class for parsing CEA-708, which is the standard for closed captioning for ATSC DTV.
45  *
46  * <p>ATSC DTV closed caption data are carried on picture user data of video streams.
47  * This class starts to parse from picture user data payload, so extraction process of user_data
48  * from video streams is up to outside of this code.
49  *
50  * <p>There are 4 steps to decode user_data to provide closed caption services.
51  *
52  * <h3>Step 1. user_data -&gt; CcPacket ({@link #parseClosedCaption} method)</h3>
53  *
54  * <p>First, user_data consists of cc_data packets, which are 3-byte segments. Here, CcPacket is a
55  * collection of cc_data packets in a frame along with same presentation timestamp. Because cc_data
56  * packets must be reassembled in the frame display order, CcPackets are reordered.
57  *
58  * <h3>Step 2. CcPacket -&gt; DTVCC packet ({@link #parseCcPacket} method)</h3>
59  *
60  * <p>Each cc_data packet has a one byte for declaring a type of itself and data validity, and the
61  * subsequent two bytes for input data of a DTVCC packet. There are 4 types for cc_data packet.
62  * We're interested in DTVCC_PACKET_START(type 3) and DTVCC_PACKET_DATA(type 2). Each DTVCC packet
63  * begins with DTVCC_PACKET_START(type 3) and the following cc_data packets which has
64  * DTVCC_PACKET_DATA(type 2) are appended into the DTVCC packet being assembled.
65  *
66  * <h3>Step 3. DTVCC packet -&gt; Service Blocks ({@link #parseDtvCcPacket} method)</h3>
67  *
68  * <p>A DTVCC packet consists of multiple service blocks. Each service block represents a caption
69  * track and has a service number, which ranges from 1 to 63, that denotes caption track identity.
70  * In here, we listen at most one chosen caption track by {@link #mListenServiceNumber}.
71  * Otherwise, just skip the other service blocks.
72  *
73  * <h3>Step 4. Interpreting Service Block Data ({@link #parseServiceBlockData}, {@code parseXX},
74  * and {@link #parseExt1} methods)</h3>
75  *
76  * <p>Service block data is actual caption stream. it looks similar to telnet. It uses most parts of
77  * ASCII table and consists of specially defined commands and some ASCII control codes which work
78  * in a behavior slightly different from their original purpose. ASCII control codes and caption
79  * commands are explicit instructions that control the state of a closed caption service and the
80  * other ASCII and text codes are implicit instructions that send their characters to buffer.
81  *
82  * <p>There are 4 main code groups and 4 extended code groups. Both the range of code groups are the
83  * same as the range of a byte.
84  *
85  * <p>4 main code groups: C0, C1, G0, G1
86  * <br>4 extended code groups: C2, C3, G2, G3
87  *
88  * <p>Each code group has its own handle method. For example, {@link #parseC0} handles C0 code group
89  * and so on. And {@link #parseServiceBlockData} method maps a stream on the main code groups while
90  * {@link #parseExt1} method maps on the extended code groups.
91  *
92  * <p>The main code groups:
93  * <ul>
94  * <li>C0 - contains modified ASCII control codes. It is not intended by CEA-708 but Korea TTA
95  *      standard for ATSC CC uses P16 character heavily, which is unclear entity in CEA-708 doc,
96  *      even for the alphanumeric characters instead of ASCII characters.</li>
97  * <li>C1 - contains the caption commands. There are 3 categories of a caption command.</li>
98  * <ul>
99  * <li>Window commands: The window commands control a caption window which is addressable area being
100  *                  with in the Safe title area. (CWX, CLW, DSW, HDW, TGW, DLW, SWA, DFX)</li>
101  * <li>Pen commands: Th pen commands control text style and location. (SPA, SPC, SPL)</li>
102  * <li>Job commands: The job commands make a delay and recover from the delay. (DLY, DLC, RST)</li>
103  * </ul>
104  * <li>G0 - same as printable ASCII character set except music note character.</li>
105  * <li>G1 - same as ISO 8859-1 Latin 1 character set.</li>
106  * </ul>
107  * <p>Most of the extended code groups are being skipped.
108  *
109  */
110 public class Cea708Parser {
111     private static final String TAG = "Cea708Parser";
112     private static final boolean DEBUG = false;
113 
114     // According to CEA-708B, the maximum value of closed caption bandwidth is 9600bps.
115     private static final int MAX_ALLOCATED_SIZE = 9600 / 8;
116     private static final String MUSIC_NOTE_CHAR = new String(
117             "\u266B".getBytes(StandardCharsets.UTF_8), StandardCharsets.UTF_8);
118 
119     // The following values are denoting the type of closed caption data.
120     // See CEA-708B section 4.4.1.
121     private static final int CC_TYPE_DTVCC_PACKET_START = 3;
122     private static final int CC_TYPE_DTVCC_PACKET_DATA = 2;
123 
124     // The following values are defined in CEA-708B Figure 4 and 6.
125     private static final int DTVCC_MAX_PACKET_SIZE = 64;
126     private static final int DTVCC_PACKET_SIZE_SCALE_FACTOR = 2;
127     private static final int DTVCC_EXTENDED_SERVICE_NUMBER_POINT = 7;
128 
129     // The following values are for seeking closed caption tracks.
