libavcodec/utils.c:455: error: Null Dereference
  pointer `desc` last assigned on line 454 could be null and is dereferenced at line 455, column 22.

libavcodec/utils.c:451:1: start of procedure video_get_buffer()
449. }
450. 
451. static int video_get_buffer(AVCodecContext *s, AVFrame *pic)
     ^
452. {
453.     FramePool *pool = s->internal->pool;

libavcodec/utils.c:453:5: 
451. static int video_get_buffer(AVCodecContext *s, AVFrame *pic)
452. {
453.     FramePool *pool = s->internal->pool;
         ^
454.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pic->format);
455.     int pixel_size = desc->comp[0].step_minus1 + 1;

libavcodec/utils.c:454:5: 
452. {
453.     FramePool *pool = s->internal->pool;
454.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pic->format);
         ^
455.     int pixel_size = desc->comp[0].step_minus1 + 1;
456.     int h_chroma_shift, v_chroma_shift;

libavutil/pixdesc.c:1440:1: start of procedure av_pix_fmt_desc_get()
  1438. }
  1439. 
  1440. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1441. {
  1442.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1442:9: Taking false branch
  1440. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1441. {
  1442.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1443.         return NULL;
  1444.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1442:24: Taking true branch
  1440. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1441. {
  1442.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1443.         return NULL;
  1444.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1443:9: 
  1441. {
  1442.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1443.         return NULL;
                ^
  1444.     return &av_pix_fmt_descriptors[pix_fmt];
  1445. }

libavutil/pixdesc.c:1445:1: return from a call to av_pix_fmt_desc_get
  1443.         return NULL;
  1444.     return &av_pix_fmt_descriptors[pix_fmt];
  1445. }
        ^
  1446. 
  1447. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

libavcodec/utils.c:455:5: 
453.     FramePool *pool = s->internal->pool;
454.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pic->format);
455.     int pixel_size = desc->comp[0].step_minus1 + 1;
         ^
456.     int h_chroma_shift, v_chroma_shift;
457.     int i;
