git.sesse.net Git - ffmpeg/blob - libavcodec/h2645_parse.c

   1 /*
   2  * H.264/HEVC common parsing code
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * FFmpeg is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with FFmpeg; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include <string.h>
  22
  23 #include "config.h"
  24
  25 #include "libavutil/intmath.h"
  26 #include "libavutil/intreadwrite.h"
  27 #include "libavutil/mem.h"
  28
  29 #include "bytestream.h"
  30 #include "hevc.h"
  31 #include "h264.h"
  32 #include "h2645_parse.h"
  33
  34 int ff_h2645_extract_rbsp(const uint8_t *src, int length,
  35                           H2645RBSP *rbsp, H2645NAL *nal, int small_padding)
  36 {
  37     int i, si, di;
  38     uint8_t *dst;
  39
  40     nal->skipped_bytes = 0;
  41 #define STARTCODE_TEST                                                  \
  42         if (i + 2 < length && src[i + 1] == 0 && src[i + 2] <= 3) {     \
  43             if (src[i + 2] != 3 && src[i + 2] != 0) {                   \
  44                 /* startcode, so we must be past the end */             \
  45                 length = i;                                             \
  46             }                                                           \
  47             break;                                                      \
  48         }
  49 #if HAVE_FAST_UNALIGNED
  50 #define FIND_FIRST_ZERO                                                 \
  51         if (i > 0 && !src[i])                                           \
  52             i--;                                                        \
  53         while (src[i])                                                  \
  54             i++
  55 #if HAVE_FAST_64BIT
  56     for (i = 0; i + 1 < length; i += 9) {
  57         if (!((~AV_RN64(src + i) &
  58                (AV_RN64(src + i) - 0x0100010001000101ULL)) &
  59               0x8000800080008080ULL))
  60             continue;
  61         FIND_FIRST_ZERO;
  62         STARTCODE_TEST;
  63         i -= 7;
  64     }
  65 #else
  66     for (i = 0; i + 1 < length; i += 5) {
  67         if (!((~AV_RN32(src + i) &
  68                (AV_RN32(src + i) - 0x01000101U)) &
  69               0x80008080U))
  70             continue;
  71         FIND_FIRST_ZERO;
  72         STARTCODE_TEST;
  73         i -= 3;
  74     }
  75 #endif /* HAVE_FAST_64BIT */
  76 #else
  77     for (i = 0; i + 1 < length; i += 2) {
  78         if (src[i])
  79             continue;
  80         if (i > 0 && src[i - 1] == 0)
  81             i--;
  82         STARTCODE_TEST;
  83     }
  84 #endif /* HAVE_FAST_UNALIGNED */
  85
  86     if (i >= length - 1 && small_padding) { // no escaped 0
  87         nal->data     =
  88         nal->raw_data = src;
  89         nal->size     =
  90         nal->raw_size = length;
  91         return length;
  92     } else if (i > length)
  93         i = length;
  94
  95     nal->rbsp_buffer = &rbsp->rbsp_buffer[rbsp->rbsp_buffer_size];
  96     dst = nal->rbsp_buffer;
  97
  98     memcpy(dst, src, i);
  99     si = di = i;
