1/* 2 * H.26L/H.264/AVC/JVT/14496-10/... parser 3 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at> 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/** 23 * @file 24 * H.264 / AVC / MPEG4 part10 parser. 25 * @author Michael Niedermayer <michaelni@gmx.at> 26 */ 27 28#include "parser.h" 29#include "h264_parser.h" 30#include "h264data.h" 31#include "golomb.h" 32 33#include <assert.h> 34 35 36int ff_h264_find_frame_end(H264Context *h, const uint8_t *buf, int buf_size) 37{ 38 int i; 39 uint32_t state; 40 ParseContext *pc = &(h->s.parse_context); 41//printf("first %02X%02X%02X%02X\n", buf[0], buf[1],buf[2],buf[3]); 42// mb_addr= pc->mb_addr - 1; 43 state= pc->state; 44 if(state>13) 45 state= 7; 46 47 for(i=0; i<buf_size; i++){ 48 if(state==7){ 49#if HAVE_FAST_UNALIGNED 50 /* we check i<buf_size instead of i+3/7 because its simpler 51 * and there should be FF_INPUT_BUFFER_PADDING_SIZE bytes at the end 52 */ 53# if HAVE_FAST_64BIT 54 while(i<buf_size && !((~*(const uint64_t*)(buf+i) & (*(const uint64_t*)(buf+i) - 0x0101010101010101ULL)) & 0x8080808080808080ULL)) 55 i+=8; 56# else 57 while(i<buf_size && !((~*(const uint32_t*)(buf+i) & (*(const uint32_t*)(buf+i) - 0x01010101U)) & 0x80808080U)) 58 i+=4; 59# endif 60#endif 61 for(; i<buf_size; i++){ 62 if(!buf[i]){ 63 state=2; 64 break; 65 } 66 } 67 }else if(state<=2){ 68 if(buf[i]==1) state^= 5; //2->7, 1->4, 0->5 69 else if(buf[i]) state = 7; 70 else state>>=1; //2->1, 1->0, 0->0 71 }else if(state<=5){ 72 int v= buf[i] & 0x1F; 73 if(v==6 || v==7 || v==8 || v==9){ 74 if(pc->frame_start_found){ 75 i++; 76 goto found; 77 } 78 }else if(v==1 || v==2 || v==5){ 79 if(pc->frame_start_found){ 80 state+=8; 81 continue; 82 }else 83 pc->frame_start_found = 1; 84 } 85 state= 7; 86 }else{ 87 if(buf[i] & 0x80) 88 goto found; 89 state= 7; 90 } 91 } 92 pc->state= state; 93 return END_NOT_FOUND; 94 95found: 96 pc->state=7; 97 pc->frame_start_found= 0; 98 return i-(state&5); 99} 100 101/*! 102 * Parse NAL units of found picture and decode some basic information. 103 * 104 * @param s parser context. 105 * @param avctx codec context. 106 * @param buf buffer with field/frame data. 107 * @param buf_size size of the buffer. 108 */ 109static inline int parse_nal_units(AVCodecParserContext *s, 110 AVCodecContext *avctx, 111 const uint8_t *buf, int buf_size) 112{ 113 H264Context *h = s->priv_data; 114 const uint8_t *buf_end = buf + buf_size; 115 unsigned int pps_id; 116 unsigned int slice_type; 117 int state = -1; 118 const uint8_t *ptr; 119 120 /* set some sane default values */ 121 s->pict_type = FF_I_TYPE; 122 s->key_frame = 0; 123 124 h->s.avctx= avctx; 125 h->sei_recovery_frame_cnt = -1; 126 h->sei_dpb_output_delay = 0; 127 h->sei_cpb_removal_delay = -1; 128 h->sei_buffering_period_present = 0; 129 130 for(;;) { 131 int src_length, dst_length, consumed; 132 buf = ff_find_start_code(buf, buf_end, &state); 133 if(buf >= buf_end) 134 break; 135 --buf; 136 src_length = buf_end - buf; 137 switch (state & 0x1f) { 138 case NAL_SLICE: 139 case NAL_IDR_SLICE: 140 // Do not walk the whole buffer just to decode slice header 141 if (src_length > 20) 142 src_length = 20; 143 break; 144 } 145 ptr= ff_h264_decode_nal(h, buf, &dst_length, &consumed, src_length); 146 if (ptr==NULL || dst_length < 0) 147 break; 148 149 init_get_bits(&h->s.gb, ptr, 8*dst_length); 150 switch(h->nal_unit_type) { 151 case NAL_SPS: 152 ff_h264_decode_seq_parameter_set(h); 153 break; 154 case NAL_PPS: 155 ff_h264_decode_picture_parameter_set(h, h->s.gb.size_in_bits); 156 break; 157 case NAL_SEI: 158 ff_h264_decode_sei(h); 159 break; 160 case NAL_IDR_SLICE: 161 s->key_frame = 1; 162 /* fall through */ 163 case NAL_SLICE: 164 get_ue_golomb(&h->s.gb); // skip first_mb_in_slice 165 slice_type = get_ue_golomb_31(&h->s.gb); 166 s->pict_type = golomb_to_pict_type[slice_type % 5]; 167 if (h->sei_recovery_frame_cnt >= 0) { 168 /* key frame, since recovery_frame_cnt is set */ 169 s->key_frame = 1; 170 } 171 pps_id= get_ue_golomb(&h->s.gb); 172 if(pps_id>=MAX_PPS_COUNT) { 173 av_log(h->s.avctx, AV_LOG_ERROR, "pps_id out of range\n"); 174 return -1; 175 } 176 if(!h->pps_buffers[pps_id]) { 177 av_log(h->s.avctx, AV_LOG_ERROR, "non-existing PPS referenced\n"); 178 return -1; 179 } 180 h->pps= *h->pps_buffers[pps_id]; 181 if(!h->sps_buffers[h->pps.sps_id]) { 182 av_log(h->s.avctx, AV_LOG_ERROR, "non-existing SPS referenced\n"); 183 return -1; 184 } 185 h->sps = *h->sps_buffers[h->pps.sps_id]; 186 h->frame_num = get_bits(&h->s.gb, h->sps.log2_max_frame_num); 187 188 avctx->profile = h->sps.profile_idc; 189 avctx->level = h->sps.level_idc; 190 191 if(h->sps.frame_mbs_only_flag){ 192 h->s.picture_structure= PICT_FRAME; 193 }else{ 194 if(get_bits1(&h->s.gb)) { //field_pic_flag 195 h->s.picture_structure= PICT_TOP_FIELD + get_bits1(&h->s.gb); //bottom_field_flag 196 } else { 197 h->s.picture_structure= PICT_FRAME; 198 } 199 } 200 201 if(h->sps.pic_struct_present_flag) { 202 switch (h->sei_pic_struct) { 203 case SEI_PIC_STRUCT_TOP_FIELD: 204 case SEI_PIC_STRUCT_BOTTOM_FIELD: 205 s->repeat_pict = 0; 206 break; 207 case SEI_PIC_STRUCT_FRAME: 208 case SEI_PIC_STRUCT_TOP_BOTTOM: 209 case SEI_PIC_STRUCT_BOTTOM_TOP: 210 s->repeat_pict = 1; 211 break; 212 case SEI_PIC_STRUCT_TOP_BOTTOM_TOP: 213 case SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM: 214 s->repeat_pict = 2; 215 break; 216 case SEI_PIC_STRUCT_FRAME_DOUBLING: 217 s->repeat_pict = 3; 218 break; 219 case SEI_PIC_STRUCT_FRAME_TRIPLING: 220 s->repeat_pict = 5; 221 break; 222 default: 223 s->repeat_pict = h->s.picture_structure == PICT_FRAME ? 1 : 0; 224 break; 225 } 226 } else { 227 s->repeat_pict = h->s.picture_structure == PICT_FRAME ? 1 : 0; 228 } 229 230 return 0; /* no need to evaluate the rest */ 231 } 232 buf += consumed; 233 } 234 /* didn't find a picture! */ 235 av_log(h->s.avctx, AV_LOG_ERROR, "missing picture in access unit\n"); 236 return -1; 237} 238 239static int h264_parse(AVCodecParserContext *s, 240 AVCodecContext *avctx, 241 const uint8_t **poutbuf, int *poutbuf_size, 242 const uint8_t *buf, int buf_size) 243{ 244 H264Context *h = s->priv_data; 245 ParseContext *pc = &h->s.parse_context; 246 int next; 247 248 if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){ 249 next= buf_size; 250 }else{ 251 next= ff_h264_find_frame_end(h, buf, buf_size); 252 253 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) { 254 *poutbuf = NULL; 255 *poutbuf_size = 0; 256 return buf_size; 257 } 258 259 if(next<0 && next != END_NOT_FOUND){ 260 assert(pc->last_index + next >= 0 ); 261 ff_h264_find_frame_end(h, &pc->buffer[pc->last_index + next], -next); //update state 262 } 263 264 parse_nal_units(s, avctx, buf, buf_size); 265 266 if (h->sei_cpb_removal_delay >= 0) { 267 s->dts_sync_point = h->sei_buffering_period_present; 268 s->dts_ref_dts_delta = h->sei_cpb_removal_delay; 269 s->pts_dts_delta = h->sei_dpb_output_delay; 270 } else { 271 s->dts_sync_point = INT_MIN; 272 s->dts_ref_dts_delta = INT_MIN; 273 s->pts_dts_delta = INT_MIN; 274 } 275 } 276 277 *poutbuf = buf; 278 *poutbuf_size = buf_size; 279 return next; 280} 281 282static int h264_split(AVCodecContext *avctx, 283 const uint8_t *buf, int buf_size) 284{ 285 int i; 286 uint32_t state = -1; 287 int has_sps= 0; 288 289 for(i=0; i<=buf_size; i++){ 290 if((state&0xFFFFFF1F) == 0x107) 291 has_sps=1; 292/* if((state&0xFFFFFF1F) == 0x101 || (state&0xFFFFFF1F) == 0x102 || (state&0xFFFFFF1F) == 0x105){ 293 }*/ 294 if((state&0xFFFFFF00) == 0x100 && (state&0xFFFFFF1F) != 0x107 && (state&0xFFFFFF1F) != 0x108 && (state&0xFFFFFF1F) != 0x109){ 295 if(has_sps){ 296 while(i>4 && buf[i-5]==0) i--; 297 return i-4; 298 } 299 } 300 if (i<buf_size) 301 state= (state<<8) | buf[i]; 302 } 303 return 0; 304} 305 306static void close(AVCodecParserContext *s) 307{ 308 H264Context *h = s->priv_data; 309 ParseContext *pc = &h->s.parse_context; 310 311 av_free(pc->buffer); 312 ff_h264_free_context(h); 313} 314 315static int init(AVCodecParserContext *s) 316{ 317 H264Context *h = s->priv_data; 318 h->thread_context[0] = h; 319 return 0; 320} 321 322AVCodecParser h264_parser = { 323 { CODEC_ID_H264 }, 324 sizeof(H264Context), 325 init, 326 h264_parse, 327 close, 328 h264_split, 329}; 330