[FFmpeg-devel] [PATCH] Fix linesize computation for NV formats

Michael Niedermayer michaelni
Wed Nov 25 19:16:37 CET 2009


On Wed, Nov 25, 2009 at 03:24:03PM -0200, Ramiro Polla wrote:
> On Tue, Nov 24, 2009 at 12:27 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
> > On Fri, Nov 20, 2009 at 02:16:44PM -0200, Ramiro Polla wrote:
> >> On Fri, Nov 20, 2009 at 9:56 AM, Ramiro Polla <ramiro.polla at gmail.com> wrote:
> >> > On Thu, Nov 19, 2009 at 10:54 PM, Ramiro Polla <ramiro.polla at gmail.com> wrote:
> >> >> On Thu, Nov 19, 2009 at 10:38 PM, Stefano Sabatini
> >> >> <stefano.sabatini-lala at poste.it> wrote:
> >> >>> On date Thursday 2009-11-19 17:51:30 +0100, Michael Niedermayer encoded:
> >> >>>> On Thu, Nov 19, 2009 at 01:37:03AM +0100, Stefano Sabatini wrote:
> >> >>> [...]
> >> >>>> > So basically all the code affected by the change is indeed code which
> >> >>>> > is never used, my patch simply makes the linesize params semantics for
> >> >>>> > NV formats consistent with that of all the other formats (thus
> >> >>>> > simplifying the code if we choose to use pixdesc for ff_fill_XXX).
> >> >>>>
> >> >>>> if no code uses NV12 it should be removed (i dont belive this though)
> >> >>>> if any code uses NV12 your patch will break it.
> >> >>>
> >> >>> ffmpeg doesn't support NV12 as input, but can convert to NV12 /
> >> >>> NV21. So we can create a stream with pix_fmt nv12 but there is no mean
> >> >>> to visually test it (e.g. with ffplay) or convert it back to a stream
> >> >>> which is playable by ffmpeg, but maybe someone can suggest some way to
> >> >>> display such a format e.g. with mplayer or vlc.
> >> >>>
> >> >>> Also I wonder how hard would be to add it as an input format in lsws.
> >> >>
> >> >> I have a device with a hardware decoder to nv12 that also displays in
> >> >> nv12 at work. I might take a look tomorrow if I manage to find some
> >> >> time...
> >> >
> >> > One more change was needed to get raw nv12 output properly. With
> >> > attached patch I can
> >> > ./ffmpeg_g -i input.avi -s 1280x720 -pix_fmt nv12 -f rawvideo -y output.nv12
> >> > and then feed output.nv12 to the display frame by frame.
> >> >
> >> > I haven't worked on nv12 support as input to swscale yet. I'll do it
> >> > either this afternoon or in two weeks =)
> >>
> >> And here is a patch to take nv12 and nv21 as input for swscale
> >> (depends on the previous patch).
> >>
> >> Ramiro Polla
> >
> >> ?swscale.c ? ? ? ? ?| ? ?2 ++
> >> ?swscale_template.c | ? 23 +++++++++++++++++++++++
> >> ?2 files changed, 25 insertions(+)
> >> 7e95c118694ad7ee4d89e948fea7e3252238d5d9 ?nv12in.diff
> >> Index: libswscale/swscale.c
> >> ===================================================================
> >> --- libswscale/swscale.c ? ? ?(revis?o 29937)
> >> +++ libswscale/swscale.c ? ? ?(c?pia de trabalho)
> >> @@ -134,6 +134,8 @@
> >> ? ? ? ? ?|| (x)==PIX_FMT_GRAY8 ? ? ? \
> >> ? ? ? ? ?|| (x)==PIX_FMT_YUV410P ? ? \
> >> ? ? ? ? ?|| (x)==PIX_FMT_YUV440P ? ? \
> >> + ? ? ? ?|| (x)==PIX_FMT_NV12 ? ? ? ?\
> >> + ? ? ? ?|| (x)==PIX_FMT_NV21 ? ? ? ?\
> >> ? ? ? ? ?|| (x)==PIX_FMT_GRAY16BE ? ?\
> >> ? ? ? ? ?|| (x)==PIX_FMT_GRAY16LE ? ?\
> >> ? ? ? ? ?|| (x)==PIX_FMT_YUV444P ? ? \
> >> Index: libswscale/swscale_template.c
> >> ===================================================================
> >> --- libswscale/swscale_template.c ? ? (revis?o 29937)
> >> +++ libswscale/swscale_template.c ? ? (c?pia de trabalho)
> >> @@ -1784,6 +1784,27 @@
> >> ?#endif
> >> ?}
> >>
> >> +#define NVxxToUV(U, V) ? ? ? ? ? ? ?\
> >> + ? ?int i; ? ? ? ? ? ? ? ? ? ? ? ? ?\
> >> + ? ?for (i = 0; i < width; i++) { ? \
> >> + ? ? ? ?dstU[i]= src1[2*i+U]; ? ? ? \
> >> + ? ? ? ?dstV[i]= src1[2*i+V]; ? ? ? \
> >> + ? ?} ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? \
> >> +
> >> +static inline void RENAME(nv12ToUV)(uint8_t *dstU, uint8_t *dstV,
> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?const uint8_t *src1, const uint8_t *src2,
> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?long width, uint32_t *unused)
> >> +{
> >> + ? ?NVxxToUV(0, 1);
> >> +}
> >> +
> >> +static inline void RENAME(nv21ToUV)(uint8_t *dstU, uint8_t *dstV,
> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?const uint8_t *src1, const uint8_t *src2,
> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?long width, uint32_t *unused)
> >> +{
> >> + ? ?NVxxToUV(1, 0);
> >> +}
> >
> > you need just 1 function, just exchange the 2 dst pointers
> 
> Like in attached?

