[FFmpeg-devel] [PATCH 12/12] avfilter/ffmpeg_filter: rate control all filter graphs

[Marton Balint]

It was never reliable to detect if a filtergraph have sources, because a filter
can act as a source only after some time, for example the loop filter.

So it is better to remove the source detection entirely and always give the
scheduler an oppurtunity to stop processing.

Fixes ticket #11604.

Signed-off-by: Marton Balint <cus at passwd.hu>
---
 fftools/ffmpeg_filter.c | 25 ++++---------------------
 1 file changed, 4 insertions(+), 21 deletions(-)

diff --git a/fftools/ffmpeg_filter.c b/fftools/ffmpeg_filter.c
index f6e496158c..2822335e15 100644
--- a/fftools/ffmpeg_filter.c
+++ b/fftools/ffmpeg_filter.c
@@ -53,8 +53,6 @@ typedef struct FilterGraphPriv {
     // true when the filtergraph contains only meta filters
     // that do not modify the frame data
     int              is_meta;
-    // source filters are present in the graph
-    int              have_sources;
     int              disable_conversions;
 
     unsigned         nb_outputs_done;
@@ -1112,16 +1110,6 @@ int fg_create(FilterGraph **pfg, char *graph_desc, Scheduler *sch)
     if (ret < 0)
         goto fail;
 
-    for (unsigned i = 0; i < graph->nb_filters; i++) {
-        const AVFilter *f = graph->filters[i]->filter;
-        if ((!avfilter_filter_pad_count(f, 0) &&
-             !(f->flags & AVFILTER_FLAG_DYNAMIC_INPUTS)) ||
-            !strcmp(f->name, "apad")) {
-            fgp->have_sources = 1;
-            break;
-        }
-    }
-
     for (AVFilterInOut *cur = inputs; cur; cur = cur->next) {
         InputFilter *const ifilter = ifilter_alloc(fg);
 
@@ -1648,10 +1636,8 @@ static int configure_output_audio_filter(FilterGraphPriv *fgp, AVFilterGraph *gr
         pad_idx = 0;
     }
 
-    if (ofilter->apad) {
+    if (ofilter->apad)
         AUTO_INSERT_FILTER("-apad", "apad", ofilter->apad);
-        fgp->have_sources = 1;
-    }
 
     snprintf(name, sizeof(name), "trim for output %s", ofilter->output_name);
     ret = insert_trim(fgp, ofp->trim_start_us, ofp->trim_duration_us,
@@ -2647,7 +2633,6 @@ static int read_frames(FilterGraph *fg, FilterGraphThread *fgt,
                        AVFrame *frame)
 {
     FilterGraphPriv *fgp = fgp_from_fg(fg);
-    int did_step = 0;
 
     // graph not configured, just select the input to request
     if (!fgt->graph) {
@@ -2666,7 +2651,7 @@ static int read_frames(FilterGraph *fg, FilterGraphThread *fgt,
         return AVERROR_BUG;
     }
 
-    while (fgp->nb_outputs_done < fg->nb_outputs) {
+    if (fgp->nb_outputs_done < fg->nb_outputs) {
         int ret;
 
         /* Reap all buffers present in the buffer sinks */
@@ -2681,9 +2666,6 @@ static int read_frames(FilterGraph *fg, FilterGraphThread *fgt,
             }
         }
 
-        // return after one iteration, so that scheduler can rate-control us
-        if (did_step && fgp->have_sources)
-            return 0;
 
         ret = avfilter_graph_request_oldest(fgt->graph);
         if (ret == AVERROR(EAGAIN)) {
@@ -2700,7 +2682,8 @@ static int read_frames(FilterGraph *fg, FilterGraphThread *fgt,
         }
         fgt->next_in = fg->nb_inputs;
 
-        did_step = 1;
+        // return so that scheduler can rate-control us
+        return 0;
     }
 
     return AVERROR_EOF;
-- 
2.43.0