media/libstagefright/mpeg2ts/MPEG2PSExtractor.cpp - third_party/android/platform/frameworks/av - Git at Google

 /*
  * Copyright (C) 2011 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 //#define LOG_NDEBUG 0
 #define LOG_TAG "MPEG2PSExtractor"
 #include <utils/Log.h>

 #include "include/MPEG2PSExtractor.h"

 #include "AnotherPacketSource.h"
 #include "ESQueue.h"

 #include <media/stagefright/foundation/ABitReader.h>
 #include <media/stagefright/foundation/ABuffer.h>
 #include <media/stagefright/foundation/ADebug.h>
 #include <media/stagefright/foundation/AMessage.h>
 #include <media/stagefright/foundation/hexdump.h>
 #include <media/stagefright/DataSource.h>
 #include <media/stagefright/MediaDefs.h>
 #include <media/stagefright/MediaErrors.h>
 #include <media/stagefright/MediaSource.h>
 #include <media/stagefright/MetaData.h>
 #include <media/stagefright/Utils.h>
 #include <utils/String8.h>

 #include <inttypes.h>

 namespace android {

 struct MPEG2PSExtractor::Track : public MediaSource {
     Track(MPEG2PSExtractor *extractor,
           unsigned stream_id, unsigned stream_type);

     virtual status_t start(MetaData *params);
     virtual status_t stop();
     virtual sp<MetaData> getFormat();

     virtual status_t read(
             MediaBuffer **buffer, const ReadOptions *options);

 protected:
     virtual ~Track();

 private:
     friend struct MPEG2PSExtractor;

     MPEG2PSExtractor *mExtractor;

     unsigned mStreamID;
     unsigned mStreamType;
     ElementaryStreamQueue *mQueue;
     sp<AnotherPacketSource> mSource;

     status_t appendPESData(
             unsigned PTS_DTS_flags,
             uint64_t PTS, uint64_t DTS,
             const uint8_t *data, size_t size);

     DISALLOW_EVIL_CONSTRUCTORS(Track);
 };

 struct MPEG2PSExtractor::WrappedTrack : public MediaSource {
     WrappedTrack(const sp<MPEG2PSExtractor> &extractor, const sp<Track> &track);

     virtual status_t start(MetaData *params);
     virtual status_t stop();
     virtual sp<MetaData> getFormat();

     virtual status_t read(
             MediaBuffer **buffer, const ReadOptions *options);

 protected:
     virtual ~WrappedTrack();

 private:
     sp<MPEG2PSExtractor> mExtractor;
     sp<MPEG2PSExtractor::Track> mTrack;

     DISALLOW_EVIL_CONSTRUCTORS(WrappedTrack);
 };

 ////////////////////////////////////////////////////////////////////////////////

 MPEG2PSExtractor::MPEG2PSExtractor(const sp<DataSource> &source)
     : mDataSource(source),
       mOffset(0),
       mFinalResult(OK),
       mBuffer(new ABuffer(0)),
       mScanning(true),
       mProgramStreamMapValid(false) {
     for (size_t i = 0; i < 500; ++i) {
         if (feedMore() != OK) {
             break;
         }
     }

     // Remove all tracks that were unable to determine their format.
     for (size_t i = mTracks.size(); i > 0;) {
         i--;
         if (mTracks.valueAt(i)->getFormat() == NULL) {
             mTracks.removeItemsAt(i);
         }
     }

     mScanning = false;
 }

 MPEG2PSExtractor::~MPEG2PSExtractor() {
 }

 size_t MPEG2PSExtractor::countTracks() {
     return mTracks.size();
 }

 sp<IMediaSource> MPEG2PSExtractor::getTrack(size_t index) {
     if (index >= mTracks.size()) {
         return NULL;
     }

     return new WrappedTrack(this, mTracks.valueAt(index));
 }

 sp<MetaData> MPEG2PSExtractor::getTrackMetaData(
         size_t index, uint32_t /* flags */) {
     if (index >= mTracks.size()) {
         return NULL;
     }

     return mTracks.valueAt(index)->getFormat();
 }

 sp<MetaData> MPEG2PSExtractor::getMetaData() {
     sp<MetaData> meta = new MetaData;
     meta->setCString(kKeyMIMEType, MEDIA_MIMETYPE_CONTAINER_MPEG2PS);

     return meta;
 }

 uint32_t MPEG2PSExtractor::flags() const {
     return CAN_PAUSE;
 }

 status_t MPEG2PSExtractor::feedMore() {
     Mutex::Autolock autoLock(mLock);

     // How much data we're reading at a time
     static const size_t kChunkSize = 8192;

     for (;;) {
         status_t err = dequeueChunk();

         if (err == -EAGAIN && mFinalResult == OK) {
             memmove(mBuffer->base(), mBuffer->data(), mBuffer->size());
             mBuffer->setRange(0, mBuffer->size());

             if (mBuffer->size() + kChunkSize > mBuffer->capacity()) {
                 size_t newCapacity = mBuffer->capacity() + kChunkSize;
                 sp<ABuffer> newBuffer = new ABuffer(newCapacity);
                 memcpy(newBuffer->data(), mBuffer->data(), mBuffer->size());
                 newBuffer->setRange(0, mBuffer->size());
                 mBuffer = newBuffer;
             }

             ssize_t n = mDataSource->readAt(
                     mOffset, mBuffer->data() + mBuffer->size(), kChunkSize);

             if (n < (ssize_t)kChunkSize) {
                 mFinalResult = (n < 0) ? (status_t)n : ERROR_END_OF_STREAM;
                 return mFinalResult;
             }

             mBuffer->setRange(mBuffer->offset(), mBuffer->size() + n);
             mOffset += n;
         } else if (err != OK) {
             mFinalResult = err;
             return err;
         } else {
             return OK;
         }
     }
 }

