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TSDemuxer:systematically reparse PMT to discover new PIDs ASAP
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related to #502
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@mangui
mangui committed Apr 14, 2016
1 parent 3988b57 commit 1996789
Showing 1 changed file with 72 additions and 64 deletions.
136 changes: 72 additions & 64 deletions src/org/mangui/hls/demux/TSDemuxer.as
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Original file line number Diff line number Diff line change
Expand Up @@ -221,67 +221,67 @@ package org.mangui.hls.demux {
private function readCC(pes : PES):void
{
var country_code : uint = pes.data.readUnsignedByte();

if (country_code == 181)
{
var provider_code : uint = pes.data.readUnsignedShort();

if (provider_code == 49)
{
var user_structure : uint = pes.data.readUnsignedInt();

if (user_structure == 0x47413934) // GA94
{
var user_data_type : uint = pes.data.readUnsignedByte();

// CEA-608 wrapped in 708 ( user_data_type == 4 is raw 608, not handled yet )
if (user_data_type == 3)
{
// cc -- the first 8 bits are 1-Boolean-0 and the 5 bits for the number of CCs
var byte:uint = pes.data.readUnsignedByte();

// get the total number of cc_datas
var total:uint = 31 & byte;
var count:uint = 0;

// supposedly a flag to process the cc_datas or not
// isn't working for me, so i don't use it yet
var process:Boolean = !((64 & byte) == 0);

var size:uint = total * 3;

// em_data, do we need? It's not used for anything, but it's there, so i need to pull it out
var otherByte:uint = pes.data.readUnsignedByte();

if (pes.data.bytesAvailable >= size)
{
// ByteArray for onCaptionInfo event
var sei : ByteArray = new ByteArray();

// onCaptionInfo payloads need to know the size of the binary data
// there's two two bytes we just read, plus the cc_datas, which are 3 bytes each
sei.writeUnsignedInt(2+3*total);

// write those two bytes
sei.writeByte(byte);
sei.writeByte(otherByte);

// write the cc_datas
pes.data.readBytes(sei, 6, 3*total);

pes.data.position -= total * 3;

// onCaptionInfo expects Base64 data...
var sei_data:String = Base64.encode(sei);

var cc_data:Object = {
type: "708",
data: sei_data
};

// add a new FLVTag with the onCaptionInfo call
var tag:FLVTag = new FLVTag(FLVTag.METADATA, pes.pts, pes.pts, false);

var data : ByteArray = new ByteArray();
data.objectEncoding = ObjectEncoding.AMF0;
data.writeObject("onCaptionInfo");
Expand All @@ -303,7 +303,7 @@ package org.mangui.hls.demux {
}
}
}

/** Parse a limited amount of packets each time to avoid blocking **/
private function _parseTimer(e : Event) : void {
var start_time : int = getTimer();
Expand Down Expand Up @@ -612,16 +612,16 @@ package org.mangui.hls.demux {
pes.data.readBytes(pps, 0, frame.length);
ppsvect.push(pps);
} else if (frame.type == 6) {

//unescape Emulation Prevention bytes
Nalu.unescapeStream(pes.data,frame.start,frame.start + frame.length);

// We already know it's 6, so skip first byte
pes.data.position = frame.start + 1;

// we need at least 12 bytes to retrieve Caption length
if(pes.data.bytesAvailable > 12) {