130     private static final int DISCOVERY_PERIOD_MS = 10000; // 10 sec
131     private static final int DISCOVERY_NUM_BYTES_THRESHOLD = 10; // 10 bytes
132     private static final int DISCOVERY_CC_SERVICE_NUMBER_START = 1; // CC1
133     private static final int DISCOVERY_CC_SERVICE_NUMBER_END = 4; // CC4
134 
135     private final ByteArrayBuffer mDtvCcPacket = new ByteArrayBuffer(MAX_ALLOCATED_SIZE);
136     private final TreeSet<CcPacket> mCcPackets = new TreeSet<>();
137     private final StringBuffer mBuffer = new StringBuffer();
138     private final SparseIntArray mDiscoveredNumBytes = new SparseIntArray(); // per service number
139     private long mLastDiscoveryLaunchedMs = SystemClock.elapsedRealtime();
140     private int mCommand = 0;
141     private int mListenServiceNumber = 0;
142     private boolean mDtvCcPacking = false;
143 
144     // Assign a dummy listener in order to avoid null checks.
145     private OnCea708ParserListener mListener = new OnCea708ParserListener() {
146         @Override
147         public void emitEvent(CaptionEvent event) {
148             // do nothing
149         }
150 
151         @Override
152         public void discoverServiceNumber(int serviceNumber) {
153             // do nothing
154         }
155     };
156 
157     /**
158      * {@link Cea708Parser} emits caption event of three different types.
159      * {@link OnCea708ParserListener#emitEvent} is invoked with the parameter
160      * {@link CaptionEvent} to pass all the results to an observer of the decoding process.
161      *
162      * <p>{@link CaptionEvent#type} determines the type of the result and
163      * {@link CaptionEvent#obj} contains the output value of a caption event.
164      * The observer must do the casting to the corresponding type.
165      *
166      * <ul><li>{@code CAPTION_EMIT_TYPE_BUFFER}: Passes a caption text buffer to a observer.
167      * {@code obj} must be of {@link String}.</li>
168      *
169      * <li>{@code CAPTION_EMIT_TYPE_CONTROL}: Passes a caption character control code to a observer.
170      * {@code obj} must be of {@link Character}.</li>
171      *
172      * <li>{@code CAPTION_EMIT_TYPE_CLEAR_COMMAND}: Passes a clear command to a observer.
173      * {@code obj} must be {@code NULL}.</li></ul>
174      */
175     @IntDef({CAPTION_EMIT_TYPE_BUFFER, CAPTION_EMIT_TYPE_CONTROL, CAPTION_EMIT_TYPE_COMMAND_CWX,
176         CAPTION_EMIT_TYPE_COMMAND_CLW, CAPTION_EMIT_TYPE_COMMAND_DSW, CAPTION_EMIT_TYPE_COMMAND_HDW,
177         CAPTION_EMIT_TYPE_COMMAND_TGW, CAPTION_EMIT_TYPE_COMMAND_DLW, CAPTION_EMIT_TYPE_COMMAND_DLY,
178         CAPTION_EMIT_TYPE_COMMAND_DLC, CAPTION_EMIT_TYPE_COMMAND_RST, CAPTION_EMIT_TYPE_COMMAND_SPA,
179         CAPTION_EMIT_TYPE_COMMAND_SPC, CAPTION_EMIT_TYPE_COMMAND_SPL, CAPTION_EMIT_TYPE_COMMAND_SWA,
180         CAPTION_EMIT_TYPE_COMMAND_DFX})
181     @Retention(RetentionPolicy.SOURCE)
182     public @interface CaptionEmitType {}
183     public static final int CAPTION_EMIT_TYPE_BUFFER = 1;
184     public static final int CAPTION_EMIT_TYPE_CONTROL = 2;
185     public static final int CAPTION_EMIT_TYPE_COMMAND_CWX = 3;
186     public static final int CAPTION_EMIT_TYPE_COMMAND_CLW = 4;
187     public static final int CAPTION_EMIT_TYPE_COMMAND_DSW = 5;
188     public static final int CAPTION_EMIT_TYPE_COMMAND_HDW = 6;
189     public static final int CAPTION_EMIT_TYPE_COMMAND_TGW = 7;
190     public static final int CAPTION_EMIT_TYPE_COMMAND_DLW = 8;
191     public static final int CAPTION_EMIT_TYPE_COMMAND_DLY = 9;
192     public static final int CAPTION_EMIT_TYPE_COMMAND_DLC = 10;
193     public static final int CAPTION_EMIT_TYPE_COMMAND_RST = 11;
194     public static final int CAPTION_EMIT_TYPE_COMMAND_SPA = 12;
195     public static final int CAPTION_EMIT_TYPE_COMMAND_SPC = 13;
196     public static final int CAPTION_EMIT_TYPE_COMMAND_SPL = 14;
197     public static final int CAPTION_EMIT_TYPE_COMMAND_SWA = 15;
198     public static final int CAPTION_EMIT_TYPE_COMMAND_DFX = 16;
199 
200     public interface OnCea708ParserListener {
emitEvent(CaptionEvent event)201         void emitEvent(CaptionEvent event);
discoverServiceNumber(int serviceNumber)202         void discoverServiceNumber(int serviceNumber);
203     }
204 
setListener(OnCea708ParserListener listener)205     public void setListener(OnCea708ParserListener listener) {
206         if (listener != null) {
207             mListener = listener;
208         }
209     }
210 
setListenServiceNumber(int serviceNumber)211     public void setListenServiceNumber(int serviceNumber) {
212         mListenServiceNumber = serviceNumber;
213     }
214 
emitCaptionEvent(CaptionEvent captionEvent)215     private void emitCaptionEvent(CaptionEvent captionEvent) {
216         // Emit the existing string buffer before a new event is arrived.
