1/* 2 * HEVC Annex B format parser 3 * 4 * Copyright (C) 2012 - 2013 Guillaume Martres 5 * 6 * This file is part of FFmpeg. 7 * 8 * FFmpeg is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU Lesser General Public 10 * License as published by the Free Software Foundation; either 11 * version 2.1 of the License, or (at your option) any later version. 12 * 13 * FFmpeg is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 16 * Lesser General Public License for more details. 17 * 18 * You should have received a copy of the GNU Lesser General Public 19 * License along with FFmpeg; if not, write to the Free Software 20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 21 */ 22 23#include "libavutil/common.h" 24 25#include "parser.h" 26#include "hevc.h" 27#include "golomb.h" 28 29#define START_CODE 0x000001 ///< start_code_prefix_one_3bytes 30 31typedef struct HEVCParseContext { 32 HEVCContext h; 33 ParseContext pc; 34} HEVCParseContext; 35 36/** 37 * Find the end of the current frame in the bitstream. 38 * @return the position of the first byte of the next frame, or END_NOT_FOUND 39 */ 40static int hevc_find_frame_end(AVCodecParserContext *s, const uint8_t *buf, 41 int buf_size) 42{ 43 int i; 44 ParseContext *pc = &((HEVCParseContext *)s->priv_data)->pc; 45 46 for (i = 0; i < buf_size; i++) { 47 int nut; 48 49 pc->state64 = (pc->state64 << 8) | buf[i]; 50 51 if (((pc->state64 >> 3 * 8) & 0xFFFFFF) != START_CODE) 52 continue; 53 54 nut = (pc->state64 >> 2 * 8 + 1) & 0x3F; 55 // Beginning of access unit 56 if ((nut >= NAL_VPS && nut <= NAL_AUD) || nut == NAL_SEI_PREFIX || 57 (nut >= 41 && nut <= 44) || (nut >= 48 && nut <= 55)) { 58 if (pc->frame_start_found) { 59 pc->frame_start_found = 0; 60 return i - 5; 61 } 62 } else if (nut <= NAL_RASL_R || 63 (nut >= NAL_BLA_W_LP && nut <= NAL_CRA_NUT)) { 64 int first_slice_segment_in_pic_flag = buf[i] >> 7; 65 if (first_slice_segment_in_pic_flag) { 66 if (!pc->frame_start_found) { 67 pc->frame_start_found = 1; 68 } else { // First slice of next frame found 69 pc->frame_start_found = 0; 70 return i - 5; 71 } 72 } 73 } 74 } 75 76 return END_NOT_FOUND; 77} 78 79/** 80 * Parse NAL units of found picture and decode some basic information. 81 * 82 * @param s parser context. 83 * @param avctx codec context. 84 * @param buf buffer with field/frame data. 85 * @param buf_size size of the buffer. 86 */ 87static inline int parse_nal_units(AVCodecParserContext *s, AVCodecContext *avctx, 88 const uint8_t *buf, int buf_size) 89{ 90 HEVCContext *h = &((HEVCParseContext *)s->priv_data)->h; 91 GetBitContext *gb = &h->HEVClc->gb; 92 SliceHeader *sh = &h->sh; 93 const uint8_t *buf_end = buf + buf_size; 94 int state = -1, i; 95 HEVCNAL *nal; 96 97 /* set some sane default values */ 98 s->pict_type = AV_PICTURE_TYPE_I; 99 s->key_frame = 0; 100 s->picture_structure = AV_PICTURE_STRUCTURE_UNKNOWN; 101 102 h->avctx = avctx; 103 104 if (!buf_size) 105 return 0; 106 107 if (h->nals_allocated < 1) { 108 HEVCNAL *tmp = av_realloc_array(h->nals, 1, sizeof(*tmp)); 109 if (!tmp) 110 return AVERROR(ENOMEM); 111 h->nals = tmp; 112 memset(h->nals, 0, sizeof(*tmp)); 113 h->nals_allocated = 1; 114 } 115 116 nal = &h->nals[0]; 117 118 for (;;) { 119 int src_length, consumed; 120 buf = avpriv_find_start_code(buf, buf_end, &state); 121 if (--buf + 2 >= buf_end) 122 break; 123 src_length = buf_end - buf; 124 125 h->nal_unit_type = (*buf >> 1) & 0x3f; 126 h->temporal_id = (*(buf + 1) & 0x07) - 1; 127 if (h->nal_unit_type <= NAL_CRA_NUT) { 128 // Do not walk the whole buffer just to decode slice segment header 129 if (src_length > 20) 130 src_length = 20; 131 } 132 133 consumed = ff_hevc_extract_rbsp(h, buf, src_length, nal); 134 if (consumed < 0) 135 return consumed; 136 137 init_get_bits8(gb, nal->data + 2, nal->size); 138 switch (h->nal_unit_type) { 139 case NAL_VPS: 140 ff_hevc_decode_nal_vps(h); 141 break; 142 case NAL_SPS: 143 ff_hevc_decode_nal_sps(h); 144 break; 145 case NAL_PPS: 146 ff_hevc_decode_nal_pps(h); 147 break; 148 case NAL_SEI_PREFIX: 149 case NAL_SEI_SUFFIX: 150 ff_hevc_decode_nal_sei(h); 151 break; 152 case NAL_TRAIL_N: 153 case NAL_TRAIL_R: 154 case NAL_TSA_N: 155 case NAL_TSA_R: 156 case NAL_STSA_N: 157 case NAL_STSA_R: 158 case NAL_RADL_N: 159 case NAL_RADL_R: 160 case NAL_RASL_N: 161 case NAL_RASL_R: 162 case NAL_BLA_W_LP: 163 case NAL_BLA_W_RADL: 164 case NAL_BLA_N_LP: 165 case NAL_IDR_W_RADL: 166 case NAL_IDR_N_LP: 167 case NAL_CRA_NUT: 168 sh->first_slice_in_pic_flag = get_bits1(gb); 169 s->picture_structure = h->picture_struct; 170 s->field_order = h->picture_struct; 171 172 if (IS_IRAP(h)) { 173 s->key_frame = 1; 174 sh->no_output_of_prior_pics_flag = get_bits1(gb); 175 } 176 177 sh->pps_id = get_ue_golomb(gb); 178 if (sh->pps_id >= MAX_PPS_COUNT || !h->pps_list[sh->pps_id]) { 179 av_log(h->avctx, AV_LOG_ERROR, "PPS id out of range: %d\n", sh->pps_id); 180 return AVERROR_INVALIDDATA; 181 } 182 h->pps = (HEVCPPS*)h->pps_list[sh->pps_id]->data; 183 184 if (h->pps->sps_id >= MAX_SPS_COUNT || !h->sps_list[h->pps->sps_id]) { 185 av_log(h->avctx, AV_LOG_ERROR, "SPS id out of range: %d\n", h->pps->sps_id); 186 return AVERROR_INVALIDDATA; 187 } 188 if (h->sps != (HEVCSPS*)h->sps_list[h->pps->sps_id]->data) { 189 h->sps = (HEVCSPS*)h->sps_list[h->pps->sps_id]->data; 190 h->vps = (HEVCVPS*)h->vps_list[h->sps->vps_id]->data; 191 } 192 193 if (!sh->first_slice_in_pic_flag) { 194 int slice_address_length; 195 196 if (h->pps->dependent_slice_segments_enabled_flag) 197 sh->dependent_slice_segment_flag = get_bits1(gb); 198 else 199 sh->dependent_slice_segment_flag = 0; 200 201 slice_address_length = av_ceil_log2_c(h->sps->ctb_width * 202 h->sps->ctb_height); 203 sh->slice_segment_addr = get_bits(gb, slice_address_length); 204 if (sh->slice_segment_addr >= h->sps->ctb_width * h->sps->ctb_height) { 205 av_log(h->avctx, AV_LOG_ERROR, "Invalid slice segment address: %u.\n", 206 sh->slice_segment_addr); 207 return AVERROR_INVALIDDATA; 208 } 209 } else 210 sh->dependent_slice_segment_flag = 0; 211 212 if (sh->dependent_slice_segment_flag) 213 break; 214 215 for (i = 0; i < h->pps->num_extra_slice_header_bits; i++) 216 skip_bits(gb, 1); // slice_reserved_undetermined_flag[] 217 218 sh->slice_type = get_ue_golomb(gb); 219 if (!(sh->slice_type == I_SLICE || sh->slice_type == P_SLICE || 220 sh->slice_type == B_SLICE)) { 221 av_log(h->avctx, AV_LOG_ERROR, "Unknown slice type: %d.