// get the SEI payload type
var payload_type : uint = 0;
var payload_size : uint = 0;
Expand All @@ -634,7 +634,7 @@ package org.mangui.hls.demux {
// Parse payload size.
payload_size = 0;
do {
payload_size += pes.data.readUnsignedByte();
payload_size += pes.data.readUnsignedByte();
} while (pes.data.bytesAvailable!=0 && payload_size == 0xFF);
// Process the payload. We only support EIA-608 payloads currently.
if (payload_type == 4) {
Expand Down Expand Up @@ -844,21 +844,22 @@ package org.mangui.hls.demux {
Log.warn("TS: reparsing PMT, unknown PID found");
}
}
todo -= _parsePMT(stt,data);
// if PMT was not parsed before, and some unknown packets have been skipped in between,
// rewind to beginning of the stream, it helps recovering bad segmented content
// in theory there should be no A/V packets before PAT/PMT)
if (_pmtParsed == false && _unknownPIDFound == true) {
CONFIG::LOGGING {
Log.warn("TS: late PMT found, rewinding at beginning of TS");
}
_pmtParsed = true;
_readPosition = 0;
return;
}
// always reparse PMT
todo -= _parsePMT(stt,data);
// if PMT was not parsed before, and some unknown packets have been skipped in between,
// rewind to beginning of the stream, it helps recovering bad segmented content
// in theory there should be no A/V packets before PAT/PMT)
if (_pmtParsed == false && _unknownPIDFound == true) {
CONFIG::LOGGING {
Log.warn("TS: late PMT found, rewinding at beginning of TS");
}
_pmtParsed = true;
_unknownPIDFound = false;
_readPosition = 0;
return;
}
_pmtParsed = true;
_unknownPIDFound = false;
break;
case _audioId:
if (_pmtParsed == false) {
Expand Down Expand Up @@ -1012,9 +1013,11 @@ package org.mangui.hls.demux {
} else if (typ == 0x1B) {
// ITU-T Rec. H.264 and ISO/IEC 14496-10 (lower bit-rate video)
if(_audioOnly == false) {
_avcId = sid;
CONFIG::LOGGING {
Log.debug("TS: Selected video PID: " + _avcId);
if(_avcId != sid) {
_avcId = sid;
CONFIG::LOGGING {
Log.debug("TS: Selected video PID: " + _avcId);
}
}
} else {
CONFIG::LOGGING {
Expand All @@ -1027,9 +1030,11 @@ package org.mangui.hls.demux {
audioList.push(new AudioTrack('TS/MP3 ' + audioList.length, AudioTrack.FROM_DEMUX, sid, (audioList.length == 0), false));
} else if (typ == 0x15) {
// ID3 pid
_id3Id = sid;
CONFIG::LOGGING {
Log.debug("TS: Selected ID3 PID: " + _id3Id);
if(_id3Id != sid) {
_id3Id = sid;
CONFIG::LOGGING {
Log.debug("TS: Selected ID3 PID: " + _id3Id);
}
}
}
// es_info_length
Expand All @@ -1039,34 +1044,37 @@ package org.mangui.hls.demux {
read += sel + 5;
}

CONFIG::LOGGING {
if (audioList.length) {
Log.debug("TS: Found " + audioList.length + " audio tracks");
}
}
// provide audio track List to audio select callback. this callback will return the selected audio track
var audioPID : int;
_audioFound = (audioList.length > 0);
var audioTrack : AudioTrack = _callback_audioselect(audioList);
if (audioTrack) {
audioPID = audioTrack.id;
_audioIsAAC = audioTrack.isAAC;
_audioSelected = true;
var audioFound : Boolean = (audioList.length > 0);
if (audioFound != _audioFound) {
CONFIG::LOGGING {
Log.debug("TS: selected " + (_audioIsAAC ? "AAC" : "MP3") + " PID: " + audioPID);
if (audioFound) {
Log.debug("TS: Found " + audioList.length + " audio tracks");
}
}
} else {
audioPID = -1;
_audioSelected = false;
CONFIG::LOGGING {
Log.debug("TS: no audio selected");
_audioFound = audioFound;
var audioTrack : AudioTrack = _callback_audioselect(audioList);
if (audioTrack) {
audioPID = audioTrack.id;
_audioIsAAC = audioTrack.isAAC;
_audioSelected = true;
CONFIG::LOGGING {
Log.debug("TS: selected " + (_audioIsAAC ? "AAC" : "MP3") + " PID: " + audioPID);
}
} else {
audioPID = -1;
_audioSelected = false;
CONFIG::LOGGING {
Log.debug("TS: no audio selected");
}
}
// in case audio PID change, flush any partially parsed audio PES packet
if (audioPID != _audioId) {
_curAudioPES = null;
_adtsFrameOverflow = null;
_audioId = audioPID;
}
}
// in case audio PID change, flush any partially parsed audio PES packet
if (audioPID != _audioId) {
_curAudioPES = null;
_adtsFrameOverflow = null;
_audioId = audioPID;
}
return len + pointerField;
};
Expand Down

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