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/*
* PES elementary stream functions
* Copyright (C) 2010-2011 Unix Solutions Ltd.
*
* Released under MIT license.
* See LICENSE-MIT.txt for license terms.
*/
#include <netdb.h>
#include <string.h>
#include "tsfuncs.h"
int ts_pes_es_mpeg_audio_header_parse(struct mpeg_audio_header *mpghdr, uint8_t *data, int datasz) {
if (datasz < 4)
return 0;
uint8_t d1 = data[0];
uint8_t d2 = data[1];
uint8_t d3 = data[2];
uint8_t d4 = data[3];
mpghdr->syncword = (int)d1 << 4 | (d2 >> 4); // 12 bits
mpghdr->ID = bit_on(d2, bit_4); // 1 bit
mpghdr->layer = (d2 &~ 0xf9) >> 1; // 2 bits
mpghdr->protection_bit = bit_on(d2, bit_1); // 1 bit
mpghdr->bitrate_index = d3 >> 4; // 4 bits
mpghdr->sampl_freq = (d3 &~ 0xf3) >> 2; // 2 bits
mpghdr->padding_bit = bit_on(d3, bit_2); // 1 bit
mpghdr->private_bit = bit_on(d3, bit_1); // 1 bit
mpghdr->mode = d4 >> 6; // 2 bits
mpghdr->mode_extension = (d4 &~ 0xcf) >> 4; // 2 bits
mpghdr->copyright = bit_on(d4, bit_4); // 1 bit
mpghdr->org_home = bit_on(d4, bit_3); // 1 bit
mpghdr->emphasis = d4 &~ 0xfc; // 2 bits
if (mpghdr->syncword != 0xfff) {
ts_LOGf("!!! Error parsing mpeg audio header! Syncword should be 0xfff but it is 0x%03x!\n", mpghdr->syncword);
return 0;
} else {
mpghdr->initialized = 1;
return 1;
}
}
void ts_pes_es_mpeg_audio_header_dump(struct mpeg_audio_header *mpghdr) {
if (!mpghdr->initialized)
return;
// See ISO-11172-3 for more info
ts_LOGf(" - ES analyze audio frame\n");
ts_LOGf(" - Syncword : %x\n", mpghdr->syncword);
if (mpghdr->syncword != 0xfff) {
ts_LOGf("!!! ERROR: MPEG audo Syncword should be 0xfff!\n");
return;
}
ts_LOGf(" - ID : %d (%s)\n", mpghdr->ID, mpghdr->ID ? "MPEG Audio" : "Other");
ts_LOGf(" - layer : %d (%s)\n", mpghdr->layer,
mpghdr->layer == 0 ? "reserved" :
mpghdr->layer == 1 ? "Layer III" :
mpghdr->layer == 2 ? "Layer II" :
mpghdr->layer == 3 ? "Layer I" : "reserved"
);
ts_LOGf(" - protection_bit: %x\n", mpghdr->protection_bit);
int br = 0;
if (mpghdr->layer > 0 && mpghdr->layer < 4) {
int bitrate_index_table[4][16] = {
[3] = { 0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448, -1}, // Layer 1
[2] = { 0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, -1}, // Layer 2
[1] = { 0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, -1} // Layer 3
};
br = bitrate_index_table[mpghdr->layer][mpghdr->bitrate_index];
}
ts_LOGf(" - bitrate_index : %d (%d kBit/s)\n", mpghdr->bitrate_index, br);
ts_LOGf(" - sampl_freq : %d (%s)\n", mpghdr->sampl_freq,
mpghdr->sampl_freq == 0 ? "44.1 kHz" :
mpghdr->sampl_freq == 1 ? "48 kHz" :
mpghdr->sampl_freq == 2 ? "32 kHz" : "reserved"
);
ts_LOGf(" - padding_bit : %d\n", mpghdr->padding_bit);
ts_LOGf(" - private_bit : %d\n", mpghdr->private_bit);
ts_LOGf(" - mode : %d (%s)\n", mpghdr->mode,
mpghdr->mode == 0 ? "stereo" :
mpghdr->mode == 1 ? "join_stereo" :
mpghdr->mode == 2 ? "dual_channel" : "single_channel"
);
ts_LOGf(" - mode_extension: %x\n", mpghdr->mode_extension);
ts_LOGf(" - copyright : %x\n", mpghdr->copyright);
ts_LOGf(" - org_home : %x\n", mpghdr->org_home);
ts_LOGf(" - emphasis : %d (%s)\n", mpghdr->emphasis,
mpghdr->emphasis == 0 ? "none" :
mpghdr->emphasis == 1 ? "50/15 microseconds" :
mpghdr->emphasis == 2 ? "reserved" : "CCITT J.17"
);
}
void ts_pes_es_parse(struct ts_pes *pes) {
if (!pes->es_data)
return;
// Parse MPEG audio packet header
if ((pes->is_audio_mpeg1 || pes->is_audio_mpeg2) && pes->es_data_size > 4) {
struct mpeg_audio_header mpghdr;
memset(&mpghdr, 0, sizeof(struct mpeg_audio_header));
ts_pes_es_mpeg_audio_header_parse(&mpghdr, pes->es_data, pes->es_data_size);
if (mpghdr.initialized) {
pes->mpeg_audio_header = mpghdr;
if (mpghdr.ID) {
switch (mpghdr.layer) {
case 3: pes->is_audio_mpeg1l1 = 1; break;
case 2: pes->is_audio_mpeg1l2 = 1; break;
case 1: pes->is_audio_mpeg1l3 = 1; break;
}
}
}
}
// Look into elementary streams to detect AC3/DTS
if (pes->is_audio_ac3) {
if (pes->real_pes_packet_len >= 2 && (pes->es_data[0] == 0x0B && pes->es_data[1] == 0x77)) {
pes->is_audio = 1;
pes->is_audio_ac3 = 1;
pes->is_audio_dts = 0;
}
if (pes->real_pes_packet_len >= 4 && (pes->es_data[0] == 0x7f && pes->es_data[1] == 0xfe && pes->es_data[2] == 0x80 && pes->es_data[3] == 0x01)) {
pes->is_audio = 1;
pes->is_audio_ac3 = 0;
pes->is_audio_dts = 1;
}
}
}
void ts_pes_es_dump(struct ts_pes *pes) {
if (pes->is_audio && pes->mpeg_audio_header.initialized) {
ts_pes_es_mpeg_audio_header_dump(&pes->mpeg_audio_header);
}
}
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