1/* 2 * AVC helper functions for muxers 3 * Copyright (c) 2006 Baptiste Coudurier <baptiste.coudurier@smartjog.com> 4 * 5 * This file is part of FFmpeg. 6 * 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. 11 * 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. 16 * 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 20 */ 21 22#include "libavutil/intreadwrite.h" 23#include "avformat.h" 24#include "avio.h" 25 26const uint8_t *ff_avc_find_startcode(const uint8_t *p, const uint8_t *end) 27{ 28 const uint8_t *a = p + 4 - ((long)p & 3); 29 30 for( end -= 3; p < a && p < end; p++ ) { 31 if( p[0] == 0 && p[1] == 0 && p[2] == 1 ) 32 return p; 33 } 34 35 for( end -= 3; p < end; p += 4 ) { 36 uint32_t x = *(const uint32_t*)p; 37// if( (x - 0x01000100) & (~x) & 0x80008000 ) // little endian 38// if( (x - 0x00010001) & (~x) & 0x00800080 ) // big endian 39 if( (x - 0x01010101) & (~x) & 0x80808080 ) { // generic 40 if( p[1] == 0 ) { 41 if( p[0] == 0 && p[2] == 1 ) 42 return p-1; 43 if( p[2] == 0 && p[3] == 1 ) 44 return p; 45 } 46 if( p[3] == 0 ) { 47 if( p[2] == 0 && p[4] == 1 ) 48 return p+1; 49 if( p[4] == 0 && p[5] == 1 ) 50 return p+2; 51 } 52 } 53 } 54 55 for( end += 3; p < end; p++ ) { 56 if( p[0] == 0 && p[1] == 0 && p[2] == 1 ) 57 return p; 58 } 59 60 return end + 3; 61} 62 63int ff_avc_parse_nal_units(ByteIOContext *pb, const uint8_t *buf_in, int size) 64{ 65 const uint8_t *p = buf_in; 66 const uint8_t *end = p + size; 67 const uint8_t *nal_start, *nal_end; 68 69 size = 0; 70 nal_start = ff_avc_find_startcode(p, end); 71 while (nal_start < end) { 72 while(!*(nal_start++)); 73 nal_end = ff_avc_find_startcode(nal_start, end); 74 put_be32(pb, nal_end - nal_start); 75 put_buffer(pb, nal_start, nal_end - nal_start); 76 size += 4 + nal_end - nal_start; 77 nal_start = nal_end; 78 } 79 return size; 80} 81 82int ff_avc_parse_nal_units_buf(const uint8_t *buf_in, uint8_t **buf, int *size) 83{ 84 ByteIOContext *pb; 85 int ret = url_open_dyn_buf(&pb); 86 if(ret < 0) 87 return ret; 88 89 ff_avc_parse_nal_units(pb, buf_in, *size); 90 91 av_freep(buf); 92 *size = url_close_dyn_buf(pb, buf); 93 return 0; 94} 95 96int ff_isom_write_avcc(ByteIOContext *pb, const uint8_t *data, int len) 97{ 98 if (len > 6) { 99 /* check for h264 start code */ 100 if (AV_RB32(data) == 0x00000001 || 101 AV_RB24(data) == 0x000001) { 102 uint8_t *buf=NULL, *end, *start; 103 uint32_t sps_size=0, pps_size=0; 104 uint8_t *sps=0, *pps=0; 105 106 int ret = ff_avc_parse_nal_units_buf(data, &buf, &len); 107 if (ret < 0) 108 return ret; 109 start = buf; 110 end = buf + len; 111 112 /* look for sps and pps */ 113 while (buf < end) { 114 unsigned int size; 115 uint8_t nal_type; 116 size = AV_RB32(buf); 117 nal_type = buf[4] & 0x1f; 118 if (nal_type == 7) { /* SPS */ 119 sps = buf + 4; 120 sps_size = size; 121 } else if (nal_type == 8) { /* PPS */ 122 pps = buf + 4; 123 pps_size = size; 124 } 125 buf += size + 4; 126 } 127 assert(sps); 128 assert(pps); 129 130 put_byte(pb, 1); /* version */ 131 put_byte(pb, sps[1]); /* profile */ 132 put_byte(pb, sps[2]); /* profile compat */ 133 put_byte(pb, sps[3]); /* level */ 134 put_byte(pb, 0xff); /* 6 bits reserved (111111) + 2 bits nal size length - 1 (11) */ 135 put_byte(pb, 0xe1); /* 3 bits reserved (111) + 5 bits number of sps (00001) */ 136 137 put_be16(pb, sps_size); 138 put_buffer(pb, sps, sps_size); 139 put_byte(pb, 1); /* number of pps */ 140 put_be16(pb, pps_size); 141 put_buffer(pb, pps, pps_size); 142 av_free(start); 143 } else { 144 put_buffer(pb, data, len); 145 } 146 } 147 return 0; 148} 149