avfilter/formats: Make ff_formats_pixdesc_filter return AVFilterFormats*

Up until now, it has returned the AVFilterFormats list via
an AVFilterFormats** parameter; the actual return value was an int
that was always AVERROR(ENOMEM) on error. The AVFilterFormats**
argument was a pure output parameter which was only documented
by naming the parameter rfmts. Yet nevertheless all callers
initialized the underlying AVFilterFormats* to NULL.

This commit changes this to return a pointer to AVFilterFormats
directly. This is more in line with the API in general, as it
allows to avoid checks for intermediate values.

Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

1 files changed, 4 insertions, 9 deletions

diff --git a/libavfilter/vf_swaprect.c b/libavfilter/vf_swaprect.c
index fff9b53dc4..e03603fe5a 100644
--- a/libavfilter/vf_swaprect.c
+++ b/libavfilter/vf_swaprect.c
@@ -57,16 +57,11 @@ AVFILTER_DEFINE_CLASS(swaprect);
 
 static int query_formats(AVFilterContext *ctx)
 {
-    AVFilterFormats *pix_fmts = NULL;
-    int ret;
+    int reject_flags = AV_PIX_FMT_FLAG_PAL     |
+                       AV_PIX_FMT_FLAG_HWACCEL |
+                       AV_PIX_FMT_FLAG_BITSTREAM;
 
-    ret = ff_formats_pixdesc_filter(&pix_fmts, 0, AV_PIX_FMT_FLAG_PAL     |
-                                                  AV_PIX_FMT_FLAG_HWACCEL |
-                                                  AV_PIX_FMT_FLAG_BITSTREAM);
-    if (ret < 0)
-        return ret;
-
-    return ff_set_common_formats(ctx, pix_fmts);
+    return ff_set_common_formats(ctx, ff_formats_pixdesc_filter(0, reject_flags));
 }
 
 static const char *const var_names[] = {   "w",   "h",   "a",   "n",   "t",   "pos",   "sar",   "dar",        NULL };