217         emitCaptionBuffer();
218         mListener.emitEvent(captionEvent);
219     }
220 
emitCaptionBuffer()221     private void emitCaptionBuffer() {
222         if (mBuffer.length() > 0) {
223             mListener.emitEvent(new CaptionEvent(CAPTION_EMIT_TYPE_BUFFER, mBuffer.toString()));
224             mBuffer.setLength(0);
225         }
226     }
227 
228     // Step 1. user_data -> CcPacket ({@link #parseClosedCaption} method)
parseClosedCaption(ByteBuffer data, long framePtsUs)229     public void parseClosedCaption(ByteBuffer data, long framePtsUs) {
230         int ccCount = data.limit() / 3;
231         byte[] ccBytes = new byte[3 * ccCount];
232         for (int i = 0; i < 3 * ccCount; i++) {
233             ccBytes[i] = data.get(i);
234         }
235         CcPacket ccPacket = new CcPacket(ccBytes, ccCount, framePtsUs);
236         mCcPackets.add(ccPacket);
237     }
238 
processClosedCaptions(long framePtsUs)239     public boolean processClosedCaptions(long framePtsUs) {
240         // To get the sorted cc packets that have lower frame pts than current frame pts,
241         // the following offset divides off the lower side of the packets.
242         CcPacket offsetPacket = new CcPacket(new byte[0], 0, framePtsUs);
243         offsetPacket = mCcPackets.lower(offsetPacket);
244         boolean processed = false;
245         if (offsetPacket != null) {
246             while (!mCcPackets.isEmpty() && offsetPacket.compareTo(mCcPackets.first()) >= 0) {
247                 CcPacket packet = mCcPackets.pollFirst();
248                 parseCcPacket(packet);
249                 processed = true;
250             }
251         }
252         return processed;
253     }
254 
255     // Step 2. CcPacket -> DTVCC packet ({@link #parseCcPacket} method)
parseCcPacket(CcPacket ccPacket)256     private void parseCcPacket(CcPacket ccPacket) {
257         // For the details of cc packet, see ATSC TSG-676 - Table A8.
258         byte[] bytes = ccPacket.bytes;
259         int pos = 0;
260         for (int i = 0; i < ccPacket.ccCount; ++i) {
261             boolean ccValid = (bytes[pos] & 0x04) != 0;
262             int ccType = bytes[pos] & 0x03;
263 
264             // The dtvcc should be considered complete:
265             // - if either ccValid is set and ccType is 3
266             // - or ccValid is clear and ccType is 2 or 3.
267             if (ccValid) {
268                 if (ccType == CC_TYPE_DTVCC_PACKET_START) {
269                     if (mDtvCcPacking) {
270                         parseDtvCcPacket(mDtvCcPacket.buffer(), mDtvCcPacket.length());
271                         mDtvCcPacket.clear();
272                     }
273                     mDtvCcPacking = true;
274                     mDtvCcPacket.append(bytes[pos + 1]);
275                     mDtvCcPacket.append(bytes[pos + 2]);
276                 } else if (mDtvCcPacking && ccType == CC_TYPE_DTVCC_PACKET_DATA) {
277                     mDtvCcPacket.append(bytes[pos + 1]);
278                     mDtvCcPacket.append(bytes[pos + 2]);
279                 }
280             } else {
281                 if ((ccType == CC_TYPE_DTVCC_PACKET_START || ccType == CC_TYPE_DTVCC_PACKET_DATA)
282                         && mDtvCcPacking) {
283                     mDtvCcPacking = false;
284                     parseDtvCcPacket(mDtvCcPacket.buffer(), mDtvCcPacket.length());
285                     mDtvCcPacket.clear();
286                 }
287             }
288             pos += 3;
289         }
290     }
291 
292     // Step 3. DTVCC packet -> Service Blocks ({@link #parseDtvCcPacket} method)
parseDtvCcPacket(byte[] data, int limit)293     private void parseDtvCcPacket(byte[] data, int limit) {
294         // For the details of DTVCC packet, see CEA-708B Figure 4.