 status_t MPEG2PSExtractor::dequeueChunk() {
     if (mBuffer->size() < 4) {
         return -EAGAIN;
     }

     if (memcmp("\x00\x00\x01", mBuffer->data(), 3)) {
         return ERROR_MALFORMED;
     }

     unsigned chunkType = mBuffer->data()[3];

     ssize_t res;

     switch (chunkType) {
         case 0xba:
         {
             res = dequeuePack();
             break;
         }

         case 0xbb:
         {
             res = dequeueSystemHeader();
             break;
         }

         default:
         {
             res = dequeuePES();
             break;
         }
     }

     if (res > 0) {
         if (mBuffer->size() < (size_t)res) {
             return -EAGAIN;
         }

         mBuffer->setRange(mBuffer->offset() + res, mBuffer->size() - res);
         res = OK;
     }

     return res;
 }

 ssize_t MPEG2PSExtractor::dequeuePack() {
     // 32 + 2 + 3 + 1 + 15 + 1 + 15+ 1 + 9 + 1 + 22 + 1 + 1 | +5

     if (mBuffer->size() < 14) {
         return -EAGAIN;
     }

     unsigned pack_stuffing_length = mBuffer->data()[13] & 7;

     return pack_stuffing_length + 14;
 }

 ssize_t MPEG2PSExtractor::dequeueSystemHeader() {
     if (mBuffer->size() < 6) {
         return -EAGAIN;
     }

     unsigned header_length = U16_AT(mBuffer->data() + 4);

     return header_length + 6;
 }

 ssize_t MPEG2PSExtractor::dequeuePES() {
     if (mBuffer->size() < 6) {
         return -EAGAIN;
     }

     unsigned PES_packet_length = U16_AT(mBuffer->data() + 4);
     if (PES_packet_length == 0u) {
         ALOGE("PES_packet_length is 0");
         return -EAGAIN;
     }

     size_t n = PES_packet_length + 6;

     if (mBuffer->size() < n) {
         return -EAGAIN;
     }

     ABitReader br(mBuffer->data(), n);

     unsigned packet_startcode_prefix = br.getBits(24);

     ALOGV("packet_startcode_prefix = 0x%08x", packet_startcode_prefix);

     if (packet_startcode_prefix != 1) {
         ALOGV("Supposedly payload_unit_start=1 unit does not start "
              "with startcode.");

         return ERROR_MALFORMED;
     }

     if (packet_startcode_prefix != 0x000001u) {
         ALOGE("Wrong PES prefix");
         return ERROR_MALFORMED;
     }

     unsigned stream_id = br.getBits(8);
     ALOGV("stream_id = 0x%02x", stream_id);

     /* unsigned PES_packet_length = */br.getBits(16);

     if (stream_id == 0xbc) {
         // program_stream_map

         if (!mScanning) {
             return n;
         }

         mStreamTypeByESID.clear();

         /* unsigned current_next_indicator = */br.getBits(1);
         /* unsigned reserved = */br.getBits(2);
         /* unsigned program_stream_map_version = */br.getBits(5);
         /* unsigned reserved = */br.getBits(7);
         /* unsigned marker_bit = */br.getBits(1);
         unsigned program_stream_info_length = br.getBits(16);

         size_t offset = 0;
         while (offset < program_stream_info_length) {
             if (offset + 2 > program_stream_info_length) {
                 return ERROR_MALFORMED;
             }

             unsigned descriptor_tag = br.getBits(8);
             unsigned descriptor_length = br.getBits(8);

             ALOGI("found descriptor tag 0x%02x of length %u",
                  descriptor_tag, descriptor_length);

             if (offset + 2 + descriptor_length > program_stream_info_length) {
                 return ERROR_MALFORMED;
             }

             br.skipBits(8 * descriptor_length);

             offset += 2 + descriptor_length;
         }

         unsigned elementary_stream_map_length = br.getBits(16);

         offset = 0;
         while (offset < elementary_stream_map_length) {
             if (offset + 4 > elementary_stream_map_length) {
                 return ERROR_MALFORMED;
             }

             unsigned stream_type = br.getBits(8);
             unsigned elementary_stream_id = br.getBits(8);

             ALOGI("elementary stream id 0x%02x has stream type 0x%02x",
                  elementary_stream_id, stream_type);

             mStreamTypeByESID.add(elementary_stream_id, stream_type);

             unsigned elementary_stream_info_length = br.getBits(16);

             if (offset + 4 + elementary_stream_info_length
                     > elementary_stream_map_length) {
                 return ERROR_MALFORMED;
             }

             offset += 4 + elementary_stream_info_length;
         }

         /* unsigned CRC32 = */br.getBits(32);

         mProgramStreamMapValid = true;
     } else if (stream_id != 0xbe  // padding_stream
             && stream_id != 0xbf  // private_stream_2
             && stream_id != 0xf0  // ECM
             && stream_id != 0xf1  // EMM
             && stream_id != 0xff  // program_stream_directory
             && stream_id != 0xf2  // DSMCC
             && stream_id != 0xf8) {  // H.222.1 type E
         /* unsigned PES_marker_bits = */br.getBits(2);  // should be 0x2(hex)
         /* unsigned PES_scrambling_control = */br.getBits(2);
         /* unsigned PES_priority = */br.getBits(1);
         /* unsigned data_alignment_indicator = */br.getBits(1);
         /* unsigned copyright = */br.getBits(1);
         /* unsigned original_or_copy = */br.getBits(1);

         unsigned PTS_DTS_flags = br.getBits(2);
         ALOGV("PTS_DTS_flags = %u", PTS_DTS_flags);

         unsigned ESCR_flag = br.getBits(1);
         ALOGV("ESCR_flag = %u", ESCR_flag);

         unsigned ES_rate_flag = br.getBits(1);
         ALOGV("ES_rate_flag = %u", ES_rate_flag);

         unsigned DSM_trick_mode_flag = br.getBits(1);
         ALOGV("DSM_trick_mode_flag = %u", DSM_trick_mode_flag);

         unsigned additional_copy_info_flag = br.getBits(1);
         ALOGV("additional_copy_info_flag = %u", additional_copy_info_flag);

