libavformat/nal.h

   1 /*
   2  * NAL helper functions for muxers
   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 #ifndef AVFORMAT_NAL_H
  22 #define AVFORMAT_NAL_H
  23
  24 #include <stdint.h>
  25 #include "avio.h"
  26
  27 typedef struct NALU {
  28     int offset;
  29     uint32_t size;
  30 } NALU;
  31
  32 typedef struct NALUList {
  33     NALU *nalus;
  34     unsigned nalus_array_size;
  35     unsigned nb_nalus;          ///< valid entries in nalus
  36 } NALUList;
  37
  38 /* This function will parse the given annex B buffer and create
  39  * a NALUList from it. This list can be passed to ff_nal_units_write_list()
  40  * to write the access unit reformatted to mp4.
  41  *
  42  * @param list A NALUList. The list->nalus and list->nalus_array_size
  43  *             must be valid when calling this function and may be updated.
  44  *             nb_nalus is set by this function on success.
  45  * @param buf  buffer containing annex B H.264 or H.265. Must be padded.
  46  * @param size size of buf, excluding padding.
  47  * @return < 0 on error, the size of the mp4-style packet on success.
  48  */
  49 int ff_nal_units_create_list(NALUList *list, const uint8_t *buf, int size);
  50
  51 /* Writes a NALUList to the specified AVIOContext. The list must originate
  52  * from ff_nal_units_create_list() with the same buf. */
  53 void ff_nal_units_write_list(const NALUList *list, AVIOContext *pb,
  54                              const uint8_t *buf);
  55
  56 const uint8_t *ff_nal_find_startcode(const uint8_t *p, const uint8_t *end);
  57 const uint8_t *ff_nal_mp4_find_startcode(const uint8_t *start,
  58                                          const uint8_t *end,
  59                                          int nal_length_size);
  60
  61 int ff_nal_parse_units(AVIOContext *s, const uint8_t *buf, int size);
  62 int ff_nal_parse_units_buf(const uint8_t *buf_in, uint8_t **buf, int *size);
  63
  64 uint8_t *ff_nal_unit_extract_rbsp(const uint8_t *src, uint32_t src_len,
  65                                   uint32_t *dst_len, int header_len);
  66
  67 #endif /* AVFORMAT_NAL_H */