295         int pos = 0;
296         int packetSize = data[pos] & 0x3f;
297         if (packetSize == 0) {
298             packetSize = DTVCC_MAX_PACKET_SIZE;
299         }
300         int calculatedPacketSize = packetSize * DTVCC_PACKET_SIZE_SCALE_FACTOR;
301         if (limit != calculatedPacketSize) {
302             return;
303         }
304         ++pos;
305         int len = pos + calculatedPacketSize;
306         while (pos < len) {
307             // For the details of Service Block, see CEA-708B Figure 5 and 6.
308             int serviceNumber = (data[pos] & 0xe0) >> 5;
309             int blockSize = data[pos] & 0x1f;
310             ++pos;
311             if (serviceNumber == DTVCC_EXTENDED_SERVICE_NUMBER_POINT) {
312                 serviceNumber = (data[pos] & 0x3f);
313                 ++pos;
314 
315                 // Return if invalid service number
316                 if (serviceNumber < DTVCC_EXTENDED_SERVICE_NUMBER_POINT) {
317                     return;
318                 }
319             }
320             if (pos + blockSize > limit) {
321                 return;
322             }
323 
324             // Send parsed service number in order to find unveiled closed caption tracks which
325             // are not specified in any ATSC PSIP sections. Since some broadcasts send empty closed
326             // caption tracks, it detects the proper closed caption tracks by counting the number of
327             // bytes sent with the same service number during a discovery period.
328             // The viewer in most TV sets chooses between CC1, CC2, CC3, CC4 to view different
329             // language captions. Therefore, only CC1, CC2, CC3, CC4 are allowed to be reported.
330             if (blockSize > 0 && serviceNumber >= DISCOVERY_CC_SERVICE_NUMBER_START
331                     && serviceNumber <= DISCOVERY_CC_SERVICE_NUMBER_END) {
332                 mDiscoveredNumBytes.put(
333                         serviceNumber, blockSize + mDiscoveredNumBytes.get(serviceNumber, 0));
334             }
335             if (mLastDiscoveryLaunchedMs + DISCOVERY_PERIOD_MS < SystemClock.elapsedRealtime()) {
336                 for (int i = 0; i < mDiscoveredNumBytes.size(); ++i) {
337                     int discoveredNumBytes = mDiscoveredNumBytes.valueAt(i);
338                     if (discoveredNumBytes >= DISCOVERY_NUM_BYTES_THRESHOLD) {
339                         int discoveredServiceNumber = mDiscoveredNumBytes.keyAt(i);
340                         mListener.discoverServiceNumber(discoveredServiceNumber);
341                     }
342                 }
343                 mDiscoveredNumBytes.clear();
344                 mLastDiscoveryLaunchedMs = SystemClock.elapsedRealtime();
345             }
346 
347             // Skip current service block if either there is no block data or the service number
348             // is not same as listening service number.
349             if (blockSize == 0 || serviceNumber != mListenServiceNumber) {
350                 pos += blockSize;
351                 continue;
352             }
353 
354             // From this point, starts to read DTVCC coding layer.
355             // First, identify code groups, which is defined in CEA-708B Section 7.1.
356             int blockLimit = pos + blockSize;
357             while (pos < blockLimit) {
358                 pos = parseServiceBlockData(data, pos);
359             }
360 
361             // Emit the buffer after reading codes.
362             emitCaptionBuffer();
363             pos = blockLimit;
364         }
365     }
366 
367     // Step 4. Main code groups
parseServiceBlockData(byte[] data, int pos)368     private int parseServiceBlockData(byte[] data, int pos) {
369         // For the details of the ranges of DTVCC code groups, see CEA-708B Table 6.
370         mCommand = data[pos] & 0xff;
371         ++pos;
372         if (mCommand == Cea708Data.CODE_C0_EXT1) {
373             pos = parseExt1(data, pos);
374         } else if (mCommand >= Cea708Data.CODE_C0_RANGE_START
375                 && mCommand <= Cea708Data.CODE_C0_RANGE_END) {
376             pos = parseC0(data, pos);
377         } else if (mCommand >= Cea708Data.CODE_C1_RANGE_START
378                 && mCommand <= Cea708Data.CODE_C1_RANGE_END) {
379             pos = parseC1(data, pos);
380         } else if (mCommand >= Cea708Data.CODE_G0_RANGE_START
381                 && mCommand <= Cea708Data.CODE_G0_RANGE_END) {
382             pos = parseG0(data, pos);
383         } else if (mCommand >= Cea708Data.CODE_G1_RANGE_START
384                 && mCommand <= Cea708Data.CODE_G1_RANGE_END) {
385             pos = parseG1(data, pos);
386         }
387         return pos;
388     }
389 
parseC0(byte[] data, int pos)390     private int parseC0(byte[] data, int pos) {
391         // For the details of C0 code group, see CEA-708B Section 7.4.1.
392         // CL Group: C0 Subset of ASCII Control codes
393         if (mCommand >= Cea708Data.CODE_C0_SKIP2_RANGE_START
394                 && mCommand <= Cea708Data.CODE_C0_SKIP2_RANGE_END) {
395             if (mCommand == Cea708Data.CODE_C0_P16) {
396                 // TODO : P16 escapes next two bytes for the large character maps.(no standard rule)
397                 // TODO : For korea broadcasting, express whole letters by using this.
