1 /*
2 * PES elementary stream functions
3 * Copyright (C) 2010-2011 Unix Solutions Ltd.
4 *
5 * Released under MIT license.
6 * See LICENSE-MIT.txt for license terms.
7 */
8 #include <netdb.h>
9 #include <string.h>
10
11 #include "tsfuncs.h"
12
ts_pes_es_mpeg_audio_header_parse(struct mpeg_audio_header * mpghdr,uint8_t * data,int datasz)13 int ts_pes_es_mpeg_audio_header_parse(struct mpeg_audio_header *mpghdr, uint8_t *data, int datasz) {
14 if (datasz < 4)
15 return 0;
16
17 uint8_t d1 = data[0];
18 uint8_t d2 = data[1];
19 uint8_t d3 = data[2];
20 uint8_t d4 = data[3];
21
22 mpghdr->syncword = (int)d1 << 4 | (d2 >> 4); // 12 bits
23 mpghdr->ID = bit_on(d2, bit_4); // 1 bit
24 mpghdr->layer = (d2 &~ 0xf9) >> 1; // 2 bits
25 mpghdr->protection_bit = bit_on(d2, bit_1); // 1 bit
26
27 mpghdr->bitrate_index = d3 >> 4; // 4 bits
28 mpghdr->sampl_freq = (d3 &~ 0xf3) >> 2; // 2 bits
29 mpghdr->padding_bit = bit_on(d3, bit_2); // 1 bit
30 mpghdr->private_bit = bit_on(d3, bit_1); // 1 bit
31
32 mpghdr->mode = d4 >> 6; // 2 bits
33 mpghdr->mode_extension = (d4 &~ 0xcf) >> 4; // 2 bits
34 mpghdr->copyright = bit_on(d4, bit_4); // 1 bit
35 mpghdr->org_home = bit_on(d4, bit_3); // 1 bit
36 mpghdr->emphasis = d4 &~ 0xfc; // 2 bits
37
38 if (mpghdr->syncword != 0xfff) {
39 ts_LOGf("!!! Error parsing mpeg audio header! Syncword should be 0xfff but it is 0x%03x!\n", mpghdr->syncword);
40 return 0;
41 } else {
42 mpghdr->initialized = 1;
43 return 1;
44 }
45 }
46
ts_pes_es_mpeg_audio_header_dump(struct mpeg_audio_header * mpghdr)47 void ts_pes_es_mpeg_audio_header_dump(struct mpeg_audio_header *mpghdr) {
48 if (!mpghdr->initialized)
49 return;
50 // See ISO-11172-3 for more info
51 ts_LOGf(" - ES analyze audio frame\n");
52 ts_LOGf(" - Syncword : %x\n", mpghdr->syncword);
53 if (mpghdr->syncword != 0xfff) {
54 ts_LOGf("!!! ERROR: MPEG audo Syncword should be 0xfff!\n");
55 return;
56 }
57 ts_LOGf(" - ID : %d (%s)\n", mpghdr->ID, mpghdr->ID ? "MPEG Audio" : "Other");
58 ts_LOGf(" - layer : %d (%s)\n", mpghdr->layer,
59 mpghdr->layer == 0 ? "reserved" :
60 mpghdr->layer == 1 ? "Layer III" :
61 mpghdr->layer == 2 ? "Layer II" :
62 mpghdr->layer == 3 ? "Layer I" : "reserved"
63 );
64 ts_LOGf(" - protection_bit: %x\n", mpghdr->protection_bit);
65 int br = 0;
66 if (mpghdr->layer > 0 && mpghdr->layer < 4) {
67 int bitrate_index_table[4][16] = {
68 [3] = { 0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448, -1}, // Layer 1
69 [2] = { 0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, -1}, // Layer 2
70 [1] = { 0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, -1} // Layer 3
71 };
72 br = bitrate_index_table[mpghdr->layer][mpghdr->bitrate_index];
73 }
74 ts_LOGf(" - bitrate_index : %d (%d kBit/s)\n", mpghdr->bitrate_index, br);
75 ts_LOGf(" - sampl_freq : %d (%s)\n", mpghdr->sampl_freq,
76 mpghdr->sampl_freq == 0 ? "44.1 kHz" :
77 mpghdr->sampl_freq == 1 ? "48 kHz" :
78 mpghdr->sampl_freq == 2 ? "32 kHz" : "reserved"
79 );
80 ts_LOGf(" - padding_bit : %d\n", mpghdr->padding_bit);
81 ts_LOGf(" - private_bit : %d\n", mpghdr->private_bit);
82 ts_LOGf(" - mode : %d (%s)\n", mpghdr->mode,
83 mpghdr->mode == 0 ? "stereo" :
84 mpghdr->mode == 1 ? "join_stereo" :
85 mpghdr->mode == 2 ? "dual_channel" : "single_channel"
86 );
87 ts_LOGf(" - mode_extension: %x\n", mpghdr->mode_extension);
88 ts_LOGf(" - copyright : %x\n", mpghdr->copyright);
89 ts_LOGf(" - org_home : %x\n", mpghdr->org_home);
90 ts_LOGf(" - emphasis : %d (%s)\n", mpghdr->emphasis,
91 mpghdr->emphasis == 0 ? "none" :
92 mpghdr->emphasis == 1 ? "50/15 microseconds" :
93 mpghdr->emphasis == 2 ? "reserved" : "CCITT J.17"
94 );
95 }
96
ts_pes_es_parse(struct ts_pes * pes)97 void ts_pes_es_parse(struct ts_pes *pes) {
98 if (!pes->es_data)
99 return;
100
101 // Parse MPEG audio packet header
102 if ((pes->is_audio_mpeg1 || pes->is_audio_mpeg2) && pes->es_data_size > 4) {
103 struct mpeg_audio_header mpghdr;
104 memset(&mpghdr, 0, sizeof(struct mpeg_audio_header));
105 ts_pes_es_mpeg_audio_header_parse(&mpghdr, pes->es_data, pes->es_data_size);
106 if (mpghdr.initialized) {
107 pes->mpeg_audio_header = mpghdr;
108 if (mpghdr.ID) {
109 switch (mpghdr.layer) {
110 case 3: pes->is_audio_mpeg1l1 = 1; break;
111 case 2: pes->is_audio_mpeg1l2 = 1; break;
112 case 1: pes->is_audio_mpeg1l3 = 1; break;
113 }
114 }
115 }
116 }
117
118 // Look into elementary streams to detect AC3/DTS
119 if (pes->is_audio_ac3) {
120 if (pes->real_pes_packet_len >= 2 && (pes->es_data[0] == 0x0B && pes->es_data[1] == 0x77)) {
121 pes->is_audio = 1;
122 pes->is_audio_ac3 = 1;
123 pes->is_audio_dts = 0;
124 }
125 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)) {
126 pes->is_audio = 1;
127 pes->is_audio_ac3 = 0;
128 pes->is_audio_dts = 1;
129 }
130 }
131 }
132
ts_pes_es_dump(struct ts_pes * pes)133 void ts_pes_es_dump(struct ts_pes *pes) {
134 if (pes->is_audio && pes->mpeg_audio_header.initialized) {
135 ts_pes_es_mpeg_audio_header_dump(&pes->mpeg_audio_header);
136 }
137 }
138