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 "libavcodec/h264.h" 24#include "libavcodec/get_bits.h" 25#include "avformat.h" 26#include "avio.h" 27#include "avc.h" 28#include "avio_internal.h" 29 30static const uint8_t *avc_find_startcode_internal(const uint8_t *p, const uint8_t *end) 31{ 32 const uint8_t *a = p + 4 - ((intptr_t)p & 3); 33 34 for (end -= 3; p < a && p < end; p++) { 35 if (p[0] == 0 && p[1] == 0 && p[2] == 1) 36 return p; 37 } 38 39 for (end -= 3; p < end; p += 4) { 40 uint32_t x = *(const uint32_t*)p; 41// if ((x - 0x01000100) & (~x) & 0x80008000) // little endian 42// if ((x - 0x00010001) & (~x) & 0x00800080) // big endian 43 if ((x - 0x01010101) & (~x) & 0x80808080) { // generic 44 if (p[1] == 0) { 45 if (p[0] == 0 && p[2] == 1) 46 return p; 47 if (p[2] == 0 && p[3] == 1) 48 return p+1; 49 } 50 if (p[3] == 0) { 51 if (p[2] == 0 && p[4] == 1) 52 return p+2; 53 if (p[4] == 0 && p[5] == 1) 54 return p+3; 55 } 56 } 57 } 58 59 for (end += 3; p < end; p++) { 60 if (p[0] == 0 && p[1] == 0 && p[2] == 1) 61 return p; 62 } 63 64 return end + 3; 65} 66 67const uint8_t *ff_avc_find_startcode(const uint8_t *p, const uint8_t *end){ 68 const uint8_t *out = avc_find_startcode_internal(p, end); 69 if(p<out && out<end && !out[-1]) out--; 70 return out; 71} 72 73static int avc_parse_nal_units(AVIOContext *pb, NALUList *list, 74 const uint8_t *buf_in, int size) 75{ 76 const uint8_t *p = buf_in; 77 const uint8_t *end = p + size; 78 const uint8_t *nal_start, *nal_end; 79 80 size = 0; 81 nal_start = ff_avc_find_startcode(p, end); 82 for (;;) { 83 const size_t nalu_limit = SIZE_MAX / sizeof(*list->nalus); 84 while (nal_start < end && !*(nal_start++)); 85 if (nal_start == end) 86 break; 87 88 nal_end = ff_avc_find_startcode(nal_start, end); 89 if (pb) { 90 avio_wb32(pb, nal_end - nal_start); 91 avio_write(pb, nal_start, nal_end - nal_start); 92 } else if (list->nb_nalus >= nalu_limit) { 93 return AVERROR(ERANGE); 94 } else { 95 NALU *tmp = av_fast_realloc(list->nalus, &list->nalus_array_size, 96 (list->nb_nalus + 1) * sizeof(*list->nalus)); 97 if (!tmp) 98 return AVERROR(ENOMEM); 99 list->nalus = tmp; 100 tmp[list->nb_nalus++] = (NALU){ .offset = nal_start - p, 101 .size = nal_end - nal_start }; 102 } 103 size += 4 + nal_end - nal_start; 104 nal_start = nal_end; 105 } 106 return size; 107} 108 109int ff_avc_parse_nal_units(AVIOContext *pb, const uint8_t *buf_in, int size) 110{ 111 return avc_parse_nal_units(pb, NULL, buf_in, size); 112} 113 114int ff_nal_units_create_list(NALUList *list, const uint8_t *buf, int size) 115{ 116 list->nb_nalus = 0; 117 return avc_parse_nal_units(NULL, list, buf, size); 118} 119 120void ff_nal_units_write_list(const NALUList *list, AVIOContext *pb, 121 const uint8_t *buf) 122{ 123 for (unsigned i = 0; i < list->nb_nalus; i++) { 124 avio_wb32(pb, list->nalus[i].size); 125 avio_write(pb, buf + list->nalus[i].offset, list->nalus[i].size); 126 } 127} 128 129int ff_avc_parse_nal_units_buf(const uint8_t *buf_in, uint8_t **buf, int *size) 130{ 131 AVIOContext *pb; 132 int ret = avio_open_dyn_buf(&pb); 133 if(ret < 0) 134 return ret; 135 136 ff_avc_parse_nal_units(pb, buf_in, *size); 137 138 *size = avio_close_dyn_buf(pb, buf); 139 return 0; 140} 141 142int ff_isom_write_avcc(AVIOContext *pb, const uint8_t *data, int len) 143{ 144 AVIOContext *sps_pb = NULL, *pps_pb = NULL, *sps_ext_pb = NULL; 145 uint8_t *buf, *end, *start; 146 uint8_t *sps, *pps, *sps_ext; 147 uint32_t sps_size = 0, pps_size = 0, sps_ext_size = 0; 148 int ret, nb_sps = 0, nb_pps = 0, nb_sps_ext = 0; 149 150 if (len <= 6) 151 return AVERROR_INVALIDDATA; 152 153 /* check for H.264 start code */ 154 if (AV_RB32(data) != 0x00000001 && 155 AV_RB24(data) != 0x000001) { 156 avio_write(pb, data, len); 157 return 0; 158 } 159 160 ret = ff_avc_parse_nal_units_buf(data, &buf, &len); 161 if (ret < 0) 162 return ret; 163 start = buf; 164 end = buf + len; 165 166 ret = avio_open_dyn_buf(&sps_pb); 167 if (ret < 0) 168 goto fail; 169 ret = avio_open_dyn_buf(&pps_pb); 170 if (ret < 0) 171 goto fail; 172 ret = avio_open_dyn_buf(&sps_ext_pb); 173 if (ret < 0) 174 goto fail; 175 176 /* look for sps and pps */ 177 while (end - buf > 4) { 178 uint32_t size; 179 uint8_t nal_type; 180 size = FFMIN(AV_RB32(buf), end - buf - 4); 181 buf += 4; 182 nal_type = buf[0] & 0x1f; 183 184 if (nal_type == 7) { /* SPS */ 185 nb_sps++; 186 if (size > UINT16_MAX || nb_sps >= H264_MAX_SPS_COUNT) { 187 ret = AVERROR_INVALIDDATA; 188 goto fail; 189 } 190 avio_wb16(sps_pb, size); 191 avio_write(sps_pb, buf, size); 192 } else if (nal_type == 8) { /* PPS */ 193 nb_pps++; 194 if (size > UINT16_MAX || nb_pps >= H264_MAX_PPS_COUNT) { 195 ret = AVERROR_INVALIDDATA; 196 goto fail; 197 } 198 avio_wb16(pps_pb, size); 199 avio_write(pps_pb, buf, size); 200 } else if (nal_type == 13) { /* SPS_EXT */ 201 nb_sps_ext++; 202 if (size > UINT16_MAX || nb_sps_ext >= 256) { 203 ret = AVERROR_INVALIDDATA; 204 goto fail; 205 } 206 avio_wb16(sps_ext_pb, size); 207 avio_write(sps_ext_pb, buf, size); 208 } 209 210 buf += size; 211 } 212 sps_size = avio_get_dyn_buf(sps_pb, &sps); 213 pps_size = avio_get_dyn_buf(pps_pb, &pps); 214 sps_ext_size = avio_get_dyn_buf(sps_ext_pb, &sps_ext); 215 216 if (sps_size < 6 || !pps_size) { 217 ret = AVERROR_INVALIDDATA; 218 goto fail; 219 } 220 221 avio_w8(pb, 1); /* version */ 222 avio_w8(pb, sps[3]); /* profile */ 223 avio_w8(pb, sps[4]); /* profile compat */ 224 