Getting dshow device stream with libVLC

[FL53]

Hi,

I am trying to get a video stream from a device (a webcam with specific format). I can get the stream using VLC but not through libVLC.
Command line in VLC is :

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vlc dshow:// :dshow-vdev="MyDevice" :dshow-adev=none :dshow-size=200x400 :dshow-chroma=YUYV

Same options in libVLC fail to get the stream.
Any idea ? Did someone encounter the same issue ?

Best regards

[mfkl]

Hey,

Can you share your code that interacts with libvlc as well as logs please?

Maybe this helps https://forum.videolan.org/viewtopic.ph ... 84#p333431

[FL53]

Hi,

I didn't see your post before ... Thank you for the link, I will try that this afternoon and give you feedback. This sounds good ! I've already used the add_option method but not with the params given in the thread.
Regards

[FL53]

I tried and I can get the dshow device without any problem now!
I tried to add option to the media using quotes since my device name has space in its name but it is not working if so (libvlc_media_add_option(m_media, ":dshow-vdev=\"my device has spaces in its name\""); will fail)

Working code is below (be careful to use libvlc_media_new_location instead of libvlc_media_new_path):

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m_media = libvlc_media_new_location(m_vlc, "dshow://"); libvlc_media_add_option(m_media, ":dshow-vdev=my device has spaces in its name"); libvlc_media_add_option(m_media, ":dshow-adev=none");

Is it possible to limit the latency to display the image using a parameter/option ? I can get the image but with an annoying delay for my purpose ?

[mfkl]

try

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--dshow-tuner-frequency=<integer>

Otherwise check https://wiki.videolan.org/VLC_command-line_help/

[FL53]

I may not understand but tuner-frequency seems to be for tuner device, I was thinking more of an option to limit buffering. I tried with videoInput lib (which is not as complete as libVLC but I would like to compare) and I can get the images really quickly. My device is an IR webcam and I would like to get the data asap to display the image (and maybe, in the future, process it).

Moreover, ther is another issue I though I could fix alone: it seems conversion is not done properly : dshow device is registrated as providing YUY2 format but resulting image is green ( black are too much black, white too much white and it should be grey), any idea to fix that ? I am still searching for a way to correct this and found an image which illustrates my issue (even if my webcam is used under Windows 10, not Android).

[mfkl]

I don't know