avconv.c:1498: error: Null Dereference
  pointer `desc` last assigned on line 1495 could be null and is dereferenced at line 1498, column 15.

avconv.c:1488:1: start of procedure get_format()
1486. }
1487. 
1488. static enum AVPixelFormat get_format(AVCodecContext *s, const enum AVPixelFormat *pix_fmts)
      ^
1489. {
1490.     InputStream *ist = s->opaque;

avconv.c:1490:5: 
1488. static enum AVPixelFormat get_format(AVCodecContext *s, const enum AVPixelFormat *pix_fmts)
1489. {
1490.     InputStream *ist = s->opaque;
          ^
1491.     const enum AVPixelFormat *p;
1492.     int ret;

avconv.c:1494:10: 
1492.     int ret;
1493. 
1494.     for (p = pix_fmts; *p != -1; p++) {
               ^
1495.         const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(*p);
1496.         const HWAccel *hwaccel;

avconv.c:1494:24: Loop condition is true. Entering loop body
1492.     int ret;
1493. 
1494.     for (p = pix_fmts; *p != -1; p++) {
                             ^
1495.         const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(*p);
1496.         const HWAccel *hwaccel;

avconv.c:1495:9: 
1493. 
1494.     for (p = pix_fmts; *p != -1; p++) {
1495.         const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(*p);
              ^
1496.         const HWAccel *hwaccel;
1497. 

libavutil/pixdesc.c:1676:1: start of procedure av_pix_fmt_desc_get()
  1674. }
  1675. 
  1676. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1677. {
  1678.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1678:9: Taking false branch
  1676. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1677. {
  1678.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1679.         return NULL;
  1680.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1678:24: Taking true branch
  1676. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1677. {
  1678.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1679.         return NULL;
  1680.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1679:9: 
  1677. {
  1678.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1679.         return NULL;
                ^
  1680.     return &av_pix_fmt_descriptors[pix_fmt];
  1681. }

libavutil/pixdesc.c:1681:1: return from a call to av_pix_fmt_desc_get
  1679.         return NULL;
  1680.     return &av_pix_fmt_descriptors[pix_fmt];
  1681. }
        ^
  1682. 
  1683. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

avconv.c:1498:15: 
1496.         const HWAccel *hwaccel;
1497. 
1498.         if (!(desc->flags & AV_PIX_FMT_FLAG_HWACCEL))
                    ^
1499.             break;
1500. 