 100     while (si + 2 < length) {
 101         // remove escapes (very rare 1:2^22)
 102         if (src[si + 2] > 3) {
 103             dst[di++] = src[si++];
 104             dst[di++] = src[si++];
 105         } else if (src[si] == 0 && src[si + 1] == 0 && src[si + 2] != 0) {
 106             if (src[si + 2] == 3) { // escape
 107                 dst[di++] = 0;
 108                 dst[di++] = 0;
 109                 si       += 3;
 110
 111                 if (nal->skipped_bytes_pos) {
 112                     nal->skipped_bytes++;
 113                     if (nal->skipped_bytes_pos_size < nal->skipped_bytes) {
 114                         nal->skipped_bytes_pos_size *= 2;
 115                         av_assert0(nal->skipped_bytes_pos_size >= nal->skipped_bytes);
 116                         av_reallocp_array(&nal->skipped_bytes_pos,
 117                                 nal->skipped_bytes_pos_size,
 118                                 sizeof(*nal->skipped_bytes_pos));
 119                         if (!nal->skipped_bytes_pos) {
 120                             nal->skipped_bytes_pos_size = 0;
 121                             return AVERROR(ENOMEM);
 122                         }
 123                     }
 124                     if (nal->skipped_bytes_pos)
 125                         nal->skipped_bytes_pos[nal->skipped_bytes-1] = di - 1;
 126                 }
 127                 continue;
 128             } else // next start code
 129                 goto nsc;
 130         }
 131
 132         dst[di++] = src[si++];
 133     }
 134     while (si < length)
 135         dst[di++] = src[si++];
 136
 137 nsc:
 138     memset(dst + di, 0, AV_INPUT_BUFFER_PADDING_SIZE);
 139
 140     nal->data = dst;
 141     nal->size = di;
 142     nal->raw_data = src;
 143     nal->raw_size = si;
 144     rbsp->rbsp_buffer_size += si;
 145
 146     return si;
 147 }
 148
 149 static const char *const hevc_nal_type_name[64] = {
 150     "TRAIL_N", // HEVC_NAL_TRAIL_N
 151     "TRAIL_R", // HEVC_NAL_TRAIL_R
 152     "TSA_N", // HEVC_NAL_TSA_N
 153     "TSA_R", // HEVC_NAL_TSA_R
 154     "STSA_N", // HEVC_NAL_STSA_N
 155     "STSA_R", // HEVC_NAL_STSA_R
 156     "RADL_N", // HEVC_NAL_RADL_N
 157     "RADL_R", // HEVC_NAL_RADL_R
 158     "RASL_N", // HEVC_NAL_RASL_N
 159     "RASL_R", // HEVC_NAL_RASL_R
 160     "RSV_VCL_N10", // HEVC_NAL_VCL_N10
 161     "RSV_VCL_R11", // HEVC_NAL_VCL_R11
 162     "RSV_VCL_N12", // HEVC_NAL_VCL_N12
 163     "RSV_VLC_R13", // HEVC_NAL_VCL_R13
 164     "RSV_VCL_N14", // HEVC_NAL_VCL_N14
 165     "RSV_VCL_R15", // HEVC_NAL_VCL_R15
 166     "BLA_W_LP", // HEVC_NAL_BLA_W_LP
 167     "BLA_W_RADL", // HEVC_NAL_BLA_W_RADL
 168     "BLA_N_LP", // HEVC_NAL_BLA_N_LP
 169     "IDR_W_RADL", // HEVC_NAL_IDR_W_RADL
 170     "IDR_N_LP", // HEVC_NAL_IDR_N_LP
 171     "CRA_NUT", // HEVC_NAL_CRA_NUT
 172     "RSV_IRAP_VCL22", // HEVC_NAL_RSV_IRAP_VCL22
 173     "RSV_IRAP_VCL23", // HEVC_NAL_RSV_IRAP_VCL23
 174     "RSV_VCL24", // HEVC_NAL_RSV_VCL24
 175     "RSV_VCL25", // HEVC_NAL_RSV_VCL25
 176     "RSV_VCL26", // HEVC_NAL_RSV_VCL26
 177     "RSV_VCL27", // HEVC_NAL_RSV_VCL27