398                 try {
399                     if (data[pos] == 0) {
400                         mBuffer.append((char) data[pos + 1]);
401                     } else {
402                         String value = new String(
403                                 Arrays.copyOfRange(data, pos, pos + 2),
404                                 "EUC-KR");
405                         mBuffer.append(value);
406                     }
407                 } catch (UnsupportedEncodingException e) {
408                     Log.e(TAG, "P16 Code - Could not find supported encoding", e);
409                 }
410             }
411             pos += 2;
412         } else if (mCommand >= Cea708Data.CODE_C0_SKIP1_RANGE_START
413                 && mCommand <= Cea708Data.CODE_C0_SKIP1_RANGE_END) {
414             ++pos;
415         } else {
416             // NUL, BS, FF, CR interpreted as they are in ASCII control codes.
417             // HCR moves the pen location to th beginning of the current line and deletes contents.
418             // FF clears the screen and moves the pen location to (0,0).
419             // ETX is the NULL command which is used to flush text to the current window when no
420             // other command is pending.
421             switch (mCommand) {
422                 case Cea708Data.CODE_C0_NUL:
423                     break;
424                 case Cea708Data.CODE_C0_ETX:
425                     emitCaptionEvent(new CaptionEvent(CAPTION_EMIT_TYPE_CONTROL, (char) mCommand));
426                     break;
427                 case Cea708Data.CODE_C0_BS:
428                     emitCaptionEvent(new CaptionEvent(CAPTION_EMIT_TYPE_CONTROL, (char) mCommand));
429                     break;
430                 case Cea708Data.CODE_C0_FF:
431                     emitCaptionEvent(new CaptionEvent(CAPTION_EMIT_TYPE_CONTROL, (char) mCommand));
432                     break;
433                 case Cea708Data.CODE_C0_CR:
434                     mBuffer.append('\n');
435                     break;
436                 case Cea708Data.CODE_C0_HCR:
437                     emitCaptionEvent(new CaptionEvent(CAPTION_EMIT_TYPE_CONTROL, (char) mCommand));
438                     break;
439                 default:
440                     break;
441             }
442         }
443         return pos;
444     }
445 
parseC1(byte[] data, int pos)446     private int parseC1(byte[] data, int pos) {
447         // For the details of C1 code group, see CEA-708B Section 8.10.
448         // CR Group: C1 Caption Control Codes
449         switch (mCommand) {
450             case Cea708Data.CODE_C1_CW0:
451             case Cea708Data.CODE_C1_CW1:
452             case Cea708Data.CODE_C1_CW2:
453             case Cea708Data.CODE_C1_CW3:
454             case Cea708Data.CODE_C1_CW4:
455             case Cea708Data.CODE_C1_CW5:
456             case Cea708Data.CODE_C1_CW6:
457             case Cea708Data.CODE_C1_CW7: {
458                 // SetCurrentWindow0-7
459                 int windowId = mCommand - Cea708Data.CODE_C1_CW0;
460                 emitCaptionEvent(new CaptionEvent(CAPTION_EMIT_TYPE_COMMAND_CWX, windowId));
461                 if (DEBUG) {
462                     Log.d(TAG, String.format("CaptionCommand CWX windowId: %d", windowId));
463                 }
464                 break;
465             }
466 
467             case Cea708Data.CODE_C1_CLW: {
468                 // ClearWindows
469                 int windowBitmap = data[pos] & 0xff;
470                 ++pos;
471                 emitCaptionEvent(new CaptionEvent(CAPTION_EMIT_TYPE_COMMAND_CLW, windowBitmap));
472                 if (DEBUG) {
473                     Log.d(TAG, String.format("CaptionCommand CLW windowBitmap: %d", windowBitmap));
474                 }
475                 break;
476             }
477 
478             case Cea708Data.CODE_C1_DSW: {
479                 // DisplayWindows
480                 int windowBitmap = data[pos] & 0xff;
481                 ++pos;
482                 emitCaptionEvent(new CaptionEvent(CAPTION_EMIT_TYPE_COMMAND_DSW, windowBitmap));
483                 if (DEBUG) {
484                     Log.d(TAG, String.format("CaptionCommand DSW windowBitmap: %d", windowBitmap));
485                 }
486                 break;
487             }
488 
489             case Cea708Data.CODE_C1_HDW: {
490                 // HideWindows
491                 int windowBitmap = data[pos] & 0xff;
492                 ++pos;
493                 emitCaptionEvent(new CaptionEvent(CAPTION_EMIT_TYPE_COMMAND_HDW, windowBitmap));
494                 if (DEBUG) {
495                     Log.d(TAG, String.format("CaptionCommand HDW windowBitmap: %d", windowBitmap));
496                 }
497                 break;
498             }
499 
500             case Cea708Data.CODE_C1_TGW: {
501                 // ToggleWindows
502                 int windowBitmap = data[pos] & 0xff;
503                 ++pos;
504                 emitCaptionEvent(new CaptionEvent(CAPTION_EMIT_TYPE_COMMAND_TGW, windowBitmap));
505                 if (DEBUG) {
506                     Log.d(TAG, String.format("CaptionCommand TGW windowBitmap: %d", windowBitmap));
