libavcodec/utils.c:456: error: Null Dereference
  pointer `desc` last assigned on line 455 could be null and is dereferenced at line 456, column 22.

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

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

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

libavutil/pixdesc.c:1464:1: start of procedure av_pix_fmt_desc_get()
  1462. }
  1463. 
  1464. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1465. {
  1466.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1466:9: Taking false branch
  1464. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1465. {
  1466.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1467.         return NULL;
  1468.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1466:24: Taking true branch
  1464. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1465. {
  1466.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1467.         return NULL;
  1468.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1467:9: 
  1465. {
  1466.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1467.         return NULL;
                ^
  1468.     return &av_pix_fmt_descriptors[pix_fmt];
  1469. }

libavutil/pixdesc.c:1469:1: return from a call to av_pix_fmt_desc_get
  1467.         return NULL;
  1468.     return &av_pix_fmt_descriptors[pix_fmt];
  1469. }
        ^
  1470. 
  1471. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

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