 178     "RSV_VCL28", // HEVC_NAL_RSV_VCL28
 179     "RSV_VCL29", // HEVC_NAL_RSV_VCL29
 180     "RSV_VCL30", // HEVC_NAL_RSV_VCL30
 181     "RSV_VCL31", // HEVC_NAL_RSV_VCL31
 182     "VPS", // HEVC_NAL_VPS
 183     "SPS", // HEVC_NAL_SPS
 184     "PPS", // HEVC_NAL_PPS
 185     "AUD", // HEVC_NAL_AUD
 186     "EOS_NUT", // HEVC_NAL_EOS_NUT
 187     "EOB_NUT", // HEVC_NAL_EOB_NUT
 188     "FD_NUT", // HEVC_NAL_FD_NUT
 189     "SEI_PREFIX", // HEVC_NAL_SEI_PREFIX
 190     "SEI_SUFFIX", // HEVC_NAL_SEI_SUFFIX
 191     "RSV_NVCL41", // HEVC_NAL_RSV_NVCL41
 192     "RSV_NVCL42", // HEVC_NAL_RSV_NVCL42
 193     "RSV_NVCL43", // HEVC_NAL_RSV_NVCL43
 194     "RSV_NVCL44", // HEVC_NAL_RSV_NVCL44
 195     "RSV_NVCL45", // HEVC_NAL_RSV_NVCL45
 196     "RSV_NVCL46", // HEVC_NAL_RSV_NVCL46
 197     "RSV_NVCL47", // HEVC_NAL_RSV_NVCL47
 198     "UNSPEC48", // HEVC_NAL_UNSPEC48
 199     "UNSPEC49", // HEVC_NAL_UNSPEC49
 200     "UNSPEC50", // HEVC_NAL_UNSPEC50
 201     "UNSPEC51", // HEVC_NAL_UNSPEC51
 202     "UNSPEC52", // HEVC_NAL_UNSPEC52
 203     "UNSPEC53", // HEVC_NAL_UNSPEC53
 204     "UNSPEC54", // HEVC_NAL_UNSPEC54
 205     "UNSPEC55", // HEVC_NAL_UNSPEC55
 206     "UNSPEC56", // HEVC_NAL_UNSPEC56
 207     "UNSPEC57", // HEVC_NAL_UNSPEC57
 208     "UNSPEC58", // HEVC_NAL_UNSPEC58
 209     "UNSPEC59", // HEVC_NAL_UNSPEC59
 210     "UNSPEC60", // HEVC_NAL_UNSPEC60
 211     "UNSPEC61", // HEVC_NAL_UNSPEC61
 212     "UNSPEC62", // HEVC_NAL_UNSPEC62
 213     "UNSPEC63", // HEVC_NAL_UNSPEC63
 214 };
 215
 216 static const char *hevc_nal_unit_name(int nal_type)
 217 {
 218     av_assert0(nal_type >= 0 && nal_type < 64);
 219     return hevc_nal_type_name[nal_type];
 220 }
 221
 222 static const char *const h264_nal_type_name[32] = {
 223     "Unspecified 0", //H264_NAL_UNSPECIFIED
 224     "Coded slice of a non-IDR picture", // H264_NAL_SLICE
 225     "Coded slice data partition A", // H264_NAL_DPA
 226     "Coded slice data partition B", // H264_NAL_DPB
 227     "Coded slice data partition C", // H264_NAL_DPC
 228     "IDR", // H264_NAL_IDR_SLICE
 229     "SEI", // H264_NAL_SEI
 230     "SPS", // H264_NAL_SPS
 231     "PPS", // H264_NAL_PPS
 232     "AUD", // H264_NAL_AUD
 233     "End of sequence", // H264_NAL_END_SEQUENCE
 234     "End of stream", // H264_NAL_END_STREAM
 235     "Filler data", // H264_NAL_FILLER_DATA
 236     "SPS extension", // H264_NAL_SPS_EXT
 237     "Prefix", // H264_NAL_PREFIX
 238     "Subset SPS", // H264_NAL_SUB_SPS
 239     "Depth parameter set", // H264_NAL_DPS
 240     "Reserved 17", // H264_NAL_RESERVED17
 241     "Reserved 18", // H264_NAL_RESERVED18
 242     "Auxiliary coded picture without partitioning", // H264_NAL_AUXILIARY_SLICE
 243     "Slice extension", // H264_NAL_EXTEN_SLICE
 244     "Slice extension for a depth view or a 3D-AVC texture view", // H264_NAL_DEPTH_EXTEN_SLICE
 245     "Reserved 22", // H264_NAL_RESERVED22
 246     "Reserved 23", // H264_NAL_RESERVED23
 247     "Unspecified 24", // H264_NAL_UNSPECIFIED24
 248     "Unspecified 25", // H264_NAL_UNSPECIFIED25
 249     "Unspecified 26", // H264_NAL_UNSPECIFIED26