507                 }
508                 break;
509             }
510 
511             case Cea708Data.CODE_C1_DLW: {
512                 // DeleteWindows
513                 int windowBitmap = data[pos] & 0xff;
514                 ++pos;
515                 emitCaptionEvent(new CaptionEvent(CAPTION_EMIT_TYPE_COMMAND_DLW, windowBitmap));
516                 if (DEBUG) {
517                     Log.d(TAG, String.format("CaptionCommand DLW windowBitmap: %d", windowBitmap));
518                 }
519                 break;
520             }
521 
522             case Cea708Data.CODE_C1_DLY: {
523                 // Delay
524                 int tenthsOfSeconds = data[pos] & 0xff;
525                 ++pos;
526                 emitCaptionEvent(new CaptionEvent(CAPTION_EMIT_TYPE_COMMAND_DLY, tenthsOfSeconds));
527                 if (DEBUG) {
528                     Log.d(TAG, String.format("CaptionCommand DLY %d tenths of seconds",
529                             tenthsOfSeconds));
530                 }
531                 break;
532             }
533             case Cea708Data.CODE_C1_DLC: {
534                 // DelayCancel
535                 emitCaptionEvent(new CaptionEvent(CAPTION_EMIT_TYPE_COMMAND_DLC, null));
536                 if (DEBUG) {
537                     Log.d(TAG, "CaptionCommand DLC");
538                 }
539                 break;
540             }
541 
542             case Cea708Data.CODE_C1_RST: {
543                 // Reset
544                 emitCaptionEvent(new CaptionEvent(CAPTION_EMIT_TYPE_COMMAND_RST, null));
545                 if (DEBUG) {
546                     Log.d(TAG, "CaptionCommand RST");
547                 }
548                 break;
549             }
550 
551             case Cea708Data.CODE_C1_SPA: {
552                 // SetPenAttributes
553                 int textTag = (data[pos] & 0xf0) >> 4;
554                 int penSize = data[pos] & 0x03;
555                 int penOffset = (data[pos] & 0x0c) >> 2;
556                 boolean italic = (data[pos + 1] & 0x80) != 0;
557                 boolean underline = (data[pos + 1] & 0x40) != 0;
558                 int edgeType = (data[pos + 1] & 0x38) >> 3;
559                 int fontTag = data[pos + 1] & 0x7;
560                 pos += 2;
561                 emitCaptionEvent(new CaptionEvent(CAPTION_EMIT_TYPE_COMMAND_SPA,
562                         new CaptionPenAttr(penSize, penOffset, textTag, fontTag, edgeType,
563                                 underline, italic)));
564                 if (DEBUG) {
565                     Log.d(TAG, String.format(
566                             "CaptionCommand SPA penSize: %d, penOffset: %d, textTag: %d, "
567                                     + "fontTag: %d, edgeType: %d, underline: %s, italic: %s",
568                             penSize, penOffset, textTag, fontTag, edgeType, underline, italic));
569                 }
570                 break;
571             }
572 
573             case Cea708Data.CODE_C1_SPC: {
574                 // SetPenColor
575                 int opacity = (data[pos] & 0xc0) >> 6;
576                 int red = (data[pos] & 0x30) >> 4;
577                 int green = (data[pos] & 0x0c) >> 2;
578                 int blue = data[pos] & 0x03;
579                 CaptionColor foregroundColor = new CaptionColor(opacity, red, green, blue);
580                 ++pos;
581                 opacity = (data[pos] & 0xc0) >> 6;
582                 red = (data[pos] & 0x30) >> 4;
583                 green = (data[pos] & 0x0c) >> 2;
584                 blue = data[pos] & 0x03;
585                 CaptionColor backgroundColor = new CaptionColor(opacity, red, green, blue);
586                 ++pos;
587                 red = (data[pos] & 0x30) >> 4;
588                 green = (data[pos] & 0x0c) >> 2;
589                 blue = data[pos] & 0x03;
590                 CaptionColor edgeColor = new CaptionColor(
591                         CaptionColor.OPACITY_SOLID, red, green, blue);
592                 ++pos;
593                 emitCaptionEvent(new CaptionEvent(CAPTION_EMIT_TYPE_COMMAND_SPC,
594                         new CaptionPenColor(foregroundColor, backgroundColor, edgeColor)));
595                 if (DEBUG) {
596                     Log.d(TAG, String.format(
597                             "CaptionCommand SPC foregroundColor %s backgroundColor %s edgeColor %s",
598                             foregroundColor, backgroundColor, edgeColor));
599                 }
600                 break;
601             }
602 
603             case Cea708Data.CODE_C1_SPL: {
604                 // SetPenLocation
605                 // column is normally 0-31 for 4:3 formats, and 0-41 for 16:9 formats
606                 int row = data[pos] & 0x0f;
607                 int column = data[pos + 1] & 0x3f;
608                 pos += 2;
609                 emitCaptionEvent(new CaptionEvent(CAPTION_EMIT_TYPE_COMMAND_SPL,
610                         new CaptionPenLocation(row, column)));
611                 if (DEBUG) {
612                     Log.d(TAG, String.format("CaptionCommand SPL row: %d, column: %d",
613                             row, column));
