Support for CEA-708 closed caption
Bug: 24314667, Bug: 24889604
Change-Id: Ica8a8405b143921de82ca6075a1f7b1f6f9ff345
diff --git a/media/libmediaplayerservice/nuplayer/NuPlayerCCDecoder.cpp b/media/libmediaplayerservice/nuplayer/NuPlayerCCDecoder.cpp
index ac3c6b6..13716cf 100644
--- a/media/libmediaplayerservice/nuplayer/NuPlayerCCDecoder.cpp
+++ b/media/libmediaplayerservice/nuplayer/NuPlayerCCDecoder.cpp
@@ -30,6 +30,9 @@
namespace android {
+// In CEA-708B, the maximum bandwidth of CC is set to 9600bps.
+static const size_t kMaxBandwithSizeBytes = 9600 / 8;
+
struct CCData {
CCData(uint8_t type, uint8_t data1, uint8_t data2)
: mType(type), mData1(data1), mData2(data2) {
@@ -116,15 +119,19 @@
NuPlayer::CCDecoder::CCDecoder(const sp<AMessage> ¬ify)
: mNotify(notify),
- mCurrentChannel(0),
- mSelectedTrack(-1) {
- for (size_t i = 0; i < sizeof(mTrackIndices)/sizeof(mTrackIndices[0]); ++i) {
- mTrackIndices[i] = -1;
- }
+ mSelectedTrack(-1),
+ mDTVCCPacket(new ABuffer(kMaxBandwithSizeBytes)) {
+ mDTVCCPacket->setRange(0, 0);
+
+ // In CEA-608, streams from packets which have the value 0 of cc_type contain CC1 and CC2, and
+ // streams from packets which have the value 1 of cc_type contain CC3 and CC4.
+ // The following array indicates the current transmitting channels for each value of cc_type.
+ mLine21Channels[0] = 0; // CC1
+ mLine21Channels[1] = 2; // CC3
}
size_t NuPlayer::CCDecoder::getTrackCount() const {
- return mFoundChannels.size();
+ return mTracks.size();
}
sp<AMessage> NuPlayer::CCDecoder::getTrackInfo(size_t index) const {
@@ -134,13 +141,31 @@
sp<AMessage> format = new AMessage();
+ CCTrack track = mTracks[index];
+
format->setInt32("type", MEDIA_TRACK_TYPE_SUBTITLE);
format->setString("language", "und");
- format->setString("mime", MEDIA_MIMETYPE_TEXT_CEA_608);
- //CC1, field 0 channel 0
- bool isDefaultAuto = (mFoundChannels[index] == 0);
+
+ switch (track.mTrackType) {
+ case kTrackTypeCEA608:
+ format->setString("mime", MEDIA_MIMETYPE_TEXT_CEA_608);
+ break;
+ case kTrackTypeCEA708:
+ format->setString("mime", MEDIA_MIMETYPE_TEXT_CEA_708);
+ break;
+ default:
+ ALOGE("Unknown track type: %d", track.mTrackType);
+ return NULL;
+ }
+
+ // For CEA-608 CC1, field 0 channel 0
+ bool isDefaultAuto = track.mTrackType == kTrackTypeCEA608
+ && track.mTrackChannel == 0;
+ // For CEA-708, Primary Caption Service.
+ bool isDefaultOnly = track.mTrackType == kTrackTypeCEA708
+ && track.mTrackChannel == 1;
format->setInt32("auto", isDefaultAuto);
- format->setInt32("default", isDefaultAuto);
+ format->setInt32("default", isDefaultAuto || isDefaultOnly);
format->setInt32("forced", 0);
return format;
@@ -167,24 +192,20 @@
mSelectedTrack = -1;
}
+ // Clear the previous track payloads
+ mCCMap.clear();
+
return OK;
}
bool NuPlayer::CCDecoder::isSelected() const {
- return mSelectedTrack >= 0 && mSelectedTrack < (int32_t) getTrackCount();
+ return mSelectedTrack >= 0 && mSelectedTrack < (int32_t)getTrackCount();
}
bool NuPlayer::CCDecoder::isTrackValid(size_t index) const {
return index < getTrackCount();
}
-int32_t NuPlayer::CCDecoder::getTrackIndex(size_t channel) const {
- if (channel < sizeof(mTrackIndices)/sizeof(mTrackIndices[0])) {
- return mTrackIndices[channel];
- }
- return -1;
-}
-
// returns true if a new CC track is found
bool NuPlayer::CCDecoder::extractFromSEI(const sp<ABuffer> &accessUnit) {
sp<ABuffer> sei;
