[FFmpeg-cvslog] avcodec/cbs_internal: Use unions to shrink size of descriptors
Andreas Rheinhardt
git at videolan.org
Mon Aug 8 12:45:30 EEST 2022
ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at outlook.com> | Thu Aug 4 11:02:14 2022 +0200| [9638f5b1a2369aa8ab32ffb68c928bb5343932fd] | committer: Andreas Rheinhardt
avcodec/cbs_internal: Use unions to shrink size of descriptors
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=9638f5b1a2369aa8ab32ffb68c928bb5343932fd
---
libavcodec/cbs.c | 26 +++++++++---------
libavcodec/cbs_internal.h | 69 ++++++++++++++++++++++++++---------------------
libavcodec/cbs_mpeg2.c | 10 +++----
3 files changed, 57 insertions(+), 48 deletions(-)
diff --git a/libavcodec/cbs.c b/libavcodec/cbs.c
index c81297ec93..57b57238ed 100644
--- a/libavcodec/cbs.c
+++ b/libavcodec/cbs.c
@@ -857,8 +857,8 @@ static void cbs_default_free_unit_content(void *opaque, uint8_t *data)
const CodedBitstreamUnitTypeDescriptor *desc = opaque;
if (desc->content_type == CBS_CONTENT_TYPE_INTERNAL_REFS) {
int i;
- for (i = 0; i < desc->nb_ref_offsets; i++) {
- void **ptr = (void**)(data + desc->ref_offsets[i]);
+ for (i = 0; i < desc->type.ref.nb_offsets; i++) {
+ void **ptr = (void**)(data + desc->type.ref.offsets[i]);
av_buffer_unref((AVBufferRef**)(ptr + 1));
}
}
@@ -880,12 +880,12 @@ static const CodedBitstreamUnitTypeDescriptor
if (desc->nb_unit_types == 0)
break;
if (desc->nb_unit_types == CBS_UNIT_TYPE_RANGE) {
- if (unit->type >= desc->unit_type_range_start &&
- unit->type <= desc->unit_type_range_end)
+ if (unit->type >= desc->unit_type.range.start &&
+ unit->type <= desc->unit_type.range.end)
return desc;
} else {
for (j = 0; j < desc->nb_unit_types; j++) {
- if (desc->unit_types[j] == unit->type)
+ if (desc->unit_type.list[j] == unit->type)
return desc;
}
}
@@ -910,7 +910,8 @@ int ff_cbs_alloc_unit_content2(CodedBitstreamContext *ctx,
unit->content_ref =
av_buffer_create(unit->content, desc->content_size,
- desc->content_free ? desc->content_free
+ desc->content_type == CBS_CONTENT_TYPE_COMPLEX
+ ? desc->type.complex.content_free
: cbs_default_free_unit_content,
(void*)desc, 0);
if (!unit->content_ref) {
@@ -936,10 +937,10 @@ static int cbs_clone_internal_refs_unit_content(AVBufferRef **clone_ref,
if (!copy)
return AVERROR(ENOMEM);
- for (i = 0; i < desc->nb_ref_offsets; i++) {
- const uint8_t *const *src_ptr = (const uint8_t* const*)(src + desc->ref_offsets[i]);
+ for (i = 0; i < desc->type.ref.nb_offsets; i++) {
+ const uint8_t *const *src_ptr = (const uint8_t* const*)(src + desc->type.ref.offsets[i]);
const AVBufferRef *src_buf = *(AVBufferRef**)(src_ptr + 1);
- uint8_t **copy_ptr = (uint8_t**)(copy + desc->ref_offsets[i]);
+ uint8_t **copy_ptr = (uint8_t**)(copy + desc->type.ref.offsets[i]);
AVBufferRef **copy_buf = (AVBufferRef**)(copy_ptr + 1);
if (!*src_ptr) {
@@ -962,7 +963,6 @@ static int cbs_clone_internal_refs_unit_content(AVBufferRef **clone_ref,
}
*clone_ref = av_buffer_create(copy, desc->content_size,
- desc->content_free ? desc->content_free :
cbs_default_free_unit_content,
(void*)desc, 0);
if (!*clone_ref) {
@@ -974,7 +974,7 @@ static int cbs_clone_internal_refs_unit_content(AVBufferRef **clone_ref,
fail:
for (--i; i >= 0; i--)
- av_buffer_unref((AVBufferRef**)(copy + desc->ref_offsets[i]));
+ av_buffer_unref((AVBufferRef**)(copy + desc->type.ref.offsets[i]));
av_freep(©);
*clone_ref = NULL;
return err;
@@ -1010,9 +1010,9 @@ static int cbs_clone_unit_content(CodedBitstreamContext *ctx,
break;
case CBS_CONTENT_TYPE_COMPLEX:
- if (!desc->content_clone)
+ if (!desc->type.complex.content_clone)
return AVERROR_PATCHWELCOME;
- err = desc->content_clone(&ref, unit);
+ err = desc->type.complex.content_clone(&ref, unit);
break;
default:
diff --git a/libavcodec/cbs_internal.h b/libavcodec/cbs_internal.h
index 314d54daea..4030b76f1c 100644
--- a/libavcodec/cbs_internal.h
+++ b/libavcodec/cbs_internal.h
@@ -60,13 +60,16 @@ typedef const struct CodedBitstreamUnitTypeDescriptor {
// 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;
+ union {
+ // Array of unit types that this entry describes.
