mirror of
https://git.videolan.org/git/ffmpeg.git
synced 2024-08-21 08:45:06 +02:00
156 lines
4.8 KiB
C
156 lines
4.8 KiB
C
/*
|
|
* AVC helper functions for muxers
|
|
* Copyright (c) 2006 Baptiste Coudurier <baptiste.coudurier@smartjog.com>
|
|
*
|
|
* 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
|
|
*/
|
|
|
|
#include "libavutil/intreadwrite.h"
|
|
#include "avformat.h"
|
|
#include "avio.h"
|
|
#include "avc.h"
|
|
|
|
static const uint8_t *ff_avc_find_startcode_internal(const uint8_t *p, const uint8_t *end)
|
|
{
|
|
const uint8_t *a = p + 4 - ((intptr_t)p & 3);
|
|
|
|
for (end -= 3; p < a && p < end; p++) {
|
|
if (p[0] == 0 && p[1] == 0 && p[2] == 1)
|
|
return p;
|
|
}
|
|
|
|
for (end -= 3; p < end; p += 4) {
|
|
uint32_t x = *(const uint32_t*)p;
|
|
// if ((x - 0x01000100) & (~x) & 0x80008000) // little endian
|
|
// if ((x - 0x00010001) & (~x) & 0x00800080) // big endian
|
|
if ((x - 0x01010101) & (~x) & 0x80808080) { // generic
|
|
if (p[1] == 0) {
|
|
if (p[0] == 0 && p[2] == 1)
|
|
return p;
|
|
if (p[2] == 0 && p[3] == 1)
|
|
return p+1;
|
|
}
|
|
if (p[3] == 0) {
|
|
if (p[2] == 0 && p[4] == 1)
|
|
return p+2;
|
|
if (p[4] == 0 && p[5] == 1)
|
|
return p+3;
|
|
}
|
|
}
|
|
}
|
|
|
|
for (end += 3; p < end; p++) {
|
|
if (p[0] == 0 && p[1] == 0 && p[2] == 1)
|
|
return p;
|
|
}
|
|
|
|
return end + 3;
|
|
}
|
|
|
|
const uint8_t *ff_avc_find_startcode(const uint8_t *p, const uint8_t *end){
|
|
const uint8_t *out= ff_avc_find_startcode_internal(p, end);
|
|
if(p<out && out<end && !out[-1]) out--;
|
|
return out;
|
|
}
|
|
|
|
int ff_avc_parse_nal_units(ByteIOContext *pb, const uint8_t *buf_in, int size)
|
|
{
|
|
const uint8_t *p = buf_in;
|
|
const uint8_t *end = p + size;
|
|
const uint8_t *nal_start, *nal_end;
|
|
|
|
size = 0;
|
|
nal_start = ff_avc_find_startcode(p, end);
|
|
while (nal_start < end) {
|
|
while(!*(nal_start++));
|
|
nal_end = ff_avc_find_startcode(nal_start, end);
|
|
put_be32(pb, nal_end - nal_start);
|
|
put_buffer(pb, nal_start, nal_end - nal_start);
|
|
size += 4 + nal_end - nal_start;
|
|
nal_start = nal_end;
|
|
}
|
|
return size;
|
|
}
|
|
|
|
int ff_avc_parse_nal_units_buf(const uint8_t *buf_in, uint8_t **buf, int *size)
|
|
{
|
|
ByteIOContext *pb;
|
|
int ret = url_open_dyn_buf(&pb);
|
|
if(ret < 0)
|
|
return ret;
|
|
|
|
ff_avc_parse_nal_units(pb, buf_in, *size);
|
|
|
|
av_freep(buf);
|
|
*size = url_close_dyn_buf(pb, buf);
|
|
return 0;
|
|
}
|
|
|
|
int ff_isom_write_avcc(ByteIOContext *pb, const uint8_t *data, int len)
|
|
{
|
|
if (len > 6) {
|
|
/* check for h264 start code */
|
|
if (AV_RB32(data) == 0x00000001 ||
|
|
AV_RB24(data) == 0x000001) {
|
|
uint8_t *buf=NULL, *end, *start;
|
|
uint32_t sps_size=0, pps_size=0;
|
|
uint8_t *sps=0, *pps=0;
|
|
|
|
int ret = ff_avc_parse_nal_units_buf(data, &buf, &len);
|
|
if (ret < 0)
|
|
return ret;
|
|
start = buf;
|
|
end = buf + len;
|
|
|
|
/* look for sps and pps */
|
|
while (buf < end) {
|
|
unsigned int size;
|
|
uint8_t nal_type;
|
|
size = AV_RB32(buf);
|
|
nal_type = buf[4] & 0x1f;
|
|
if (nal_type == 7) { /* SPS */
|
|
sps = buf + 4;
|
|
sps_size = size;
|
|
} else if (nal_type == 8) { /* PPS */
|
|
pps = buf + 4;
|
|
pps_size = size;
|
|
}
|
|
buf += size + 4;
|
|
}
|
|
assert(sps);
|
|
assert(pps);
|
|
|
|
put_byte(pb, 1); /* version */
|
|
put_byte(pb, sps[1]); /* profile */
|
|
put_byte(pb, sps[2]); /* profile compat */
|
|
put_byte(pb, sps[3]); /* level */
|
|
put_byte(pb, 0xff); /* 6 bits reserved (111111) + 2 bits nal size length - 1 (11) */
|
|
put_byte(pb, 0xe1); /* 3 bits reserved (111) + 5 bits number of sps (00001) */
|
|
|
|
put_be16(pb, sps_size);
|
|
put_buffer(pb, sps, sps_size);
|
|
put_byte(pb, 1); /* number of pps */
|
|
put_be16(pb, pps_size);
|
|
put_buffer(pb, pps, pps_size);
|
|
av_free(start);
|
|
} else {
|
|
put_buffer(pb, data, len);
|
|
}
|
|
}
|
|
return 0;
|
|
}
|