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 "h2645_parse.h"
  32
  33 int ff_h2645_extract_rbsp(const uint8_t *src, int length,
  34                           H2645RBSP *rbsp, H2645NAL *nal, int small_padding)
  35 {
  36     int i, si, di;
  37     uint8_t *dst;
  38
  39     nal->skipped_bytes = 0;
  40 #define STARTCODE_TEST                                                  \
  41         if (i + 2 < length && src[i + 1] == 0 && src[i + 2] <= 3) {     \
  42             if (src[i + 2] != 3 && src[i + 2] != 0) {                   \
  43                 /* startcode, so we must be past the end */             \
  44                 length = i;                                             \
  45             }                                                           \
  46             break;                                                      \
  47         }
  48 #if HAVE_FAST_UNALIGNED
  49 #define FIND_FIRST_ZERO                                                 \
  50         if (i > 0 && !src[i])                                           \
  51             i--;                                                        \
  52         while (src[i])                                                  \
  53             i++
  54 #if HAVE_FAST_64BIT
  55     for (i = 0; i + 1 < length; i += 9) {
  56         if (!((~AV_RN64(src + i) &
  57                (AV_RN64(src + i) - 0x0100010001000101ULL)) &
  58               0x8000800080008080ULL))
  59             continue;
  60         FIND_FIRST_ZERO;
  61         STARTCODE_TEST;
  62         i -= 7;
  63     }
  64 #else
  65     for (i = 0; i + 1 < length; i += 5) {
  66         if (!((~AV_RN32(src + i) &
  67                (AV_RN32(src + i) - 0x01000101U)) &
  68               0x80008080U))
  69             continue;
  70         FIND_FIRST_ZERO;
  71         STARTCODE_TEST;
  72         i -= 3;
  73     }
  74 #endif /* HAVE_FAST_64BIT */
  75 #else
  76     for (i = 0; i + 1 < length; i += 2) {
  77         if (src[i])
  78             continue;
  79         if (i > 0 && src[i - 1] == 0)
  80             i--;
  81         STARTCODE_TEST;
  82     }
  83 #endif /* HAVE_FAST_UNALIGNED */
  84
  85     if (i >= length - 1 && small_padding) { // no escaped 0
  86         nal->data     =
  87         nal->raw_data = src;
  88         nal->size     =
  89         nal->raw_size = length;
  90         return length;
  91     } else if (i > length)
  92         i = length;
  93
  94     nal->rbsp_buffer = &rbsp->rbsp_buffer[rbsp->rbsp_buffer_size];
  95     dst = nal->rbsp_buffer;
  96
  97     memcpy(dst, src, i);
  98     si = di = i;
  99     while (si + 2 < length) {
 100         // remove escapes (very rare 1:2^22)
 101         if (src[si + 2] > 3) {
 102             dst[di++] = src[si++];
 103             dst[di++] = src[si++];
 104         } else if (src[si] == 0 && src[si + 1] == 0 && src[si + 2] != 0) {
 105             if (src[si + 2] == 3) { // escape
 106                 dst[di++] = 0;
 107                 dst[di++] = 0;
 108                 si       += 3;
 109
 110                 if (nal->skipped_bytes_pos) {
 111                     nal->skipped_bytes++;
 112                     if (nal->skipped_bytes_pos_size < nal->skipped_bytes) {
 113                         nal->skipped_bytes_pos_size *= 2;
 114                         av_assert0(nal->skipped_bytes_pos_size >= nal->skipped_bytes);
 115                         av_reallocp_array(&nal->skipped_bytes_pos,
 116                                 nal->skipped_bytes_pos_size,
 117                                 sizeof(*nal->skipped_bytes_pos));
 118                         if (!nal->skipped_bytes_pos) {
 119                             nal->skipped_bytes_pos_size = 0;
 120                             return AVERROR(ENOMEM);
 121                         }
 122                     }
 123                     if (nal->skipped_bytes_pos)