         /* unsigned PES_CRC_flag = */br.getBits(1);
         /* PES_extension_flag = */br.getBits(1);

         unsigned PES_header_data_length = br.getBits(8);
         ALOGV("PES_header_data_length = %u", PES_header_data_length);

         unsigned optional_bytes_remaining = PES_header_data_length;

         uint64_t PTS = 0, DTS = 0;

         if (PTS_DTS_flags == 2 || PTS_DTS_flags == 3) {
             if (optional_bytes_remaining < 5u) {
                 return ERROR_MALFORMED;
             }

             if (br.getBits(4) != PTS_DTS_flags) {
                 return ERROR_MALFORMED;
             }

             PTS = ((uint64_t)br.getBits(3)) << 30;
             if (br.getBits(1) != 1u) {
                 return ERROR_MALFORMED;
             }
             PTS |= ((uint64_t)br.getBits(15)) << 15;
             if (br.getBits(1) != 1u) {
                 return ERROR_MALFORMED;
             }
             PTS |= br.getBits(15);
             if (br.getBits(1) != 1u) {
                 return ERROR_MALFORMED;
             }

             ALOGV("PTS = %" PRIu64, PTS);
             // ALOGI("PTS = %.2f secs", PTS / 90000.0f);

             optional_bytes_remaining -= 5;

             if (PTS_DTS_flags == 3) {
                 if (optional_bytes_remaining < 5u) {
                     return ERROR_MALFORMED;
                 }

                 if (br.getBits(4) != 1u) {
                     return ERROR_MALFORMED;
                 }

                 DTS = ((uint64_t)br.getBits(3)) << 30;
                 if (br.getBits(1) != 1u) {
                     return ERROR_MALFORMED;
                 }
                 DTS |= ((uint64_t)br.getBits(15)) << 15;
                 if (br.getBits(1) != 1u) {
                     return ERROR_MALFORMED;
                 }
                 DTS |= br.getBits(15);
                 if (br.getBits(1) != 1u) {
                     return ERROR_MALFORMED;
                 }

                 ALOGV("DTS = %" PRIu64, DTS);

                 optional_bytes_remaining -= 5;
             }
         }

         if (ESCR_flag) {
             if (optional_bytes_remaining < 6u) {
                 return ERROR_MALFORMED;
             }

             br.getBits(2);

             uint64_t ESCR = ((uint64_t)br.getBits(3)) << 30;
             if (br.getBits(1) != 1u) {
                 return ERROR_MALFORMED;
             }
             ESCR |= ((uint64_t)br.getBits(15)) << 15;
             if (br.getBits(1) != 1u) {
                 return ERROR_MALFORMED;
             }
             ESCR |= br.getBits(15);
             if (br.getBits(1) != 1u) {
                 return ERROR_MALFORMED;
             }

             ALOGV("ESCR = %" PRIu64, ESCR);
             /* unsigned ESCR_extension = */br.getBits(9);

             if (br.getBits(1) != 1u) {
                 return ERROR_MALFORMED;
             }

             optional_bytes_remaining -= 6;
         }

         if (ES_rate_flag) {
             if (optional_bytes_remaining < 3u) {
                 return ERROR_MALFORMED;
             }

             if (br.getBits(1) != 1u) {
                 return ERROR_MALFORMED;
             }
             /* unsigned ES_rate = */br.getBits(22);
             if (br.getBits(1) != 1u) {
                 return ERROR_MALFORMED;
             }

             optional_bytes_remaining -= 3;
         }

         if (br.numBitsLeft() < optional_bytes_remaining * 8) {
             return ERROR_MALFORMED;
         }

         br.skipBits(optional_bytes_remaining * 8);

         // ES data follows.

         if (PES_packet_length < PES_header_data_length + 3) {
             return ERROR_MALFORMED;
         }

         unsigned dataLength =
             PES_packet_length - 3 - PES_header_data_length;

         if (br.numBitsLeft() < dataLength * 8) {
             ALOGE("PES packet does not carry enough data to contain "
                  "payload. (numBitsLeft = %zu, required = %u)",
                  br.numBitsLeft(), dataLength * 8);

             return ERROR_MALFORMED;
         }

         if (br.numBitsLeft() < dataLength * 8) {
             return ERROR_MALFORMED;
         }

         ssize_t index = mTracks.indexOfKey(stream_id);
         if (index < 0 && mScanning) {
             unsigned streamType;

             ssize_t streamTypeIndex;
             if (mProgramStreamMapValid
                     && (streamTypeIndex =
                             mStreamTypeByESID.indexOfKey(stream_id)) >= 0) {
                 streamType = mStreamTypeByESID.valueAt(streamTypeIndex);
             } else if ((stream_id & ~0x1f) == 0xc0) {
                 // ISO/IEC 13818-3 or ISO/IEC 11172-3 or ISO/IEC 13818-7
                 // or ISO/IEC 14496-3 audio
                 streamType = ATSParser::STREAMTYPE_MPEG2_AUDIO;
             } else if ((stream_id & ~0x0f) == 0xe0) {
                 // ISO/IEC 13818-2 or ISO/IEC 11172-2 or ISO/IEC 14496-2 video
                 streamType = ATSParser::STREAMTYPE_MPEG2_VIDEO;
             } else {
                 streamType = ATSParser::STREAMTYPE_RESERVED;
             }

             index = mTracks.add(
                     stream_id, new Track(this, stream_id, streamType));
         }

         status_t err = OK;

         if (index >= 0) {
             err =
                 mTracks.editValueAt(index)->appendPESData(
                     PTS_DTS_flags, PTS, DTS, br.data(), dataLength);
         }

