From e2ff87732d0b11de548a6930e6aa507df847ac87 Mon Sep 17 00:00:00 2001 From: Philipp Zabel Date: Thu, 24 Jan 2019 16:12:13 +0100 Subject: [PATCH] v4l2videodec: support orphaning Recent kernels allow REQBUFS(0) on a queue that still has buffers in use (mmapped or exported via dmabuf), orphaning all buffers on the queue. If this is supported, the v4l2videodec element does not have to send a drain request downstream. --- sys/v4l2/gstv4l2videodec.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/sys/v4l2/gstv4l2videodec.c b/sys/v4l2/gstv4l2videodec.c index 5699519fd2..e461a4612d 100644 --- a/sys/v4l2/gstv4l2videodec.c +++ b/sys/v4l2/gstv4l2videodec.c @@ -233,19 +233,20 @@ gst_v4l2_video_dec_set_format (GstVideoDecoder * decoder, gst_v4l2_video_dec_finish (decoder); gst_v4l2_object_stop (self->v4l2output); - /* The renegotiation flow don't blend with the base class flow. To - * properly stop the capture pool we need to reclaim our buffers, which - * will happend through the allocation query. The allocation query is - * triggered by gst_video_decoder_negotiate() which requires the output - * caps to be set, but we can't know this information as we rely on the - * decoder, which requires the capture queue to be stopped. + /* The renegotiation flow don't blend with the base class flow. To properly + * stop the capture pool, if the buffers can't be orphaned, we need to + * reclaim our buffers, which will happend through the allocation query. + * The allocation query is triggered by gst_video_decoder_negotiate() which + * requires the output caps to be set, but we can't know this information + * as we rely on the decoder, which requires the capture queue to be + * stopped. * * To workaround this issue, we simply run an allocation query with the * old negotiated caps in order to drain/reclaim our buffers. That breaks * the complexity and should not have much impact in performance since the * following allocation query will happen on a drained pipeline and won't * block. */ - { + if (!gst_v4l2_buffer_pool_orphan (&self->v4l2capture->pool)) { GstCaps *caps = gst_pad_get_current_caps (decoder->srcpad); if (caps) { GstQuery *query = gst_query_new_allocation (caps, FALSE);