cbs: Remove useless initializations

Up until now, a temporary variable was used and initialized every time a
value was read in CBS; if reading turned out to be successfull, this
value was overwritten (without having ever been looked at) with the
value read if reading was successfull; on failure the variable wasn't
touched either. Therefore these initializations can be and have been
removed.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
(cherry picked from commit b71a0367)

libavcodec/cbs_av1.c

@@ -574,7 +574,7 @@ static size_t cbs_av1_get_payload_bytes_left(GetBitContext *gbc)
 #define RWContext GetBitContext
 
 #define xf(width, name, var, range_min, range_max, subs, ...) do { \
-        uint32_t value = range_min; \
+        uint32_t value; \
         CHECK(ff_cbs_read_unsigned(ctx, rw, width, #name, \
                                    SUBSCRIPTS(subs, __VA_ARGS__), \
                                    &value, range_min, range_max)); \
@@ -582,7 +582,7 @@ static size_t cbs_av1_get_payload_bytes_left(GetBitContext *gbc)
     } while (0)
 
 #define xsu(width, name, var, subs, ...) do { \
-        int32_t value = 0; \
+        int32_t value; \
         CHECK(ff_cbs_read_signed(ctx, rw, width, #name, \
                                  SUBSCRIPTS(subs, __VA_ARGS__), &value, \
                                  MIN_INT_BITS(width), \
@@ -591,27 +591,27 @@ static size_t cbs_av1_get_payload_bytes_left(GetBitContext *gbc)
     } while (0)
 
 #define uvlc(name, range_min, range_max) do { \
-        uint32_t value = range_min; \
+        uint32_t value; \
         CHECK(cbs_av1_read_uvlc(ctx, rw, #name, \
                                 &value, range_min, range_max)); \
         current->name = value; \
     } while (0)
 
 #define ns(max_value, name, subs, ...) do { \
-        uint32_t value = 0; \
+        uint32_t value; \
         CHECK(cbs_av1_read_ns(ctx, rw, max_value, #name, \
                               SUBSCRIPTS(subs, __VA_ARGS__), &value)); \
         current->name = value; \
     } while (0)
 
 #define increment(name, min, max) do { \
-        uint32_t value = 0; \
+        uint32_t value; \
         CHECK(cbs_av1_read_increment(ctx, rw, min, max, #name, &value)); \
         current->name = value; \
     } while (0)
 
 #define subexp(name, max, subs, ...) do { \
-        uint32_t value = 0; \
+        uint32_t value; \
         CHECK(cbs_av1_read_subexp(ctx, rw, max, #name, \
                                   SUBSCRIPTS(subs, __VA_ARGS__), &value)); \
         current->name = value; \
@@ -629,7 +629,7 @@ static size_t cbs_av1_get_payload_bytes_left(GetBitContext *gbc)
     } while (0)
 
 #define leb128(name) do { \
-        uint64_t value = 0; \
+        uint64_t value; \
         CHECK(cbs_av1_read_leb128(ctx, rw, #name, &value)); \
         current->name = value; \
     } while (0)

libavcodec/cbs_h2645.c

@@ -289,28 +289,28 @@ static int cbs_write_se_golomb(CodedBitstreamContext *ctx, PutBitContext *pbc,
 #define RWContext GetBitContext
 
 #define xu(width, name, var, range_min, range_max, subs, ...) do { \
-        uint32_t value = range_min; \
+        uint32_t value; \
         CHECK(ff_cbs_read_unsigned(ctx, rw, width, #name, \
                                    SUBSCRIPTS(subs, __VA_ARGS__), \
                                    &value, range_min, range_max)); \
         var = value; \
     } while (0)
 #define xue(name, var, range_min, range_max, subs, ...) do { \
-        uint32_t value = range_min; \
+        uint32_t value; \
         CHECK(cbs_read_ue_golomb(ctx, rw, #name, \
                                  SUBSCRIPTS(subs, __VA_ARGS__), \
                                  &value, range_min, range_max)); \
         var = value; \
     } while (0)
 #define xi(width, name, var, range_min, range_max, subs, ...) do { \
-        int32_t value = range_min; \
+        int32_t value; \
         CHECK(ff_cbs_read_signed(ctx, rw, width, #name, \
                                  SUBSCRIPTS(subs, __VA_ARGS__), \
                                  &value, range_min, range_max)); \
         var = value; \
     } while (0)
 #define xse(name, var, range_min, range_max, subs, ...) do { \
-        int32_t value = range_min; \
+        int32_t value; \
         CHECK(cbs_read_se_golomb(ctx, rw, #name, \
                                  SUBSCRIPTS(subs, __VA_ARGS__), \
                                  &value, range_min, range_max)); \

libavcodec/cbs_jpeg.c

@@ -45,7 +45,7 @@
 #define FUNC(name) cbs_jpeg_read_ ## name
 
 #define xu(width, name, range_min, range_max, subs, ...) do { \
-        uint32_t value = range_min; \
+        uint32_t value; \
         CHECK(ff_cbs_read_unsigned(ctx, rw, width, #name, \
                                    SUBSCRIPTS(subs, __VA_ARGS__), \
                                    &value, range_min, range_max)); \

libavcodec/cbs_mpeg2.c

@@ -57,7 +57,7 @@
 #define RWContext GetBitContext
 
 #define xui(width, name, var, range_min, range_max, subs, ...) do { \
-        uint32_t value = 0; \
+        uint32_t value; \
         CHECK(ff_cbs_read_unsigned(ctx, rw, width, #name, \
                                    SUBSCRIPTS(subs, __VA_ARGS__), \
                                    &value, range_min, range_max)); \

libavcodec/cbs_vp9.c

@@ -267,14 +267,14 @@ static int cbs_vp9_write_le(CodedBitstreamContext *ctx, PutBitContext *pbc,
 #define RWContext GetBitContext
 
 #define xf(width, name, var, subs, ...) do { \
-        uint32_t value = 0; \
+        uint32_t value; \
         CHECK(ff_cbs_read_unsigned(ctx, rw, width, #name, \
                                    SUBSCRIPTS(subs, __VA_ARGS__), \
                                    &value, 0, (1 << width) - 1)); \
         var = value; \
     } while (0)
 #define xs(width, name, var, subs, ...) do { \
-        int32_t value = 0; \
+        int32_t value; \
         CHECK(cbs_vp9_read_s(ctx, rw, width, #name, \
                              SUBSCRIPTS(subs, __VA_ARGS__), &value)); \
         var = value; \
@@ -282,7 +282,7 @@ static int cbs_vp9_write_le(CodedBitstreamContext *ctx, PutBitContext *pbc,
 
 
 #define increment(name, min, max) do { \
-        uint32_t value = 0; \
+        uint32_t value; \
         CHECK(cbs_vp9_read_increment(ctx, rw, min, max, #name, &value)); \
         current->name = value; \
     } while (0)
@@ -315,7 +315,7 @@ static int cbs_vp9_write_le(CodedBitstreamContext *ctx, PutBitContext *pbc,
     } while (0)
 
 #define fixed(width, name, value) do { \
-        av_unused uint32_t fixed_value = value; \
+        av_unused uint32_t fixed_value; \
         CHECK(ff_cbs_read_unsigned(ctx, rw, width, #name, \
                                    0, &fixed_value, value, value)); \
     } while (0)