cf29f49d8a
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: Martin Storsjö <martin@martin.st>
110 lines
3.4 KiB
C
110 lines
3.4 KiB
C
/*
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* RTP packetization for H.264 (RFC3984)
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* Copyright (c) 2008 Luca Abeni
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*
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* This file is part of Libav.
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*
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* Libav is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* Libav is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with Libav; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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* @file
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* @brief H.264 packetization
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* @author Luca Abeni <lucabe72@email.it>
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*/
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#include "avformat.h"
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#include "avc.h"
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#include "rtpenc.h"
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static const uint8_t *avc_mp4_find_startcode(const uint8_t *start, const uint8_t *end, int nal_length_size)
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{
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unsigned int res = 0;
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if (end - start < nal_length_size)
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return NULL;
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while (nal_length_size--)
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res = (res << 8) | *start++;
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if (res > end - start)
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return NULL;
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return start + res;
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}
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static void nal_send(AVFormatContext *s1, const uint8_t *buf, int size, int last)
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{
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RTPMuxContext *s = s1->priv_data;
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av_log(s1, AV_LOG_DEBUG, "Sending NAL %x of len %d M=%d\n", buf[0] & 0x1F, size, last);
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if (size <= s->max_payload_size) {
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ff_rtp_send_data(s1, buf, size, last);
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} else {
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uint8_t type = buf[0] & 0x1F;
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uint8_t nri = buf[0] & 0x60;
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if (s->flags & FF_RTP_FLAG_H264_MODE0) {
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av_log(s1, AV_LOG_ERROR,
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"NAL size %d > %d, try -slice-max-size %d\n", size,
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s->max_payload_size, s->max_payload_size);
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return;
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}
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av_log(s1, AV_LOG_DEBUG, "NAL size %d > %d\n", size, s->max_payload_size);
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s->buf[0] = 28; /* FU Indicator; Type = 28 ---> FU-A */
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s->buf[0] |= nri;
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s->buf[1] = type;
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s->buf[1] |= 1 << 7;
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buf += 1;
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size -= 1;
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while (size + 2 > s->max_payload_size) {
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memcpy(&s->buf[2], buf, s->max_payload_size - 2);
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ff_rtp_send_data(s1, s->buf, s->max_payload_size, 0);
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buf += s->max_payload_size - 2;
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size -= s->max_payload_size - 2;
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s->buf[1] &= ~(1 << 7);
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}
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s->buf[1] |= 1 << 6;
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memcpy(&s->buf[2], buf, size);
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ff_rtp_send_data(s1, s->buf, size + 2, last);
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}
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}
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void ff_rtp_send_h264(AVFormatContext *s1, const uint8_t *buf1, int size)
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{
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const uint8_t *r, *end = buf1 + size;
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RTPMuxContext *s = s1->priv_data;
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s->timestamp = s->cur_timestamp;
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if (s->nal_length_size)
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r = avc_mp4_find_startcode(buf1, end, s->nal_length_size) ? buf1 : end;
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else
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r = ff_avc_find_startcode(buf1, end);
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while (r < end) {
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const uint8_t *r1;
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if (s->nal_length_size) {
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r1 = avc_mp4_find_startcode(r, end, s->nal_length_size);
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if (!r1)
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r1 = end;
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r += s->nal_length_size;
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} else {
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while (!*(r++));
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r1 = ff_avc_find_startcode(r, end);
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}
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nal_send(s1, r, r1 - r, r1 == end);
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r = r1;
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}
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}
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