swscale: reintroduce sws_format_name() symbol

Reintroduce the internal symbol which was removed in:

commit e1197b9e
Author: Stefano Sabatini <stefano.sabatini-lala@poste.it>
Date:   Sun May 29 17:57:40 2011 +0200

    swscale: remove sws_format_name()

    Use av_get_pix_fmt_name() instead.

The symbol is used by some external libs (hi libx264!), this gives
time to them to use the recently added av_get_pix_fmt_name() rather
than an internal symbol.

libswscale/swscale.h

@@ -31,7 +31,7 @@
 
 #define LIBSWSCALE_VERSION_MAJOR 0
 #define LIBSWSCALE_VERSION_MINOR 14
-#define LIBSWSCALE_VERSION_MICRO 0
+#define LIBSWSCALE_VERSION_MICRO 1
 
 #define LIBSWSCALE_VERSION_INT  AV_VERSION_INT(LIBSWSCALE_VERSION_MAJOR, \
                                                LIBSWSCALE_VERSION_MINOR, \
@@ -53,6 +53,9 @@
 #ifndef FF_API_SWS_CPU_CAPS
 #define FF_API_SWS_CPU_CAPS    (LIBSWSCALE_VERSION_MAJOR < 2)
 #endif
+#ifndef FF_API_SWS_FORMAT_NAME
+#define FF_API_SWS_FORMAT_NAME  (LIBSWSCALE_VERSION_MAJOR < 2)
+#endif
 
 /**
  * Returns the LIBSWSCALE_VERSION_INT constant.

libswscale/swscale_internal.h

@@ -349,6 +349,14 @@ void ff_yuv2packedX_altivec(SwsContext *c, const int16_t *lumFilter,
                             const int16_t **chrVSrc, int chrFilterSize,
                             uint8_t *dest, int dstW, int dstY);
 
+#if FF_API_SWS_FORMAT_NAME
+/**
+ * @deprecated Use av_get_pix_fmt_name() instead.
+ */
+attribute_deprecated
+const char *sws_format_name(enum PixelFormat format);
+#endif
+
 //FIXME replace this with something faster
 #define is16BPS(x)      (           \
            (x)==PIX_FMT_GRAY16BE    \

libswscale/utils.c

@@ -165,6 +165,13 @@ int sws_isSupportedOutput(enum PixelFormat pix_fmt)
 
 extern const int32_t ff_yuv2rgb_coeffs[8][4];
 
+#if FF_API_SWS_FORMAT_NAME
+const char *sws_format_name(enum PixelFormat format)
+{
+    return av_get_pix_fmt_name(format);
+}
+#endif
+
 static double getSplineCoeff(double a, double b, double c, double d, double dist)
 {
     if (dist<=1.0) return ((d*dist + c)*dist + b)*dist +a;