[FFmpeg-devel] [PATCH v2 10/15] avcodec/cinepakenc: Fix invalid shifts

Tomas Härdin tjoppen at acc.umu.se
Sat Sep 28 17:43:56 EEST 2019


lör 2019-09-28 klockan 04:26 +0200 skrev Andreas Rheinhardt:
> Fixes: left shift of 1 by 31 places cannot be represented in type 'int'.
> Affected the FATE-tests vsynth1-cinepak, vsynth2-cinepak and
> vsynth_lena-cinepak.
> 
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
> ---
>  libavcodec/cinepakenc.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/libavcodec/cinepakenc.c b/libavcodec/cinepakenc.c
> index 93917fafe8..6024df0fba 100644
> --- a/libavcodec/cinepakenc.c
> +++ b/libavcodec/cinepakenc.c
> @@ -544,8 +544,9 @@ static int encode_mode(CinepakEncContext *s, int h,
>                         uint8_t *last_data[4], int last_linesize[4],
>                         strip_info *info, unsigned char *buf)
>  {
> -    int x, y, z, flags, bits, temp_size, header_ofs, ret = 0, mb_count = s->w * h / MB_AREA;
> +    int x, y, z, bits, temp_size, header_ofs, ret = 0, mb_count = s->w * h / MB_AREA;
>      int needs_extra_bit, should_write_temp;
> +    uint32_t flags;
>      unsigned char temp[64]; // 32/2 = 16 V4 blocks at 4 B each -> 64 B
>      mb_info *mb;
>      uint8_t *sub_scratch_data[4] = { 0 }, *sub_last_data[4] = { 0 };
> @@ -599,7 +600,7 @@ static int encode_mode(CinepakEncContext *s, int h,
>              flags = 0;
>              for (y = x; y < FFMIN(x + 32, mb_count); y++)
>                  if (s->mb[y].best_encoding == ENC_V4)
> -                    flags |= 1 << (31 - y + x);
> +                    flags |= 1U << (31 - y + x);
>  
>              AV_WB32(&buf[ret], flags);
>              ret += 4;
> @@ -626,13 +627,13 @@ static int encode_mode(CinepakEncContext *s, int h,
>  
>          for (x = 0; x < mb_count; x++) {
>              mb                = &s->mb[x];
> -            flags            |= (mb->best_encoding != ENC_SKIP) << (31 - bits++);
> +            flags            |= (uint32_t)(mb->best_encoding != ENC_SKIP) << (31 - bits++);
>              needs_extra_bit   = 0;
>              should_write_temp = 0;
>  
>              if (mb->best_encoding != ENC_SKIP) {
>                  if (bits < 32)
> -                    flags |= (mb->best_encoding == ENC_V4) << (31 - bits++);
> +                    flags |= (uint32_t)(mb->best_encoding == ENC_V4) << (31 - bits++);
>                  else
>                      needs_extra_bit = 1;
>              }
> @@ -651,7 +652,7 @@ static int encode_mode(CinepakEncContext *s, int h,
>              }
>  
>              if (needs_extra_bit) {
> -                flags = (mb->best_encoding == ENC_V4) << 31;
> +                flags = (uint32_t)(mb->best_encoding == ENC_V4) << 31;
>                  bits  = 1;
>              }
>  

Looks OK

/Tomas



More information about the ffmpeg-devel mailing list