 124                         nal->skipped_bytes_pos[nal->skipped_bytes-1] = di - 1;
 125                 }
 126                 continue;
 127             } else // next start code
 128                 goto nsc;
 129         }
 130
 131         dst[di++] = src[si++];
 132     }
 133     while (si < length)
 134         dst[di++] = src[si++];
 135
 136 nsc:
 137     memset(dst + di, 0, AV_INPUT_BUFFER_PADDING_SIZE);
 138
 139     nal->data = dst;
 140     nal->size = di;
 141     nal->raw_data = src;
 142     nal->raw_size = si;
 143     rbsp->rbsp_buffer_size += si;
 144
 145     return si;
 146 }
 147
 148 static const char *hevc_nal_type_name[64] = {
 149     "TRAIL_N", // HEVC_NAL_TRAIL_N
 150     "TRAIL_R", // HEVC_NAL_TRAIL_R
 151     "TSA_N", // HEVC_NAL_TSA_N
 152     "TSA_R", // HEVC_NAL_TSA_R
 153     "STSA_N", // HEVC_NAL_STSA_N
 154     "STSA_R", // HEVC_NAL_STSA_R
 155     "RADL_N", // HEVC_NAL_RADL_N
 156     "RADL_R", // HEVC_NAL_RADL_R
 157     "RASL_N", // HEVC_NAL_RASL_N
 158     "RASL_R", // HEVC_NAL_RASL_R
 159     "RSV_VCL_N10", // HEVC_NAL_VCL_N10
 160     "RSV_VCL_R11", // HEVC_NAL_VCL_R11
 161     "RSV_VCL_N12", // HEVC_NAL_VCL_N12
 162     "RSV_VLC_R13", // HEVC_NAL_VCL_R13
 163     "RSV_VCL_N14", // HEVC_NAL_VCL_N14
 164     "RSV_VCL_R15", // HEVC_NAL_VCL_R15
 165     "BLA_W_LP", // HEVC_NAL_BLA_W_LP
 166     "BLA_W_RADL", // HEVC_NAL_BLA_W_RADL
 167     "BLA_N_LP", // HEVC_NAL_BLA_N_LP
 168     "IDR_W_RADL", // HEVC_NAL_IDR_W_RADL
 169     "IDR_N_LP", // HEVC_NAL_IDR_N_LP
 170     "CRA_NUT", // HEVC_NAL_CRA_NUT
 171     "IRAP_IRAP_VCL22", // HEVC_NAL_IRAP_VCL22
 172     "IRAP_IRAP_VCL23", // HEVC_NAL_IRAP_VCL23
 173     "RSV_VCL24", // HEVC_NAL_RSV_VCL24
 174     "RSV_VCL25", // HEVC_NAL_RSV_VCL25
 175     "RSV_VCL26", // HEVC_NAL_RSV_VCL26
 176     "RSV_VCL27", // HEVC_NAL_RSV_VCL27
 177     "RSV_VCL28", // HEVC_NAL_RSV_VCL28
 178     "RSV_VCL29", // HEVC_NAL_RSV_VCL29
 179     "RSV_VCL30", // HEVC_NAL_RSV_VCL30
 180     "RSV_VCL31", // HEVC_NAL_RSV_VCL31
 181     "VPS", // HEVC_NAL_VPS
 182     "SPS", // HEVC_NAL_SPS
 183     "PPS", // HEVC_NAL_PPS
 184     "AUD", // HEVC_NAL_AUD
 185     "EOS_NUT", // HEVC_NAL_EOS_NUT
 186     "EOB_NUT", // HEVC_NAL_EOB_NUT
 187     "FD_NUT", // HEVC_NAL_FD_NUT
 188     "SEI_PREFIX", // HEVC_NAL_SEI_PREFIX
 189     "SEI_SUFFIX", // HEVC_NAL_SEI_SUFFIX
 190     "RSV_NVCL41", // HEVC_NAL_RSV_NVCL41
 191     "RSV_NVCL42", // HEVC_NAL_RSV_NVCL42
 192     "RSV_NVCL43", // HEVC_NAL_RSV_NVCL43
 193     "RSV_NVCL44", // HEVC_NAL_RSV_NVCL44
 194     "RSV_NVCL45", // HEVC_NAL_RSV_NVCL45
 195     "RSV_NVCL46", // HEVC_NAL_RSV_NVCL46
 196     "RSV_NVCL47", // HEVC_NAL_RSV_NVCL47
 197     "UNSPEC48", // HEVC_NAL_UNSPEC48
 198     "UNSPEC49", // HEVC_NAL_UNSPEC49
 199     "UNSPEC50", // HEVC_NAL_UNSPEC50
 200     "UNSPEC51", // HEVC_NAL_UNSPEC51
 201     "UNSPEC52", // HEVC_NAL_UNSPEC52
 202     "UNSPEC53", // HEVC_NAL_UNSPEC53
 203     "UNSPEC54", // HEVC_NAL_UNSPEC54
 204     "UNSPEC55", // HEVC_NAL_UNSPEC55
 205     "UNSPEC56", // HEVC_NAL_UNSPEC56
 206     "UNSPEC57", // HEVC_NAL_UNSPEC57
 207     "UNSPEC58", // HEVC_NAL_UNSPEC58
 208     "UNSPEC59", // HEVC_NAL_UNSPEC59
 209     "UNSPEC60", // HEVC_NAL_UNSPEC60
 210     "UNSPEC61", // HEVC_NAL_UNSPEC61
 211     "UNSPEC62", // HEVC_NAL_UNSPEC62
 212     "UNSPEC63", // HEVC_NAL_UNSPEC63
 213 };
 214
 215 static const char *nal_unit_name(int nal_type)
 216 {
 217     av_assert0(nal_type >= 0 && nal_type < 64);
 218     return hevc_nal_type_name[nal_type];
 219 }
 220
 221 static int get_bit_length(H2645NAL *nal, int skip_trailing_zeros)
 222 {
 223     int size = nal->size;
 224     int v;
 225
 226     while (skip_trailing_zeros && size > 0 && nal->data[size - 1] == 0)
 227         size--;
 228
 229     if (!size)
 230         return 0;
 231
 232     v = nal->data[size - 1];
 233
 234     if (size > INT_MAX / 8)
 235         return AVERROR(ERANGE);
