[FFmpeg-devel] [PATCH v4 5/5] lavfi/format: add a hwmap auto conversion filter

[Tong Wu]

When two formats lists cannot be merged, a scale filter is
auto-inserted. However, when it comes to hardware map, we have to
manually add a hwmap filter to do the conversion. This patch introduces
an auto hwmap filter to do the hwmap conversion automatically.

Signed-off-by: Tong Wu <tong1.wu at intel.com>
---
 libavfilter/avfiltergraph.c | 3 ++-
 libavfilter/formats.c       | 4 ++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/libavfilter/avfiltergraph.c b/libavfilter/avfiltergraph.c
index 102c1f7693..8e63007cac 100644
--- a/libavfilter/avfiltergraph.c
+++ b/libavfilter/avfiltergraph.c
@@ -402,7 +402,8 @@ static int insert_auto_filter(AVFilterContext **convert, AVFilterGraph *graph,
     AVFilterContext *ctx;
     AVFilterLink *inlink, *outlink;
     char inst_name[30];
-    const char *opts = FF_FIELD_AT(char *, neg->conversion_filters[conv_step].conversion_opts_offset, *graph);
+    const char *opts = neg->conversion_filters[conv_step].conversion_opts_offset == 0 ? NULL :
+                       FF_FIELD_AT(char *, neg->conversion_filters[conv_step].conversion_opts_offset, *graph);
     const char *name = neg->conversion_filters[conv_step].conversion_filter;
 
     if (!(filter = avfilter_get_by_name(name))) {
diff --git a/libavfilter/formats.c b/libavfilter/formats.c
index c8e20e5b20..fee10fa0ee 100644
--- a/libavfilter/formats.c
+++ b/libavfilter/formats.c
@@ -331,6 +331,10 @@ static const AVFilterFormatsFilter filters_video[] = {
         .conversion_filter = "scale",
         .conversion_opts_offset = offsetof(AVFilterGraph, scale_sws_opts),
     },
+    {
+        .conversion_filter = "hwmap",
+        .conversion_opts_offset = 0,
+    }
 };
 
 static const AVFilterFormatsFilter filters_audio[] = {
-- 
2.35.1.windows.2