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var
mp2t = require('../lib/m2ts'),
id3Generator = require('./utils/id3-generator'),
MP2T_PACKET_LENGTH = mp2t.MP2T_PACKET_LENGTH,
PMT,
PAT,
generatePMT,
pesHeader,
packetize,
transportPacket,
videoPes,
adtsFrame,
audioPes,
timedMetadataPes,
binaryStringToArrayOfBytes,
leftPad;
PMT = [
0x47, // sync byte
// tei:0 pusi:1 tp:0 pid:0 0000 0010 0000
0x40, 0x10,
// tsc:01 afc:01 cc:0000 pointer_field:0000 0000
0x50, 0x00,
// tid:0000 0010 ssi:0 0:0 r:00 sl:0000 0001 1100
0x02, 0x00, 0x1c,
// pn:0000 0000 0000 0001
0x00, 0x01,
// r:00 vn:00 000 cni:1 sn:0000 0000 lsn:0000 0000
0x01, 0x00, 0x00,
// r:000 ppid:0 0011 1111 1111
0x03, 0xff,
// r:0000 pil:0000 0000 0000
0x00, 0x00,
// h264
// st:0001 1010 r:000 epid:0 0000 0001 0001
0x1b, 0x00, 0x11,
// r:0000 esil:0000 0000 0000
0x00, 0x00,
// adts
// st:0000 1111 r:000 epid:0 0000 0001 0010
0x0f, 0x00, 0x12,
// r:0000 esil:0000 0000 0000
0x00, 0x00,
// timed metadata
// st:0001 0111 r:000 epid:0 0000 0001 0011
0x15, 0x00, 0x13,
// r:0000 esil:0000 0000 0000
0x00, 0x00,
// crc
0x00, 0x00, 0x00, 0x00
];
/*
Packet Header:
| sb | tei pusi tp pid:5 | pid | tsc afc cc |
with af:
| afl | ... | <data> |
without af:
| <data> |
PAT:
| pf? | ... |
| tid | ssi '0' r sl:4 | sl | tsi:8 |
| tsi | r vn cni | sn | lsn |
with program_number == '0':
| pn | pn | r np:5 | np |
otherwise:
| pn | pn | r pmp:5 | pmp |
*/
PAT = [
0x47, // sync byte
// tei:0 pusi:1 tp:0 pid:0 0000 0000 0000
0x40, 0x00,
// tsc:01 afc:01 cc:0000 pointer_field:0000 0000
0x50, 0x00,
// tid:0000 0000 ssi:0 0:0 r:00 sl:0000 0000 0000
0x00, 0x00, 0x00,
// tsi:0000 0000 0000 0000
0x00, 0x00,
// r:00 vn:00 000 cni:1 sn:0000 0000 lsn:0000 0000
0x01, 0x00, 0x00,
// pn:0000 0000 0000 0001
0x00, 0x01,
// r:000 pmp:0 0000 0010 0000
0x00, 0x10,
// crc32:0000 0000 0000 0000 0000 0000 0000 0000
0x00, 0x00, 0x00, 0x00
];
generatePMT = function(options) {
var PMT = [
0x47, // sync byte
// tei:0 pusi:1 tp:0 pid:0 0000 0010 0000
0x40, 0x10,
// tsc:01 afc:01 cc:0000 pointer_field:0000 0000
0x50, 0x00,
// tid:0000 0010 ssi:0 0:0 r:00 sl:0000 0001 1100
0x02, 0x00, 0x1c,
// pn:0000 0000 0000 0001
0x00, 0x01,
// r:00 vn:00 000 cni:1 sn:0000 0000 lsn:0000 0000
0x01, 0x00, 0x00,
// r:000 ppid:0 0011 1111 1111
0x03, 0xff,
// r:0000 pil:0000 0000 0000
0x00, 0x00];
if (options.hasVideo) {
// h264
PMT = PMT.concat([
// st:0001 1010 r:000 epid:0 0000 0001 0001
0x1b, 0x00, 0x11,
// r:0000 esil:0000 0000 0000
0x00, 0x00
]);
}
if (options.hasAudio) {
// adts
PMT = PMT.concat([
// st:0000 1111 r:000 epid:0 0000 0001 0010
0x0f, 0x00, 0x12,
// r:0000 esil:0000 0000 0000
0x00, 0x00
]);
}
if (options.hasMetadata) {
// timed metadata
PMT = PMT.concat([
// st:0001 0111 r:000 epid:0 0000 0001 0011
0x15, 0x00, 0x13,
// r:0000 esil:0000 0000 0000
0x00, 0x00
]);
}
// crc
return PMT.concat([0x00, 0x00, 0x00, 0x00]);
};
pesHeader = function(first, pts, dataLength) {
if (!dataLength) {
dataLength = 0;
} else {
// Add the pes header length (only the portion after the
// pes_packet_length field)
dataLength += 3;
}
// PES_packet(), Rec. ITU-T H.222.0, Table 2-21
var result = [
// pscp:0000 0000 0000 0000 0000 0001
0x00, 0x00, 0x01,
// sid:0000 0000 ppl:0000 0000 0000 0000
0x00, 0x00, 0x00,
// 10 psc:00 pp:0 dai:1 c:0 ooc:0
0x84,
// pdf:?0 ef:1 erf:0 dtmf:0 acif:0 pcf:0 pef:0
0x20 | (pts ? 0x80 : 0x00),
// phdl:0000 0000
(first ? 0x01 : 0x00) + (pts ? 0x05 : 0x00)
];
// Only store 15 bits of the PTS for QUnit.testing purposes
if (pts) {
var
pts32 = Math.floor(pts / 2), // right shift by 1
