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"
23 #include "libavcodec/h264.h"
28 static const uint8_t *ff_avc_find_startcode_internal(const uint8_t *p, const uint8_t *end)
30 const uint8_t *a = p + 4 - ((intptr_t)p & 3);
32 for (end -= 3; p < a && p < end; p++) {
33 if (p[0] == 0 && p[1] == 0 && p[2] == 1)
37 for (end -= 3; p < end; p += 4) {
38 uint32_t x = *(const uint32_t*)p;
39 // if ((x - 0x01000100) & (~x) & 0x80008000) // little endian
40 // if ((x - 0x00010001) & (~x) & 0x00800080) // big endian
41 if ((x - 0x01010101) & (~x) & 0x80808080) { // generic
43 if (p[0] == 0 && p[2] == 1)
45 if (p[2] == 0 && p[3] == 1)
49 if (p[2] == 0 && p[4] == 1)
51 if (p[4] == 0 && p[5] == 1)
57 for (end += 3; p < end; p++) {
58 if (p[0] == 0 && p[1] == 0 && p[2] == 1)
65 const uint8_t *ff_avc_find_startcode(const uint8_t *p, const uint8_t *end){
66 const uint8_t *out= ff_avc_find_startcode_internal(p, end);
67 if(p<out && out<end && !out[-1]) out--;
71 int ff_avc_parse_nal_units(AVIOContext *pb, const uint8_t *buf_in, int size)
73 const uint8_t *p = buf_in;
74 const uint8_t *end = p + size;
75 const uint8_t *nal_start, *nal_end;
78 nal_start = ff_avc_find_startcode(p, end);
80 while (nal_start < end && !*(nal_start++));
84 nal_end = ff_avc_find_startcode(nal_start, end);
85 avio_wb32(pb, nal_end - nal_start);
86 avio_write(pb, nal_start, nal_end - nal_start);
87 size += 4 + nal_end - nal_start;
93 int ff_avc_parse_nal_units_buf(const uint8_t *buf_in, uint8_t **buf, int *size)
96 int ret = avio_open_dyn_buf(&pb);
100 ff_avc_parse_nal_units(pb, buf_in, *size);
103 *size = avio_close_dyn_buf(pb, buf);
107 int ff_isom_write_avcc(AVIOContext *pb, const uint8_t *data, int len)
109 AVIOContext *sps_pb = NULL, *pps_pb = NULL;
110 uint8_t *buf = NULL, *end, *start = NULL;
111 uint8_t *sps = NULL, *pps = NULL;
112 uint32_t sps_size = 0, pps_size = 0;
113 int ret, nb_sps = 0, nb_pps = 0;
116 return AVERROR_INVALIDDATA;
118 /* check for H.264 start code */
119 if (AV_RB32(data) != 0x00000001 &&
120 AV_RB24(data) != 0x000001) {
121 avio_write(pb, data, len);
125 ret = ff_avc_parse_nal_units_buf(data, &buf, &len);
131 ret = avio_open_dyn_buf(&sps_pb);
134 ret = avio_open_dyn_buf(&pps_pb);
138 /* look for sps and pps */
139 while (end - buf > 4) {
142 size = FFMIN(AV_RB32(buf), end - buf - 4);
144 nal_type = buf[0] & 0x1f;
146 if (nal_type == 7) { /* SPS */
148 if (size > UINT16_MAX || nb_sps >= H264_MAX_SPS_COUNT) {
149 ret = AVERROR_INVALIDDATA;
152 avio_wb16(sps_pb, size);
153 avio_write(sps_pb, buf, size);
154 } else if (nal_type == 8) { /* PPS */
156 if (size > UINT16_MAX || nb_pps >= H264_MAX_PPS_COUNT) {
157 ret = AVERROR_INVALIDDATA;
160 avio_wb16(pps_pb, size);
161 avio_write(pps_pb, buf, size);
166 sps_size = avio_close_dyn_buf(sps_pb, &sps);
167 pps_size = avio_close_dyn_buf(pps_pb, &pps);
169 if (sps_size < 6 || !pps_size) {
170 ret = AVERROR_INVALIDDATA;
174 avio_w8(pb, 1); /* version */
175 avio_w8(pb, sps[3]); /* profile */
176 avio_w8(pb, sps[4]); /* profile compat */
177 avio_w8(pb, sps[5]); /* level */
178 avio_w8(pb, 0xff); /* 6 bits reserved (111111) + 2 bits nal size length - 1 (11) */
179 avio_w8(pb, 0xe0 | nb_sps); /* 3 bits reserved (111) + 5 bits number of sps */
181 avio_write(pb, sps, sps_size);
182 avio_w8(pb, nb_pps); /* number of pps */
183 avio_write(pb, pps, pps_size);
187 avio_close_dyn_buf(sps_pb, &sps);
189 avio_close_dyn_buf(pps_pb, &pps);
197 int ff_avc_write_annexb_extradata(const uint8_t *in, uint8_t **buf, int *size)
199 uint16_t sps_size, pps_size;
204 if (*size >= 4 && (AV_RB32(in) == 0x00000001 || AV_RB24(in) == 0x000001))
206 if (*size < 11 || in[0] != 1)
207 return AVERROR_INVALIDDATA;
209 sps_size = AV_RB16(&in[6]);
210 if (11 + sps_size > *size)
211 return AVERROR_INVALIDDATA;
212 pps_size = AV_RB16(&in[9 + sps_size]);
213 if (11 + sps_size + pps_size > *size)
214 return AVERROR_INVALIDDATA;
215 out_size = 8 + sps_size + pps_size;
216 out = av_mallocz(out_size + AV_INPUT_BUFFER_PADDING_SIZE);
218 return AVERROR(ENOMEM);
219 AV_WB32(&out[0], 0x00000001);
220 memcpy(out + 4, &in[8], sps_size);
221 AV_WB32(&out[4 + sps_size], 0x00000001);
222 memcpy(out + 8 + sps_size, &in[11 + sps_size], pps_size);
228 const uint8_t *ff_avc_mp4_find_startcode(const uint8_t *start,
232 unsigned int res = 0;
234 if (end - start < nal_length_size)
236 while (nal_length_size--)
237 res = (res << 8) | *start++;
239 if (res > end - start)