\n", 222 sh->slice_type); 223 return AVERROR_INVALIDDATA; 224 } 225 s->pict_type = sh->slice_type == B_SLICE ? AV_PICTURE_TYPE_B : 226 sh->slice_type == P_SLICE ? AV_PICTURE_TYPE_P : 227 AV_PICTURE_TYPE_I; 228 229 if (h->pps->output_flag_present_flag) 230 sh->pic_output_flag = get_bits1(gb); 231 232 if (h->sps->separate_colour_plane_flag) 233 sh->colour_plane_id = get_bits(gb, 2); 234 235 if (!IS_IDR(h)) { 236 sh->pic_order_cnt_lsb = get_bits(gb, h->sps->log2_max_poc_lsb); 237 s->output_picture_number = h->poc = ff_hevc_compute_poc(h, sh->pic_order_cnt_lsb); 238 } else 239 s->output_picture_number = h->poc = 0; 240 241 if (h->temporal_id == 0 && 242 h->nal_unit_type != NAL_TRAIL_N && 243 h->nal_unit_type != NAL_TSA_N && 244 h->nal_unit_type != NAL_STSA_N && 245 h->nal_unit_type != NAL_RADL_N && 246 h->nal_unit_type != NAL_RASL_N && 247 h->nal_unit_type != NAL_RADL_R && 248 h->nal_unit_type != NAL_RASL_R) 249 h->pocTid0 = h->poc; 250 251 return 0; /* no need to evaluate the rest */ 252 } 253 buf += consumed; 254 } 255 /* didn't find a picture! */ 256 av_log(h->avctx, AV_LOG_ERROR, "missing picture in access unit\n"); 257 return -1; 258} 259 260static int hevc_parse(AVCodecParserContext *s, 261 AVCodecContext *avctx, 262 const uint8_t **poutbuf, int *poutbuf_size, 263 const uint8_t *buf, int buf_size) 264{ 265 int next; 266 ParseContext *pc = &((HEVCParseContext *)s->priv_data)->pc; 267 268 if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) { 269 next = buf_size; 270 } else { 271 next = hevc_find_frame_end(s, buf, buf_size); 272 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) { 273 *poutbuf = NULL; 274 *poutbuf_size = 0; 275 return buf_size; 276 } 277 } 278 279 parse_nal_units(s, avctx, buf, buf_size); 280 281 *poutbuf = buf; 282 *poutbuf_size = buf_size; 283 return next; 284} 285 286// Split after the parameter sets at the beginning of the stream if they exist. 287static int hevc_split(AVCodecContext *avctx, const uint8_t *buf, int buf_size) 288{ 289 int i; 290 uint32_t state = -1; 291 int has_ps = 0; 292 293 for (i = 0; i < buf_size; i++) { 294 state = (state << 8) | buf[i]; 295 if (((state >> 8) & 0xFFFFFF) == START_CODE) { 296 int nut = (state >> 1) & 0x3F; 297 if (nut >= NAL_VPS && nut <= NAL_PPS) 298 has_ps = 1; 299 else if (has_ps) 300 return i - 3; 301 else // no parameter set at the beginning of the stream 302 return 0; 303 } 304 } 305 return 0; 306} 307 308static int hevc_init(AVCodecParserContext *s) 309{ 310 HEVCContext *h = &((HEVCParseContext *)s->priv_data)->h; 311 h->HEVClc = av_mallocz(sizeof(HEVCLocalContext)); 312 h->skipped_bytes_pos_size = INT_MAX; 313 314 return 0; 315} 316 317static void hevc_close(AVCodecParserContext *s) 318{ 319 int i; 320 HEVCContext *h = &((HEVCParseContext *)s->priv_data)->h; 321 ParseContext *pc = &((HEVCParseContext *)s->priv_data)->pc; 322 323 av_freep(&h->skipped_bytes_pos); 324 av_freep(&h->HEVClc); 325 av_freep(&pc->buffer); 326 327 for (i = 0; i < FF_ARRAY_ELEMS(h->vps_list); i++) 328 av_buffer_unref(&h->vps_list[i]); 329 for (i = 0; i < FF_ARRAY_ELEMS(h->sps_list); i++) 330 av_buffer_unref(&h->sps_list[i]); 331 for (i = 0; i < FF_ARRAY_ELEMS(h->pps_list); i++) 332 av_buffer_unref(&h->pps_list[i]); 333 334 av_buffer_unref(&h->current_sps); 335 h->sps = NULL; 336 337 for (i = 0; i < h->nals_allocated; i++) 338 av_freep(&h->nals[i].rbsp_buffer); 339 av_freep(&h->nals); 340 h->nals_allocated = 0; 341} 342 343AVCodecParser ff_hevc_parser = { 344 .codec_ids = { AV_CODEC_ID_HEVC }, 345 .priv_data_size = sizeof(HEVCParseContext), 346 .parser_init = hevc_init, 347 .parser_parse = hevc_parse, 348 .parser_close = hevc_close, 349 .split = hevc_split, 350}; 351