[FFmpeg-devel] [PATCH 1/2] acvodec/lipopenjpeg: Fix pixel value shift for 12-bit pixel formats

[Michael Niedermayer]

On Tue, Mar 03, 2015 at 12:54:43PM -0700, Michael Bradshaw wrote:
> On Tue, Mar 3, 2015 at 1:19 AM, Vilius Grigaliūnas <
> vilius.grigaliunas at gmail.com> wrote:
> 
> > This fixes pixel values not being properly shifted in
> > libopenjpeg_copyto16 and libopenjpeg_copy_to_packed16 methods.
> >
> > Pixel formats like xyz12le need to be shifted by
> > AVComponentDescriptor::shift
> > to get the correct values.
> > ---
> >  libavcodec/libopenjpegdec.c |    6 ++++--
> >  1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/libavcodec/libopenjpegdec.c b/libavcodec/libopenjpegdec.c
> > index 02b1ceb..1cd1b9b 100644
> > --- a/libavcodec/libopenjpegdec.c
> > +++ b/libavcodec/libopenjpegdec.c
> > @@ -184,10 +184,11 @@ static inline void
> > libopenjpeg_copy_to_packed8(AVFrame *picture, opj_image_t *im
> >
> >  static inline void libopenjpeg_copy_to_packed16(AVFrame *picture,
> > opj_image_t *image) {
> >      uint16_t *img_ptr;
> > +    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(picture->format);
> >      int index, x, y, c;
> >      int adjust[4];
> >      for (x = 0; x < image->numcomps; x++)
> > -        adjust[x] =
> > FFMAX(FFMIN(av_pix_fmt_desc_get(picture->format)->comp[x].depth_minus1 + 1
> > - image->comps[x].prec, 8), 0);
> > +        adjust[x] = FFMAX(FFMIN(desc->comp[x].depth_minus1 + 1 -
> > image->comps[x].prec, 8), 0) + desc->comp[x].shift;
> >
> >      for (y = 0; y < picture->height; y++) {
> >          index   = y * picture->width;
> > @@ -220,10 +221,11 @@ static inline void libopenjpeg_copyto8(AVFrame
> > *picture, opj_image_t *image) {
> >  static inline void libopenjpeg_copyto16(AVFrame *picture, opj_image_t
> > *image) {
> >      int *comp_data;
> >      uint16_t *img_ptr;
> > +    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(picture->format);
> >      int index, x, y;
> >      int adjust[4];
> >      for (x = 0; x < image->numcomps; x++)
> > -        adjust[x] =
> > FFMAX(FFMIN(av_pix_fmt_desc_get(picture->format)->comp[x].depth_minus1 + 1
> > - image->comps[x].prec, 8), 0);
> > +        adjust[x] = FFMAX(FFMIN(desc->comp[x].depth_minus1 + 1 -
> > image->comps[x].prec, 8), 0) + desc->comp[x].shift;
> >
> >      for (index = 0; index < image->numcomps; index++) {
> >          comp_data = image->comps[index].data;
> >
> 
> Overall, looks good to me. Maybe the "+ desc->comp[x].shift;" part should
> be moved inside the FFMIN macro?

> Seems okay as is, though.

applied
hopefully the intended thing, its a bit hard to follow this thread ;)

thanks

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

It is what and why we do it that matters, not just one of them.
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