swscale/utils: Detect and skip unneeded sws_setColorspaceDetails() calls

This avoids running various table inits unnecessarily
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit cc538e9d)

Conflicts:

	libswscale/utils.c

libswscale/utils.c

@@ -818,8 +818,6 @@ int sws_setColorspaceDetails(struct SwsContext *c, const int inv_table[4],
     const AVPixFmtDescriptor *desc_dst;
     const AVPixFmtDescriptor *desc_src;
     int need_reinit = 0;
-    memmove(c->srcColorspaceTable, inv_table, sizeof(int) * 4);
-    memmove(c->dstColorspaceTable, table, sizeof(int) * 4);
 
     handle_formats(c);
     desc_dst = av_pix_fmt_desc_get(c->dstFormat);
@@ -830,11 +828,24 @@ int sws_setColorspaceDetails(struct SwsContext *c, const int inv_table[4],
     if(!isYUV(c->srcFormat) && !isGray(c->srcFormat))
         srcRange = 0;
 
+    if (c->srcRange != srcRange ||
+        c->dstRange != dstRange ||
+        c->brightness != brightness ||
+        c->contrast   != contrast ||
+        c->saturation != saturation ||
+        memcmp(c->srcColorspaceTable, inv_table, sizeof(int) * 4) ||
+        memcmp(c->dstColorspaceTable,     table, sizeof(int) * 4)
+    )
+        need_reinit = 1;
+
+    memmove(c->srcColorspaceTable, inv_table, sizeof(int) * 4);
+    memmove(c->dstColorspaceTable, table, sizeof(int) * 4);
+
+
+
     c->brightness = brightness;
     c->contrast   = contrast;
     c->saturation = saturation;
-    if (c->srcRange != srcRange || c->dstRange != dstRange)
-        need_reinit = 1;
     c->srcRange   = srcRange;
     c->dstRange   = dstRange;
 
@@ -849,6 +860,9 @@ int sws_setColorspaceDetails(struct SwsContext *c, const int inv_table[4],
     c->dstFormatBpp = av_get_bits_per_pixel(desc_dst);
     c->srcFormatBpp = av_get_bits_per_pixel(desc_src);
 
+    if (!need_reinit)
+        return 0;
+
     if (!isYUV(c->dstFormat) && !isGray(c->dstFormat)) {
         ff_yuv2rgb_c_init_tables(c, inv_table, srcRange, brightness,
                                  contrast, saturation);