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