@@ -197,7 +218,7 @@
bool trackAdded = false;
- const NALPosition *nal = (NALPosition *) sei->data();
+ const NALPosition *nal = (NALPosition *)sei->data();
for (size_t i = 0; i < sei->size() / sizeof(NALPosition); ++i, ++nal) {
trackAdded |= parseSEINalUnit(
@@ -208,9 +229,8 @@
}
// returns true if a new CC track is found
-bool NuPlayer::CCDecoder::parseSEINalUnit(
- int64_t timeUs, const uint8_t *nalStart, size_t nalSize) {
- unsigned nalType = nalStart[0] & 0x1f;
+bool NuPlayer::CCDecoder::parseSEINalUnit(int64_t timeUs, const uint8_t *data, size_t size) {
+ unsigned nalType = data[0] & 0x1f;
// the buffer should only have SEI in it
if (nalType != 6) {
@@ -218,7 +238,8 @@
}
bool trackAdded = false;
- NALBitReader br(nalStart + 1, nalSize - 1);
+ NALBitReader br(data + 1, size - 1);
+
// sei_message()
while (br.atLeastNumBitsLeft(16)) { // at least 16-bit for sei_message()
uint32_t payload_type = 0;
@@ -256,53 +277,7 @@
}
if (isCC && payload_size > 2) {
- // MPEG_cc_data()
- // ATSC A/53 Part 4: 6.2.3.1
- br.skipBits(1); //process_em_data_flag
- bool process_cc_data_flag = br.getBits(1);
- br.skipBits(1); //additional_data_flag
- size_t cc_count = br.getBits(5);
- br.skipBits(8); // em_data;
- payload_size -= 2;
-
- if (process_cc_data_flag) {
- AString out;
-
- sp<ABuffer> ccBuf = new ABuffer(cc_count * sizeof(CCData));
- ccBuf->setRange(0, 0);
-
- for (size_t i = 0; i < cc_count && payload_size >= 3; i++) {
- uint8_t marker = br.getBits(5);
- CHECK_EQ(marker, 0x1f);
-
- bool cc_valid = br.getBits(1);
- uint8_t cc_type = br.getBits(2);
- // remove odd parity bit
- uint8_t cc_data_1 = br.getBits(8) & 0x7f;
- uint8_t cc_data_2 = br.getBits(8) & 0x7f;
-
- payload_size -= 3;
-
- if (cc_valid
- && (cc_type == 0 || cc_type == 1)) {
- CCData cc(cc_type, cc_data_1, cc_data_2);
- if (!isNullPad(&cc)) {
- size_t channel;
- if (cc.getChannel(&channel) && getTrackIndex(channel) < 0) {
- mTrackIndices[channel] = mFoundChannels.size();
- mFoundChannels.push_back(channel);
- trackAdded = true;
- }
- memcpy(ccBuf->data() + ccBuf->size(),
- (void *)&cc, sizeof(cc));
- ccBuf->setRange(0, ccBuf->size() + sizeof(CCData));
- }
- }
- }
-
- mCCMap.add(timeUs, ccBuf);
- break;
- }
+ trackAdded |= parseMPEGCCData(timeUs, br.data(), br.numBitsLeft() / 8);
} else {
ALOGV("Malformed SEI payload type 4");
}
@@ -317,31 +292,202 @@
return trackAdded;
}
-sp<ABuffer> NuPlayer::CCDecoder::filterCCBuf(
- const sp<ABuffer> &ccBuf, size_t index) {
- sp<ABuffer> filteredCCBuf = new ABuffer(ccBuf->size());
- filteredCCBuf->setRange(0, 0);
+// returns true if a new CC track is found
+bool NuPlayer::CCDecoder::extractFromMPEGUserData(const sp<ABuffer> &accessUnit) {
+ sp<ABuffer> mpegUserData;
+ if (!accessUnit->meta()->findBuffer("mpegUserData", &mpegUserData)
+ || mpegUserData == NULL) {
+ return false;
+ }
- size_t cc_count = ccBuf->size() / sizeof(CCData);
- const CCData* cc_data = (const CCData*)ccBuf->data();
+ int64_t timeUs;
+ CHECK(accessUnit->meta()->findInt64("timeUs", &timeUs));
+
+ bool trackAdded = false;
+
+ const size_t *userData = (size_t *)mpegUserData->data();
+
+ for (size_t i = 0; i < mpegUserData->size() / sizeof(size_t); ++i) {
+ trackAdded |= parseMPEGUserDataUnit(
+ timeUs, accessUnit->data() + userData[i], accessUnit->size() - userData[i]);
+ }
+
+ return trackAdded;
+}
+
+// returns true if a new CC track is found
