X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavcodec%2Fcbs_internal.h;h=a392880036ed15f454239602ecd225dbd30a6a59;hb=6ad61e30a16d338eab23b649365813fb150066ef;hp=172b8a2515983aa15c04836e44b52472e7af6e47;hpb=768b07e3bca7e81d2f9c60badb3973d3d88481dc;p=ffmpeg diff --git a/libavcodec/cbs_internal.h b/libavcodec/cbs_internal.h index 172b8a25159..a392880036e 100644 --- a/libavcodec/cbs_internal.h +++ b/libavcodec/cbs_internal.h @@ -25,11 +25,79 @@ #include "put_bits.h" +enum CBSContentType { + // Unit content is a simple structure. + CBS_CONTENT_TYPE_POD, + // Unit content contains some references to other structures, but all + // managed via buffer reference counting. The descriptor defines the + // structure offsets of every buffer reference. + CBS_CONTENT_TYPE_INTERNAL_REFS, + // Unit content is something more complex. The descriptor defines + // special functions to manage the content. + CBS_CONTENT_TYPE_COMPLEX, +}; + +enum { + // Maximum number of unit types described by the same unit type + // descriptor. + CBS_MAX_UNIT_TYPES = 3, + // Maximum number of reference buffer offsets in any one unit. + CBS_MAX_REF_OFFSETS = 2, + // Special value used in a unit type descriptor to indicate that it + // applies to a large range of types rather than a set of discrete + // values. + CBS_UNIT_TYPE_RANGE = -1, +}; + +typedef const struct CodedBitstreamUnitTypeDescriptor { + // Number of entries in the unit_types array, or the special value + // CBS_UNIT_TYPE_RANGE to indicate that the range fields should be + // used instead. + int nb_unit_types; + + // Array of unit types that this entry describes. + const CodedBitstreamUnitType unit_types[CBS_MAX_UNIT_TYPES]; + + // Start and end of unit type range, used if nb_unit_types is + // CBS_UNIT_TYPE_RANGE. + const CodedBitstreamUnitType unit_type_range_start; + const CodedBitstreamUnitType unit_type_range_end; + + // The type of content described. + enum CBSContentType content_type; + // The size of the structure which should be allocated to contain + // the decomposed content of this type of unit. + size_t content_size; + + // Number of entries in the ref_offsets array. Only used if the + // content_type is CBS_CONTENT_TYPE_INTERNAL_REFS. + int nb_ref_offsets; + // The structure must contain two adjacent elements: + // type *field; + // AVBufferRef *field_ref; + // where field points to something in the buffer referred to by + // field_ref. This offset is then set to offsetof(struct, field). + size_t ref_offsets[CBS_MAX_REF_OFFSETS]; + + void (*content_free)(void *opaque, uint8_t *data); + int (*content_clone)(AVBufferRef **ref, CodedBitstreamUnit *unit); +} CodedBitstreamUnitTypeDescriptor; + typedef struct CodedBitstreamType { enum AVCodecID codec_id; + // A class for the private data, used to declare private AVOptions. + // This field is NULL for types that do not declare any options. + // If this field is non-NULL, the first member of the filter private data + // must be a pointer to AVClass. + const AVClass *priv_class; + size_t priv_data_size; + // List of unit type descriptors for this codec. + // Terminated by a descriptor with nb_unit_types equal to zero. + const CodedBitstreamUnitTypeDescriptor *unit_types; + // Split frag->data into coded bitstream units, creating the // frag->units array. Fill data but not content on each unit. // The header argument should be set if the fragment came from @@ -44,15 +112,20 @@ typedef struct CodedBitstreamType { int (*read_unit)(CodedBitstreamContext *ctx, CodedBitstreamUnit *unit); - // Write the unit->data bitstream from unit->content. + // Write the data bitstream from unit->content into pbc. + // Return value AVERROR(ENOSPC) indicates that pbc was too small. int (*write_unit)(CodedBitstreamContext *ctx, - CodedBitstreamUnit *unit); + CodedBitstreamUnit *unit, + PutBitContext *pbc); // Read the data from all of frag->units and assemble it into // a bitstream for the whole fragment. int (*assemble_fragment)(CodedBitstreamContext *ctx, CodedBitstreamFragment *frag); + // Reset the codec internal state. + void (*flush)(CodedBitstreamContext *ctx); + // Free the codec internal state. void (*close)(CodedBitstreamContext *ctx); } CodedBitstreamType; @@ -81,13 +154,57 @@ int ff_cbs_write_unsigned(CodedBitstreamContext *ctx, PutBitContext *pbc, const int *subscripts, uint32_t value, uint32_t range_min, uint32_t range_max); -// The largest value representable in N bits, suitable for use as +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); + +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); + +// The largest unsigned value representable in N bits, suitable for use as // range_max in the above functions. #define MAX_UINT_BITS(length) ((UINT64_C(1) << (length)) - 1) - +// The largest signed value representable in N bits, suitable for use as +// range_max in the above functions. +#define MAX_INT_BITS(length) ((INT64_C(1) << ((length) - 1)) - 1) + +// The smallest signed value representable in N bits, suitable for use as +// range_min in the above functions. +#define MIN_INT_BITS(length) (-(INT64_C(1) << ((length) - 1))) + + +#define CBS_UNIT_TYPE_POD(type, structure) { \ + .nb_unit_types = 1, \ + .unit_types = { type }, \ + .content_type = CBS_CONTENT_TYPE_POD, \ + .content_size = sizeof(structure), \ + } +#define CBS_UNIT_TYPE_INTERNAL_REF(type, structure, ref_field) { \ + .nb_unit_types = 1, \ + .unit_types = { type }, \ + .content_type = CBS_CONTENT_TYPE_INTERNAL_REFS, \ + .content_size = sizeof(structure), \ + .nb_ref_offsets = 1, \ + .ref_offsets = { offsetof(structure, ref_field) }, \ + } +#define CBS_UNIT_TYPE_COMPLEX(type, structure, free_func) { \ + .nb_unit_types = 1, \ + .unit_types = { type }, \ + .content_type = CBS_CONTENT_TYPE_COMPLEX, \ + .content_size = sizeof(structure), \ + .content_free = free_func, \ + } +#define CBS_UNIT_TYPE_END_OF_LIST { .nb_unit_types = 0 } + + +extern const CodedBitstreamType ff_cbs_type_av1; extern const CodedBitstreamType ff_cbs_type_h264; extern const CodedBitstreamType ff_cbs_type_h265; +extern const CodedBitstreamType ff_cbs_type_jpeg; extern const CodedBitstreamType ff_cbs_type_mpeg2; extern const CodedBitstreamType ff_cbs_type_vp9;