 250     "Unspecified 27", // H264_NAL_UNSPECIFIED27
 251     "Unspecified 28", // H264_NAL_UNSPECIFIED28
 252     "Unspecified 29", // H264_NAL_UNSPECIFIED29
 253     "Unspecified 30", // H264_NAL_UNSPECIFIED30
 254     "Unspecified 31", // H264_NAL_UNSPECIFIED31
 255 };
 256
 257 static const char *h264_nal_unit_name(int nal_type)
 258 {
 259     av_assert0(nal_type >= 0 && nal_type < 32);
 260     return h264_nal_type_name[nal_type];
 261 }
 262
 263 static int get_bit_length(H2645NAL *nal, int skip_trailing_zeros)
 264 {
 265     int size = nal->size;
 266     int v;
 267
 268     while (skip_trailing_zeros && size > 0 && nal->data[size - 1] == 0)
 269         size--;
 270
 271     if (!size)
 272         return 0;
 273
 274     v = nal->data[size - 1];
 275
 276     if (size > INT_MAX / 8)
 277         return AVERROR(ERANGE);
 278     size *= 8;
 279
 280     /* remove the stop bit and following trailing zeros,
 281      * or nothing for damaged bitstreams */
 282     if (v)
 283         size -= ff_ctz(v) + 1;
 284
 285     return size;
 286 }
 287
 288 /**
 289  * @return AVERROR_INVALIDDATA if the packet is not a valid NAL unit,
 290  * 0 otherwise
 291  */
 292 static int hevc_parse_nal_header(H2645NAL *nal, void *logctx)
 293 {
 294     GetBitContext *gb = &nal->gb;
 295
 296     if (get_bits1(gb) != 0)
 297         return AVERROR_INVALIDDATA;
 298
 299     nal->type = get_bits(gb, 6);
 300
 301     nal->nuh_layer_id = get_bits(gb, 6);
 302     nal->temporal_id = get_bits(gb, 3) - 1;
 303     if (nal->temporal_id < 0)
 304         return AVERROR_INVALIDDATA;
 305
 306     av_log(logctx, AV_LOG_DEBUG,
 307            "nal_unit_type: %d(%s), nuh_layer_id: %d, temporal_id: %d\n",
 308            nal->type, hevc_nal_unit_name(nal->type), nal->nuh_layer_id, nal->temporal_id);
 309
 310     return 0;
 311 }
 312
 313 static int h264_parse_nal_header(H2645NAL *nal, void *logctx)
 314 {
 315     GetBitContext *gb = &nal->gb;
 316
 317     if (get_bits1(gb) != 0)
 318         return AVERROR_INVALIDDATA;
 319
 320     nal->ref_idc = get_bits(gb, 2);
 321     nal->type    = get_bits(gb, 5);
 322
 323     av_log(logctx, AV_LOG_DEBUG,
 324            "nal_unit_type: %d(%s), nal_ref_idc: %d\n",
 325            nal->type, h264_nal_unit_name(nal->type), nal->ref_idc);
 326
 327     return 0;
 328 }
 329
 330 static int find_next_start_code(const uint8_t *buf, const uint8_t *next_avc)
 331 {
 332     int i = 0;
 333
 334     if (buf + 3 >= next_avc)
 335         return next_avc - buf;
 336
 337     while (buf + i + 3 < next_avc) {
 338         if (buf[i] == 0 && buf[i + 1] == 0 && buf[i + 2] == 1)
 339             break;
 340         i++;
 341     }
 342     return i + 3;
 343 }
 344
 345 static void alloc_rbsp_buffer(H2645RBSP *rbsp, unsigned int size, int use_ref)
 346 {
 347     int min_size = size;
 348
 349     if (size > INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE)
 350         goto fail;
 351     size += AV_INPUT_BUFFER_PADDING_SIZE;
 352
 353     if (rbsp->rbsp_buffer_alloc_size >= size &&
 354         (!rbsp->rbsp_buffer_ref || av_buffer_is_writable(rbsp->rbsp_buffer_ref))) {