614                 }
615                 break;
616             }
617 
618             case Cea708Data.CODE_C1_SWA: {
619                 // SetWindowAttributes
620                 int opacity = (data[pos] & 0xc0) >> 6;
621                 int red = (data[pos] & 0x30) >> 4;
622                 int green = (data[pos] & 0x0c) >> 2;
623                 int blue = data[pos] & 0x03;
624                 CaptionColor fillColor = new CaptionColor(opacity, red, green, blue);
625                 int borderType = (data[pos + 1] & 0xc0) >> 6 | (data[pos + 2] & 0x80) >> 5;
626                 red = (data[pos + 1] & 0x30) >> 4;
627                 green = (data[pos + 1] & 0x0c) >> 2;
628                 blue = data[pos + 1] & 0x03;
629                 CaptionColor borderColor = new CaptionColor(
630                         CaptionColor.OPACITY_SOLID, red, green, blue);
631                 boolean wordWrap = (data[pos + 2] & 0x40) != 0;
632                 int printDirection = (data[pos + 2] & 0x30) >> 4;
633                 int scrollDirection = (data[pos + 2] & 0x0c) >> 2;
634                 int justify = (data[pos + 2] & 0x03);
635                 int effectSpeed = (data[pos + 3] & 0xf0) >> 4;
636                 int effectDirection = (data[pos + 3] & 0x0c) >> 2;
637                 int displayEffect = data[pos + 3] & 0x3;
638                 pos += 4;
639                 emitCaptionEvent(new CaptionEvent(CAPTION_EMIT_TYPE_COMMAND_SWA,
640                         new CaptionWindowAttr(fillColor, borderColor, borderType, wordWrap,
641                                 printDirection, scrollDirection, justify,
642                                 effectDirection, effectSpeed, displayEffect)));
643                 if (DEBUG) {
644                     Log.d(TAG, String.format(
645                             "CaptionCommand SWA fillColor: %s, borderColor: %s, borderType: %d"
646                                     + "wordWrap: %s, printDirection: %d, scrollDirection: %d, "
647                                     + "justify: %s, effectDirection: %d, effectSpeed: %d, "
648                                     + "displayEffect: %d",
649                             fillColor, borderColor, borderType, wordWrap, printDirection,
650                             scrollDirection, justify, effectDirection, effectSpeed, displayEffect));
651                 }
652                 break;
653             }
654 
655             case Cea708Data.CODE_C1_DF0:
656             case Cea708Data.CODE_C1_DF1:
657             case Cea708Data.CODE_C1_DF2:
658             case Cea708Data.CODE_C1_DF3:
659             case Cea708Data.CODE_C1_DF4:
660             case Cea708Data.CODE_C1_DF5:
661             case Cea708Data.CODE_C1_DF6:
662             case Cea708Data.CODE_C1_DF7: {
663                 // DefineWindow0-7
664                 int windowId = mCommand - Cea708Data.CODE_C1_DF0;
665                 boolean visible = (data[pos] & 0x20) != 0;
666                 boolean rowLock = (data[pos] & 0x10) != 0;
667                 boolean columnLock = (data[pos] & 0x08) != 0;
668                 int priority = data[pos] & 0x07;
669                 boolean relativePositioning = (data[pos + 1] & 0x80) != 0;
670                 int anchorVertical = data[pos + 1] & 0x7f;
671                 int anchorHorizontal = data[pos + 2] & 0xff;
672                 int anchorId = (data[pos + 3] & 0xf0) >> 4;
673                 int rowCount = data[pos + 3] & 0x0f;
674                 int columnCount = data[pos + 4] & 0x3f;
675                 int windowStyle = (data[pos + 5] & 0x38) >> 3;
676                 int penStyle = data[pos + 5] & 0x07;
677                 pos += 6;
678                 emitCaptionEvent(new CaptionEvent(CAPTION_EMIT_TYPE_COMMAND_DFX,
679                         new CaptionWindow(windowId, visible, rowLock, columnLock, priority,
680                                 relativePositioning, anchorVertical, anchorHorizontal, anchorId,
681                                 rowCount, columnCount, penStyle, windowStyle)));
682                 if (DEBUG) {
683                     Log.d(TAG, String.format(
684                             "CaptionCommand DFx windowId: %d, priority: %d, columnLock: %s, "
685                                     + "rowLock: %s, visible: %s, anchorVertical: %d, "
686                                     + "relativePositioning: %s, anchorHorizontal: %d, "
687                                     + "rowCount: %d, anchorId: %d, columnCount: %d, penStyle: %d, "
688                                     + "windowStyle: %d",
689                             windowId, priority, columnLock, rowLock, visible, anchorVertical,
690                             relativePositioning, anchorHorizontal, rowCount, anchorId, columnCount,
691                             penStyle, windowStyle));
692                 }
693                 break;
694             }
695 
696             default:
697                 break;
698         }
699         return pos;
700     }
701 
parseG0(byte[] data, int pos)702     private int parseG0(byte[] data, int pos) {
703         // For the details of G0 code group, see CEA-708B Section 7.4.3.
