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rtpenc_h261.c
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1 /*
2  * RTP packetization for H.261 video (RFC 4587)
3  * Copyright (c) 2014 Thomas Volkert <thomas@homer-conferencing.com>
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 "avformat.h"
23 #include "rtpenc.h"
24 
25 void ff_rtp_send_h261(AVFormatContext *s1, const uint8_t *frame_buf, int frame_size)
26 {
27  RTPMuxContext *rtp_ctx = s1->priv_data;
28  int processed_frame_size;
29  int last_packet_of_frame;
30  uint8_t *tmp_buf_ptr;
31 
32  /* use the default 90 KHz time stamp */
33  rtp_ctx->timestamp = rtp_ctx->cur_timestamp;
34 
35  /* continue as long as not all frame data is processed */
36  while (frame_size > 0) {
37  tmp_buf_ptr = rtp_ctx->buf;
38  *tmp_buf_ptr++ = 1; /* V=1 */
39  *tmp_buf_ptr++ = 0;
40  *tmp_buf_ptr++ = 0;
41  *tmp_buf_ptr++ = 0;
42 
43  processed_frame_size = FFMIN(rtp_ctx->max_payload_size - 4, frame_size);
44 
45  //XXX: parse the h.261 bitstream and improve frame splitting here
46 
47  last_packet_of_frame = (processed_frame_size == frame_size);
48 
49  memcpy(tmp_buf_ptr, frame_buf, processed_frame_size);
50  tmp_buf_ptr += processed_frame_size;
51 
52  ff_rtp_send_data(s1, rtp_ctx->buf, tmp_buf_ptr - rtp_ctx->buf, last_packet_of_frame);
53 
54  frame_buf += processed_frame_size;
55  frame_size -= processed_frame_size;
56  }
57 }