[FFmpeg-devel] [PATCH] avcodec/mpegvideo: remove redundant workaround to recalculate last nonzero coefficient

[Ramiro Polla]

On Thu, Aug 22, 2024 at 1:24 AM Ramiro Polla <ramiro.polla at gmail.com> wrote:
> The x86 optimized dct_quantize only calculates the last nonzero
> coefficient correctly if the zigzag scan order is used. For the
> alternate scan order, this value is incorrect.
>
> To work around this, the dct_unquantize functions process the entire
> block if the alternate scan order is used.
>
> But a second workaround (bb198e198ab) was added that recalculates the
> last nonzero coefficient after dct_quantize is called if the alternate
> scan order is used.
>
> This commit removes the first workaround, which became redundant.
> ---
>  libavcodec/mpegvideo.c     | 9 +++------
>  libavcodec/x86/mpegvideo.c | 6 ++----
>  2 files changed, 5 insertions(+), 10 deletions(-)

Michael, could you please check if my analysis and the changes are correct?

Thanks,
Ramiro