From d3c079ae9859011d118f94616d0069c2987013ed Mon Sep 17 00:00:00 2001 From: Changwan Ryu Date: Mon, 28 Oct 2013 11:08:44 +0900 Subject: Support TS + AC3 for ATSC standard Change-Id: I141667f3f54b242bafdf0ab9db86852c56f49ffa --- media/libstagefright/mpeg2ts/ATSParser.cpp | 6 + media/libstagefright/mpeg2ts/ATSParser.h | 4 + media/libstagefright/mpeg2ts/ESQueue.cpp | 190 +++++++++++++++++++++++++++++ media/libstagefright/mpeg2ts/ESQueue.h | 2 + 4 files changed, 202 insertions(+) (limited to 'media/libstagefright/mpeg2ts') diff --git a/media/libstagefright/mpeg2ts/ATSParser.cpp b/media/libstagefright/mpeg2ts/ATSParser.cpp index 9850a46..f87b9da 100644 --- a/media/libstagefright/mpeg2ts/ATSParser.cpp +++ b/media/libstagefright/mpeg2ts/ATSParser.cpp @@ -506,6 +506,11 @@ ATSParser::Stream::Stream( ElementaryStreamQueue::PCM_AUDIO); break; + case STREAMTYPE_AC3: + mQueue = new ElementaryStreamQueue( + ElementaryStreamQueue::AC3); + break; + default: break; } @@ -614,6 +619,7 @@ bool ATSParser::Stream::isAudio() const { case STREAMTYPE_MPEG2_AUDIO: case STREAMTYPE_MPEG2_AUDIO_ADTS: case STREAMTYPE_PCM_AUDIO: + case STREAMTYPE_AC3: return true; default: diff --git a/media/libstagefright/mpeg2ts/ATSParser.h b/media/libstagefright/mpeg2ts/ATSParser.h index a10edc9..d4e30b4 100644 --- a/media/libstagefright/mpeg2ts/ATSParser.h +++ b/media/libstagefright/mpeg2ts/ATSParser.h @@ -88,6 +88,10 @@ struct ATSParser : public RefBase { STREAMTYPE_MPEG2_AUDIO_ADTS = 0x0f, STREAMTYPE_MPEG4_VIDEO = 0x10, STREAMTYPE_H264 = 0x1b, + + // From ATSC A/53 Part 3:2009, 6.7.1 + STREAMTYPE_AC3 = 0x81, + STREAMTYPE_PCM_AUDIO = 0x83, }; diff --git a/media/libstagefright/mpeg2ts/ESQueue.cpp b/media/libstagefright/mpeg2ts/ESQueue.cpp index 8f9c9c8..ea79885 100644 --- a/media/libstagefright/mpeg2ts/ESQueue.cpp +++ b/media/libstagefright/mpeg2ts/ESQueue.cpp @@ -56,6 +56,122 @@ void ElementaryStreamQueue::clear(bool clearFormat) { } } +// Parse AC3 header assuming the current ptr is start position of syncframe, +// update metadata only applicable, and return the payload size +static unsigned parseAC3SyncFrame( + const uint8_t *ptr, size_t size, sp *metaData) { + static const unsigned channelCountTable[] = {2, 1, 2, 3, 4, 4, 5, 6}; + static const unsigned samplingRateTable[] = {48000, 44100, 32000}; + static const unsigned rates[] = {32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, + 320, 384, 448, 512, 576, 640}; + + static const unsigned frameSizeTable[19][3] = { + { 64, 69, 96 }, + { 80, 87, 120 }, + { 96, 104, 144 }, + { 112, 121, 168 }, + { 128, 139, 192 }, + { 160, 174, 240 }, + { 192, 208, 288 }, + { 224, 243, 336 }, + { 256, 278, 384 }, + { 320, 348, 480 }, + { 384, 417, 576 }, + { 448, 487, 672 }, + { 512, 557, 768 }, + { 640, 696, 960 }, + { 768, 835, 1152 }, + { 896, 975, 1344 }, + { 1024, 1114, 1536 }, + { 1152, 1253, 1728 }, + { 1280, 1393, 1920 }, + }; + + ABitReader bits(ptr, size); + unsigned syncStartPos = 0; // in bytes + if (bits.numBitsLeft() < 16) { + return 0; + } + if (bits.getBits(16) != 0x0B77) { + return 0; + } + + if (bits.numBitsLeft() < 16 + 2 + 6 + 5 + 3 + 3) { + ALOGV("Not enough bits left for further parsing"); + return 0; + } + bits.skipBits(16); // crc1 + + unsigned fscod = bits.getBits(2); + if (fscod == 3) { + ALOGW("Incorrect fscod in AC3 header"); + return 0; + } + + unsigned frmsizecod = bits.getBits(6); + if (frmsizecod > 37) { + ALOGW("Incorrect frmsizecod in AC3 header"); + return 0; + } + + unsigned bsid = bits.getBits(5); + if (bsid > 8) { + ALOGW("Incorrect bsid in AC3 header. Possibly E-AC-3?"); + return 0; + } + + unsigned bsmod = bits.getBits(3); + unsigned acmod = bits.getBits(3); + unsigned cmixlev = 0; + unsigned surmixlev = 0; + unsigned dsurmod = 0; + + if ((acmod & 1) > 0 && acmod != 1) { + if (bits.numBitsLeft() < 2) { + return 0; + } + cmixlev = bits.getBits(2); + } + if ((acmod & 4) > 0) { + if (bits.numBitsLeft() < 2) { + return 0; + } + surmixlev = bits.getBits(2); + } + if (acmod == 2) { + if (bits.numBitsLeft() < 2) { + return 0; + } + dsurmod = bits.getBits(2); + } + + if (bits.numBitsLeft() < 1) { + return 0; + } + unsigned lfeon = bits.getBits(1); + + unsigned samplingRate = samplingRateTable[fscod]; + unsigned payloadSize = frameSizeTable[frmsizecod >> 1][fscod]; + if (fscod == 1) { + payloadSize += frmsizecod & 1; + } + payloadSize <<= 1; // convert from 16-bit words to bytes + + unsigned channelCount = channelCountTable[acmod] + lfeon; + + if (metaData != NULL) { + (*metaData)->setCString(kKeyMIMEType, MEDIA_MIMETYPE_AUDIO_AC3); + (*metaData)->setInt32(kKeyChannelCount, channelCount); + (*metaData)->setInt32(kKeySampleRate, samplingRate); + } + + return payloadSize; +} + +static bool IsSeeminglyValidAC3Header(const uint8_t *ptr, size_t size) { + return parseAC3SyncFrame(ptr, size, NULL) > 0; +} + static bool IsSeeminglyValidADTSHeader(const uint8_t *ptr, size_t size) { if (size < 3) { // Not enough data to verify header. @@ -224,6 +340,33 @@ status_t ElementaryStreamQueue::appendData( break; } + case AC3: + { + uint8_t *ptr = (uint8_t *)data; + + ssize_t startOffset = -1; + for (size_t i = 0; i < size; ++i) { + if (IsSeeminglyValidAC3Header(&ptr[i], size - i)) { + startOffset = i; + break; + } + } + + if (startOffset < 0) { + return ERROR_MALFORMED; + } + + if (startOffset > 0) { + ALOGI("found something resembling an AC3 syncword at " + "offset %d", + startOffset); + } + + data = &ptr[startOffset]; + size -= startOffset; + break; + } + case MPEG_AUDIO: { uint8_t *ptr = (uint8_t *)data; @@ -328,6 +471,8 @@ sp ElementaryStreamQueue::dequeueAccessUnit() { return dequeueAccessUnitH264(); case AAC: return dequeueAccessUnitAAC(); + case AC3: + return dequeueAccessUnitAC3(); case MPEG_VIDEO: return dequeueAccessUnitMPEGVideo(); case MPEG4_VIDEO: @@ -340,6 +485,51 @@ sp ElementaryStreamQueue::dequeueAccessUnit() { } } +sp ElementaryStreamQueue::dequeueAccessUnitAC3() { + unsigned syncStartPos = 0; // in bytes + unsigned payloadSize = 0; + sp format = new MetaData; + while (true) { + if (syncStartPos + 2 >= mBuffer->size()) { + return NULL; + } + + payloadSize = parseAC3SyncFrame( + mBuffer->data() + syncStartPos, + mBuffer->size() - syncStartPos, + &format); + if (payloadSize > 0) { + break; + } + ++syncStartPos; + } + + if (mBuffer->size() < syncStartPos + payloadSize) { + ALOGV("Not enough buffer size for AC3"); + return NULL; + } + + if (mFormat == NULL) { + mFormat = format; + } + + sp accessUnit = new ABuffer(syncStartPos + payloadSize); + memcpy(accessUnit->data(), mBuffer->data(), syncStartPos + payloadSize); + + int64_t timeUs = fetchTimestamp(syncStartPos + payloadSize); + CHECK_GE(timeUs, 0ll); + accessUnit->meta()->setInt64("timeUs", timeUs); + + memmove( + mBuffer->data(), + mBuffer->data() + syncStartPos + payloadSize, + mBuffer->size() - syncStartPos - payloadSize); + + mBuffer->setRange(0, mBuffer->size() - syncStartPos - payloadSize); + + return accessUnit; +} + sp ElementaryStreamQueue::dequeueAccessUnitPCMAudio() { if (mBuffer->size() < 4) { return NULL; diff --git a/media/libstagefright/mpeg2ts/ESQueue.h b/media/libstagefright/mpeg2ts/ESQueue.h index 66a8087..a2cca77 100644 --- a/media/libstagefright/mpeg2ts/ESQueue.h +++ b/media/libstagefright/mpeg2ts/ESQueue.h @@ -32,6 +32,7 @@ struct ElementaryStreamQueue { enum Mode { H264, AAC, + AC3, MPEG_AUDIO, MPEG_VIDEO, MPEG4_VIDEO, @@ -67,6 +68,7 @@ private: sp dequeueAccessUnitH264(); sp dequeueAccessUnitAAC(); + sp dequeueAccessUnitAC3(); sp dequeueAccessUnitMPEGAudio(); sp dequeueAccessUnitMPEGVideo(); sp dequeueAccessUnitMPEG4Video(); -- cgit v1.1