mirror of
https://git.videolan.org/git/ffmpeg.git
synced 2024-08-14 21:35:06 +02:00
![Xi Wang](/assets/img/avatar_default.png)
The check `start + res < start' is broken since pointer overflow is undefined behavior in C. Many compilers such as gcc/clang optimize away this check. Use `res > end - start' instead. Also change `res' to unsigned int to avoid signed left-shift overflow. Signed-off-by: Xi Wang <xi.wang@gmail.com> Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
110 lines
3.4 KiB
C
110 lines
3.4 KiB
C
/*
|
|
* RTP packetization for H.264 (RFC3984)
|
|
* Copyright (c) 2008 Luca Abeni
|
|
*
|
|
* 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
|
|
*/
|
|
|
|
/**
|
|
* @file
|
|
* @brief H.264 packetization
|
|
* @author Luca Abeni <lucabe72@email.it>
|
|
*/
|
|
|
|
#include "avformat.h"
|
|
#include "avc.h"
|
|
#include "rtpenc.h"
|
|
|
|
static const uint8_t *avc_mp4_find_startcode(const uint8_t *start, const uint8_t *end, int nal_length_size)
|
|
{
|
|
unsigned int res = 0;
|
|
|
|
if (end - start < nal_length_size)
|
|
return NULL;
|
|
while (nal_length_size--)
|
|
res = (res << 8) | *start++;
|
|
|
|
if (res > end - start)
|
|
return NULL;
|
|
|
|
return start + res;
|
|
}
|
|
|
|
static void nal_send(AVFormatContext *s1, const uint8_t *buf, int size, int last)
|
|
{
|
|
RTPMuxContext *s = s1->priv_data;
|
|
|
|
av_log(s1, AV_LOG_DEBUG, "Sending NAL %x of len %d M=%d\n", buf[0] & 0x1F, size, last);
|
|
if (size <= s->max_payload_size) {
|
|
ff_rtp_send_data(s1, buf, size, last);
|
|
} else {
|
|
uint8_t type = buf[0] & 0x1F;
|
|
uint8_t nri = buf[0] & 0x60;
|
|
|
|
if (s->flags & FF_RTP_FLAG_H264_MODE0) {
|
|
av_log(s1, AV_LOG_ERROR,
|
|
"NAL size %d > %d, try -slice-max-size %d\n", size,
|
|
s->max_payload_size, s->max_payload_size);
|
|
return;
|
|
}
|
|
av_log(s1, AV_LOG_DEBUG, "NAL size %d > %d\n", size, s->max_payload_size);
|
|
s->buf[0] = 28; /* FU Indicator; Type = 28 ---> FU-A */
|
|
s->buf[0] |= nri;
|
|
s->buf[1] = type;
|
|
s->buf[1] |= 1 << 7;
|
|
buf += 1;
|
|
size -= 1;
|
|
while (size + 2 > s->max_payload_size) {
|
|
memcpy(&s->buf[2], buf, s->max_payload_size - 2);
|
|
ff_rtp_send_data(s1, s->buf, s->max_payload_size, 0);
|
|
buf += s->max_payload_size - 2;
|
|
size -= s->max_payload_size - 2;
|
|
s->buf[1] &= ~(1 << 7);
|
|
}
|
|
s->buf[1] |= 1 << 6;
|
|
memcpy(&s->buf[2], buf, size);
|
|
ff_rtp_send_data(s1, s->buf, size + 2, last);
|
|
}
|
|
}
|
|
|
|
void ff_rtp_send_h264(AVFormatContext *s1, const uint8_t *buf1, int size)
|
|
{
|
|
const uint8_t *r, *end = buf1 + size;
|
|
RTPMuxContext *s = s1->priv_data;
|
|
|
|
s->timestamp = s->cur_timestamp;
|
|
if (s->nal_length_size)
|
|
r = avc_mp4_find_startcode(buf1, end, s->nal_length_size) ? buf1 : end;
|
|
else
|
|
r = ff_avc_find_startcode(buf1, end);
|
|
while (r < end) {
|
|
const uint8_t *r1;
|
|
|
|
if (s->nal_length_size) {
|
|
r1 = avc_mp4_find_startcode(r, end, s->nal_length_size);
|
|
if (!r1)
|
|
r1 = end;
|
|
r += s->nal_length_size;
|
|
} else {
|
|
while (!*(r++));
|
|
r1 = ff_avc_find_startcode(r, end);
|
|
}
|
|
nal_send(s1, r, r1 - r, r1 == end);
|
|
r = r1;
|
|
}
|
|
}
|