 236     size *= 8;
 237
 238     /* remove the stop bit and following trailing zeros,
 239      * or nothing for damaged bitstreams */
 240     if (v)
 241         size -= ff_ctz(v) + 1;
 242
 243     return size;
 244 }
 245
 246 /**
 247  * @return AVERROR_INVALIDDATA if the packet is not a valid NAL unit,
 248  * 0 if the unit should be skipped, 1 otherwise
 249  */
 250 static int hevc_parse_nal_header(H2645NAL *nal, void *logctx)
 251 {
 252     GetBitContext *gb = &nal->gb;
 253     int nuh_layer_id;
 254
 255     if (get_bits1(gb) != 0)
 256         return AVERROR_INVALIDDATA;
 257
 258     nal->type = get_bits(gb, 6);
 259
 260     nuh_layer_id   = get_bits(gb, 6);
 261     nal->temporal_id = get_bits(gb, 3) - 1;
 262     if (nal->temporal_id < 0)
 263         return AVERROR_INVALIDDATA;
 264
 265     av_log(logctx, AV_LOG_DEBUG,
 266            "nal_unit_type: %d(%s), nuh_layer_id: %d, temporal_id: %d\n",
 267            nal->type, nal_unit_name(nal->type), nuh_layer_id, nal->temporal_id);
 268
 269     return nuh_layer_id == 0;
 270 }
 271
 272 static int h264_parse_nal_header(H2645NAL *nal, void *logctx)
 273 {
 274     GetBitContext *gb = &nal->gb;
 275
 276     if (get_bits1(gb) != 0)
 277         return AVERROR_INVALIDDATA;
 278
 279     nal->ref_idc = get_bits(gb, 2);
 280     nal->type    = get_bits(gb, 5);
 281
 282     av_log(logctx, AV_LOG_DEBUG,
 283            "nal_unit_type: %d, nal_ref_idc: %d\n",
 284            nal->type, nal->ref_idc);
 285
 286     return 1;
 287 }
 288
 289 static int find_next_start_code(const uint8_t *buf, const uint8_t *next_avc)
 290 {
 291     int i = 0;
 292
 293     if (buf + 3 >= next_avc)
 294         return next_avc - buf;
 295
 296     while (buf + i + 3 < next_avc) {
 297         if (buf[i] == 0 && buf[i + 1] == 0 && buf[i + 2] == 1)
 298             break;
 299         i++;
 300     }
 301     return i + 3;
 302 }
 303
 304 int ff_h2645_packet_split(H2645Packet *pkt, const uint8_t *buf, int length,
 305                           void *logctx, int is_nalff, int nal_length_size,
 306                           enum AVCodecID codec_id, int small_padding)
 307 {
 308     GetByteContext bc;
 309     int consumed, ret = 0;
 310     int next_avc = is_nalff ? 0 : length;
 311     int64_t padding = small_padding ? 0 : MAX_MBPAIR_SIZE;
 312
 313     bytestream2_init(&bc, buf, length);
 314     av_fast_padded_malloc(&pkt->rbsp.rbsp_buffer, &pkt->rbsp.rbsp_buffer_alloc_size, length + padding);
 315     if (!pkt->rbsp.rbsp_buffer)
 316         return AVERROR(ENOMEM);
 317
 318     pkt->rbsp.rbsp_buffer_size = 0;
 319     pkt->nb_nals = 0;
 320     while (bytestream2_get_bytes_left(&bc) >= 4) {
 321         H2645NAL *nal;
 322         int extract_length = 0;
 323         int skip_trailing_zeros = 1;
 324
 325         if (bytestream2_tell(&bc) == next_avc) {
 326             int i = 0;
 327             extract_length = get_nalsize(nal_length_size,
 328                                          bc.buffer, bytestream2_get_bytes_left(&bc), &i, logctx);
 329             if (extract_length < 0)
 330                 return extract_length;
 331
 332             bytestream2_skip(&bc, nal_length_size);
 333
 334             next_avc = bytestream2_tell(&bc) + extract_length;
 335         } else {
 336             int buf_index;
 337
 338             if (bytestream2_tell(&bc) > next_avc)
 339                 av_log(logctx, AV_LOG_WARNING, "Exceeded next NALFF position, re-syncing.\n");
 340
 341             /* search start code */
 342             buf_index = find_next_start_code(bc.buffer, buf + next_avc);
 343
 344             bytestream2_skip(&bc, buf_index);
 345
 346             if (!bytestream2_get_bytes_left(&bc)) {
 347                 if (pkt->nb_nals > 0) {
 348                     // No more start codes: we discarded some irrelevant
 349                     // bytes at the end of the packet.
