libswscale/swscale_unscaled.c:473: error: Null Dereference
  pointer `desc_dst` last assigned on line 466 could be null and is dereferenced at line 473, column 39.

libswscale/swscale_unscaled.c:458:1: start of procedure findRgbConvFn()
456. /* {RGB,BGR}{15,16,24,32,32_1} -> {RGB,BGR}{15,16,24,32} */
457. typedef void (* rgbConvFn) (const uint8_t *, uint8_t *, int);
458. static rgbConvFn findRgbConvFn(SwsContext *c)
     ^
459. {
460.     const enum AVPixelFormat srcFormat = c->srcFormat;

libswscale/swscale_unscaled.c:460:5: 
458. static rgbConvFn findRgbConvFn(SwsContext *c)
459. {
460.     const enum AVPixelFormat srcFormat = c->srcFormat;
         ^
461.     const enum AVPixelFormat dstFormat = c->dstFormat;
462.     const int srcId = c->srcFormatBpp;

libswscale/swscale_unscaled.c:461:5: 
459. {
460.     const enum AVPixelFormat srcFormat = c->srcFormat;
461.     const enum AVPixelFormat dstFormat = c->dstFormat;
         ^
462.     const int srcId = c->srcFormatBpp;
463.     const int dstId = c->dstFormatBpp;

libswscale/swscale_unscaled.c:462:5: 
460.     const enum AVPixelFormat srcFormat = c->srcFormat;
461.     const enum AVPixelFormat dstFormat = c->dstFormat;
462.     const int srcId = c->srcFormatBpp;
         ^
463.     const int dstId = c->dstFormatBpp;
464.     rgbConvFn conv = NULL;

libswscale/swscale_unscaled.c:463:5: 
461.     const enum AVPixelFormat dstFormat = c->dstFormat;
462.     const int srcId = c->srcFormatBpp;
463.     const int dstId = c->dstFormatBpp;
         ^
464.     rgbConvFn conv = NULL;
465.     const AVPixFmtDescriptor *desc_src = av_pix_fmt_desc_get(srcFormat);

libswscale/swscale_unscaled.c:464:5: 
462.     const int srcId = c->srcFormatBpp;
463.     const int dstId = c->dstFormatBpp;
464.     rgbConvFn conv = NULL;
         ^
465.     const AVPixFmtDescriptor *desc_src = av_pix_fmt_desc_get(srcFormat);
466.     const AVPixFmtDescriptor *desc_dst = av_pix_fmt_desc_get(dstFormat);

libswscale/swscale_unscaled.c:465:5: 
463.     const int dstId = c->dstFormatBpp;
464.     rgbConvFn conv = NULL;
465.     const AVPixFmtDescriptor *desc_src = av_pix_fmt_desc_get(srcFormat);
         ^
466.     const AVPixFmtDescriptor *desc_dst = av_pix_fmt_desc_get(dstFormat);
467. 

libavutil/pixdesc.c:1199:1: start of procedure av_pix_fmt_desc_get()
  1197. }
  1198. 
  1199. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1200. {
  1201.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1201:9: Taking false branch
  1199. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1200. {
  1201.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1202.         return NULL;
  1203.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1201:24: Taking false branch
  1199. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1200. {
  1201.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1202.         return NULL;
  1203.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1203:5: 
  1201.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1202.         return NULL;
  1203.     return &av_pix_fmt_descriptors[pix_fmt];
            ^
  1204. }
  1205. 

libavutil/pixdesc.c:1204:1: return from a call to av_pix_fmt_desc_get
  1202.         return NULL;
  1203.     return &av_pix_fmt_descriptors[pix_fmt];
  1204. }
        ^
  1205. 
  1206. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

libswscale/swscale_unscaled.c:466:5: 
464.     rgbConvFn conv = NULL;
465.     const AVPixFmtDescriptor *desc_src = av_pix_fmt_desc_get(srcFormat);
466.     const AVPixFmtDescriptor *desc_dst = av_pix_fmt_desc_get(dstFormat);
         ^
467. 
468. #define IS_NOT_NE(bpp, desc) \

libavutil/pixdesc.c:1199:1: start of procedure av_pix_fmt_desc_get()
  1197. }
  1198. 
  1199. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1200. {
  1201.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1201:9: Taking false branch
  1199. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1200. {
  1201.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1202.         return NULL;
  1203.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1201:24: Taking true branch
  1199. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1200. {
  1201.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1202.         return NULL;
  1203.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1202:9: 
  1200. {
  1201.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1202.         return NULL;
                ^
  1203.     return &av_pix_fmt_descriptors[pix_fmt];
  1204. }

libavutil/pixdesc.c:1204:1: return from a call to av_pix_fmt_desc_get
  1202.         return NULL;
  1203.     return &av_pix_fmt_descriptors[pix_fmt];
  1204. }
        ^
  1205. 
  1206. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

libswscale/swscale_unscaled.c:473:9: Taking false branch
471. 
472.     /* if this is non-native rgb444/555/565, don't handle it here. */
473.     if (IS_NOT_NE(srcId, desc_src) || IS_NOT_NE(dstId, desc_dst))
             ^
474.         return NULL;
475. 

libswscale/swscale_unscaled.c:473:39: Taking true branch
471. 
472.     /* if this is non-native rgb444/555/565, don't handle it here. */
473.     if (IS_NOT_NE(srcId, desc_src) || IS_NOT_NE(dstId, desc_dst))
                                           ^
474.         return NULL;
475. 
