2 * AVC helper functions for muxers
3 * Copyright (c) 2006 Baptiste Coudurier <baptiste.coudurier@smartjog.com>
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 #include "libavutil/intreadwrite.h"
27 static const uint8_t *ff_avc_find_startcode_internal(const uint8_t *p, const uint8_t *end)
29 const uint8_t *a = p + 4 - ((intptr_t)p & 3);
31 for (end -= 3; p < a && p < end; p++) {
32 if (p[0] == 0 && p[1] == 0 && p[2] == 1)
36 for (end -= 3; p < end; p += 4) {
37 uint32_t x = *(const uint32_t*)p;
38 // if ((x - 0x01000100) & (~x) & 0x80008000) // little endian
39 // if ((x - 0x00010001) & (~x) & 0x00800080) // big endian
40 if ((x - 0x01010101) & (~x) & 0x80808080) { // generic
42 if (p[0] == 0 && p[2] == 1)
44 if (p[2] == 0 && p[3] == 1)
48 if (p[2] == 0 && p[4] == 1)
50 if (p[4] == 0 && p[5] == 1)
56 for (end += 3; p < end; p++) {
57 if (p[0] == 0 && p[1] == 0 && p[2] == 1)
64 const uint8_t *ff_avc_find_startcode(const uint8_t *p, const uint8_t *end){
65 const uint8_t *out= ff_avc_find_startcode_internal(p, end);
66 if(p<out && out<end && !out[-1]) out--;
70 int ff_avc_parse_nal_units(AVIOContext *pb, const uint8_t *buf_in, int size)
72 const uint8_t *p = buf_in;
73 const uint8_t *end = p + size;
74 const uint8_t *nal_start, *nal_end;
77 nal_start = ff_avc_find_startcode(p, end);
78 while (nal_start < end) {
79 while(!*(nal_start++));
80 nal_end = ff_avc_find_startcode(nal_start, end);
81 put_be32(pb, nal_end - nal_start);
82 put_buffer(pb, nal_start, nal_end - nal_start);
83 size += 4 + nal_end - nal_start;
89 int ff_avc_parse_nal_units_buf(const uint8_t *buf_in, uint8_t **buf, int *size)
92 int ret = url_open_dyn_buf(&pb);
96 ff_avc_parse_nal_units(pb, buf_in, *size);
99 *size = url_close_dyn_buf(pb, buf);
103 int ff_isom_write_avcc(AVIOContext *pb, const uint8_t *data, int len)
106 /* check for h264 start code */
107 if (AV_RB32(data) == 0x00000001 ||
108 AV_RB24(data) == 0x000001) {
109 uint8_t *buf=NULL, *end, *start;
110 uint32_t sps_size=0, pps_size=0;
111 uint8_t *sps=0, *pps=0;
113 int ret = ff_avc_parse_nal_units_buf(data, &buf, &len);
119 /* look for sps and pps */
124 nal_type = buf[4] & 0x1f;
125 if (nal_type == 7) { /* SPS */
128 } else if (nal_type == 8) { /* PPS */
137 put_byte(pb, 1); /* version */
138 put_byte(pb, sps[1]); /* profile */
139 put_byte(pb, sps[2]); /* profile compat */
140 put_byte(pb, sps[3]); /* level */
141 put_byte(pb, 0xff); /* 6 bits reserved (111111) + 2 bits nal size length - 1 (11) */
142 put_byte(pb, 0xe1); /* 3 bits reserved (111) + 5 bits number of sps (00001) */
144 put_be16(pb, sps_size);
145 put_buffer(pb, sps, sps_size);
146 put_byte(pb, 1); /* number of pps */
147 put_be16(pb, pps_size);
148 put_buffer(pb, pps, pps_size);
151 put_buffer(pb, data, len);