Internal Data Stream Error Occurs When Adding Two Caps Filters with Different Resolutions in Webcam GStreamer Pipeline Using Tee

[Nicolas Dufresne]

Hi,

Le jeu. 13 juill. 2023, 22 h 12, Sulthan Amanu <sulthan4380 at gmail.com> a
écrit :

> Fwd...
>
> On Fri, Jul 14, 2023, 01:33 Sulthan Amanu <sulthan4380 at gmail.com> wrote:
>
>> Hi Nicolas,
>>
>> Thank you for your response,
>>
>> I have one query about Gstermer pipeline , Can we able to change webcam
>> video resolution without terminate current pipeline?
>>
>

This is supported by v4l2src, it possible libcamerasrx needs some
adjustments. Here's an example application:

https://gitlab.freedesktop.org/gstreamer/gstreamer/-/blob/main/subprojects/gst-plugins-good/tests/examples/v4l2/v4l2src-renegotiate.c


For HDMI/SDI like receivers, v4l2src internally have code to detect and
adjust accordingly. Though not for UVC as this is missing in the UVC spec.


Nicolas


>> Can you please share pipeline or code snippet for above requirement.
>>
>> Regards,
>> Sulthan
>>
>> On Fri, Jul 14, 2023, 00:40 Nicolas Dufresne <nicolas at ndufresne.ca>
>> wrote:
>>
>>> Le jeudi 13 juillet 2023 à 19:46 +0200, Florian Echtler via
>>> gstreamer-devel a
>>> écrit :
>>> > Hello Sulthan,
>>> >
>>> > I'm pretty certain this won't be possible without videoscale & friends.
>>> >
>>> > Reason: almost all V4L2 cameras are configured to stream a single
>>> resolution at
>>> > the hardware level, and even if the camera would be capable of
>>> delivering two
>>> > streams at different resolutions, I'm nearly 100% sure the
>>> V4L2-Gstreamer path
>>> > won't be able to deliver that. Your only option, as far as I can tell,
>>> is to get
>>> > the larger resolution from the device directly and scale it down.
>>>
>>> With exception of uvch264src, but finding compatible cameras is pretty
>>> hard
>>> these days.
>>>
>>> >
>>> > (*) Should you happen to use a Raspberry Pi camera, which can do
>>> separate
>>> > preview and main streams, then you might have a shot by using the
>>> libcamera
>>> > stack. But for generic V4L2 devices, I don't think you can avoid the
>>> software
>>> > scaler.
>>>
>>> Yes, PI can deliver multiple streams, use libcamerasrc for that.
>>>
>>> regards,
>>> Nicolas
>>>
>>> >
>>> > Best, Florian
>>> >
>>> > On 13.07.23 19:37, Sulthan Amanu via gstreamer-devel wrote:
>>> > > Hi Team,
>>> > >
>>> > > I have encountered an issue while
>>> > > creating a GStreamer pipeline with a webcam source and two caps
>>> filters using
>>> > > the tee element. The pipeline is designed to apply different
>>> resolutions to the
>>> > > video stream. Below is an example of the pipeline:
>>> > >
>>> > > gst-launch-1.0 -e v4l2src device=/dev/video0 ! \
>>> > >      tee name=t ! \
>>> > >          queue ! \
>>> > >          videoconvert ! \
>>> > >          capsfilter caps="video/x-raw, width=640, height=480" ! \
>>> > >          autovideosink t. ! \
>>> > >          queue ! \
>>> > >          videoconvert ! \
>>> > >          capsfilter caps="video/x-raw, width=1280, height=720" ! \
>>> > >          autovideosink
>>> > >
>>> > >
>>> > > However, when executing the pipeline, I encountered the following
>>> error message:
>>> > >
>>> > > Setting pipeline to PAUSED ...
>>> > > Pipeline is live and does not need PREROLL ...
>>> > > Setting pipeline to PLAYING ...
>>> > > New clock: GstSystemClock
>>> > > ERROR: from element /GstPipeline:pipeline0/GstV4l2Src:v4l2src0:
>>> Internal data
>>> > > stream error.
>>> > > Additional debug info:
>>> > > gstbasesrc.c(3055): gst_base_src_loop ():
>>> > > /GstPipeline:pipeline0/GstV4l2Src:v4l2src0:
>>> > > streaming stopped, reason not-negotiated (-4)
>>> > > EOS on shutdown enabled -- waiting for EOS after Error
>>> > > Waiting for EOS...
>>> > >
>>> > >
>>> > > I kindly request your assistance in resolving this issue and
>>> achieving the
>>> > > desired behavior without utilizing the *videoscale ,
>>> videoconvertscale, other
>>> > > frame resize element. And I need to orignal data of both resolution.*
>>> > > *
>>> > > *
>>> > > Issue link -
>>> > >
>>> https://gitlab.freedesktop.org/gstreamer/gstreamer/-/issues/2808#note_1999618
>>> > > <
>>> https://gitlab.freedesktop.org/gstreamer/gstreamer/-/issues/2808#note_1999618
>>> >
>>> > > *
>>> > > *
>>> > > Regards,
>>> > > Sulthan
>>> >
>>> > --
>>> > SENT FROM MY DEC VT50 TERMINAL
>>> >
>>>
>>>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/gstreamer-devel/attachments/20230714/9db4f716/attachment.htm>