avio_w8(pb, sps[5]); /* level */ 225 avio_w8(pb, 0xff); /* 6 bits reserved (111111) + 2 bits nal size length - 1 (11) */ 226 avio_w8(pb, 0xe0 | nb_sps); /* 3 bits reserved (111) + 5 bits number of sps */ 227 228 avio_write(pb, sps, sps_size); 229 avio_w8(pb, nb_pps); /* number of pps */ 230 avio_write(pb, pps, pps_size); 231 232 if (sps[3] != 66 && sps[3] != 77 && sps[3] != 88) { 233 H264SPS seq; 234 ret = ff_avc_decode_sps(&seq, sps + 3, sps_size - 3); 235 if (ret < 0) 236 goto fail; 237 238 avio_w8(pb, 0xfc | seq.chroma_format_idc); /* 6 bits reserved (111111) + chroma_format_idc */ 239 avio_w8(pb, 0xf8 | (seq.bit_depth_luma - 8)); /* 5 bits reserved (11111) + bit_depth_luma_minus8 */ 240 avio_w8(pb, 0xf8 | (seq.bit_depth_chroma - 8)); /* 5 bits reserved (11111) + bit_depth_chroma_minus8 */ 241 avio_w8(pb, nb_sps_ext); /* number of sps ext */ 242 if (nb_sps_ext) 243 avio_write(pb, sps_ext, sps_ext_size); 244 } 245 246fail: 247 ffio_free_dyn_buf(&sps_pb); 248 ffio_free_dyn_buf(&pps_pb); 249 ffio_free_dyn_buf(&sps_ext_pb); 250 av_free(start); 251 252 return ret; 253} 254 255int ff_avc_write_annexb_extradata(const uint8_t *in, uint8_t **buf, int *size) 256{ 257 uint16_t sps_size, pps_size; 258 uint8_t *out; 259 int out_size; 260 261 *buf = NULL; 262 if (*size >= 4 && (AV_RB32(in) == 0x00000001 || AV_RB24(in) == 0x000001)) 263 return 0; 264 if (*size < 11 || in[0] != 1) 265 return AVERROR_INVALIDDATA; 266 267 sps_size = AV_RB16(&in[6]); 268 if (11 + sps_size > *size) 269 return AVERROR_INVALIDDATA; 270 pps_size = AV_RB16(&in[9 + sps_size]); 271 if (11 + sps_size + pps_size > *size) 272 return AVERROR_INVALIDDATA; 273 out_size = 8 + sps_size + pps_size; 274 out = av_mallocz(out_size + AV_INPUT_BUFFER_PADDING_SIZE); 275 if (!out) 276 return AVERROR(ENOMEM); 277 AV_WB32(&out[0], 0x00000001); 278 memcpy(out + 4, &in[8], sps_size); 279 AV_WB32(&out[4 + sps_size], 0x00000001); 280 memcpy(out + 8 + sps_size, &in[11 + sps_size], pps_size); 281 *buf = out; 282 *size = out_size; 283 return 0; 284} 285 286const uint8_t *ff_avc_mp4_find_startcode(const uint8_t *start, 287 const uint8_t *end, 288 int nal_length_size) 289{ 290 unsigned int res = 0; 291 292 if (end - start < nal_length_size) 293 return NULL; 294 while (nal_length_size--) 295 res = (res << 8) | *start++; 296 297 if (res > end - start) 298 return NULL; 299 300 return start + res; 301} 302 303uint8_t *ff_nal_unit_extract_rbsp(const uint8_t *src, uint32_t src_len, 304 uint32_t *dst_len, int header_len) 305{ 306 uint8_t *dst; 307 uint32_t i, len; 308 309 dst = av_malloc(src_len + AV_INPUT_BUFFER_PADDING_SIZE); 310 if (!dst) 311 return NULL; 312 313 /* NAL unit header */ 314 i = len = 0; 315 while (i < header_len && i < src_len) 