         br.skipBits(dataLength * 8);

         if (err != OK) {
             return err;
         }
     } else if (stream_id == 0xbe) {  // padding_stream
         if (PES_packet_length == 0u) {
             return ERROR_MALFORMED;
         }
         br.skipBits(PES_packet_length * 8);
     } else {
         if (PES_packet_length == 0u) {
             return ERROR_MALFORMED;
         }
         br.skipBits(PES_packet_length * 8);
     }

     return n;
 }

 ////////////////////////////////////////////////////////////////////////////////

 MPEG2PSExtractor::Track::Track(
         MPEG2PSExtractor *extractor, unsigned stream_id, unsigned stream_type)
     : mExtractor(extractor),
       mStreamID(stream_id),
       mStreamType(stream_type),
       mQueue(NULL) {
     bool supported = true;
     ElementaryStreamQueue::Mode mode;

     switch (mStreamType) {
         case ATSParser::STREAMTYPE_H264:
             mode = ElementaryStreamQueue::H264;
             break;
         case ATSParser::STREAMTYPE_MPEG2_AUDIO_ADTS:
             mode = ElementaryStreamQueue::AAC;
             break;
         case ATSParser::STREAMTYPE_MPEG1_AUDIO:
         case ATSParser::STREAMTYPE_MPEG2_AUDIO:
             mode = ElementaryStreamQueue::MPEG_AUDIO;
             break;

         case ATSParser::STREAMTYPE_MPEG1_VIDEO:
         case ATSParser::STREAMTYPE_MPEG2_VIDEO:
             mode = ElementaryStreamQueue::MPEG_VIDEO;
             break;

         case ATSParser::STREAMTYPE_MPEG4_VIDEO:
             mode = ElementaryStreamQueue::MPEG4_VIDEO;
             break;

         default:
             supported = false;
             break;
     }

     if (supported) {
         mQueue = new ElementaryStreamQueue(mode);
     } else {
         ALOGI("unsupported stream ID 0x%02x", stream_id);
     }
 }

 MPEG2PSExtractor::Track::~Track() {
     delete mQueue;
     mQueue = NULL;
 }

 status_t MPEG2PSExtractor::Track::start(MetaData *params) {
     if (mSource == NULL) {
         return NO_INIT;
     }

     return mSource->start(params);
 }

 status_t MPEG2PSExtractor::Track::stop() {
     if (mSource == NULL) {
         return NO_INIT;
     }

     return mSource->stop();
 }

 sp<MetaData> MPEG2PSExtractor::Track::getFormat() {
     if (mSource == NULL) {
         return NULL;
     }

     return mSource->getFormat();
 }

 status_t MPEG2PSExtractor::Track::read(
         MediaBuffer **buffer, const ReadOptions *options) {
     if (mSource == NULL) {
         return NO_INIT;
     }

     status_t finalResult;
     while (!mSource->hasBufferAvailable(&finalResult)) {
         if (finalResult != OK) {
             return ERROR_END_OF_STREAM;
         }

         status_t err = mExtractor->feedMore();

         if (err != OK) {
             mSource->signalEOS(err);
         }
     }

     return mSource->read(buffer, options);
 }

 status_t MPEG2PSExtractor::Track::appendPESData(
         unsigned PTS_DTS_flags,
         uint64_t PTS, uint64_t /* DTS */,
         const uint8_t *data, size_t size) {
     if (mQueue == NULL) {
         return OK;
     }

     int64_t timeUs;
     if (PTS_DTS_flags == 2 || PTS_DTS_flags == 3) {
         timeUs = (PTS * 100) / 9;
     } else {
         timeUs = 0;
     }

     status_t err = mQueue->appendData(data, size, timeUs);

     if (err != OK) {
         return err;
     }

     sp<ABuffer> accessUnit;
     while ((accessUnit = mQueue->dequeueAccessUnit()) != NULL) {
         if (mSource == NULL) {
             sp<MetaData> meta = mQueue->getFormat();

             if (meta != NULL) {
                 ALOGV("Stream ID 0x%02x now has data.", mStreamID);

                 mSource = new AnotherPacketSource(meta);
                 mSource->queueAccessUnit(accessUnit);
             }
         } else if (mQueue->getFormat() != NULL) {
             mSource->queueAccessUnit(accessUnit);
         }
     }

     return OK;
 }

 ////////////////////////////////////////////////////////////////////////////////

 MPEG2PSExtractor::WrappedTrack::WrappedTrack(
         const sp<MPEG2PSExtractor> &extractor, const sp<Track> &track)
     : mExtractor(extractor),
       mTrack(track) {
 }

 MPEG2PSExtractor::WrappedTrack::~WrappedTrack() {
 }

 status_t MPEG2PSExtractor::WrappedTrack::start(MetaData *params) {
     return mTrack->start(params);
 }

 status_t MPEG2PSExtractor::WrappedTrack::stop() {
     return mTrack->stop();
 }

 sp<MetaData> MPEG2PSExtractor::WrappedTrack::getFormat() {
     return mTrack->getFormat();
 }

 status_t MPEG2PSExtractor::WrappedTrack::read(
         MediaBuffer **buffer, const ReadOptions *options) {
     return mTrack->read(buffer, options);
 }

 ////////////////////////////////////////////////////////////////////////////////

 bool SniffMPEG2PS(
         const sp<DataSource> &source, String8 *mimeType, float *confidence,
         sp<AMessage> *) {
     uint8_t header[5];
     if (source->readAt(0, header, sizeof(header)) < (ssize_t)sizeof(header)) {
         return false;
     }

     if (memcmp("\x00\x00\x01\xba", header, 4) || (header[4] >> 6) != 1) {
         return false;
     }

