public static extern void sws_freeFilter(libswscale.SwsFilter *filter);
public static extern libswscale.SwsContext *sws_getCachedContext(libswscale.SwsContext * context, int srcW, int srcH, libavutil.AVPixelFormat srcFormat, int dstW, int dstH, libavutil.AVPixelFormat dstFormat, int flags, libswscale.SwsFilter * srcFilter, libswscale.SwsFilter * dstFilter, double *param);
public static extern int sws_init_context(libswscale.SwsContext *sws_context, libswscale.SwsFilter *srcFilter, libswscale.SwsFilter *dstFilter);