NuPlayerCCDecoder.cpp revision 78acc89eae9789366b6384707861f4563addf2d3 
1/*
2 * Copyright 2014 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//#define LOG_NDEBUG 0
18#define LOG_TAG "NuPlayerCCDecoder"
19#include <utils/Log.h>
20#include <inttypes.h>
21
22#include "avc_utils.h"
23#include "NuPlayerCCDecoder.h"
24
25#include <media/stagefright/foundation/ABitReader.h>
26#include <media/stagefright/foundation/ABuffer.h>
27#include <media/stagefright/foundation/ADebug.h>
28#include <media/stagefright/foundation/AMessage.h>
29#include <media/stagefright/MediaDefs.h>
30
31namespace android {
32
33struct CCData {
34    CCData(uint8_t type, uint8_t data1, uint8_t data2)
35        : mType(type), mData1(data1), mData2(data2) {
36    }
37    bool getChannel(size_t *channel) const {
38        if (mData1 >= 0x10 && mData1 <= 0x1f) {
39            *channel = (mData1 >= 0x18 ? 1 : 0) + (mType ? 2 : 0);
40            return true;
41        }
42        return false;
43    }
44
45    uint8_t mType;
46    uint8_t mData1;
47    uint8_t mData2;
48};
49
50static bool isNullPad(CCData *cc) {
51    return cc->mData1 < 0x10 && cc->mData2 < 0x10;
52}
53
54static void dumpBytePair(const sp<ABuffer> &ccBuf) {
55    size_t offset = 0;
56    AString out;
57
58    while (offset < ccBuf->size()) {
59        char tmp[128];
60
61        CCData *cc = (CCData *) (ccBuf->data() + offset);
62
63        if (isNullPad(cc)) {
64            // 1 null pad or XDS metadata, ignore
65            offset += sizeof(CCData);
66            continue;
67        }
68
69        if (cc->mData1 >= 0x20 && cc->mData1 <= 0x7f) {
70            // 2 basic chars
71            sprintf(tmp, "[%d]Basic: %c %c", cc->mType, cc->mData1, cc->mData2);
72        } else if ((cc->mData1 == 0x11 || cc->mData1 == 0x19)
73                 && cc->mData2 >= 0x30 && cc->mData2 <= 0x3f) {
74            // 1 special char
75            sprintf(tmp, "[%d]Special: %02x %02x", cc->mType, cc->mData1, cc->mData2);
76        } else if ((cc->mData1 == 0x12 || cc->mData1 == 0x1A)
77                 && cc->mData2 >= 0x20 && cc->mData2 <= 0x3f){
78            // 1 Spanish/French char
79            sprintf(tmp, "[%d]Spanish: %02x %02x", cc->mType, cc->mData1, cc->mData2);
80        } else if ((cc->mData1 == 0x13 || cc->mData1 == 0x1B)
81                 && cc->mData2 >= 0x20 && cc->mData2 <= 0x3f){
82            // 1 Portuguese/German/Danish char
83            sprintf(tmp, "[%d]German: %02x %02x", cc->mType, cc->mData1, cc->mData2);
84        } else if ((cc->mData1 == 0x11 || cc->mData1 == 0x19)
85                 && cc->mData2 >= 0x20 && cc->mData2 <= 0x2f){
86            // Mid-Row Codes (Table 69)
87            sprintf(tmp, "[%d]Mid-row: %02x %02x", cc->mType, cc->mData1, cc->mData2);
88        } else if (((cc->mData1 == 0x14 || cc->mData1 == 0x1c)
89                  && cc->mData2 >= 0x20 && cc->mData2 <= 0x2f)
90                  ||
91                   ((cc->mData1 == 0x17 || cc->mData1 == 0x1f)
92                  && cc->mData2 >= 0x21 && cc->mData2 <= 0x23)){
93            // Misc Control Codes (Table 70)
94            sprintf(tmp, "[%d]Ctrl: %02x %02x", cc->mType, cc->mData1, cc->mData2);
95        } else if ((cc->mData1 & 0x70) == 0x10
96                && (cc->mData2 & 0x40) == 0x40
97                && ((cc->mData1 & 0x07) || !(cc->mData2 & 0x20)) ) {
98            // Preamble Address Codes (Table 71)
99            sprintf(tmp, "[%d]PAC: %02x %02x", cc->mType, cc->mData1, cc->mData2);
100        } else {
101            sprintf(tmp, "[%d]Invalid: %02x %02x", cc->mType, cc->mData1, cc->mData2);
102        }
103
104        if (out.size() > 0) {
105            out.append(", ");
106        }
107
108        out.append(tmp);
109
110        offset += sizeof(CCData);
111    }
112
113    ALOGI("%s", out.c_str());
114}
115
116NuPlayer::CCDecoder::CCDecoder(const sp<AMessage> &notify)
117    : mNotify(notify),
118      mCurrentChannel(0),
119      mSelectedTrack(-1) {
120      for (size_t i = 0; i < sizeof(mTrackIndices)/sizeof(mTrackIndices[0]); ++i) {
121          mTrackIndices[i] = -1;
122      }
123}
124
125size_t NuPlayer::CCDecoder::getTrackCount() const {
126    return mFoundChannels.size();
127}
128
129sp<AMessage> NuPlayer::CCDecoder::getTrackInfo(size_t index) const {
130    if (!isTrackValid(index)) {
131        return NULL;
132    }
133
134    sp<AMessage> format = new AMessage();
135
136    format->setInt32("type", MEDIA_TRACK_TYPE_SUBTITLE);