     *confidence = 0.25f;  // Slightly larger than .mp3 extractor's confidence

     mimeType->setTo(MEDIA_MIMETYPE_CONTAINER_MPEG2PS);

     return true;
 }

 }  // namespace android
	/*
	* Copyright (C) 2011 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	//#define LOG_NDEBUG 0
	#define LOG_TAG "MPEG2PSExtractor"
	#include <utils/Log.h>

	#include "include/MPEG2PSExtractor.h"

	#include "AnotherPacketSource.h"
	#include "ESQueue.h"

	#include <media/stagefright/foundation/ABitReader.h>
	#include <media/stagefright/foundation/ABuffer.h>
	#include <media/stagefright/foundation/ADebug.h>
	#include <media/stagefright/foundation/AMessage.h>
	#include <media/stagefright/foundation/hexdump.h>
	#include <media/stagefright/DataSource.h>
	#include <media/stagefright/MediaDefs.h>
	#include <media/stagefright/MediaErrors.h>
	#include <media/stagefright/MediaSource.h>
	#include <media/stagefright/MetaData.h>
	#include <media/stagefright/Utils.h>
	#include <utils/String8.h>

	#include <inttypes.h>

	namespace android {

	struct MPEG2PSExtractor::Track : public MediaSource {
	Track(MPEG2PSExtractor *extractor,
	unsigned stream_id, unsigned stream_type);

	virtual status_t start(MetaData *params);
	virtual status_t stop();
	virtual sp<MetaData> getFormat();

	virtual status_t read(
	MediaBuffer *buffer, const ReadOptions options);

	protected:
	virtual ~Track();

	private:
	friend struct MPEG2PSExtractor;

	MPEG2PSExtractor *mExtractor;

	unsigned mStreamID;
	unsigned mStreamType;
	ElementaryStreamQueue *mQueue;
	sp<AnotherPacketSource> mSource;

	status_t appendPESData(
	unsigned PTS_DTS_flags,
	uint64_t PTS, uint64_t DTS,
	const uint8_t *data, size_t size);

	DISALLOW_EVIL_CONSTRUCTORS(Track);
	};

	struct MPEG2PSExtractor::WrappedTrack : public MediaSource {
	WrappedTrack(const sp<MPEG2PSExtractor> &extractor, const sp<Track> &track);

	virtual status_t start(MetaData *params);
	virtual status_t stop();
	virtual sp<MetaData> getFormat();

	virtual status_t read(
	MediaBuffer *buffer, const ReadOptions options);

	protected:
	virtual ~WrappedTrack();

	private:
	sp<MPEG2PSExtractor> mExtractor;
	sp<MPEG2PSExtractor::Track> mTrack;

	DISALLOW_EVIL_CONSTRUCTORS(WrappedTrack);
	};

	////////////////////////////////////////////////////////////////////////////////

	MPEG2PSExtractor::MPEG2PSExtractor(const sp<DataSource> &source)
	: mDataSource(source),
	mOffset(0),
	mFinalResult(OK),
	mBuffer(new ABuffer(0)),
	mScanning(true),
	mProgramStreamMapValid(false) {
	for (size_t i = 0; i < 500; ++i) {
	if (feedMore() != OK) {
	break;
	}
	}

	// Remove all tracks that were unable to determine their format.
	for (size_t i = mTracks.size(); i > 0;) {
	i--;
	if (mTracks.valueAt(i)->getFormat() == NULL) {
	mTracks.removeItemsAt(i);
	}
	}

	mScanning = false;
	}

	MPEG2PSExtractor::~MPEG2PSExtractor() {
	}

	size_t MPEG2PSExtractor::countTracks() {
	return mTracks.size();
	}

	sp<IMediaSource> MPEG2PSExtractor::getTrack(size_t index) {
	if (index >= mTracks.size()) {
	return NULL;
	}

	return new WrappedTrack(this, mTracks.valueAt(index));
	}

	sp<MetaData> MPEG2PSExtractor::getTrackMetaData(
	size_t index, uint32_t /* flags */) {
	if (index >= mTracks.size()) {
	return NULL;
	}

	return mTracks.valueAt(index)->getFormat();
	}

	sp<MetaData> MPEG2PSExtractor::getMetaData() {
	sp<MetaData> meta = new MetaData;
	meta->setCString(kKeyMIMEType, MEDIA_MIMETYPE_CONTAINER_MPEG2PS);

	return meta;
	}

	uint32_t MPEG2PSExtractor::flags() const {
	return CAN_PAUSE;
	}

	status_t MPEG2PSExtractor::feedMore() {
	Mutex::Autolock autoLock(mLock);

	// How much data we're reading at a time
	static const size_t kChunkSize = 8192;

	for (;;) {
	status_t err = dequeueChunk();

	if (err == -EAGAIN && mFinalResult == OK) {
	memmove(mBuffer->base(), mBuffer->data(), mBuffer->size());
	mBuffer->setRange(0, mBuffer->size());

	if (mBuffer->size() + kChunkSize > mBuffer->capacity()) {
	size_t newCapacity = mBuffer->capacity() + kChunkSize;
	sp<ABuffer> newBuffer = new ABuffer(newCapacity);
	memcpy(newBuffer->data(), mBuffer->data(), mBuffer->size());
	newBuffer->setRange(0, mBuffer->size());
	mBuffer = newBuffer;
	}

	ssize_t n = mDataSource->readAt(
	mOffset, mBuffer->data() + mBuffer->size(), kChunkSize);

	if (n < (ssize_t)kChunkSize) {
	mFinalResult = (n < 0) ? (status_t)n : ERROR_END_OF_STREAM;
	return mFinalResult;
	}

	mBuffer->setRange(mBuffer->offset(), mBuffer->size() + n);
	mOffset += n;
	} else if (err != OK) {
	mFinalResult = err;
	return err;
	} else {
	return OK;
	}
	}
	}

