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rtpenc_vp8.c
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1 /*
2  * RTP VP8 Packetizer
3  * Copyright (c) 2010 Josh Allmann
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "rtpenc.h"
23 
24 /* Based on a draft spec for VP8 RTP.
25  * ( http://tools.ietf.org/html/draft-ietf-payload-vp8-05 ) */
27 {
28  RTPMuxContext *s = s1->priv_data;
29  int len, max_packet_size, header_size;
30 
31  s->buf_ptr = s->buf;
32  s->timestamp = s->cur_timestamp;
33 
34  // extended control bit set, reference frame, start of partition,
35  // partition id 0
36  *s->buf_ptr++ = 0x90;
37  *s->buf_ptr++ = 0x80; // Picture id present
38  *s->buf_ptr++ = s->frame_count++ & 0x7f;
39  // Calculate the number of remaining bytes
40  header_size = s->buf_ptr - s->buf;
41  max_packet_size = s->max_payload_size - header_size;
42 
43  while (size > 0) {
44  len = FFMIN(size, max_packet_size);
45 
46  memcpy(s->buf_ptr, buf, len);
47  // marker bit is last packet in frame
48  ff_rtp_send_data(s1, s->buf, len + header_size, size == len);
49 
50  size -= len;
51  buf += len;
52  // Clear the partition start bit, keep the rest of the header untouched
53  s->buf[0] &= ~0x10;
54  }
55 }
const char * s
Definition: avisynth_c.h:768
int max_payload_size
Definition: rtpenc.h:38
Format I/O context.
Definition: avformat.h:1327
uint8_t
unsigned int frame_count
Definition: rtpenc.h:63
uint8_t * buf
Definition: rtpenc.h:49
ptrdiff_t size
Definition: opengl_enc.c:101
#define FFMIN(a, b)
Definition: common.h:96
void ff_rtp_send_data(AVFormatContext *s1, const uint8_t *buf1, int len, int m)
Definition: rtpenc.c:330
uint32_t cur_timestamp
Definition: rtpenc.h:37
void ff_rtp_send_vp8(AVFormatContext *s1, const uint8_t *buf, int size)
Definition: rtpenc_vp8.c:26
void * buf
Definition: avisynth_c.h:690
#define s1
Definition: regdef.h:38
uint8_t * buf_ptr
Definition: rtpenc.h:50
uint32_t timestamp
Definition: rtpenc.h:35
int len
void * priv_data
Format private data.
Definition: avformat.h:1355