libavcodec/utils.c:491: error: Null Dereference
  pointer `desc` last assigned on line 490 could be null and is dereferenced at line 491, column 22.

libavcodec/utils.c:487:1: start of procedure video_get_buffer()
485. }
486. 
487. static int video_get_buffer(AVCodecContext *s, AVFrame *pic)
     ^
488. {
489.     FramePool *pool = s->internal->pool;

libavcodec/utils.c:489:5: 
487. static int video_get_buffer(AVCodecContext *s, AVFrame *pic)
488. {
489.     FramePool *pool = s->internal->pool;
         ^
490.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pic->format);
491.     int pixel_size = desc->comp[0].step_minus1 + 1;

libavcodec/utils.c:490:5: 
488. {
489.     FramePool *pool = s->internal->pool;
490.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pic->format);
         ^
491.     int pixel_size = desc->comp[0].step_minus1 + 1;
492.     int h_chroma_shift, v_chroma_shift;

libavutil/pixdesc.c:1574:1: start of procedure av_pix_fmt_desc_get()
  1572. }
  1573. 
  1574. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1575. {
  1576.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1576:9: Taking false branch
  1574. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1575. {
  1576.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1577.         return NULL;
  1578.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1576:24: Taking true branch
  1574. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1575. {
  1576.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1577.         return NULL;
  1578.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1577:9: 
  1575. {
  1576.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1577.         return NULL;
                ^
  1578.     return &av_pix_fmt_descriptors[pix_fmt];
  1579. }

libavutil/pixdesc.c:1579:1: return from a call to av_pix_fmt_desc_get
  1577.         return NULL;
  1578.     return &av_pix_fmt_descriptors[pix_fmt];
  1579. }
        ^
  1580. 
  1581. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

libavcodec/utils.c:491:5: 
489.     FramePool *pool = s->internal->pool;
490.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pic->format);
491.     int pixel_size = desc->comp[0].step_minus1 + 1;
         ^
492.     int h_chroma_shift, v_chroma_shift;
493.     int i;
