acvodec/lipopenjpeg: Fix pixel value shift for 12-bit pixel formats

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.
Reviewed-by: Michael Bradshaw <mjbshaw@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

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;