+bool NuPlayer::CCDecoder::parseMPEGUserDataUnit(int64_t timeUs, const uint8_t *data, size_t size) {
+ ABitReader br(data + 4, 5);
+
+ uint32_t user_identifier = br.getBits(32);
+ uint8_t user_data_type = br.getBits(8);
+
+ if (user_identifier == 'GA94' && user_data_type == 0x3) {
+ return parseMPEGCCData(timeUs, data + 9, size - 9);
+ }
+
+ return false;
+}
+
+// returns true if a new CC track is found
+bool NuPlayer::CCDecoder::parseMPEGCCData(int64_t timeUs, const uint8_t *data, size_t size) {
+ bool trackAdded = false;
+
+ // MPEG_cc_data()
+ // ATSC A/53 Part 4: 6.2.3.1
+ ABitReader br(data, size);
+
+ if (br.numBitsLeft() <= 16) {
+ return false;
+ }
+
+ br.skipBits(1);
+ bool process_cc_data_flag = br.getBits(1);
+ br.skipBits(1);
+ size_t cc_count = br.getBits(5);
+ br.skipBits(8);
+
+ if (!process_cc_data_flag || 3 * 8 * cc_count >= br.numBitsLeft()) {
+ return false;
+ }
+
+ sp<ABuffer> line21CCBuf = NULL;
+
for (size_t i = 0; i < cc_count; ++i) {
- size_t channel;
- if (cc_data[i].getChannel(&channel)) {
- mCurrentChannel = channel;
- }
- if (mCurrentChannel == mFoundChannels[index]) {
- memcpy(filteredCCBuf->data() + filteredCCBuf->size(),
- (void *)&cc_data[i], sizeof(CCData));
- filteredCCBuf->setRange(0, filteredCCBuf->size() + sizeof(CCData));
+ br.skipBits(5);
+ bool cc_valid = br.getBits(1);
+ uint8_t cc_type = br.getBits(2);
+
+ if (cc_valid) {
+ if (cc_type == 3) {
+ if (mDTVCCPacket->size() > 0) {
+ trackAdded |= parseDTVCCPacket(
+ timeUs, mDTVCCPacket->data(), mDTVCCPacket->size());
+ mDTVCCPacket->setRange(0, 0);
+ }
+ memcpy(mDTVCCPacket->data() + mDTVCCPacket->size(), br.data(), 2);
+ mDTVCCPacket->setRange(0, mDTVCCPacket->size() + 2);
+ br.skipBits(16);
+ } else if (mDTVCCPacket->size() > 0 && cc_type == 2) {
+ memcpy(mDTVCCPacket->data() + mDTVCCPacket->size(), br.data(), 2);
+ mDTVCCPacket->setRange(0, mDTVCCPacket->size() + 2);
+ br.skipBits(16);
+ } else if (cc_type == 0 || cc_type == 1) {
+ uint8_t cc_data_1 = br.getBits(8) & 0x7f;
+ uint8_t cc_data_2 = br.getBits(8) & 0x7f;
+
+ CCData cc(cc_type, cc_data_1, cc_data_2);
+
+ if (isNullPad(&cc)) {
+ continue;
+ }
+
+ size_t channel;
+ if (cc.getChannel(&channel)) {
+ mLine21Channels[cc_type] = channel;
+
+ // create a new track if it does not exist.
+ getTrackIndex(kTrackTypeCEA608, channel, &trackAdded);
+ }
+
+ if (isSelected() && mTracks[mSelectedTrack].mTrackType == kTrackTypeCEA608
+ && mTracks[mSelectedTrack].mTrackChannel == mLine21Channels[cc_type]) {
+ if (line21CCBuf == NULL) {
+ line21CCBuf = new ABuffer((cc_count - i) * sizeof(CCData));
+ line21CCBuf->setRange(0, 0);
+ }
+ memcpy(line21CCBuf->data() + line21CCBuf->size(), &cc, sizeof(cc));
+ line21CCBuf->setRange(0, line21CCBuf->size() + sizeof(CCData));
+ }
+ } else {
+ br.skipBits(16);
+ }
+ } else {
+ if ((cc_type == 3 || cc_type == 2) && mDTVCCPacket->size() > 0) {
+ trackAdded |= parseDTVCCPacket(timeUs, mDTVCCPacket->data(), mDTVCCPacket->size());
+ mDTVCCPacket->setRange(0, 0);
+ }
+ br.skipBits(16);
}
}
- return filteredCCBuf;
+ if (isSelected() && mTracks[mSelectedTrack].mTrackType == kTrackTypeCEA608
+ && line21CCBuf != NULL && line21CCBuf->size() > 0) {
+ mCCMap.add(timeUs, line21CCBuf);
+ }
+
+ return trackAdded;
+}
+
+// returns true if a new CC track is found
+bool NuPlayer::CCDecoder::parseDTVCCPacket(int64_t timeUs, const uint8_t *data, size_t size) {
+ // CEA-708B 5 DTVCC Packet Layer.
