Change avfilter_add_colorspace() to make it accept **avff rather than

*avff, so that an AVFilterFormats struct is created and returned by
the function if *avff is NULL.

Make the function use more convenient.

Originally committed as revision 21035 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavfilter/avfilter.h

@@ -25,7 +25,7 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  1
-#define LIBAVFILTER_VERSION_MINOR 13
+#define LIBAVFILTER_VERSION_MINOR 14
 #define LIBAVFILTER_VERSION_MICRO  0
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
@@ -192,12 +192,14 @@ struct AVFilterFormats
 AVFilterFormats *avfilter_make_format_list(const enum PixelFormat *pix_fmts);
 
 /**
- * Adds pix_fmt to the list of pixel formats contained in avff.
+ * Adds pix_fmt to the list of pixel formats contained in *avff.
+ * If *avff is NULL the function allocates the filter formats struct
+ * and puts its pointer in *avff.
  *
  * @return a non negative value in case of success, or a negative
  * value corresponding to an AVERROR code in case of error
  */
-int avfilter_add_colorspace(AVFilterFormats *avff, enum PixelFormat pix_fmt);
+int avfilter_add_colorspace(AVFilterFormats **avff, enum PixelFormat pix_fmt);
 
 /**
  * Returns a list of all colorspaces supported by FFmpeg.

libavfilter/formats.c

@@ -86,28 +86,31 @@ AVFilterFormats *avfilter_make_format_list(const enum PixelFormat *pix_fmts)
     return formats;
 }
 
-int avfilter_add_colorspace(AVFilterFormats *avff, enum PixelFormat pix_fmt)
+int avfilter_add_colorspace(AVFilterFormats **avff, enum PixelFormat pix_fmt)
 {
-    enum PixelFormat *pix_fmts =
-        av_realloc(avff->formats, sizeof(avff->formats) * (avff->format_count+1));
+    enum PixelFormat *pix_fmts;
 
+    if (!(*avff) && !(*avff = av_mallocz(sizeof(AVFilterFormats))))
+        return AVERROR(ENOMEM);
+
+    pix_fmts = av_realloc((*avff)->formats,
+                          sizeof((*avff)->formats) * ((*avff)->format_count+1));
     if (!pix_fmts)
         return AVERROR(ENOMEM);
 
-    avff->formats = pix_fmts;
-    avff->formats[avff->format_count++] = pix_fmt;
+    (*avff)->formats = pix_fmts;
+    (*avff)->formats[(*avff)->format_count++] = pix_fmt;
     return 0;
 }
 
 AVFilterFormats *avfilter_all_colorspaces(void)
 {
-    AVFilterFormats *ret;
+    AVFilterFormats *ret = NULL;
     enum PixelFormat pix_fmt;
 
-    ret = av_mallocz(sizeof(AVFilterFormats));
     for (pix_fmt = 0; pix_fmt < PIX_FMT_NB; pix_fmt++)
         if (!(av_pix_fmt_descriptors[pix_fmt].flags & PIX_FMT_HWACCEL))
-            avfilter_add_colorspace(ret, pix_fmt);
+            avfilter_add_colorspace(&ret, pix_fmt);
 
     return ret;
 }