libavcodec/cbs_internal.h

   1 /*
   2  * This file is part of Libav.
   3  *
   4  * Libav is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * Libav is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with Libav; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  17  */
  18
  19 #ifndef AVCODEC_CBS_INTERNAL_H
  20 #define AVCODEC_CBS_INTERNAL_H
  21
  22 #include "avcodec.h"
  23 #include "bitstream.h"
  24 #include "cbs.h"
  25 #include "put_bits.h"
  26
  27
  28 typedef struct CodedBitstreamType {
  29     enum AVCodecID codec_id;
  30
  31     size_t priv_data_size;
  32
  33     // Split frag->data into coded bitstream units, creating the
  34     // frag->units array.  Fill data but not content on each unit.
  35     // The header argument should be set if the fragment came from
  36     // a header block, which may require different parsing for some
  37     // codecs (e.g. the AVCC header in H.264).
  38     int (*split_fragment)(CodedBitstreamContext *ctx,
  39                           CodedBitstreamFragment *frag,
  40                           int header);
  41
  42     // Read the unit->data bitstream and decompose it, creating
  43     // unit->content.
  44     int (*read_unit)(CodedBitstreamContext *ctx,
  45                      CodedBitstreamUnit *unit);
  46
  47     // Write the unit->data bitstream from unit->content.
  48     int (*write_unit)(CodedBitstreamContext *ctx,
  49                       CodedBitstreamUnit *unit);
  50
  51     // Read the data from all of frag->units and assemble it into
  52     // a bitstream for the whole fragment.
  53     int (*assemble_fragment)(CodedBitstreamContext *ctx,
  54                              CodedBitstreamFragment *frag);
  55
  56     // Free the codec internal state.
  57     void (*close)(CodedBitstreamContext *ctx);
  58 } CodedBitstreamType;
  59
  60
  61 // Helper functions for trace output.
  62
  63 void ff_cbs_trace_header(CodedBitstreamContext *ctx,
  64                          const char *name);
  65
  66 void ff_cbs_trace_syntax_element(CodedBitstreamContext *ctx,
  67                                  int position, const char *name,
  68                                  const char *bitstring, int64_t value);
  69
  70
  71 // Helper functions for read/write of common bitstream elements, including
  72 // generation of trace output.
  73
  74 int ff_cbs_read_unsigned(CodedBitstreamContext *ctx, BitstreamContext *bc,
  75                          int width, const char *name, uint32_t *write_to,
  76                          uint32_t range_min, uint32_t range_max);
  77
  78 int ff_cbs_write_unsigned(CodedBitstreamContext *ctx, PutBitContext *pbc,
  79                           int width, const char *name, uint32_t value,
  80                           uint32_t range_min, uint32_t range_max);
  81
  82
  83 extern const CodedBitstreamType ff_cbs_type_h264;
  84 extern const CodedBitstreamType ff_cbs_type_h265;
  85 extern const CodedBitstreamType ff_cbs_type_mpeg2;
  86
  87
  88 #endif /* AVCODEC_CBS_INTERNAL_H */