From 95bb0bb6711986fc2f999738fcb1158085346872 Mon Sep 17 00:00:00 2001
From: wm4 <wm4@nowhere>
Date: Thu, 18 Sep 2014 19:26:13 +0200
Subject: [PATCH] vf_lavfi: fetch output frames incrementally

Uses the new mechanism introduced in the previous commit.

Depending on the actual filter, this distributes CPU load more evenly
over time, although it probably doesn't matter.
---
 video/filter/vf_lavfi.c | 46 +++++++++++++++++++++--------------------
 1 file changed, 24 insertions(+), 22 deletions(-)

diff --git a/video/filter/vf_lavfi.c b/video/filter/vf_lavfi.c
index 8f1ee243a2..0a14f94bbb 100644
--- a/video/filter/vf_lavfi.c
+++ b/video/filter/vf_lavfi.c
@@ -315,33 +315,34 @@ static int filter_ext(struct vf_instance *vf, struct mp_image *mpi)
         return -1;
 
     AVFrame *frame = mp_to_av(vf, mpi);
-    if (av_buffersrc_add_frame(p->in, frame) < 0) {
-        av_frame_free(&frame);
-        return -1;
-    }
+    int r = av_buffersrc_add_frame(p->in, frame) < 0 ? -1 : 0;
     av_frame_free(&frame);
 
-    for (;;) {
-        frame = av_frame_alloc();
-        int err = av_buffersink_get_frame(p->out, frame);
-        if (err == AVERROR(EAGAIN) || err == AVERROR_EOF) {
-            // Not an error situation - no more output buffers in queue.
-            // AVERROR_EOF means we shouldn't even give the filter more
-            // input, but we don't handle that completely correctly.
-            av_frame_free(&frame);
-            p->eof |= err == AVERROR_EOF;
-            break;
-        }
-        if (err < 0) {
-            av_frame_free(&frame);
-            MP_ERR(vf, "libavfilter error: %d\n", err);
-            return -1;
-        }
+    return r;
+}
 
-        get_metadata_from_av_frame(vf, frame);
-        vf_add_output_frame(vf, av_to_mp(vf, frame));
+static int filter_out(struct vf_instance *vf)
+{
+    struct vf_priv_s *p = vf->priv;
+
+    AVFrame *frame = av_frame_alloc();
+    int err = av_buffersink_get_frame(p->out, frame);
+    if (err == AVERROR(EAGAIN) || err == AVERROR_EOF) {
+        // Not an error situation - no more output buffers in queue.
+        // AVERROR_EOF means we shouldn't even give the filter more
+        // input, but we don't handle that completely correctly.
+        av_frame_free(&frame);
+        p->eof |= err == AVERROR_EOF;
+        return 0;
+    }
+    if (err < 0) {
+        av_frame_free(&frame);
+        MP_ERR(vf, "libavfilter error: %d\n", err);
+        return -1;
     }
 
+    get_metadata_from_av_frame(vf, frame);
+    vf_add_output_frame(vf, av_to_mp(vf, frame));
     return 0;
 }
 
@@ -374,6 +375,7 @@ static int vf_open(vf_instance_t *vf)
     vf->reconfig = NULL;
     vf->config = config;
     vf->filter_ext = filter_ext;
+    vf->filter_out = filter_out;
     vf->filter = NULL;
     vf->query_format = query_format;
     vf->control = control;