RTP 打包H264与AAC

1. static int h264_parse(Track *tr, uint8_t *data, size_t len)  
2. {  
3.     h264_priv *priv = tr->private_data;  
4. //    double nal_time; // see page 9 and 7.4.1.2  
5.     size_t nalsize = 0, index = 0;  
6.     uint8_t *p, *q;  
7.     if (priv->is_avc) {  
8.         while (1) {  
9.             unsigned int i;  
10.             if(index >= len) break;  
11.             //get the nal size  
12.             nalsize = 0;  
13.             for(i = 0; i < priv->nal_length_size; i++)  
14.                 nalsize = (nalsize << 8) | data[index++];  
15.             if(nalsize <= 1 || nalsize > len) {  
16.                 if(nalsize == 1) {  
17.                     index++;  
18.                     continue;  
19.                 } else {  
20.                     fnc_log(FNC_LOG_VERBOSE, "[h264] AVC: nal size %d", nalsize);  
21.                     break;  
22.                 }  
23.             }  
24.             if (DEFAULT_MTU >= nalsize) {  
25.                 mparser_buffer_write(tr,  
26.                                      tr->properties.pts,  
27.                                      tr->properties.dts,  
28.                                      tr->properties.frame_duration,  
29.                                      1,  
30.                                      data + index, nalsize);  
31.                 fnc_log(FNC_LOG_VERBOSE, "[h264] single NAL");  
32.             } else {  
33.             // single NAL, to be fragmented, FU-A;  
34.                 frag_fu_a(data + index, nalsize, DEFAULT_MTU, tr);  
35.             }  
36.             index += nalsize;  
37.         }  
38.     } else {  
39.         //seek to the first startcode  
40.         for (p = data; p
41.             if (p[0] == 0 && p[1] == 0 && p[2] == 1) {  
42.                 break;  
43.             }  
44.         }  
45.         if (p >= data + len) return ERR_PARSE;  
46.         while (1) {  
47.         //seek to the next startcode [0 0 1]  
48.             for (q = p; q
49.                 if (q[0] == 0 && q[1] == 0 && q[2] == 1) {  
50.                     break;  
51.                 }  
52.             }  
53.             if (q >= data + len) break;  
54.             if (DEFAULT_MTU >= q - p) {  
55.                 fnc_log(FNC_LOG_VERBOSE, "[h264] Sending NAL %d",p[0]&0x1f);  
56.                 mparser_buffer_write(tr,  
57.                                      tr->properties.pts,  
58.                                      tr->properties.dts,  
59.                                      tr->properties.frame_duration,  
60.                                      1,  
61.                                      p, q - p);  
62.                 fnc_log(FNC_LOG_VERBOSE, "[h264] single NAL");  
63.             } else {  
64.                 //FU-A  
65.                 fnc_log(FNC_LOG_VERBOSE, "[h264] frags");  
66.                 frag_fu_a(p, q - p, DEFAULT_MTU, tr);  
67.             }  
68.             p = q;  
69.         }  
70.         // last NAL  
71.         fnc_log(FNC_LOG_VERBOSE, "[h264] last NAL %d",p[0]&0x1f);  
72.         if (DEFAULT_MTU >= len - (p - data)) {  
73.             fnc_log(FNC_LOG_VERBOSE, "[h264] no frags");  
74.             mparser_buffer_write(tr,  
75.                                  tr->properties.pts,  
76.                                  tr->properties.dts,  
77.                                  tr->properties.frame_duration,  
78.                                  1,  
79.                                  p, len - (p - data));  
80.         } else {  
81.             //FU-A  
82.             fnc_log(FNC_LOG_VERBOSE, "[h264] frags");  
83.             frag_fu_a(p, len - (p - data), DEFAULT_MTU, tr);  
84.         }  
85.     }  
86.     fnc_log(FNC_LOG_VERBOSE, "[h264] Frame completed");  
87.     return ERR_NOERROR;  
88. }  

2. AAC的RTP封包

[c-sharp] view plaincopy

 

1. static int aac_parse(Track *tr, uint8_t *data, size_t len)  
2. {  
3.     //XXX handle the last packet on EOF  
4.     int off = 0;  
5.     uint32_t payload = DEFAULT_MTU - AU_HEADER_SIZE;  
6.     uint8_t *packet = g_malloc0(DEFAULT_MTU);  
7.     if(!packet) return ERR_ALLOC;  
8. // trim away extradata  
9. //    data += AAC_EXTRA;  
10. //    len -= AAC_EXTRA;  
11.     packet[0] = 0x00;  
12.     packet[1] = 0x10;  
13.     packet[2] = (len & 0x1fe0) >> 5;  
14.     packet[3] = (len & 0x1f) << 3;  
15.     if (len > payload) {  
16.         while (len > payload) {  
17.             memcpy(packet + AU_HEADER_SIZE, data + off, payload);  
18.             mparser_buffer_write(tr,  
19.                                  tr->properties.pts,  
20.                                  tr->properties.dts,  
21.                                  tr->properties.frame_duration,  
22.                                  0,  
23.                                  packet, DEFAULT_MTU);  
24.             len -= payload;  
25.             off += payload;  
26.         }  
27.     }  
28.     memcpy(packet + AU_HEADER_SIZE, data + off, len);  
29.     mparser_buffer_write(tr,  
30.                          tr->properties.pts,  
31.                          tr->properties.dts,  
32.                          tr->properties.frame_duration,  
33.                          1,  
34.                          packet, len + AU_HEADER_SIZE);  
35.     g_free(packet);  
36.     return ERR_NOERROR;  
37. }  

上面的变量 AU_HEADER_SIZE=4

来自： http://blog.csdn.net/moruite/article/details/6102758