[FFmpeg-devel] [GSOC][PATCH] lavc/cfhd:corrected decompanding for table 9 used in cfhd

[Gagandeep Singh]

On Tue, Aug 14, 2018 at 12:58 AM Gagandeep Singh <deepgagan231197 at gmail.com>
wrote:

> ---
>  libavcodec/cfhd.c | 25 ++++++++++++++++++++++++-
>  1 file changed, 24 insertions(+), 1 deletion(-)
>
> diff --git a/libavcodec/cfhd.c b/libavcodec/cfhd.c
> index 3906d7a86d..2c538f0bbd 100644
> --- a/libavcodec/cfhd.c
> +++ b/libavcodec/cfhd.c
> @@ -114,7 +114,30 @@ static inline int dequant_and_decompand(int level,
> int quantisation, int codeboo
>  {
>      if (lossless)
>          return level;
> -    if (codebook == 0 || codebook == 1) {
> +    if (codebook == 0) {
> +        if (level >= 40 && level < 264) {
> +            if (level >= 54) {
> +                level  -= 54;
> +                level <<= 2;
> +                level  += 54;
> +            }
> +            level  -= 40;
> +            level <<= 2;
> +            level  += 40;
> +        } else if (level <= -40) {
> +            level = -level;
> +            if (level >= 54) {
> +                level  -= 54;
> +                level <<= 2;
> +                level  += 54;
> +            }
> +            level  -= 40;
> +            level <<= 2;
> +            level  += 40;
> +            level   = -level;
> +        }
> +        return level * quantisation;
> +    } else if (codebook == 1) {
>          int64_t abslevel = abs(level);
>          if (level < 264)
>              return (abslevel + ((768 * abslevel * abslevel * abslevel) /
> (255 * 255 * 255))) *
> --
> 2.17.1
>

Updated patches are in new thread. Sorry for inconvenience.

Gagandeep Singh