[FFmpeg-cvslog] avfilter: signal an empty buffersrc with an explicit activate error code

[Marton Balint]

ffmpeg | branch: master | Marton Balint <cus at passwd.hu> | Sun Jun 22 15:50:21 2025 +0200| [d41bac1333b0a9ab621922a3e306ca455ff3b9a3] | committer: Marton Balint

avfilter: signal an empty buffersrc with an explicit activate error code

No change in functionality.

Signed-off-by: Marton Balint <cus at passwd.hu>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d41bac1333b0a9ab621922a3e306ca455ff3b9a3
---

 libavfilter/avfiltergraph.c | 2 ++
 libavfilter/buffersink.c    | 5 ++++-
 libavfilter/buffersrc.c     | 4 ++--
 libavfilter/filters.h       | 1 +
 4 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/libavfilter/avfiltergraph.c b/libavfilter/avfiltergraph.c
index 2d6036df74..38b89db22a 100644
--- a/libavfilter/avfiltergraph.c
+++ b/libavfilter/avfiltergraph.c
@@ -1460,6 +1460,8 @@ int avfilter_graph_request_oldest(AVFilterGraph *graph)
     frame_count = oldesti->l.frame_count_out;
     while (frame_count == oldesti->l.frame_count_out) {
         r = ff_filter_graph_run_once(graph);
+        if (r == FFERROR_BUFFERSRC_EMPTY)
+            r = 0;
         if (r == AVERROR(EAGAIN) &&
             !oldesti->frame_wanted_out && !oldesti->frame_blocked_in &&
             !oldesti->status_in)
diff --git a/libavfilter/buffersink.c b/libavfilter/buffersink.c
index 5cd47ba69f..fb33ad59c5 100644
--- a/libavfilter/buffersink.c
+++ b/libavfilter/buffersink.c
@@ -131,8 +131,11 @@ static int get_frame_internal(AVFilterContext *ctx, AVFrame *frame, int flags, i
             return AVERROR(EAGAIN);
         } else if (li->frame_wanted_out) {
             ret = ff_filter_graph_run_once(ctx->graph);
-            if (ret < 0)
+            if (ret == FFERROR_BUFFERSRC_EMPTY) {
+                // Do nothing for now...
+            } else if (ret < 0) {
                 return ret;
+            }
         } else {
             ff_inlink_request_frame(inlink);
         }
diff --git a/libavfilter/buffersrc.c b/libavfilter/buffersrc.c
index af27306b3b..7e86d6ffd3 100644
--- a/libavfilter/buffersrc.c
+++ b/libavfilter/buffersrc.c
@@ -195,7 +195,7 @@ static int push_frame(AVFilterGraph *graph)
         ret = ff_filter_graph_run_once(graph);
         if (ret == AVERROR(EAGAIN))
             break;
-        if (ret < 0)
+        if (ret < 0 && ret != FFERROR_BUFFERSRC_EMPTY)
             return ret;
     }
     return 0;
@@ -552,7 +552,7 @@ static int activate(AVFilterContext *ctx)
         return 0;
     }
     c->nb_failed_requests++;
-    return FFERROR_NOT_READY;
+    return FFERROR_BUFFERSRC_EMPTY;
 }
 
 static const AVFilterPad avfilter_vsrc_buffer_outputs[] = {
diff --git a/libavfilter/filters.h b/libavfilter/filters.h
index e3013eda65..11152cfabf 100644
--- a/libavfilter/filters.h
+++ b/libavfilter/filters.h
@@ -31,6 +31,7 @@
  * Special return code when activate() did not do anything.
  */
 #define FFERROR_NOT_READY FFERRTAG('N','R','D','Y')
+#define FFERROR_BUFFERSRC_EMPTY FFERRTAG('M','P','T','Y')
 
 /**
  * A filter pad used for either input or output.