From e885e0e1d78b199280c8252cbf726b8a81393aba Mon Sep 17 00:00:00 2001
From: Philipp Zabel
Date: Wed, 24 Feb 2021 13:25:43 +0100
Subject: [PATCH] v4l2videodec: fix src side frame rate negotiation
Negotiating v4l2h264dec ! v4l2h264enc transcoding pipelines fails in
case the encoder does not accept framerate=(fraction)0/1.
The acquired caps used for downstream negotiation are determined from
gst_v4l2_object_acquire_format(), which sets the GstVideoInfo::fps_n
and ::fps_d fields to 0.
To fix this, copy the frame rate from the sink side.
Part-of:
---
sys/v4l2/gstv4l2videodec.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/sys/v4l2/gstv4l2videodec.c b/sys/v4l2/gstv4l2videodec.c
index 89ad3e8..c61fb25 100644
--- a/sys/v4l2/gstv4l2videodec.c
+++ b/sys/v4l2/gstv4l2videodec.c
@@ -697,6 +697,10 @@ gst_v4l2_video_dec_handle_frame (GstVideoDecoder * decoder,
if (!gst_v4l2_object_acquire_format (self->v4l2capture, &info))
goto not_negotiated;
+ /* gst_v4l2_object_acquire_format() does not set fps, copy from sink */
+ info.fps_n = self->v4l2output->info.fps_n;
+ info.fps_d = self->v4l2output->info.fps_d;
+
/* Create caps from the acquired format, remove the format field */
acquired_caps = gst_video_info_to_caps (&info);
GST_DEBUG_OBJECT (self, "Acquired caps: %" GST_PTR_FORMAT, acquired_caps);
--
2.7.4