[FFmpeg-devel] [PATCH 1/2] avcodec/vvcdec: filter, fix uninitialized variables for YUV400 format

[Nuo Mi]

On Fri, Aug 23, 2024 at 11:04 PM Nuo Mi <nuomi2021 at gmail.com> wrote:

> fix
> ==135000== Conditional jump or move depends on uninitialised value(s)
> ==135000==    at 0x169FF95: vvc_deblock_bs (filter.c:699)
> and
> ==135000== Conditional jump or move depends on uninitialised value(s)
> ==135000==    at 0x16A2E72: ff_vvc_alf_filter (filter.c:1217)
>
> Reported-by: James Almer <jamrial at gmail.com>
>
Applied. I will monitor the next result from
https://fate.ffmpeg.org/report.cgi?time=20240821174441&slot=x86_64-archlinux-gcc-valgrind
.
Thank you, James, for the report

> ---
>  libavcodec/vvc/filter.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/libavcodec/vvc/filter.c b/libavcodec/vvc/filter.c
> index c96e59df89..aa0d542271 100644
> --- a/libavcodec/vvc/filter.c
> +++ b/libavcodec/vvc/filter.c
> @@ -686,11 +686,12 @@ static void vvc_deblock_bs(const VVCLocalContext
> *lc, const int x0, const int y0
>      const int ctb_size = sps->ctb_size_y;
>      const int x_end    = FFMIN(x0 + ctb_size, pps->width) >> MIN_TU_LOG2;
>      const int y_end    = FFMIN(y0 + ctb_size, pps->height) >> MIN_TU_LOG2;
> +    const int has_chroma       = !!sps->r->sps_chroma_format_idc;
>      deblock_bs_fn deblock_bs[] = {
>          vvc_deblock_bs_luma, vvc_deblock_bs_chroma
>      };
>
> -    for (int is_chroma = 0; is_chroma <= 1; is_chroma++) {
> +    for (int is_chroma = 0; is_chroma <= has_chroma; is_chroma++) {
>          const int hs = sps->hshift[is_chroma];
>          const int vs = sps->vshift[is_chroma];
>          for (int y = y0 >> MIN_TU_LOG2; y < y_end; y++) {
> @@ -1194,6 +1195,7 @@ void ff_vvc_alf_filter(VVCLocalContext *lc, const
> int x0, const int y0)
>      const int padded_stride = EDGE_EMU_BUFFER_STRIDE << ps;
>      const int padded_offset = padded_stride * ALF_PADDING_SIZE +
> (ALF_PADDING_SIZE << ps);
>      const int c_end         = sps->r->sps_chroma_format_idc ?
> VVC_MAX_SAMPLE_ARRAYS : 1;
> +    const int has_chroma    = !!sps->r->sps_chroma_format_idc;
>      const int ctu_end       = y0 + sps->ctb_size_y;
>      const ALFParams *alf    = &CTB(fc->tab.alf, rx, ry);
>      int sb_edges[MAX_VBBS][MAX_EDGES], nb_sbs;
> @@ -1214,7 +1216,7 @@ void ff_vvc_alf_filter(VVCLocalContext *lc, const
> int x0, const int y0)
>              uint8_t *src         = POS(c_idx, sb->l, sb->t);
>              uint8_t *padded;
>
> -            if (alf->ctb_flag[c_idx] || (!c_idx && (alf->ctb_cc_idc[0] ||
> alf->ctb_cc_idc[1]))) {
> +            if (alf->ctb_flag[c_idx] || (!c_idx && has_chroma &&
> (alf->ctb_cc_idc[0] || alf->ctb_cc_idc[1]))) {
>                  padded = (c_idx ? lc->alf_buffer_chroma :
> lc->alf_buffer_luma) + padded_offset;
>                  alf_prepare_buffer(fc, padded, src, x, y, rx, ry, width,
> height,
>                      padded_stride, src_stride, c_idx, sb_edges[i]);
> --
> 2.34.1
>
>