137    format->setString("language", "und");
138    format->setString("mime", MEDIA_MIMETYPE_TEXT_CEA_608);
139    //CC1, field 0 channel 0
140    bool isDefaultAuto = (mFoundChannels[index] == 0);
141    format->setInt32("auto", isDefaultAuto);
142    format->setInt32("default", isDefaultAuto);
143    format->setInt32("forced", 0);
144
145    return format;
146}
147
148status_t NuPlayer::CCDecoder::selectTrack(size_t index, bool select) {
149    if (!isTrackValid(index)) {
150        return BAD_VALUE;
151    }
152
153    if (select) {
154        if (mSelectedTrack == (ssize_t)index) {
155            ALOGE("track %zu already selected", index);
156            return BAD_VALUE;
157        }
158        ALOGV("selected track %zu", index);
159        mSelectedTrack = index;
160    } else {
161        if (mSelectedTrack != (ssize_t)index) {
162            ALOGE("track %zu is not selected", index);
163            return BAD_VALUE;
164        }
165        ALOGV("unselected track %zu", index);
166        mSelectedTrack = -1;
167    }
168
169    return OK;
170}
171
172bool NuPlayer::CCDecoder::isSelected() const {
173    return mSelectedTrack >= 0 && mSelectedTrack < (int32_t) getTrackCount();
174}
175
176bool NuPlayer::CCDecoder::isTrackValid(size_t index) const {
177    return index < getTrackCount();
178}
179
180int32_t NuPlayer::CCDecoder::getTrackIndex(size_t channel) const {
181    if (channel < sizeof(mTrackIndices)/sizeof(mTrackIndices[0])) {
182        return mTrackIndices[channel];
183    }
184    return -1;
185}
186
187// returns true if a new CC track is found
188bool NuPlayer::CCDecoder::extractFromSEI(const sp<ABuffer> &accessUnit) {
189    sp<ABuffer> sei;
190    if (!accessUnit->meta()->findBuffer("sei", &sei) || sei == NULL) {
191        return false;
192    }
193
194    int64_t timeUs;
195    CHECK(accessUnit->meta()->findInt64("timeUs", &timeUs));
196
197    bool trackAdded = false;
198
199    const NALPosition *nal = (NALPosition *) sei->data();
200
201    for (size_t i = 0; i < sei->size() / sizeof(NALPosition); ++i, ++nal) {
202        trackAdded |= parseSEINalUnit(
203                timeUs, accessUnit->data() + nal->nalOffset, nal->nalSize);
204    }
205
206    return trackAdded;
207}
208
209// returns true if a new CC track is found
210bool NuPlayer::CCDecoder::parseSEINalUnit(
211        int64_t timeUs, const uint8_t *nalStart, size_t nalSize) {
212    unsigned nalType = nalStart[0] & 0x1f;
213
214    // the buffer should only have SEI in it
215    if (nalType != 6) {
216        return false;
217    }
218
219    bool trackAdded = false;
220    NALBitReader br(nalStart + 1, nalSize - 1);
221    // sei_message()
222    while (br.atLeastNumBitsLeft(16)) { // at least 16-bit for sei_message()
223        uint32_t payload_type = 0;
224        size_t payload_size = 0;
225        uint8_t last_byte;
226
227        do {
228            last_byte = br.getBits(8);
229            payload_type += last_byte;
230        } while (last_byte == 0xFF);
231
232        do {
233            last_byte = br.getBits(8);
234            payload_size += last_byte;
235        } while (last_byte == 0xFF);
236
237        // sei_payload()
238        if (payload_type == 4) {
239            bool isCC = false;
240            if (payload_size > 1 + 2 + 4 + 1) {
241                // user_data_registered_itu_t_t35()
242
243                // ATSC A/72: 6.4.2
244                uint8_t itu_t_t35_country_code = br.getBits(8);
245                uint16_t itu_t_t35_provider_code = br.getBits(16);
246                uint32_t user_identifier = br.getBits(32);
247                uint8_t user_data_type_code = br.getBits(8);
248
249                payload_size -= 1 + 2 + 4 + 1;
250
251                isCC = itu_t_t35_country_code == 0xB5
252                        && itu_t_t35_provider_code == 0x0031
253                        && user_identifier == 'GA94'
254                        && user_data_type_code == 0x3;
255            }
256
257            if (isCC && payload_size > 2) {
258                // MPEG_cc_data()
259                // ATSC A/53 Part 4: 6.2.3.1
260                br.skipBits(1); //process_em_data_flag
261                bool process_cc_data_flag = br.getBits(1);
262                br.skipBits(1); //additional_data_flag
263                size_t cc_count = br.getBits(5);
264                br.skipBits(8); // em_data;
265                payload_size -= 2;
266
267                if (process_cc_data_flag) {
