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rtpenc_mpv.c
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1 /*
2  * RTP packetization for MPEG video
3  * Copyright (c) 2002 Fabrice Bellard
4  * Copyright (c) 2007 Luca Abeni
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 #include "libavcodec/internal.h"
24 #include "avformat.h"
25 #include "rtpenc.h"
26 
27 /* NOTE: a single frame must be passed with sequence header if
28  needed. XXX: use slices. */
30 {
31  RTPMuxContext *s = s1->priv_data;
32  int len, h, max_packet_size;
33  uint8_t *q;
34  const uint8_t *end = buf1 + size;
35  int begin_of_slice, end_of_slice, frame_type, temporal_reference;
36 
37  max_packet_size = s->max_payload_size;
38  begin_of_slice = 1;
39  end_of_slice = 0;
40  frame_type = 0;
41  temporal_reference = 0;
42 
43  while (size > 0) {
44  int begin_of_sequence;
45 
46  begin_of_sequence = 0;
47  len = max_packet_size - 4;
48 
49  if (len >= size) {
50  len = size;
51  end_of_slice = 1;
52  } else {
53  const uint8_t *r, *r1;
54  int start_code;
55 
56  r1 = buf1;
57  while (1) {
58  start_code = -1;
59  r = avpriv_find_start_code(r1, end, &start_code);
60  if((start_code & 0xFFFFFF00) == 0x100) {
61  /* New start code found */
62  if (start_code == 0x100) {
63  frame_type = (r[1] & 0x38) >> 3;
64  temporal_reference = (int)r[0] << 2 | r[1] >> 6;
65  }
66  if (start_code == 0x1B8) {
67  begin_of_sequence = 1;
68  }
69 
70  if (r - buf1 - 4 <= len) {
71  /* The current slice fits in the packet */
72  if (begin_of_slice == 0) {
73  /* no slice at the beginning of the packet... */
74  end_of_slice = 1;
75  len = r - buf1 - 4;
76  break;
77  }
78  r1 = r;
79  } else {
80  if ((r1 - buf1 > 4) && (r - r1 < max_packet_size)) {
81  len = r1 - buf1 - 4;
82  end_of_slice = 1;
83  }
84  break;
85  }
86  } else {
87  break;
88  }
89  }
90  }
91 
92  h = 0;
93  h |= temporal_reference << 16;
94  h |= begin_of_sequence << 13;
95  h |= begin_of_slice << 12;
96  h |= end_of_slice << 11;
97  h |= frame_type << 8;
98 
99  q = s->buf;
100  *q++ = h >> 24;
101  *q++ = h >> 16;
102  *q++ = h >> 8;
103  *q++ = h;
104 
105  memcpy(q, buf1, len);
106  q += len;
107 
108  /* 90kHz time stamp */
109  s->timestamp = s->cur_timestamp;
110  ff_rtp_send_data(s1, s->buf, q - s->buf, (len == size));
111 
112  buf1 += len;
113  size -= len;
114  begin_of_slice = end_of_slice;
115  end_of_slice = 0;
116  }
117 }
const char * s
Definition: avisynth_c.h:631
int max_payload_size
Definition: rtpenc.h:38
Format I/O context.
Definition: avformat.h:1272
uint8_t
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
uint8_t * buf
Definition: rtpenc.h:49
ptrdiff_t size
Definition: opengl_enc.c:101
const uint8_t * avpriv_find_start_code(const uint8_t *p, const uint8_t *end, uint32_t *state)
const char * r
Definition: vf_curves.c:107
void ff_rtp_send_data(AVFormatContext *s1, const uint8_t *buf1, int len, int m)
Definition: rtpenc.c:306
uint32_t cur_timestamp
Definition: rtpenc.h:37
#define s1
Definition: regdef.h:38
static const uint8_t start_code[]
Definition: h264.c:1292
Main libavformat public API header.
void ff_rtp_send_mpegvideo(AVFormatContext *s1, const uint8_t *buf1, int size)
Definition: rtpenc_mpv.c:29
common internal api header.
uint32_t timestamp
Definition: rtpenc.h:35
int len
void * priv_data
Format private data.
Definition: avformat.h:1300