[FFmpeg-devel] [PATCH] Resize AVFilterBuffer data pointers, linesizes. Adjust pic refs to use only four.

[Stefano Sabatini]

On date Thursday 2010-07-22 21:59:50 -0700, S.N. Hemanth Meenakshisundaram encoded:
> 
> >>  avfilter.h |    4 ++--
> >>  defaults.c |   16 +++++++++++-----
> >>  2 files changed, 13 insertions(+), 7 deletions(-)
> >> ea6500130cae103756bee2d2ddd8e23fc879fa3b  0001-Resize-AVFilterBuffer-data-pointers-linesizes.-Adjus.patch
> >> diff --git a/libavfilter/avfilter.h b/libavfilter/avfilter.h
> >> index 066bdc3..a9bec02 100644
> >> --- a/libavfilter/avfilter.h
> >> +++ b/libavfilter/avfilter.h
> >> @@ -66,8 +66,8 @@ typedef struct AVFilterPad     AVFilterPad;
> >>   */
> >>  typedef struct AVFilterBuffer
> >>  {
> >> -    uint8_t *data[4];           ///< buffer data for each plane
> >> -    int linesize[4];            ///< number of bytes per line
> >> +    uint8_t *data[8];           ///< buffer data for each plane
> >> +    int linesize[8];            ///< number of bytes per line
> >>      int format;                 ///< media format
> >>  
> >>      unsigned refcount;          ///< number of references to this buffer
> >> diff --git a/libavfilter/defaults.c b/libavfilter/defaults.c
> >> index 27c8a3b..4253bb3 100644
> >> --- a/libavfilter/defaults.c
> >> +++ b/libavfilter/defaults.c
> >> @@ -38,6 +38,8 @@ AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link, int perms,
> >>      AVFilterPicRef *ref = av_mallocz(sizeof(AVFilterPicRef));
> >>      int i, tempsize;
> >>      char *buf;
> >> +    /* first four plane pointers and last four linesizes are unused for video */
> >> +    uint8_t *newpic = (uint8_t *)pic + 4*sizeof(uint8_t *);
> >>     
> > this is a ugly hack, the first 4 plane pointers should be used for video
> >
> >
> > [...]
> >   
> 
> To fix this is it enough to pass the regular pic pointer as AVPicture *
> and then copy the linesizes to the right location? Or should I write
> versions of ff_fill_pointers and ff_fill_linesize that will fill the new
> AVFilterBuffer instead of AVPicture?

I believe we should make those functions more generic.

int ff_fill_linesize(AVPicture *picture, enum PixelFormat pix_fmt, int width);
->
int ff_fill_image_linesize(int linesize[4], enum PixelFormat pix_fmt, int width);

ff_fill_pointer() requires the linesizes to be already filled, so we
could have:
int ff_fill_image_data(int data[4], uint8_t *ptr, enum PixelFormat pix_fmt, int height, const int const linesize[4]);

BTW these new functions should be placed in libavcore, I suggest:
libavcore/imgutils.h

(but please feel free to suggest a name which sucks less), and make
libavcodec ff_fill_linesize() and ff_fill_pointer() depend on that.

Regards.
-- 
FFmpeg = Forgiving & Forgiving Magic Portable Extended Gem