avfilter/buffersink: keep requesting frames if one activation of the graph does not provide one

A frame graph activation might not produce a frame in the requested sink, so
keep on requesting a frame there unless we encounter a filter activation with
buffersrc empty error.

This makes av_buffersink_get_frame(_flags) work according to its documentation
which claims that EAGAIN is only returned if additional frames must be inserted
into the graph.

Fate changes are because audio frames will have different sizes at segment
boundaries, but content is the same.

Signed-off-by: Marton Balint <[email protected]>

5 files changed, 18 insertions, 7 deletions

diff --git a/libavfilter/buffersink.c b/libavfilter/buffersink.c
index fb33ad59c5..50a7da2756 100644
--- a/libavfilter/buffersink.c
+++ b/libavfilter/buffersink.c
@@ -113,6 +113,7 @@ static int get_frame_internal(AVFilterContext *ctx, AVFrame *frame, int flags, i
     int status, ret;
     AVFrame *cur_frame;
     int64_t pts;
+    int buffersrc_empty = 0;
 
     if (buf->peeked_frame)
         return return_or_keep_frame(buf, frame, buf->peeked_frame, flags);
@@ -132,7 +133,11 @@ static int get_frame_internal(AVFilterContext *ctx, AVFrame *frame, int flags, i
         } else if (li->frame_wanted_out) {
             ret = ff_filter_graph_run_once(ctx->graph);
             if (ret == FFERROR_BUFFERSRC_EMPTY) {
-                // Do nothing for now...
+                buffersrc_empty = 1;
+            } else if (ret == AVERROR(EAGAIN)) {
+                if (buffersrc_empty)
+                    return ret;
+                ff_inlink_request_frame(inlink);
             } else if (ret < 0) {
                 return ret;
             }
diff --git a/tests/ref/fate/filter-asegment-samples-absolute b/tests/ref/fate/filter-asegment-samples-absolute
index 4090459aa7..ba9e9e269a 100644
--- a/tests/ref/fate/filter-asegment-samples-absolute
+++ b/tests/ref/fate/filter-asegment-samples-absolute
@@ -16,9 +16,11 @@
 0,          0,          0,     4096,    16384, 0x02ebe66b
 0,       4096,       4096,     4096,    16384, 0x35bfe081
 0,       8192,       8192,     1808,     7232, 0xa585202c
-1,      10000,      10000,     6384,    25536, 0x17309ccf
+1,      10000,      10000,     2288,     9152, 0x319ac07d
+1,      12288,      12288,     4096,    16384, 0xd389dc43
 1,      16384,      16384,     3616,    14464, 0x67e82600
-2,      20000,      20000,     4576,    18304, 0x4bc89a8b
+2,      20000,      20000,      480,     1920, 0x24bfb749
+2,      20480,      20480,     4096,    16384, 0x378ee333
 2,      24576,      24576,     4096,    16384, 0xabf6df0f
 2,      28672,      28672,     4096,    16384, 0xedefe76f
 2,      32768,      32768,     4096,    16384, 0x02ebe66b
diff --git a/tests/ref/fate/filter-asegment-samples-relative b/tests/ref/fate/filter-asegment-samples-relative
index 4090459aa7..ba9e9e269a 100644
--- a/tests/ref/fate/filter-asegment-samples-relative
+++ b/tests/ref/fate/filter-asegment-samples-relative
@@ -16,9 +16,11 @@
 0,          0,          0,     4096,    16384, 0x02ebe66b
 0,       4096,       4096,     4096,    16384, 0x35bfe081
 0,       8192,       8192,     1808,     7232, 0xa585202c
-1,      10000,      10000,     6384,    25536, 0x17309ccf
+1,      10000,      10000,     2288,     9152, 0x319ac07d
+1,      12288,      12288,     4096,    16384, 0xd389dc43
 1,      16384,      16384,     3616,    14464, 0x67e82600
-2,      20000,      20000,     4576,    18304, 0x4bc89a8b
+2,      20000,      20000,      480,     1920, 0x24bfb749
+2,      20480,      20480,     4096,    16384, 0x378ee333
 2,      24576,      24576,     4096,    16384, 0xabf6df0f
 2,      28672,      28672,     4096,    16384, 0xedefe76f
 2,      32768,      32768,     4096,    16384, 0x02ebe66b
diff --git a/tests/ref/fate/filter-asegment-timestamps-absolute b/tests/ref/fate/filter-asegment-timestamps-absolute
index b3f72c958a..5807194fc8 100644
--- a/tests/ref/fate/filter-asegment-timestamps-absolute
+++ b/tests/ref/fate/filter-asegment-timestamps-absolute
@@ -24,7 +24,8 @@
 0,      32768,      32768,     4096,    16384, 0x02ebe66b
 0,      36864,      36864,     4096,    16384, 0x35bfe081
 0,      40960,      40960,     3140,    12560, 0x13b5698a
-1,      44100,      44100,     5052,    20208, 0xadc32273
+1,      44100,      44100,      956,     3824, 0xee464a2f
+1,      45056,      45056,     4096,    16384, 0xe92bd835
 1,      49152,      49152,     4096,    16384, 0x1126dca3
 1,      53248,      53248,     4096,    16384, 0x9647edcf
 1,      57344,      57344,     4096,    16384, 0x5cc345aa
diff --git a/tests/ref/fate/filter-asegment-timestamps-relative b/tests/ref/fate/filter-asegment-timestamps-relative
index b3f72c958a..5807194fc8 100644
--- a/tests/ref/fate/filter-asegment-timestamps-relative
+++ b/tests/ref/fate/filter-asegment-timestamps-relative
@@ -24,7 +24,8 @@
 0,      32768,      32768,     4096,    16384, 0x02ebe66b
 0,      36864,      36864,     4096,    16384, 0x35bfe081
 0,      40960,      40960,     3140,    12560, 0x13b5698a
-1,      44100,      44100,     5052,    20208, 0xadc32273
+1,      44100,      44100,      956,     3824, 0xee464a2f
+1,      45056,      45056,     4096,    16384, 0xe92bd835
 1,      49152,      49152,     4096,    16384, 0x1126dca3
 1,      53248,      53248,     4096,    16384, 0x9647edcf
 1,      57344,      57344,     4096,    16384, 0x5cc345aa