>  swscale.c          |    2 ++
>  swscale_template.c |   26 ++++++++++++++++++++++++++
>  2 files changed, 28 insertions(+)
> 219c60ab14c8879cf0b3578079ced1b82df9e01f  nv12in2.diff
> Index: libswscale/swscale.c
> ===================================================================
> --- libswscale/swscale.c	(revision 29964)
> +++ libswscale/swscale.c	(working copy)
> @@ -134,6 +134,8 @@
>          || (x)==PIX_FMT_GRAY8       \
>          || (x)==PIX_FMT_YUV410P     \
>          || (x)==PIX_FMT_YUV440P     \
> +        || (x)==PIX_FMT_NV12        \
> +        || (x)==PIX_FMT_NV21        \
>          || (x)==PIX_FMT_GRAY16BE    \
>          || (x)==PIX_FMT_GRAY16LE    \
>          || (x)==PIX_FMT_YUV444P     \
> Index: libswscale/swscale_template.c
> ===================================================================
> --- libswscale/swscale_template.c	(revision 29964)
> +++ libswscale/swscale_template.c	(working copy)
> @@ -1784,6 +1784,30 @@
>  #endif
>  }
>  
> +static inline void RENAME(nvXXtoUV)(uint8_t *dst1, uint8_t *dst2,
> +                                    const uint8_t *src, long width)
> +{
> +    int i;
> +    for (i = 0; i < width; i++) {
> +        dst1[i]= src[2*i+0];
> +        dst2[i]= src[2*i+1];
> +    }
> +}
> +
> +static inline void nv12ToUV(uint8_t *dstU, uint8_t *dstV,
> +                            const uint8_t *src1, const uint8_t *src2,
> +                            long width, uint32_t *unused)
> +{
> +    RENAME(nvXXtoUV)(dstU, dstV, src1, width);
> +}
> +
> +static inline void nv21ToUV(uint8_t *dstU, uint8_t *dstV,
> +                            const uint8_t *src1, const uint8_t *src2,
> +                            long width, uint32_t *unused)
> +{
> +    RENAME(nvXXtoUV)(dstV, dstU, src1, width);
> +}

is the use of existing functions like yuy2ToY() slower?


[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Thouse who are best at talking, realize last or never when they are wrong.
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