	status_t MPEG2PSExtractor::dequeueChunk() {
	if (mBuffer->size() < 4) {
	return -EAGAIN;
	}

	if (memcmp("\x00\x00\x01", mBuffer->data(), 3)) {
	return ERROR_MALFORMED;
	}

	unsigned chunkType = mBuffer->data()[3];

	ssize_t res;

	switch (chunkType) {
	case 0xba:
	{
	res = dequeuePack();
	break;
	}

	case 0xbb:
	{
	res = dequeueSystemHeader();
	break;
	}

	default:
	{
	res = dequeuePES();
	break;
	}
	}

	if (res > 0) {
	if (mBuffer->size() < (size_t)res) {
	return -EAGAIN;
	}

	mBuffer->setRange(mBuffer->offset() + res, mBuffer->size() - res);
	res = OK;
	}

	return res;
	}

	ssize_t MPEG2PSExtractor::dequeuePack() {
	// 32 + 2 + 3 + 1 + 15 + 1 + 15+ 1 + 9 + 1 + 22 + 1 + 1 \| +5

	if (mBuffer->size() < 14) {
	return -EAGAIN;
	}

	unsigned pack_stuffing_length = mBuffer->data()[13] & 7;

	return pack_stuffing_length + 14;
	}

	ssize_t MPEG2PSExtractor::dequeueSystemHeader() {
	if (mBuffer->size() < 6) {
	return -EAGAIN;
	}

	unsigned header_length = U16_AT(mBuffer->data() + 4);

	return header_length + 6;
	}

	ssize_t MPEG2PSExtractor::dequeuePES() {
	if (mBuffer->size() < 6) {
	return -EAGAIN;
	}

	unsigned PES_packet_length = U16_AT(mBuffer->data() + 4);
	if (PES_packet_length == 0u) {
	ALOGE("PES_packet_length is 0");
	return -EAGAIN;
	}

	size_t n = PES_packet_length + 6;

	if (mBuffer->size() < n) {
	return -EAGAIN;
	}

	ABitReader br(mBuffer->data(), n);

	unsigned packet_startcode_prefix = br.getBits(24);

	ALOGV("packet_startcode_prefix = 0x%08x", packet_startcode_prefix);

	if (packet_startcode_prefix != 1) {
	ALOGV("Supposedly payload_unit_start=1 unit does not start "
	"with startcode.");

	return ERROR_MALFORMED;
	}

	if (packet_startcode_prefix != 0x000001u) {
	ALOGE("Wrong PES prefix");
	return ERROR_MALFORMED;
	}

	unsigned stream_id = br.getBits(8);
	ALOGV("stream_id = 0x%02x", stream_id);

	/* unsigned PES_packet_length = */br.getBits(16);

	if (stream_id == 0xbc) {
	// program_stream_map

	if (!mScanning) {
	return n;
	}

	mStreamTypeByESID.clear();

	/* unsigned current_next_indicator = */br.getBits(1);
	/* unsigned reserved = */br.getBits(2);
	/* unsigned program_stream_map_version = */br.getBits(5);
	/* unsigned reserved = */br.getBits(7);
	/* unsigned marker_bit = */br.getBits(1);
	unsigned program_stream_info_length = br.getBits(16);

	size_t offset = 0;
	while (offset < program_stream_info_length) {
	if (offset + 2 > program_stream_info_length) {
	return ERROR_MALFORMED;
	}

	unsigned descriptor_tag = br.getBits(8);
	unsigned descriptor_length = br.getBits(8);

	ALOGI("found descriptor tag 0x%02x of length %u",
	descriptor_tag, descriptor_length);

	if (offset + 2 + descriptor_length > program_stream_info_length) {
	return ERROR_MALFORMED;
	}

	br.skipBits(8 * descriptor_length);

	offset += 2 + descriptor_length;
	}

	unsigned elementary_stream_map_length = br.getBits(16);

	offset = 0;
	while (offset < elementary_stream_map_length) {
	if (offset + 4 > elementary_stream_map_length) {
	return ERROR_MALFORMED;
	}

	unsigned stream_type = br.getBits(8);
	unsigned elementary_stream_id = br.getBits(8);

	ALOGI("elementary stream id 0x%02x has stream type 0x%02x",
	elementary_stream_id, stream_type);

	mStreamTypeByESID.add(elementary_stream_id, stream_type);

	unsigned elementary_stream_info_length = br.getBits(16);

	if (offset + 4 + elementary_stream_info_length
	> elementary_stream_map_length) {
	return ERROR_MALFORMED;
	}

	offset += 4 + elementary_stream_info_length;
	}

	/* unsigned CRC32 = */br.getBits(32);

	mProgramStreamMapValid = true;
	} else if (stream_id != 0xbe // padding_stream
	&& stream_id != 0xbf // private_stream_2
	&& stream_id != 0xf0 // ECM
	&& stream_id != 0xf1 // EMM
	&& stream_id != 0xff // program_stream_directory
	&& stream_id != 0xf2 // DSMCC
	&& stream_id != 0xf8) { // H.222.1 type E
	/* unsigned PES_marker_bits = */br.getBits(2); // should be 0x2(hex)
	/* unsigned PES_scrambling_control = */br.getBits(2);
	/* unsigned PES_priority = */br.getBits(1);
	/* unsigned data_alignment_indicator = */br.getBits(1);
	/* unsigned copyright = */br.getBits(1);
	/* unsigned original_or_copy = */br.getBits(1);

	unsigned PTS_DTS_flags = br.getBits(2);
	ALOGV("PTS_DTS_flags = %u", PTS_DTS_flags);

	unsigned ESCR_flag = br.getBits(1);
	ALOGV("ESCR_flag = %u", ESCR_flag);

	unsigned ES_rate_flag = br.getBits(1);
	ALOGV("ES_rate_flag = %u", ES_rate_flag);

	unsigned DSM_trick_mode_flag = br.getBits(1);
	ALOGV("DSM_trick_mode_flag = %u", DSM_trick_mode_flag);

	unsigned additional_copy_info_flag = br.getBits(1);
	ALOGV("additional_copy_info_flag = %u", additional_copy_info_flag);

