FFmpeg
cbs_internal.h
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1 /*
2  * This file is part of FFmpeg.
3  *
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17  */
18 
19 #ifndef AVCODEC_CBS_INTERNAL_H
20 #define AVCODEC_CBS_INTERNAL_H
21 
22 #include "avcodec.h"
23 #include "cbs.h"
24 #include "get_bits.h"
25 #include "put_bits.h"
26 
27 
29  // Unit content is a simple structure.
31  // Unit content contains some references to other structures, but all
32  // managed via buffer reference counting. The descriptor defines the
33  // structure offsets of every buffer reference.
35  // Unit content is something more complex. The descriptor defines
36  // special functions to manage the content.
38 };
39 
40 enum {
41  // Maximum number of unit types described by the same unit type
42  // descriptor.
44  // Maximum number of reference buffer offsets in any one unit.
46  // Special value used in a unit type descriptor to indicate that it
47  // applies to a large range of types rather than a set of discrete
48  // values.
50 };
51 
52 typedef const struct CodedBitstreamUnitTypeDescriptor {
53  // Number of entries in the unit_types array, or the special value
54  // CBS_UNIT_TYPE_RANGE to indicate that the range fields should be
55  // used instead.
57 
58  // Array of unit types that this entry describes.
60 
61  // Start and end of unit type range, used if nb_unit_types is
62  // CBS_UNIT_TYPE_RANGE.
65 
66  // The type of content described.
68  // The size of the structure which should be allocated to contain
69  // the decomposed content of this type of unit.
70  size_t content_size;
71 
72  // Number of entries in the ref_offsets array. Only used if the
73  // content_type is CBS_CONTENT_TYPE_INTERNAL_REFS.
75  // The structure must contain two adjacent elements:
76  // type *field;
77  // AVBufferRef *field_ref;
78  // where field points to something in the buffer referred to by
79  // field_ref. This offset is then set to offsetof(struct, field).
81 
82  void (*content_free)(void *opaque, uint8_t *data);
85 
86 typedef struct CodedBitstreamType {
88 
90 
91  // List of unit type descriptors for this codec.
92  // Terminated by a descriptor with nb_unit_types equal to zero.
94 
95  // Split frag->data into coded bitstream units, creating the
96  // frag->units array. Fill data but not content on each unit.
97  // The header argument should be set if the fragment came from
98  // a header block, which may require different parsing for some
99  // codecs (e.g. the AVCC header in H.264).
100  int (*split_fragment)(CodedBitstreamContext *ctx,
102  int header);
103 
104  // Read the unit->data bitstream and decompose it, creating
105  // unit->content.
107  CodedBitstreamUnit *unit);
108 
109  // Write the data bitstream from unit->content into pbc.
110  // Return value AVERROR(ENOSPC) indicates that pbc was too small.
111  int (*write_unit)(CodedBitstreamContext *ctx,
112  CodedBitstreamUnit *unit,
113  PutBitContext *pbc);
114 
115  // Read the data from all of frag->units and assemble it into
116  // a bitstream for the whole fragment.
117  int (*assemble_fragment)(CodedBitstreamContext *ctx,
118  CodedBitstreamFragment *frag);
119 
120  // Free the codec internal state.
123 
124 
125 // Helper functions for trace output.
126 
128  const char *name);
129 
131  const char *name, const int *subscripts,
132  const char *bitstring, int64_t value);
133 
134 
135 // Helper functions for read/write of common bitstream elements, including
136 // generation of trace output.
137 
139  int width, const char *name,
140  const int *subscripts, uint32_t *write_to,
141  uint32_t range_min, uint32_t range_max);
142 
144  int width, const char *name,
145  const int *subscripts, uint32_t value,
146  uint32_t range_min, uint32_t range_max);
147 
149  int width, const char *name,
150  const int *subscripts, int32_t *write_to,
151  int32_t range_min, int32_t range_max);
152 
154  int width, const char *name,
155  const int *subscripts, int32_t value,
156  int32_t range_min, int32_t range_max);
157 
158 // The largest unsigned value representable in N bits, suitable for use as
159 // range_max in the above functions.
160 #define MAX_UINT_BITS(length) ((UINT64_C(1) << (length)) - 1)
161 
162 // The largest signed value representable in N bits, suitable for use as
163 // range_max in the above functions.
164 #define MAX_INT_BITS(length) ((INT64_C(1) << ((length) - 1)) - 1)
165 
166 // The smallest signed value representable in N bits, suitable for use as
167 // range_min in the above functions.