 355         av_assert0(rbsp->rbsp_buffer);
 356         memset(rbsp->rbsp_buffer + min_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
 357         return;
 358     }
 359
 360     size = FFMIN(size + size / 16 + 32, INT_MAX);
 361
 362     if (rbsp->rbsp_buffer_ref)
 363         av_buffer_unref(&rbsp->rbsp_buffer_ref);
 364     else
 365         av_free(rbsp->rbsp_buffer);
 366
 367     rbsp->rbsp_buffer = av_mallocz(size);
 368     if (!rbsp->rbsp_buffer)
 369         goto fail;
 370     rbsp->rbsp_buffer_alloc_size = size;
 371
 372     if (use_ref) {
 373         rbsp->rbsp_buffer_ref = av_buffer_create(rbsp->rbsp_buffer, size,
 374                                                  NULL, NULL, 0);
 375         if (!rbsp->rbsp_buffer_ref)
 376             goto fail;
 377     }
 378
 379     return;
 380
 381 fail:
 382     rbsp->rbsp_buffer_alloc_size = 0;
 383     if (rbsp->rbsp_buffer_ref) {
 384         av_buffer_unref(&rbsp->rbsp_buffer_ref);
 385         rbsp->rbsp_buffer = NULL;
 386     } else
 387         av_freep(&rbsp->rbsp_buffer);
 388
 389     return;
 390 }
 391
 392 int ff_h2645_packet_split(H2645Packet *pkt, const uint8_t *buf, int length,
 393                           void *logctx, int is_nalff, int nal_length_size,
 394                           enum AVCodecID codec_id, int small_padding, int use_ref)
 395 {
 396     GetByteContext bc;
 397     int consumed, ret = 0;
 398     int next_avc = is_nalff ? 0 : length;
 399     int64_t padding = small_padding ? 0 : MAX_MBPAIR_SIZE;
 400
 401     bytestream2_init(&bc, buf, length);
 402     alloc_rbsp_buffer(&pkt->rbsp, length + padding, use_ref);
 403
 404     if (!pkt->rbsp.rbsp_buffer)
 405         return AVERROR(ENOMEM);
 406
 407     pkt->rbsp.rbsp_buffer_size = 0;
 408     pkt->nb_nals = 0;
 409     while (bytestream2_get_bytes_left(&bc) >= 4) {
 410         H2645NAL *nal;
 411         int extract_length = 0;
 412         int skip_trailing_zeros = 1;
 413
 414         if (bytestream2_tell(&bc) == next_avc) {
 415             int i = 0;
 416             extract_length = get_nalsize(nal_length_size,
 417                                          bc.buffer, bytestream2_get_bytes_left(&bc), &i, logctx);
 418             if (extract_length < 0)
 419                 return extract_length;
 420
 421             bytestream2_skip(&bc, nal_length_size);
 422
 423             next_avc = bytestream2_tell(&bc) + extract_length;
 424         } else {
 425             int buf_index;
 426
 427             if (bytestream2_tell(&bc) > next_avc)
 428                 av_log(logctx, AV_LOG_WARNING, "Exceeded next NALFF position, re-syncing.\n");
 429
 430             /* search start code */
 431             buf_index = find_next_start_code(bc.buffer, buf + next_avc);
 432
 433             bytestream2_skip(&bc, buf_index);
 434
 435             if (!bytestream2_get_bytes_left(&bc)) {
 436                 if (pkt->nb_nals > 0) {
 437                     // No more start codes: we discarded some irrelevant
 438                     // bytes at the end of the packet.
