libswscale/swscale_unscaled.c:568: error: Null Dereference
  pointer `desc_src` last assigned on line 560 could be null and is dereferenced at line 568, column 9.

libswscale/swscale_unscaled.c:553:1: start of procedure findRgbConvFn()
551. /* {RGB,BGR}{15,16,24,32,32_1} -> {RGB,BGR}{15,16,24,32} */
552. typedef void (* rgbConvFn) (const uint8_t *, uint8_t *, int);
553. static rgbConvFn findRgbConvFn(SwsContext *c)
     ^
554. {
555.     const enum AVPixelFormat srcFormat = c->srcFormat;

libswscale/swscale_unscaled.c:555:5: 
553. static rgbConvFn findRgbConvFn(SwsContext *c)
554. {
555.     const enum AVPixelFormat srcFormat = c->srcFormat;
         ^
556.     const enum AVPixelFormat dstFormat = c->dstFormat;
557.     const int srcId = c->srcFormatBpp;

libswscale/swscale_unscaled.c:556:5: 
554. {
555.     const enum AVPixelFormat srcFormat = c->srcFormat;
556.     const enum AVPixelFormat dstFormat = c->dstFormat;
         ^
557.     const int srcId = c->srcFormatBpp;
558.     const int dstId = c->dstFormatBpp;

libswscale/swscale_unscaled.c:557:5: 
555.     const enum AVPixelFormat srcFormat = c->srcFormat;
556.     const enum AVPixelFormat dstFormat = c->dstFormat;
557.     const int srcId = c->srcFormatBpp;
         ^
558.     const int dstId = c->dstFormatBpp;
559.     rgbConvFn conv = NULL;

libswscale/swscale_unscaled.c:558:5: 
556.     const enum AVPixelFormat dstFormat = c->dstFormat;
557.     const int srcId = c->srcFormatBpp;
558.     const int dstId = c->dstFormatBpp;
         ^
559.     rgbConvFn conv = NULL;
560.     const AVPixFmtDescriptor *desc_src = av_pix_fmt_desc_get(srcFormat);

libswscale/swscale_unscaled.c:559:5: 
557.     const int srcId = c->srcFormatBpp;
558.     const int dstId = c->dstFormatBpp;
559.     rgbConvFn conv = NULL;
         ^
560.     const AVPixFmtDescriptor *desc_src = av_pix_fmt_desc_get(srcFormat);
561.     const AVPixFmtDescriptor *desc_dst = av_pix_fmt_desc_get(dstFormat);

libswscale/swscale_unscaled.c:560:5: 
558.     const int dstId = c->dstFormatBpp;
559.     rgbConvFn conv = NULL;
560.     const AVPixFmtDescriptor *desc_src = av_pix_fmt_desc_get(srcFormat);
         ^
561.     const AVPixFmtDescriptor *desc_dst = av_pix_fmt_desc_get(dstFormat);
562. 

libavutil/pixdesc.c:1468:1: start of procedure av_pix_fmt_desc_get()
  1466. }
  1467. 
  1468. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1469. {
  1470.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1470:9: Taking false branch
  1468. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1469. {
  1470.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1471.         return NULL;
  1472.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1470:24: Taking true branch
  1468. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1469. {
  1470.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1471.         return NULL;
  1472.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1471:9: 
  1469. {
  1470.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1471.         return NULL;
                ^
  1472.     return &av_pix_fmt_descriptors[pix_fmt];
  1473. }

libavutil/pixdesc.c:1473:1: return from a call to av_pix_fmt_desc_get
  1471.         return NULL;
  1472.     return &av_pix_fmt_descriptors[pix_fmt];
  1473. }
        ^
  1474. 
  1475. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

libswscale/swscale_unscaled.c:561:5: 
559.     rgbConvFn conv = NULL;
560.     const AVPixFmtDescriptor *desc_src = av_pix_fmt_desc_get(srcFormat);
561.     const AVPixFmtDescriptor *desc_dst = av_pix_fmt_desc_get(dstFormat);
         ^
562. 
563. #define IS_NOT_NE(bpp, desc) \

libavutil/pixdesc.c:1468:1: start of procedure av_pix_fmt_desc_get()
  1466. }
  1467. 
  1468. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
        ^
  1469. {
  1470.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)

libavutil/pixdesc.c:1470:9: Taking false branch
  1468. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1469. {
  1470.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                ^
  1471.         return NULL;
  1472.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1470:24: Taking true branch
  1468. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
  1469. {
  1470.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
                               ^
  1471.         return NULL;
  1472.     return &av_pix_fmt_descriptors[pix_fmt];

libavutil/pixdesc.c:1471:9: 
  1469. {
  1470.     if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB)
  1471.         return NULL;
                ^
  1472.     return &av_pix_fmt_descriptors[pix_fmt];
  1473. }

libavutil/pixdesc.c:1473:1: return from a call to av_pix_fmt_desc_get
  1471.         return NULL;
  1472.     return &av_pix_fmt_descriptors[pix_fmt];
  1473. }
        ^
  1474. 
  1475. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)

libswscale/swscale_unscaled.c:568:9: Taking true branch
566. 
567.     /* if this is non-native rgb444/555/565, don't handle it here. */
568.     if (IS_NOT_NE(srcId, desc_src) || IS_NOT_NE(dstId, desc_dst))
             ^
569.         return NULL;
570. 