+ CodedBitstreamUnitType list[CBS_MAX_UNIT_TYPES];
+ // Start and end of unit type range, used if nb_unit_types is
+ // CBS_UNIT_TYPE_RANGE.
+ struct {
+ CodedBitstreamUnitType start;
+ CodedBitstreamUnitType end;
+ } range;
+ } unit_type;
// The type of content described.
enum CBSContentType content_type;
@@ -74,18 +77,24 @@ typedef const struct CodedBitstreamUnitTypeDescriptor {
// 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);
+ union {
+ struct {
+ // Number of entries in the ref_offsets array. Only nonzero
+ // if the content_type is CBS_CONTENT_TYPE_INTERNAL_REFS.
+ int nb_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 offsets[CBS_MAX_REF_OFFSETS];
+ } ref;
+
+ struct {
+ void (*content_free)(void *opaque, uint8_t *data);
+ int (*content_clone)(AVBufferRef **ref, CodedBitstreamUnit *unit);
+ } complex;
+ } type;
} CodedBitstreamUnitTypeDescriptor;
typedef struct CodedBitstreamType {
@@ -184,38 +193,38 @@ int ff_cbs_write_signed(CodedBitstreamContext *ctx, PutBitContext *pbc,
#define TYPE_LIST(...) { __VA_ARGS__ }
#define CBS_UNIT_TYPE_POD(type, structure) { \
.nb_unit_types = 1, \
- .unit_types = { type }, \
+ .unit_type.list = { type }, \
.content_type = CBS_CONTENT_TYPE_POD, \
.content_size = sizeof(structure), \
}
#define CBS_UNIT_TYPES_INTERNAL_REF(types, structure, ref_field) { \
.nb_unit_types = FF_ARRAY_ELEMS((CodedBitstreamUnitType[])TYPE_LIST types), \
- .unit_types = TYPE_LIST types, \
+ .unit_type.list = TYPE_LIST types, \
.content_type = CBS_CONTENT_TYPE_INTERNAL_REFS, \
.content_size = sizeof(structure), \
- .nb_ref_offsets = 1, \
- .ref_offsets = { offsetof(structure, ref_field) }, \
+ .type.ref = { .nb_offsets = 1, \
+ .offsets = { offsetof(structure, ref_field) } }, \
}
#define CBS_UNIT_TYPE_INTERNAL_REF(type, structure, ref_field) \
CBS_UNIT_TYPES_INTERNAL_REF((type), structure, ref_field)
#define CBS_UNIT_RANGE_INTERNAL_REF(range_start, range_end, structure, ref_field) { \
- .nb_unit_types = CBS_UNIT_TYPE_RANGE, \
- .unit_type_range_start = range_start, \
- .unit_type_range_end = range_end, \
+ .nb_unit_types = CBS_UNIT_TYPE_RANGE, \
+ .unit_type.range.start = range_start, \
+ .unit_type.range.end = range_end, \
.content_type = CBS_CONTENT_TYPE_INTERNAL_REFS, \
.content_size = sizeof(structure), \
- .nb_ref_offsets = 1, \
- .ref_offsets = { offsetof(structure, ref_field) }, \
+ .type.ref = { .nb_offsets = 1, \
+ .offsets = { offsetof(structure, ref_field) } }, \
}
#define CBS_UNIT_TYPES_COMPLEX(types, structure, free_func) { \
.nb_unit_types = FF_ARRAY_ELEMS((CodedBitstreamUnitType[])TYPE_LIST types), \
- .unit_types = TYPE_LIST types, \
+ .unit_type.list = TYPE_LIST types, \
.content_type = CBS_CONTENT_TYPE_COMPLEX, \
.content_size = sizeof(structure), \
- .content_free = free_func, \
+ .type.complex = { .content_free = free_func }, \
}
#define CBS_UNIT_TYPE_COMPLEX(type, structure, free_func) \
CBS_UNIT_TYPES_COMPLEX((type), structure, free_func)
diff --git a/libavcodec/cbs_mpeg2.c b/libavcodec/cbs_mpeg2.c
index 33bd3e0998..1c9519cdaf 100644
--- a/libavcodec/cbs_mpeg2.c
+++ b/libavcodec/cbs_mpeg2.c
@@ -392,14 +392,14 @@ static const CodedBitstreamUnitTypeDescriptor cbs_mpeg2_unit_types[] = {
{
.nb_unit_types = CBS_UNIT_TYPE_RANGE,
- .unit_type_range_start = 0x01,
- .unit_type_range_end = 0xaf,
+ .unit_type.range.start = 0x01,
+ .unit_type.range.end = 0xaf,
.content_type = CBS_CONTENT_TYPE_INTERNAL_REFS,
.content_size = sizeof(MPEG2RawSlice),
- .nb_ref_offsets = 2,
- .ref_offsets = { offsetof(MPEG2RawSlice, header.extra_information_slice.extra_information),
- offsetof(MPEG2RawSlice, data) },
+ .type.ref = { .nb_offsets = 2,
+ .offsets = { offsetof(MPEG2RawSlice, header.extra_information_slice.extra_information),
+ offsetof(MPEG2RawSlice, data) } },
},
CBS_UNIT_TYPE_INTERNAL_REF(MPEG2_START_USER_DATA, MPEG2RawUserData,
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