316 dst[len++] = src[i++]; 317 318 while (i + 2 < src_len) 319 if (!src[i] && !src[i + 1] && src[i + 2] == 3) { 320 dst[len++] = src[i++]; 321 dst[len++] = src[i++]; 322 i++; // remove emulation_prevention_three_byte 323 } else 324 dst[len++] = src[i++]; 325 326 while (i < src_len) 327 dst[len++] = src[i++]; 328 329 memset(dst + len, 0, AV_INPUT_BUFFER_PADDING_SIZE); 330 331 *dst_len = len; 332 return dst; 333} 334 335static const AVRational avc_sample_aspect_ratio[17] = { 336 { 0, 1 }, 337 { 1, 1 }, 338 { 12, 11 }, 339 { 10, 11 }, 340 { 16, 11 }, 341 { 40, 33 }, 342 { 24, 11 }, 343 { 20, 11 }, 344 { 32, 11 }, 345 { 80, 33 }, 346 { 18, 11 }, 347 { 15, 11 }, 348 { 64, 33 }, 349 { 160, 99 }, 350 { 4, 3 }, 351 { 3, 2 }, 352 { 2, 1 }, 353}; 354 355static inline int get_ue_golomb(GetBitContext *gb) { 356 int i; 357 for (i = 0; i < 32 && !get_bits1(gb); i++) 358 ; 359 return get_bitsz(gb, i) + (1 << i) - 1; 360} 361 362static inline int get_se_golomb(GetBitContext *gb) { 363 int v = get_ue_golomb(gb) + 1; 364 int sign = -(v & 1); 365 return ((v >> 1) ^ sign) - sign; 366} 367 368int ff_avc_decode_sps(H264SPS *sps, const uint8_t *buf, int buf_size) 369{ 370 int i, j, ret, rbsp_size, aspect_ratio_idc, pic_order_cnt_type; 371 int num_ref_frames_in_pic_order_cnt_cycle; 372 int delta_scale, lastScale = 8, nextScale = 8; 373 int sizeOfScalingList; 374 GetBitContext gb; 375 uint8_t *rbsp_buf; 376 377 rbsp_buf = ff_nal_unit_extract_rbsp(buf, buf_size, &rbsp_size, 0); 378 if (!rbsp_buf) 379 return AVERROR(ENOMEM); 380 381 ret = init_get_bits8(&gb, rbsp_buf, rbsp_size); 382 if (ret < 0) 383 goto end; 384 385 memset(sps, 0, sizeof(*sps)); 386 387 sps->profile_idc = get_bits(&gb, 8); 388 sps->constraint_set_flags |= get_bits1(&gb) << 0; // constraint_set0_flag 389 sps->constraint_set_flags |= get_bits1(&gb) << 1; // constraint_set1_flag 390 sps->constraint_set_flags |= get_bits1(&gb) << 2; // constraint_set2_flag 391 sps->constraint_set_flags |= get_bits1(&gb) << 3; // constraint_set3_flag 392 sps->constraint_set_flags |= get_bits1(&gb) << 4; // constraint_set4_flag 393 sps->constraint_set_flags |= get_bits1(&gb) << 5; // constraint_set5_flag 394 skip_bits(&gb, 2); // reserved_zero_2bits 395 sps->level_idc = get_bits(&gb, 8); 396 sps->id = get_ue_golomb(&gb); 397 398 if (sps->profile_idc == 100 || sps->profile_idc == 110 || 399 sps->profile_idc == 122 || sps->profile_idc == 244 || sps->profile_idc == 44 || 400 sps->profile_idc == 83 || sps->profile_idc == 86 || sps->profile_idc == 118 || 401 sps->profile_idc == 128 || sps->profile_idc == 138 || sps->profile_idc == 139 || 402 sps->profile_idc == 134) { 403 sps->chroma_format_idc = get_ue_golomb(&gb); // chroma_format_idc 404 if (sps->chroma_format_idc == 3) { 405 skip_bits1(&gb); // separate_colour_plane_flag 406 } 407 sps->bit_depth_luma = get_ue_golomb(&gb) + 8; 408 sps->bit_depth_chroma = get_ue_golomb(&gb) + 8; 409 skip_bits1(&gb); // qpprime_y_zero_transform_bypass_flag 410 if (get_bits1(&gb)) { // seq_scaling_matrix_present_flag 411 for (i = 0; i < ((sps->chroma_format_idc != 3) ? 