+int sws_isSupportedOutput(enum AVPixelFormat pix_fmt);
+
+/**
+ * @param[in] pix_fmt the pixel format
+ * @return a positive value if an endianness conversion for pix_fmt is
+ * supported, 0 otherwise.
+ */
+int sws_isSupportedEndiannessConversion(enum AVPixelFormat pix_fmt);
+
+/**
+ * Allocate an empty SwsContext. This must be filled and passed to
+ * sws_init_context(). For filling see AVOptions, options.c and
+ * sws_setColorspaceDetails().
+ */
+struct SwsContext *sws_alloc_context(void);
+
+/**
+ * Initialize the swscaler context sws_context.
+ *
+ * @return zero or positive value on success, a negative value on
+ * error
+ */
+int sws_init_context(struct SwsContext *sws_context, SwsFilter *srcFilter, SwsFilter *dstFilter);