[FFmpeg-devel] [PATCH 1/2] acvodec/lipopenjpeg: Fix pixel value shift for 12-bit pixel formats
Michael Bradshaw
mjbshaw at gmail.com
Tue Mar 3 20:54:43 CET 2015
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.
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