libavcodec/utils.c:458: error: Null Dereference
  pointer `desc` last assigned on line 457 could be null and is dereferenced at line 458, column 22.

libavcodec/utils.c:454:1: start of procedure video_get_buffer()
452. }
453. 
454. static int video_get_buffer(AVCodecContext *s, AVFrame *pic)
     ^
455. {
456.     FramePool *pool = s->internal->pool;

libavcodec/utils.c:456:5: 
454. static int video_get_buffer(AVCodecContext *s, AVFrame *pic)
455. {
456.     FramePool *pool = s->internal->pool;
         ^
457.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pic->format);
458.     int pixel_size = desc->comp[0].step_minus1 + 1;

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

libavutil/pixdesc.c:1466:1: start of procedure av_pix_fmt_desc_get()
  1464. }
  1465. 
  1466. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1467. {
  1468.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1468:9: Taking false branch
  1466. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1467. {
  1468.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1469.         return NULL;
  1470.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1468:24: Taking true branch
  1466. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1467. {
  1468.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1469.         return NULL;
  1470.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1469:9: 
  1467. {
  1468.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1469.         return NULL;
                ^
  1470.     return &av_pix_fmt_descriptors[pix_fmt];
  1471. }

libavutil/pixdesc.c:1471:1: return from a call to av_pix_fmt_desc_get
  1469.         return NULL;
  1470.     return &av_pix_fmt_descriptors[pix_fmt];
  1471. }
        ^
  1472. 
  1473. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

libavcodec/utils.c:458:5: 
456.     FramePool *pool = s->internal->pool;
457.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pic->format);
458.     int pixel_size = desc->comp[0].step_minus1 + 1;
         ^
459.     int h_chroma_shift, v_chroma_shift;
460.     int i;
