third_party_ffmpeg/libavformat/rtpenc_vp8.c
Martin Storsjö 65e053271a rtpenc_vp8: Include the picture number in VP8 packets
This makes it easier for receivers to decide what to do if data
is lost.

Refactor calculating the max payload size, to avoid hardcoding the
header size in too many places, reducing the number of lines that
have to be touched if the header is adjusted further.

Signed-off-by: Martin Storsjö <martin@martin.st>
2012-12-16 21:32:13 +02:00

56 lines
1.9 KiB
C

/*
* RTP VP8 Packetizer
* Copyright (c) 2010 Josh Allmann
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "rtpenc.h"
/* Based on a draft spec for VP8 RTP.
* ( http://tools.ietf.org/html/draft-ietf-payload-vp8-05 ) */
void ff_rtp_send_vp8(AVFormatContext *s1, const uint8_t *buf, int size)
{
RTPMuxContext *s = s1->priv_data;
int len, max_packet_size, header_size;
s->buf_ptr = s->buf;
s->timestamp = s->cur_timestamp;
// extended control bit set, reference frame, start of partition,
// partition id 0
*s->buf_ptr++ = 0x90;
*s->buf_ptr++ = 0x80; // Picture id present
*s->buf_ptr++ = s->frame_count++ & 0x7f;
// Calculate the number of remaining bytes
header_size = s->buf_ptr - s->buf;
max_packet_size = s->max_payload_size - header_size;
while (size > 0) {
len = FFMIN(size, max_packet_size);
memcpy(s->buf_ptr, buf, len);
// marker bit is last packet in frame
ff_rtp_send_data(s1, s->buf, len + header_size, size == len);
size -= len;
buf += len;
// Clear the partition start bit, keep the rest of the header untouched
s->buf[0] &= ~0x10;
}
}