Hi Devarsh,
On 23/01/24 20:38, Devarsh Thakkar wrote:
Hi Rahul,
Thanks for the quick response.
On 23/01/24 20:33, Rahul T R wrote:
Hi Devarsh,
Thanks for the review !
On 23/01/24 20:05, Devarsh Thakkar wrote:
Hi Rahul,
Thanks for the patch.
On 22/01/24 21:59, Rahul T R wrote:
This is required to avoid the frame drops and increase the tolrence
for CSI capture using gsteamer
Signed-off-by: Rahul T R <[email protected]>
---
...1-gstv4l2object-Increase-min-buffers.patch | 29 +++++++++++++++++++
.../gstreamer1.0-plugins-good_1.20.%.bbappend | 3 +-
2 files changed, 31 insertions(+), 1 deletion(-)
create mode 100644
meta-arago-extras/recipes-multimedia/gstreamer/gstreamer1.0-plugins-good/0001-gstv4l2object-Increase-min-buffers.patch
diff --git
a/meta-arago-extras/recipes-multimedia/gstreamer/gstreamer1.0-plugins-good/0001-gstv4l2object-Increase-min-buffers.patch
b/meta-arago-extras/recipes-multimedia/gstreamer/gstreamer1.0-plugins-good/0001-gstv4l2object-Increase-min-buffers.patch
new file mode 100644
index 00000000..f9ff4faa
--- /dev/null
+++
b/meta-arago-extras/recipes-multimedia/gstreamer/gstreamer1.0-plugins-good/0001-gstv4l2object-Increase-min-buffers.patch
@@ -0,0 +1,29 @@
+From 9c5e0ee19be372c0477a509889d76ceaf97bdc87 Mon Sep 17 00:00:00 2001
+From: Rahul T R <[email protected]>
+Date: Tue, 10 Oct 2023 14:42:13 +0530
+Subject: [PATCH] gstv4l2object: Increase min buffers for CSI capture
+
+This will improve the latency and tolerance
+of CSI pipeline
+
I can understand the tolerance but how does it increase latency.
Starvation can lead to DMA error and driver will have to trigger drain DMA,
which might lead to some latency
Ok.
+Signed-off-by: Rahul T R <[email protected]>
+---
+ sys/v4l2/gstv4l2object.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/sys/v4l2/gstv4l2object.c b/sys/v4l2/gstv4l2object.c
+index 4ce9fac..9f5a85b 100644
+--- a/sys/v4l2/gstv4l2object.c
++++ b/sys/v4l2/gstv4l2object.c
+@@ -5172,6 +5172,8 @@ gst_v4l2_object_decide_allocation (GstV4l2Object *
obj, GstQuery * query)
+ * pool, we'll need what the driver one, and one more, so we can
dequeu */
+ if (0 == strcmp(obj->vcap.driver, "wave5-dec")) {
+ own_min = obj->min_buffers + 3;
++ } else if (0 == strcmp(obj->vcap.driver, "j721e-csi2rx")) {
++ own_min = obj->min_buffers + 4;
Could you please mention in commit message why our csi driver requires extra
buffers ? Is it due to a hardware limitation ? Also mention the use-case and
pipeline for which this is helping.
Sure, will add more details
I believe gstreamer has a fail safe flow where it allocates buffer on the fly
in case there is a starvation, ain't that helping ?
Can you point me to this code, I am not sure why this is not helping
need to analyze the code
Will share it offline once I get chance, but it was mainly for export mode,
for import mode it just waits for the downstream element to give back some
buffers.
Sure
I think it is okay to have this here as short term as we have other patches,
but from upstream point of view it looks like a hack so let's document the
reason why we did it here so that it can act as reference.
Agreed, will add more details in the commit
Also I believe this increases the memory footprint in v4l2 export mode ?
For already memory constrained platforms such as am62xSIP this may have a
negative impact. I see some vendors putting in extra env variables to let user
modify the buffering part.
This does not affect the export mode, min buffers are increased only
for import mode
Does it help if we increase the allocated buffers in downstream element ?
If that helps, that would be a better solution as it would avoid impacting
memory constrained platforms using the csi driver. Else we may have to mark
this patch to specific platforms only for now where you are running this
use-case.
No, increasing number of buffers in downstream pool is not helping
I have observed this on multiple platforms, AM62A, AM68A, TDA4VM
Regards
Rahul T R
Regards
Devarsh
Regards
Rahul T R
Regards
Devarsh
+ } else {
+ own_min = obj->min_buffers + 1;
+ }
+--
+2.34.1
+
diff --git
a/meta-arago-extras/recipes-multimedia/gstreamer/gstreamer1.0-plugins-good_1.20.%.bbappend
b/meta-arago-extras/recipes-multimedia/gstreamer/gstreamer1.0-plugins-good_1.20.%.bbappend
index 7ad943f6..bb4fdc09 100644
---
a/meta-arago-extras/recipes-multimedia/gstreamer/gstreamer1.0-plugins-good_1.20.%.bbappend
+++
b/meta-arago-extras/recipes-multimedia/gstreamer/gstreamer1.0-plugins-good_1.20.%.bbappend
@@ -5,6 +5,7 @@ SRC_URI:append = " \
file://0002-Adding-support-for-bayer-formats-with-IR-component.patch \
file://0001-v4l2-Changes-for-DMA-Buf-import-j721s2.patch \
file://0002-v4l2-Give-preference-to-contiguous-format-if-support.patch \
+ file://0001-gstv4l2object-Increase-min-buffers.patch \
"
-PR:append = ".arago1"
+PR:append = ".arago2"
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