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FFmpeg/libavformat/rtpenc_vp8.c
Kevin Wang 8ae15b5655 rtpenc_vp8: Use 15-bit PictureIDs
7-bit PictureIDs are not supported by WebRTC:
https://groups.google.com/g/discuss-webrtc/c/333-L02vuWA

In practice, 15-bit PictureIDs offer better compatibility.

Signed-off-by: Kevin Wang <kevin@muxable.com>
Signed-off-by: Martin Storsjö <martin@martin.st>
2022-03-26 00:42:00 +02:00

57 lines
1.9 KiB
C

/*
* RTP VP8 Packetizer
* Copyright (c) 2010 Josh Allmann
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; 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 & 0x7f00) >> 8) | 0x80;
*s->buf_ptr++ = s->frame_count++ & 0xff;
// 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;
}
}