	/* unsigned PES_CRC_flag = */br.getBits(1);
	/* PES_extension_flag = */br.getBits(1);

	unsigned PES_header_data_length = br.getBits(8);
	ALOGV("PES_header_data_length = %u", PES_header_data_length);

	unsigned optional_bytes_remaining = PES_header_data_length;

	uint64_t PTS = 0, DTS = 0;

	if (PTS_DTS_flags == 2 \|\| PTS_DTS_flags == 3) {
	if (optional_bytes_remaining < 5u) {
	return ERROR_MALFORMED;
	}

	if (br.getBits(4) != PTS_DTS_flags) {
	return ERROR_MALFORMED;
	}

	PTS = ((uint64_t)br.getBits(3)) << 30;
	if (br.getBits(1) != 1u) {
	return ERROR_MALFORMED;
	}
	PTS \|= ((uint64_t)br.getBits(15)) << 15;
	if (br.getBits(1) != 1u) {
	return ERROR_MALFORMED;
	}
	PTS \|= br.getBits(15);
	if (br.getBits(1) != 1u) {
	return ERROR_MALFORMED;
	}

	ALOGV("PTS = %" PRIu64, PTS);
	// ALOGI("PTS = %.2f secs", PTS / 90000.0f);

	optional_bytes_remaining -= 5;

	if (PTS_DTS_flags == 3) {
	if (optional_bytes_remaining < 5u) {
	return ERROR_MALFORMED;
	}

	if (br.getBits(4) != 1u) {
	return ERROR_MALFORMED;
	}

	DTS = ((uint64_t)br.getBits(3)) << 30;
	if (br.getBits(1) != 1u) {
	return ERROR_MALFORMED;
	}
	DTS \|= ((uint64_t)br.getBits(15)) << 15;
	if (br.getBits(1) != 1u) {
	return ERROR_MALFORMED;
	}
	DTS \|= br.getBits(15);
	if (br.getBits(1) != 1u) {
	return ERROR_MALFORMED;
	}

	ALOGV("DTS = %" PRIu64, DTS);

	optional_bytes_remaining -= 5;
	}
	}

	if (ESCR_flag) {
	if (optional_bytes_remaining < 6u) {
	return ERROR_MALFORMED;
	}

	br.getBits(2);

	uint64_t ESCR = ((uint64_t)br.getBits(3)) << 30;
	if (br.getBits(1) != 1u) {
	return ERROR_MALFORMED;
	}
	ESCR \|= ((uint64_t)br.getBits(15)) << 15;
	if (br.getBits(1) != 1u) {
	return ERROR_MALFORMED;
	}
	ESCR \|= br.getBits(15);
	if (br.getBits(1) != 1u) {
	return ERROR_MALFORMED;
	}

	ALOGV("ESCR = %" PRIu64, ESCR);
	/* unsigned ESCR_extension = */br.getBits(9);

	if (br.getBits(1) != 1u) {
	return ERROR_MALFORMED;
	}

	optional_bytes_remaining -= 6;
	}

	if (ES_rate_flag) {
	if (optional_bytes_remaining < 3u) {
	return ERROR_MALFORMED;
	}

	if (br.getBits(1) != 1u) {
	return ERROR_MALFORMED;
	}
	/* unsigned ES_rate = */br.getBits(22);
	if (br.getBits(1) != 1u) {
	return ERROR_MALFORMED;
	}

	optional_bytes_remaining -= 3;
	}

	if (br.numBitsLeft() < optional_bytes_remaining * 8) {
	return ERROR_MALFORMED;
	}

	br.skipBits(optional_bytes_remaining * 8);

	// ES data follows.

	if (PES_packet_length < PES_header_data_length + 3) {
	return ERROR_MALFORMED;
	}

	unsigned dataLength =
	PES_packet_length - 3 - PES_header_data_length;

	if (br.numBitsLeft() < dataLength * 8) {
	ALOGE("PES packet does not carry enough data to contain "
	"payload. (numBitsLeft = %zu, required = %u)",
	br.numBitsLeft(), dataLength * 8);

	return ERROR_MALFORMED;
	}

	if (br.numBitsLeft() < dataLength * 8) {
	return ERROR_MALFORMED;
	}

	ssize_t index = mTracks.indexOfKey(stream_id);
	if (index < 0 && mScanning) {
	unsigned streamType;

	ssize_t streamTypeIndex;
	if (mProgramStreamMapValid
	&& (streamTypeIndex =
	mStreamTypeByESID.indexOfKey(stream_id)) >= 0) {
	streamType = mStreamTypeByESID.valueAt(streamTypeIndex);
	} else if ((stream_id & ~0x1f) == 0xc0) {
	// ISO/IEC 13818-3 or ISO/IEC 11172-3 or ISO/IEC 13818-7
	// or ISO/IEC 14496-3 audio
	streamType = ATSParser::STREAMTYPE_MPEG2_AUDIO;
	} else if ((stream_id & ~0x0f) == 0xe0) {
	// ISO/IEC 13818-2 or ISO/IEC 11172-2 or ISO/IEC 14496-2 video
	streamType = ATSParser::STREAMTYPE_MPEG2_VIDEO;
	} else {
	streamType = ATSParser::STREAMTYPE_RESERVED;
	}

	index = mTracks.add(
	stream_id, new Track(this, stream_id, streamType));
	}

	status_t err = OK;

	if (index >= 0) {
	err =
	mTracks.editValueAt(index)->appendPESData(
	PTS_DTS_flags, PTS, DTS, br.data(), dataLength);
	}

	br.skipBits(dataLength * 8);