leftMostBit = ((pts32 & 0x80000000) >>> 31) & 0x01,
firstThree;
pts = pts & 0xffffffff; // remove left most bit
firstThree = (leftMostBit << 3) | (((pts & 0xc0000000) >>> 29) & 0x06) | 0x01;
result.push((0x2 << 4) | firstThree);
result.push((pts >>> 22) & 0xff);
result.push(((pts >>> 14) | 0x01) & 0xff);
result.push((pts >>> 7) & 0xff);
result.push(((pts << 1) | 0x01) & 0xff);
// Add the bytes spent on the pts info
dataLength += 5;
}
if (first) {
result.push(0x00);
dataLength += 1;
}
// Finally set the pes_packet_length field
result[4] = (dataLength & 0x0000FF00) >> 8;
result[5] = dataLength & 0x000000FF;
return result;
};
packetize = function(data) {
var packet = new Uint8Array(MP2T_PACKET_LENGTH);
packet.set(data);
return packet;
};
/**
* Helper function to create transport stream PES packets
* @param pid {uint8} - the program identifier (PID)
* @param data {arraylike} - the payload bytes
* @payload first {boolean} - true if this PES should be a payload
* unit start
*/
transportPacket = function(pid, data, first, pts, isVideoData) {
var
adaptationFieldLength = 188 - data.length - 14 - (first ? 1 : 0) - (pts ? 5 : 0),
// transport_packet(), Rec. ITU-T H.222.0, Table 2-2
result = [
// sync byte
0x47,
// tei:0 pusi:1 tp:0 pid:0 0000 0001 0001
0x40, pid,
// tsc:01 afc:11 cc:0000
0x70
].concat([
// afl
adaptationFieldLength & 0xff,
// di:0 rai:0 espi:0 pf:0 of:0 spf:0 tpdf:0 afef:0
0x00
]),
i;
i = adaptationFieldLength - 1;
while (i--) {
// stuffing_bytes
result.push(0xff);
}
// PES_packet(), Rec. ITU-T H.222.0, Table 2-21
result = result.concat(pesHeader(first, pts, isVideoData ? 0 : data.length));
return result.concat(data);
};
/**
* Helper function to create video PES packets
* @param data {arraylike} - the payload bytes
* @payload first {boolean} - true if this PES should be a payload
* unit start
*/
videoPes = function(data, first, pts) {
return transportPacket(0x11, [
// NAL unit start code
0x00, 0x00, 0x01
].concat(data), first, pts, true);
};
/**
* Helper function to create audio ADTS frame header
* @param dataLength {number} - the payload byte count
*/
adtsFrame = function(dataLength) {
var frameLength = dataLength + 7;
return [
0xff, 0xf1, // no CRC
0x10, // AAC Main, 44.1KHz
0xb0 | ((frameLength & 0x1800) >> 11), // 2 channels
(frameLength & 0x7f8) >> 3,
((frameLength & 0x07) << 5) + 7, // frame length in bytes
0x00 // one AAC per ADTS frame
];
};
/**
* Helper function to create audio PES packets
* @param data {arraylike} - the payload bytes
* @payload first {boolean} - true if this PES should be a payload
* unit start
*/
audioPes = function(data, first, pts) {
return transportPacket(0x12,
adtsFrame(data.length).concat(data),
first, pts);
};
timedMetadataPes = function(data) {
var id3 = id3Generator;
return transportPacket(0x13, id3.id3Tag(id3.id3Frame('PRIV', 0x00, 0x01)));
};
binaryStringToArrayOfBytes = function(string) {
var
array = [],
arrayIndex = 0,
stringIndex = 0;
while (stringIndex < string.length) {
array[arrayIndex] = parseInt(string.slice(stringIndex, stringIndex + 8), 2);
arrayIndex++;
// next byte
stringIndex += 8;
}
return array;
};
leftPad = function(string, targetLength) {
if (string.length >= targetLength) {
return string;
}
return new Array(targetLength - string.length + 1).join('0') + string;
};
module.exports = {
PMT: PMT,
PAT: PAT,
generatePMT: generatePMT,
pesHeader: pesHeader,
packetize: packetize,
transportPacket: transportPacket,
videoPes: videoPes,
adtsFrame: adtsFrame,
audioPes: audioPes,
timedMetadataPes: timedMetadataPes,
binaryStringToArrayOfBytes: binaryStringToArrayOfBytes,
leftPad: leftPad
};