268                    AString out;
269
270                    sp<ABuffer> ccBuf = new ABuffer(cc_count * sizeof(CCData));
271                    ccBuf->setRange(0, 0);
272
273                    for (size_t i = 0; i < cc_count && payload_size >= 3; i++) {
274                        uint8_t marker = br.getBits(5);
275                        CHECK_EQ(marker, 0x1f);
276
277                        bool cc_valid = br.getBits(1);
278                        uint8_t cc_type = br.getBits(2);
279                        // remove odd parity bit
280                        uint8_t cc_data_1 = br.getBits(8) & 0x7f;
281                        uint8_t cc_data_2 = br.getBits(8) & 0x7f;
282
283                        payload_size -= 3;
284
285                        if (cc_valid
286                                && (cc_type == 0 || cc_type == 1)) {
287                            CCData cc(cc_type, cc_data_1, cc_data_2);
288                            if (!isNullPad(&cc)) {
289                                size_t channel;
290                                if (cc.getChannel(&channel) && getTrackIndex(channel) < 0) {
291                                    mTrackIndices[channel] = mFoundChannels.size();
292                                    mFoundChannels.push_back(channel);
293                                    trackAdded = true;
294                                }
295                                memcpy(ccBuf->data() + ccBuf->size(),
296                                        (void *)&cc, sizeof(cc));
297                                ccBuf->setRange(0, ccBuf->size() + sizeof(CCData));
298                            }
299                        }
300                    }
301
302                    mCCMap.add(timeUs, ccBuf);
303                    break;
304                }
305            } else {
306                ALOGV("Malformed SEI payload type 4");
307            }
308        } else {
309            ALOGV("Unsupported SEI payload type %d", payload_type);
310        }
311
312        // skipping remaining bits of this payload
313        br.skipBits(payload_size * 8);
314    }
315
316    return trackAdded;
317}
318
319sp<ABuffer> NuPlayer::CCDecoder::filterCCBuf(
320        const sp<ABuffer> &ccBuf, size_t index) {
321    sp<ABuffer> filteredCCBuf = new ABuffer(ccBuf->size());
322    filteredCCBuf->setRange(0, 0);
323
324    size_t cc_count = ccBuf->size() / sizeof(CCData);
325    const CCData* cc_data = (const CCData*)ccBuf->data();
326    for (size_t i = 0; i < cc_count; ++i) {
327        size_t channel;
328        if (cc_data[i].getChannel(&channel)) {
329            mCurrentChannel = channel;
330        }
331        if (mCurrentChannel == mFoundChannels[index]) {
332            memcpy(filteredCCBuf->data() + filteredCCBuf->size(),
333                    (void *)&cc_data[i], sizeof(CCData));
334            filteredCCBuf->setRange(0, filteredCCBuf->size() + sizeof(CCData));
335        }
336    }
337
338    return filteredCCBuf;
339}
340
341void NuPlayer::CCDecoder::decode(const sp<ABuffer> &accessUnit) {
342    if (extractFromSEI(accessUnit)) {
343        ALOGI("Found CEA-608 track");
344        sp<AMessage> msg = mNotify->dup();
345        msg->setInt32("what", kWhatTrackAdded);
346        msg->post();
347    }
348    // TODO: extract CC from other sources
349}
350
351void NuPlayer::CCDecoder::display(int64_t timeUs) {
352    if (!isTrackValid(mSelectedTrack)) {
353        ALOGE("Could not find current track(index=%d)", mSelectedTrack);
354        return;
355    }
356
357    ssize_t index = mCCMap.indexOfKey(timeUs);
358    if (index < 0) {
359        ALOGV("cc for timestamp %" PRId64 " not found", timeUs);
360        return;
361    }
362
363    sp<ABuffer> ccBuf = filterCCBuf(mCCMap.valueAt(index), mSelectedTrack);
364
365    if (ccBuf->size() > 0) {
366#if 0
367        dumpBytePair(ccBuf);
368#endif
369
370        ccBuf->meta()->setInt32("trackIndex", mSelectedTrack);
371        ccBuf->meta()->setInt64("timeUs", timeUs);
372        ccBuf->meta()->setInt64("durationUs", 0ll);
373
374        sp<AMessage> msg = mNotify->dup();
375        msg->setInt32("what", kWhatClosedCaptionData);
376        msg->setBuffer("buffer", ccBuf);
377        msg->post();
378    }
379
380    // remove all entries before timeUs
381    mCCMap.removeItemsAt(0, index + 1);
382}
383
384void NuPlayer::CCDecoder::flush() {
385    mCCMap.clear();
386}
387
388}  // namespace android
389
390