avcodec/mobiclip: Rewrite code to make it clearer

In order to know that the earlier code did not use uninitialized
values one needs to know that the lowest four bits of each used
value of pframe_block4x4_coefficients_tab do not vanish identically.
E.g. Coverity did not get this and warned about it in ticket #1466632.
Fix this by slightly rewriting the code.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This commit is contained in:
Andreas Rheinhardt 2021-11-18 08:22:38 +01:00
parent f5e74e8d48
commit d6c16c5217
1 changed files with 3 additions and 4 deletions

View File

@ -491,7 +491,7 @@ static int add_pframe_coefficients(AVCodecContext *avctx, AVFrame *frame,
int ret, idx = get_ue_golomb_31(gb); int ret, idx = get_ue_golomb_31(gb);
if (idx == 0) { if (idx == 0) {
ret = add_coefficients(avctx, frame, bx, by, size, plane); return add_coefficients(avctx, frame, bx, by, size, plane);
} else if ((unsigned)idx < FF_ARRAY_ELEMS(pframe_block4x4_coefficients_tab)) { } else if ((unsigned)idx < FF_ARRAY_ELEMS(pframe_block4x4_coefficients_tab)) {
int flags = pframe_block4x4_coefficients_tab[idx]; int flags = pframe_block4x4_coefficients_tab[idx];
@ -505,11 +505,10 @@ static int add_pframe_coefficients(AVCodecContext *avctx, AVFrame *frame,
flags >>= 1; flags >>= 1;
} }
} }
return 0;
} else { } else {
ret = AVERROR_INVALIDDATA; return AVERROR_INVALIDDATA;
} }
return ret;
} }
static int adjust(int x, int size) static int adjust(int x, int size)