8 : 12); i++) { 412 if (!get_bits1(&gb)) // seq_scaling_list_present_flag 413 continue; 414 lastScale = 8; 415 nextScale = 8; 416 sizeOfScalingList = i < 6 ? 16 : 64; 417 for (j = 0; j < sizeOfScalingList; j++) { 418 if (nextScale != 0) { 419 delta_scale = get_se_golomb(&gb); 420 nextScale = (lastScale + delta_scale) & 0xff; 421 } 422 lastScale = nextScale == 0 ? lastScale : nextScale; 423 } 424 } 425 } 426 } else { 427 sps->chroma_format_idc = 1; 428 sps->bit_depth_luma = 8; 429 sps->bit_depth_chroma = 8; 430 } 431 432 get_ue_golomb(&gb); // log2_max_frame_num_minus4 433 pic_order_cnt_type = get_ue_golomb(&gb); 434 435 if (pic_order_cnt_type == 0) { 436 get_ue_golomb(&gb); // log2_max_pic_order_cnt_lsb_minus4 437 } else if (pic_order_cnt_type == 1) { 438 skip_bits1(&gb); // delta_pic_order_always_zero 439 get_se_golomb(&gb); // offset_for_non_ref_pic 440 get_se_golomb(&gb); // offset_for_top_to_bottom_field 441 num_ref_frames_in_pic_order_cnt_cycle = get_ue_golomb(&gb); 442 for (i = 0; i < num_ref_frames_in_pic_order_cnt_cycle; i++) 443 get_se_golomb(&gb); // offset_for_ref_frame 444 } 445 446 get_ue_golomb(&gb); // max_num_ref_frames 447 skip_bits1(&gb); // gaps_in_frame_num_value_allowed_flag 448 get_ue_golomb(&gb); // pic_width_in_mbs_minus1 449 get_ue_golomb(&gb); // pic_height_in_map_units_minus1 450 451 sps->frame_mbs_only_flag = get_bits1(&gb); 452 if (!sps->frame_mbs_only_flag) 453 skip_bits1(&gb); // mb_adaptive_frame_field_flag 454 455 skip_bits1(&gb); // direct_8x8_inference_flag 456 457 if (get_bits1(&gb)) { // frame_cropping_flag 458 get_ue_golomb(&gb); // frame_crop_left_offset 459 get_ue_golomb(&gb); // frame_crop_right_offset 460 get_ue_golomb(&gb); // frame_crop_top_offset 461 get_ue_golomb(&gb); // frame_crop_bottom_offset 462 } 463 464 if (get_bits1(&gb)) { // vui_parameters_present_flag 465 if (get_bits1(&gb)) { // aspect_ratio_info_present_flag 466 aspect_ratio_idc = get_bits(&gb, 8); 467 if (aspect_ratio_idc == 0xff) { 468 sps->sar.num = get_bits(&gb, 16); 469 sps->sar.den = get_bits(&gb, 16); 470 } else if (aspect_ratio_idc < FF_ARRAY_ELEMS(avc_sample_aspect_ratio)) { 471 sps->sar = avc_sample_aspect_ratio[aspect_ratio_idc]; 472 } 473 } 474 } 475 476 if (!sps->sar.den) { 477 sps->sar.num = 1; 478 sps->sar.den = 1; 479 } 480 481 ret = 0; 482 end: 483 av_free(rbsp_buf); 484 return ret; 485} 486