168 #define MIN_INT_BITS(length) (-(INT64_C(1) << ((length) - 1)))
169 
170 
171 #define CBS_UNIT_TYPE_POD(type, structure) { \
172  .nb_unit_types = 1, \
173  .unit_types = { type }, \
174  .content_type = CBS_CONTENT_TYPE_POD, \
175  .content_size = sizeof(structure), \
176  }
177 #define CBS_UNIT_TYPE_INTERNAL_REF(type, structure, ref_field) { \
178  .nb_unit_types = 1, \
179  .unit_types = { type }, \
180  .content_type = CBS_CONTENT_TYPE_INTERNAL_REFS, \
181  .content_size = sizeof(structure), \
182  .nb_ref_offsets = 1, \
183  .ref_offsets = { offsetof(structure, ref_field) }, \
184  }
185 #define CBS_UNIT_TYPE_COMPLEX(type, structure, free_func) { \
186  .nb_unit_types = 1, \
187  .unit_types = { type }, \
188  .content_type = CBS_CONTENT_TYPE_COMPLEX, \
189  .content_size = sizeof(structure), \
190  .content_free = free_func, \
191  }
192 #define CBS_UNIT_TYPE_END_OF_LIST { .nb_unit_types = 0 }
193 
194 
201 
202 
203 #endif /* AVCODEC_CBS_INTERNAL_H */
const CodedBitstreamUnitType unit_types[CBS_MAX_UNIT_TYPES]
Definition: cbs_internal.h:59
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:100
void ff_cbs_trace_syntax_element(CodedBitstreamContext *ctx, int position, const char *name, const int *subscripts, const char *bitstring, int64_t value)
Definition: cbs.c:431
uint8_t
int ff_cbs_read_signed(CodedBitstreamContext *ctx, GetBitContext *gbc, int width, const char *name, const int *subscripts, int32_t *write_to, int32_t range_min, int32_t range_max)
Definition: cbs.c:560
uint32_t CodedBitstreamUnitType
The codec-specific type of a bitstream unit.
Definition: cbs.h:43
GLsizei GLboolean const GLfloat * value
Definition: opengl_enc.c:108
const CodedBitstreamUnitTypeDescriptor * unit_types
Definition: cbs_internal.h:93
bitstream reader API header.
Coded bitstream unit structure.
Definition: cbs.h:66
void ff_cbs_trace_header(CodedBitstreamContext *ctx, const char *name)
Definition: cbs.c:422
static const uint8_t header[24]
Definition: sdr2.c:67
int(* content_clone)(AVBufferRef **ref, CodedBitstreamUnit *unit)
Definition: cbs_internal.h:83
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: codec_id.h:46
int ff_cbs_write_unsigned(CodedBitstreamContext *ctx, PutBitContext *pbc, int width, const char *name, const int *subscripts, uint32_t value, uint32_t range_min, uint32_t range_max)
Definition: cbs.c:524
const CodedBitstreamUnitType unit_type_range_end
Definition: cbs_internal.h:64
const CodedBitstreamType ff_cbs_type_mpeg2
Definition: cbs_mpeg2.c:421
size_t ref_offsets[CBS_MAX_REF_OFFSETS]
Definition: cbs_internal.h:80
const CodedBitstreamType ff_cbs_type_av1
Definition: cbs_av1.c:1241
int ff_cbs_read_unsigned(CodedBitstreamContext *ctx, GetBitContext *gbc, int width, const char *name, const int *subscripts, uint32_t *write_to, uint32_t range_min, uint32_t range_max)
Definition: cbs.c:481
#define width
typedef void(APIENTRY *FF_PFNGLACTIVETEXTUREPROC)(GLenum texture)
int32_t
AVFormatContext * ctx
Definition: movenc.c:48
enum AVCodecID codec_id
Definition: vaapi_decode.c:369
Libavcodec external API header.
Coded bitstream fragment structure, combining one or more units.
Definition: cbs.h:118
const CodedBitstreamType ff_cbs_type_jpeg
Definition: cbs_jpeg.c:461
CBSContentType
Definition: cbs_internal.h:28
Context structure for coded bitstream operations.
Definition: cbs.h:170
const CodedBitstreamType ff_cbs_type_h265
Definition: cbs_h2645.c:1486
A reference to a data buffer.
Definition: buffer.h:81
enum CBSContentType content_type
Definition: cbs_internal.h:67
int
static int ref[MAX_W *MAX_W]
Definition: jpeg2000dwt.c:107
int ff_cbs_write_signed(CodedBitstreamContext *ctx, PutBitContext *pbc, int width, const char *name, const int *subscripts, int32_t value, int32_t range_min, int32_t range_max)
Definition: cbs.c:603
const CodedBitstreamUnitType unit_type_range_start
Definition: cbs_internal.h:63
void(* content_free)(void *opaque, uint8_t *data)
Definition: cbs_internal.h:82
const CodedBitstreamType ff_cbs_type_h264
Definition: cbs_h2645.c:1471
const CodedBitstreamType ff_cbs_type_vp9
Definition: cbs_vp9.c:642
const char * name
Definition: opengl_enc.c:102
bitstream writer API