	if (err != OK) {
	return err;
	}
	} else if (stream_id == 0xbe) { // padding_stream
	if (PES_packet_length == 0u) {
	return ERROR_MALFORMED;
	}
	br.skipBits(PES_packet_length * 8);
	} else {
	if (PES_packet_length == 0u) {
	return ERROR_MALFORMED;
	}
	br.skipBits(PES_packet_length * 8);
	}

	return n;
	}

	////////////////////////////////////////////////////////////////////////////////

	MPEG2PSExtractor::Track::Track(
	MPEG2PSExtractor *extractor, unsigned stream_id, unsigned stream_type)
	: mExtractor(extractor),
	mStreamID(stream_id),
	mStreamType(stream_type),
	mQueue(NULL) {
	bool supported = true;
	ElementaryStreamQueue::Mode mode;

	switch (mStreamType) {
	case ATSParser::STREAMTYPE_H264:
	mode = ElementaryStreamQueue::H264;
	break;
	case ATSParser::STREAMTYPE_MPEG2_AUDIO_ADTS:
	mode = ElementaryStreamQueue::AAC;
	break;
	case ATSParser::STREAMTYPE_MPEG1_AUDIO:
	case ATSParser::STREAMTYPE_MPEG2_AUDIO:
	mode = ElementaryStreamQueue::MPEG_AUDIO;
	break;

	case ATSParser::STREAMTYPE_MPEG1_VIDEO:
	case ATSParser::STREAMTYPE_MPEG2_VIDEO:
	mode = ElementaryStreamQueue::MPEG_VIDEO;
	break;

	case ATSParser::STREAMTYPE_MPEG4_VIDEO:
	mode = ElementaryStreamQueue::MPEG4_VIDEO;
	break;

	default:
	supported = false;
	break;
	}

	if (supported) {
	mQueue = new ElementaryStreamQueue(mode);
	} else {
	ALOGI("unsupported stream ID 0x%02x", stream_id);
	}
	}

	MPEG2PSExtractor::Track::~Track() {
	delete mQueue;
	mQueue = NULL;
	}

	status_t MPEG2PSExtractor::Track::start(MetaData *params) {
	if (mSource == NULL) {
	return NO_INIT;
	}

	return mSource->start(params);
	}

	status_t MPEG2PSExtractor::Track::stop() {
	if (mSource == NULL) {
	return NO_INIT;
	}

	return mSource->stop();
	}

	sp<MetaData> MPEG2PSExtractor::Track::getFormat() {
	if (mSource == NULL) {
	return NULL;
	}

	return mSource->getFormat();
	}

	status_t MPEG2PSExtractor::Track::read(
	MediaBuffer *buffer, const ReadOptions options) {
	if (mSource == NULL) {
	return NO_INIT;
	}

	status_t finalResult;
	while (!mSource->hasBufferAvailable(&finalResult)) {
	if (finalResult != OK) {
	return ERROR_END_OF_STREAM;
	}

	status_t err = mExtractor->feedMore();

	if (err != OK) {
	mSource->signalEOS(err);
	}
	}

	return mSource->read(buffer, options);
	}

	status_t MPEG2PSExtractor::Track::appendPESData(
	unsigned PTS_DTS_flags,
	uint64_t PTS, uint64_t /* DTS */,
	const uint8_t *data, size_t size) {
	if (mQueue == NULL) {
	return OK;
	}

	int64_t timeUs;
	if (PTS_DTS_flags == 2 \|\| PTS_DTS_flags == 3) {
	timeUs = (PTS * 100) / 9;
	} else {
	timeUs = 0;
	}

	status_t err = mQueue->appendData(data, size, timeUs);

	if (err != OK) {
	return err;
	}

	sp<ABuffer> accessUnit;
	while ((accessUnit = mQueue->dequeueAccessUnit()) != NULL) {
	if (mSource == NULL) {
	sp<MetaData> meta = mQueue->getFormat();

	if (meta != NULL) {
	ALOGV("Stream ID 0x%02x now has data.", mStreamID);

	mSource = new AnotherPacketSource(meta);
	mSource->queueAccessUnit(accessUnit);
	}
	} else if (mQueue->getFormat() != NULL) {
	mSource->queueAccessUnit(accessUnit);
	}
	}

	return OK;
	}

	////////////////////////////////////////////////////////////////////////////////

	MPEG2PSExtractor::WrappedTrack::WrappedTrack(
	const sp<MPEG2PSExtractor> &extractor, const sp<Track> &track)
	: mExtractor(extractor),
	mTrack(track) {
	}

	MPEG2PSExtractor::WrappedTrack::~WrappedTrack() {
	}

	status_t MPEG2PSExtractor::WrappedTrack::start(MetaData *params) {
	return mTrack->start(params);
	}

	status_t MPEG2PSExtractor::WrappedTrack::stop() {
	return mTrack->stop();
	}

	sp<MetaData> MPEG2PSExtractor::WrappedTrack::getFormat() {
	return mTrack->getFormat();
	}

	status_t MPEG2PSExtractor::WrappedTrack::read(
	MediaBuffer *buffer, const ReadOptions options) {
	return mTrack->read(buffer, options);
	}

	////////////////////////////////////////////////////////////////////////////////

	bool SniffMPEG2PS(
	const sp<DataSource> &source, String8 mimeType, float confidence,
	sp<AMessage> *) {
	uint8_t header[5];
	if (source->readAt(0, header, sizeof(header)) < (ssize_t)sizeof(header)) {
	return false;
	}

	if (memcmp("\x00\x00\x01\xba", header, 4) \|\| (header[4] >> 6) != 1) {
	return false;
	}

	*confidence = 0.25f; // Slightly larger than .mp3 extractor's confidence

	mimeType->setTo(MEDIA_MIMETYPE_CONTAINER_MPEG2PS);

	return true;
	}

	} // namespace android