vaapi_h264: Add support for SEI recovery points
[libav.git] / libavcodec / vaapi_encode_h26x.c
CommitLineData
2c62fcdf
MT
1/*
2 * This file is part of Libav.
3 *
4 * Libav is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * Libav is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with Libav; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19#include <stdint.h>
20
21#include "vaapi_encode_h26x.h"
22
23int ff_vaapi_encode_h26x_nal_unit_to_byte_stream(uint8_t *dst, size_t *dst_bit_len,
24 uint8_t *src, size_t src_bit_len)
25{
26 size_t dp, sp;
27 int zero_run = 0;
28 size_t dst_len = *dst_bit_len / 8;
29 size_t src_len = (src_bit_len + 7) / 8;
30 int trailing_zeroes = src_len * 8 - src_bit_len;
31
32 if (dst_len < src_len + 4) {
33 // Definitely doesn't fit.
34 goto fail;
35 }
36
37 // Start code.
38 dst[0] = dst[1] = dst[2] = 0;
39 dst[3] = 1;
40 dp = 4;
41
42 for (sp = 0; sp < src_len; sp++) {
43 if (dp >= dst_len)
44 goto fail;
45 if (zero_run < 2) {
46 if (src[sp] == 0)
47 ++zero_run;
48 else
49 zero_run = 0;
50 } else {
51 if ((src[sp] & ~3) == 0) {
52 // emulation_prevention_three_byte
53 dst[dp++] = 3;
54 if (dp >= dst_len)
55 goto fail;
56 }
57 zero_run = src[sp] == 0;
58 }
59 dst[dp++] = src[sp];
60 }
61
62 *dst_bit_len = 8 * dp - trailing_zeroes;
63 return 0;
64
65fail:
66 *dst_bit_len = 0;
67 return AVERROR(ENOSPC);
68}