+ ABitReader br(data, size);
+ br.skipBits(2);
+
+ size_t packet_size = br.getBits(6);
+ if (packet_size == 0) packet_size = 64;
+ packet_size *= 2;
+
+ if (size != packet_size) {
+ return false;
+ }
+
+ bool trackAdded = false;
+
+ while (br.numBitsLeft() >= 16) {
+ // CEA-708B Figure 5 and 6.
+ uint8_t service_number = br.getBits(3);
+ size_t block_size = br.getBits(5);
+
+ if (service_number == 64) {
+ br.skipBits(2);
+ service_number = br.getBits(6);
+
+ if (service_number < 64) {
+ return trackAdded;
+ }
+ }
+
+ if (br.numBitsLeft() < block_size * 8) {
+ return trackAdded;
+ }
+
+ if (block_size > 0) {
+ size_t trackIndex = getTrackIndex(kTrackTypeCEA708, service_number, &trackAdded);
+ if (mSelectedTrack == (ssize_t)trackIndex) {
+ sp<ABuffer> ccPacket = new ABuffer(block_size);
+ memcpy(ccPacket->data(), br.data(), block_size);
+ mCCMap.add(timeUs, ccPacket);
+ }
+ }
+ br.skipBits(block_size * 8);
+ }
+
+ return trackAdded;
+}
+
+// return the track index for a given type and channel.
+// if the track does not exist, creates a new one.
+size_t NuPlayer::CCDecoder::getTrackIndex(
+ int32_t trackType, size_t channel, bool *trackAdded) {
+ CCTrack track(trackType, channel);
+ ssize_t index = mTrackIndices.indexOfKey(track);
+
+ if (index < 0) {
+ // A new track is added.
+ index = mTracks.size();
+ mTrackIndices.add(track, index);
+ mTracks.add(track);
+ *trackAdded = true;
+ return index;
+ }
+
+ return mTrackIndices.valueAt(index);
}
void NuPlayer::CCDecoder::decode(const sp<ABuffer> &accessUnit) {
- if (extractFromSEI(accessUnit)) {
- ALOGI("Found CEA-608 track");
+ if (extractFromMPEGUserData(accessUnit) || extractFromSEI(accessUnit)) {
sp<AMessage> msg = mNotify->dup();
msg->setInt32("what", kWhatTrackAdded);
msg->post();
@@ -350,8 +496,7 @@
}
void NuPlayer::CCDecoder::display(int64_t timeUs) {
- if (!isTrackValid(mSelectedTrack)) {
- ALOGE("Could not find current track(index=%d)", mSelectedTrack);
+ if (!isSelected()) {
return;
}
@@ -361,7 +506,26 @@
return;
}
- sp<ABuffer> ccBuf = filterCCBuf(mCCMap.valueAt(index), mSelectedTrack);
+ sp<ABuffer> ccBuf;
+
+ if (index == 0) {
+ ccBuf = mCCMap.valueAt(index);
+ } else {
+ size_t size = 0;
+
+ for (ssize_t i = 0; i <= index; ++i) {
+ size += mCCMap.valueAt(i)->size();
+ }
+
+ ccBuf = new ABuffer(size);
+ ccBuf->setRange(0, 0);
+
+ for (ssize_t i = 0; i <= index; ++i) {
+ sp<ABuffer> buf = mCCMap.valueAt(i);
+ memcpy(ccBuf->data() + ccBuf->size(), buf->data(), buf->size());
+ ccBuf->setRange(0, ccBuf->size() + buf->size());
+ }
+ }
if (ccBuf->size() > 0) {
#if 0
@@ -384,6 +548,25 @@
void NuPlayer::CCDecoder::flush() {
mCCMap.clear();
+ mDTVCCPacket->setRange(0, 0);
+}
+
+int32_t NuPlayer::CCDecoder::CCTrack::compare(const NuPlayer::CCDecoder::CCTrack& rhs) const {
+ int32_t cmp = mTrackType - rhs.mTrackType;
+ if (cmp != 0) return cmp;
+ return mTrackChannel - rhs.mTrackChannel;
+}
+
+bool NuPlayer::CCDecoder::CCTrack::operator<(const NuPlayer::CCDecoder::CCTrack& rhs) const {
+ return compare(rhs) < 0;
+}
+
+bool NuPlayer::CCDecoder::CCTrack::operator==(const NuPlayer::CCDecoder::CCTrack& rhs) const {
+ return compare(rhs) == 0;
+}
+
+bool NuPlayer::CCDecoder::CCTrack::operator!=(const NuPlayer::CCDecoder::CCTrack& rhs) const {
+ return compare(rhs) != 0;
}
} // namespace android