libavcodec/utils.c:252: error: Null Dereference
  pointer `desc` last assigned on line 251 could be null and is dereferenced at line 252, column 24.

libavcodec/utils.c:249:1: start of procedure avcodec_align_dimensions()
247. }
248. 
249. void avcodec_align_dimensions(AVCodecContext *s, int *width, int *height)
     ^
250. {
251.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(s->pix_fmt);

libavcodec/utils.c:251:5: 
249. void avcodec_align_dimensions(AVCodecContext *s, int *width, int *height)
250. {
251.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(s->pix_fmt);
         ^
252.     int chroma_shift = desc->log2_chroma_w;
253.     int linesize_align[AV_NUM_DATA_POINTERS];

libavutil/pixdesc.c:1433:1: start of procedure av_pix_fmt_desc_get()
  1431. }
  1432. 
  1433. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1434. {
  1435.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1435:9: Taking false branch
  1433. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1434. {
  1435.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1436.         return NULL;
  1437.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1435:24: Taking true branch
  1433. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1434. {
  1435.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1436.         return NULL;
  1437.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1436:9: 
  1434. {
  1435.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1436.         return NULL;
                ^
  1437.     return &av_pix_fmt_descriptors[pix_fmt];
  1438. }

libavutil/pixdesc.c:1438:1: return from a call to av_pix_fmt_desc_get
  1436.         return NULL;
  1437.     return &av_pix_fmt_descriptors[pix_fmt];
  1438. }
        ^
  1439. 
  1440. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

libavcodec/utils.c:252:5: 
250. {
251.     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(s->pix_fmt);
252.     int chroma_shift = desc->log2_chroma_w;
         ^
253.     int linesize_align[AV_NUM_DATA_POINTERS];
254.     int align;

void avcodec_align_dimensions(AVCodecContext *s, int *width, int *height)
{
    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(s->pix_fmt);
    int chroma_shift = desc->log2_chroma_w;
    int linesize_align[AV_NUM_DATA_POINTERS];
    int align;
    avcodec_align_dimensions2(s, width, height, linesize_align);
    align               = FFMAX(linesize_align[0], linesize_align[3]);
    linesize_align[1] <<= chroma_shift;
    linesize_align[2] <<= chroma_shift;
    align               = FFMAX3(align, linesize_align[1], linesize_align[2]);
    *width              = FFALIGN(*width, align);
}
['void avcodec_align_dimensions(AVCodecContext *s, int *width, int *height)\n{\n    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(s->pix_fmt);\n    int chroma_shift = desc->log2_chroma_w;\n    int linesize_align[AV_NUM_DATA_POINTERS];\n    int align;\n    avcodec_align_dimensions2(s, width, height, linesize_align);\n    align               = FFMAX(linesize_align[0], linesize_align[3]);\n    linesize_align[1] <<= chroma_shift;\n    linesize_align[2] <<= chroma_shift;\n    align               = FFMAX3(align, linesize_align[1], linesize_align[2]);\n    *width              = FFALIGN(*width, align);\n}', 'const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)\n{\n    if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)\n        return NULL;\n    return &av_pix_fmt_descriptors[pix_fmt];\n}']