 439                     return 0;
 440                 } else {
 441                     av_log(logctx, AV_LOG_ERROR, "No start code is found.\n");
 442                     return AVERROR_INVALIDDATA;
 443                 }
 444             }
 445
 446             extract_length = FFMIN(bytestream2_get_bytes_left(&bc), next_avc - bytestream2_tell(&bc));
 447
 448             if (bytestream2_tell(&bc) >= next_avc) {
 449                 /* skip to the start of the next NAL */
 450                 bytestream2_skip(&bc, next_avc - bytestream2_tell(&bc));
 451                 continue;
 452             }
 453         }
 454
 455         if (pkt->nals_allocated < pkt->nb_nals + 1) {
 456             int new_size = pkt->nals_allocated + 1;
 457             void *tmp;
 458
 459             if (new_size >= INT_MAX / sizeof(*pkt->nals))
 460                 return AVERROR(ENOMEM);
 461
 462             tmp = av_fast_realloc(pkt->nals, &pkt->nal_buffer_size, new_size * sizeof(*pkt->nals));
 463             if (!tmp)
 464                 return AVERROR(ENOMEM);
 465
 466             pkt->nals = tmp;
 467             memset(pkt->nals + pkt->nals_allocated, 0, sizeof(*pkt->nals));
 468
 469             nal = &pkt->nals[pkt->nb_nals];
 470             nal->skipped_bytes_pos_size = FFMIN(1024, extract_length/3+1); // initial buffer size
 471             nal->skipped_bytes_pos = av_malloc_array(nal->skipped_bytes_pos_size, sizeof(*nal->skipped_bytes_pos));
 472             if (!nal->skipped_bytes_pos)
 473                 return AVERROR(ENOMEM);
 474
 475             pkt->nals_allocated = new_size;
 476         }
 477         nal = &pkt->nals[pkt->nb_nals];
 478
 479         consumed = ff_h2645_extract_rbsp(bc.buffer, extract_length, &pkt->rbsp, nal, small_padding);
 480         if (consumed < 0)
 481             return consumed;
 482
 483         if (is_nalff && (extract_length != consumed) && extract_length)
 484             av_log(logctx, AV_LOG_DEBUG,
 485                    "NALFF: Consumed only %d bytes instead of %d\n",
 486                    consumed, extract_length);
 487
 488         bytestream2_skip(&bc, consumed);
 489
 490         /* see commit 3566042a0 */
 491         if (bytestream2_get_bytes_left(&bc) >= 4 &&
 492             bytestream2_peek_be32(&bc) == 0x000001E0)
 493             skip_trailing_zeros = 0;
 494
 495         nal->size_bits = get_bit_length(nal, skip_trailing_zeros);
 496
 497         if (nal->size <= 0 || nal->size_bits <= 0)
 498             continue;
 499
 500         ret = init_get_bits(&nal->gb, nal->data, nal->size_bits);
 501         if (ret < 0)
 502             return ret;
 503
 504         /* Reset type in case it contains a stale value from a previously parsed NAL */
 505         nal->type = 0;
 506
 507         if (codec_id == AV_CODEC_ID_HEVC)
 508             ret = hevc_parse_nal_header(nal, logctx);
 509         else
 510             ret = h264_parse_nal_header(nal, logctx);
 511         if (ret < 0) {
 512             av_log(logctx, AV_LOG_WARNING, "Invalid NAL unit %d, skipping.\n",
 513                    nal->type);
 514             continue;
 515         }
 516
 517         pkt->nb_nals++;
 518     }
 519
 520     return 0;
 521 }
 522
 523 void ff_h2645_packet_uninit(H2645Packet *pkt)
 524 {
 525     int i;
 526     for (i = 0; i < pkt->nals_allocated; i++) {
 527         av_freep(&pkt->nals[i].skipped_bytes_pos);
 528     }
 529     av_freep(&pkt->nals);
 530     pkt->nals_allocated = pkt->nal_buffer_size = 0;
 531     if (pkt->rbsp.rbsp_buffer_ref) {
 532         av_buffer_unref(&pkt->rbsp.rbsp_buffer_ref);
 533         pkt->rbsp.rbsp_buffer = NULL;
 534     } else
 535         av_freep(&pkt->rbsp.rbsp_buffer);
 536     pkt->rbsp.rbsp_buffer_alloc_size = pkt->rbsp.rbsp_buffer_size = 0;
 537 }