704         // GL Group: G0 Modified version of ANSI X3.4 Printable Character Set (ASCII)
705         if (mCommand == Cea708Data.CODE_G0_MUSICNOTE) {
706             // Music note.
707             mBuffer.append(MUSIC_NOTE_CHAR);
708         } else {
709             // Put ASCII code into buffer.
710             mBuffer.append((char) mCommand);
711         }
712         return pos;
713     }
714 
parseG1(byte[] data, int pos)715     private int parseG1(byte[] data, int pos) {
716         // For the details of G0 code group, see CEA-708B Section 7.4.4.
717         // GR Group: G1 ISO 8859-1 Latin 1 Characters
718         // Put ASCII Extended character set into buffer.
719         mBuffer.append((char) mCommand);
720         return pos;
721     }
722 
723     // Step 4. Extended code groups
parseExt1(byte[] data, int pos)724     private int parseExt1(byte[] data, int pos) {
725         // For the details of EXT1 code group, see CEA-708B Section 7.2.
726         mCommand = data[pos] & 0xff;
727         ++pos;
728         if (mCommand >= Cea708Data.CODE_C2_RANGE_START
729                 && mCommand <= Cea708Data.CODE_C2_RANGE_END) {
730             pos = parseC2(data, pos);
731         } else if (mCommand >= Cea708Data.CODE_C3_RANGE_START
732                 && mCommand <= Cea708Data.CODE_C3_RANGE_END) {
733             pos = parseC3(data, pos);
734         } else if (mCommand >= Cea708Data.CODE_G2_RANGE_START
735                 && mCommand <= Cea708Data.CODE_G2_RANGE_END) {
736             pos = parseG2(data, pos);
737         } else if (mCommand >= Cea708Data.CODE_G3_RANGE_START
738                 && mCommand <= Cea708Data.CODE_G3_RANGE_END) {
739             pos = parseG3(data ,pos);
740         }
741         return pos;
742     }
743 
parseC2(byte[] data, int pos)744     private int parseC2(byte[] data, int pos) {
745         // For the details of C2 code group, see CEA-708B Section 7.4.7.
746         // Extended Miscellaneous Control Codes
747         // C2 Table : No commands as of CEA-708B. A decoder must skip.
748         if (mCommand >= Cea708Data.CODE_C2_SKIP0_RANGE_START
749                 && mCommand <= Cea708Data.CODE_C2_SKIP0_RANGE_END) {
750             // Do nothing.
751         } else if (mCommand >= Cea708Data.CODE_C2_SKIP1_RANGE_START
752                 && mCommand <= Cea708Data.CODE_C2_SKIP1_RANGE_END) {
753             ++pos;
754         } else if (mCommand >= Cea708Data.CODE_C2_SKIP2_RANGE_START
755                 && mCommand <= Cea708Data.CODE_C2_SKIP2_RANGE_END) {
756             pos += 2;
757         } else if (mCommand >= Cea708Data.CODE_C2_SKIP3_RANGE_START
758                 && mCommand <= Cea708Data.CODE_C2_SKIP3_RANGE_END) {
759             pos += 3;
760         }
761         return pos;
762     }
763 
parseC3(byte[] data, int pos)764     private int parseC3(byte[] data, int pos) {
765         // For the details of C3 code group, see CEA-708B Section 7.4.8.
766         // Extended Control Code Set 2
767         // C3 Table : No commands as of CEA-708B. A decoder must skip.
768         if (mCommand >= Cea708Data.CODE_C3_SKIP4_RANGE_START
769                 && mCommand <= Cea708Data.CODE_C3_SKIP4_RANGE_END) {
770             pos += 4;
771         } else if (mCommand >= Cea708Data.CODE_C3_SKIP5_RANGE_START
772                 && mCommand <= Cea708Data.CODE_C3_SKIP5_RANGE_END) {
773             pos += 5;
774         }
775         return pos;
776     }
777 
parseG2(byte[] data, int pos)778     private int parseG2(byte[] data, int pos) {
779         // For the details of C3 code group, see CEA-708B Section 7.4.5.
780         // Extended Control Code Set 1(G2 Table)
781         switch (mCommand) {
782             case Cea708Data.CODE_G2_TSP:
783                 // TODO : TSP is the Transparent space
784                 break;
785             case Cea708Data.CODE_G2_NBTSP:
786                 // TODO : NBTSP is Non-Breaking Transparent Space.
787                 break;
788             case Cea708Data.CODE_G2_BLK:
789                 // TODO : BLK indicates a solid block which fills the entire character block
790                 // TODO : with a solid foreground color.
791                 break;
792             default:
793                 break;
794         }
795         return pos;
796     }
797 
parseG3(byte[] data, int pos)798     private int parseG3(byte[] data, int pos) {
799         // For the details of C3 code group, see CEA-708B Section 7.4.6.
800         // Future characters and icons(G3 Table)
801         if (mCommand == Cea708Data.CODE_G3_CC) {
802             // TODO : [CC] icon with square corners
803         }
804 
805         // Do nothing
806         return pos;
807     }
808 }
809