 350                     return 0;
 351                 } else {
 352                     av_log(logctx, AV_LOG_ERROR, "No start code is found.\n");
 353                     return AVERROR_INVALIDDATA;
 354                 }
 355             }
 356
 357             extract_length = FFMIN(bytestream2_get_bytes_left(&bc), next_avc - bytestream2_tell(&bc));
 358
 359             if (bytestream2_tell(&bc) >= next_avc) {
 360                 /* skip to the start of the next NAL */
 361                 bytestream2_skip(&bc, next_avc - bytestream2_tell(&bc));
 362                 continue;
 363             }
 364         }
 365
 366         if (pkt->nals_allocated < pkt->nb_nals + 1) {
 367             int new_size = pkt->nals_allocated + 1;
 368             void *tmp = av_realloc_array(pkt->nals, new_size, sizeof(*pkt->nals));
 369
 370             if (!tmp)
 371                 return AVERROR(ENOMEM);
 372
 373             pkt->nals = tmp;
 374             memset(pkt->nals + pkt->nals_allocated, 0,
 375                    (new_size - pkt->nals_allocated) * sizeof(*pkt->nals));
 376
 377             nal = &pkt->nals[pkt->nb_nals];
 378             nal->skipped_bytes_pos_size = 1024; // initial buffer size
 379             nal->skipped_bytes_pos = av_malloc_array(nal->skipped_bytes_pos_size, sizeof(*nal->skipped_bytes_pos));
 380             if (!nal->skipped_bytes_pos)
 381                 return AVERROR(ENOMEM);
 382
 383             pkt->nals_allocated = new_size;
 384         }
 385         nal = &pkt->nals[pkt->nb_nals];
 386
 387         consumed = ff_h2645_extract_rbsp(bc.buffer, extract_length, &pkt->rbsp, nal, small_padding);
 388         if (consumed < 0)
 389             return consumed;
 390
 391         if (is_nalff && (extract_length != consumed) && extract_length)
 392             av_log(logctx, AV_LOG_DEBUG,
 393                    "NALFF: Consumed only %d bytes instead of %d\n",
 394                    consumed, extract_length);
 395
 396         pkt->nb_nals++;
 397
 398         bytestream2_skip(&bc, consumed);
 399
 400         /* see commit 3566042a0 */
 401         if (bytestream2_get_bytes_left(&bc) >= 4 &&
 402             bytestream2_peek_be32(&bc) == 0x000001E0)
 403             skip_trailing_zeros = 0;
 404
 405         nal->size_bits = get_bit_length(nal, skip_trailing_zeros);
 406
 407         ret = init_get_bits(&nal->gb, nal->data, nal->size_bits);
 408         if (ret < 0)
 409             return ret;
 410
 411         if (codec_id == AV_CODEC_ID_HEVC)
 412             ret = hevc_parse_nal_header(nal, logctx);
 413         else
 414             ret = h264_parse_nal_header(nal, logctx);
 415         if (ret <= 0 || nal->size <= 0 || nal->size_bits <= 0) {
 416             if (ret < 0) {
 417                 av_log(logctx, AV_LOG_ERROR, "Invalid NAL unit %d, skipping.\n",
 418                        nal->type);
 419             }
 420             pkt->nb_nals--;
 421         }
 422     }
 423
 424     return 0;
 425 }
 426
 427 void ff_h2645_packet_uninit(H2645Packet *pkt)
 428 {
 429     int i;
 430     for (i = 0; i < pkt->nals_allocated; i++) {
 431         av_freep(&pkt->nals[i].skipped_bytes_pos);
 432     }
 433     av_freep(&pkt->nals);
 434     pkt->nals_allocated = 0;
 435     av_freep(&pkt->rbsp.rbsp_buffer);
 436     pkt->rbsp.rbsp_buffer_alloc_size = pkt->rbsp.rbsp_buffer_size = 0;
 437 }