DirectShow Capture support

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rogerdpack
Posts: 1882
Joined: Fri Aug 05, 2011 9:56 pm

Re: DirectShow Capture support

Post by rogerdpack »

Could you attach a .reg file that has the name of your device in it, so I can experiment with it?

dynamitemedia
Posts: 6
Joined: Fri Jun 29, 2012 6:57 am

Re: DirectShow Capture support

Post by dynamitemedia »

can you send me a link to a page explaining how to do that? i have never done it and would like to follow some instruction

rogerdpack
Posts: 1882
Joined: Fri Aug 05, 2011 9:56 pm

Re: DirectShow Capture support

Post by rogerdpack »

basically, run "regedit.exe" then search for

LifeCam Cinema

once you find it, right click on some "parent key" in the tree on the left, choose export, save file, attach here :)
-r

gijsendamir
Posts: 2
Joined: Thu Aug 23, 2012 10:10 am
Location: the hague

Re: DirectShow Capture support

Post by gijsendamir »

Hello guys,

I am new to the forum so let me know if this is the wrong thread,

I am using ffmpeg dshow to capture raw video from my logitech webcam for a project, so far no problem.However the webcam is a "Logitech HD Pro Webcam C920" which has an internal h264 encoder.I want to tap into the h264 stream instead of the raw stream.

If I ask the device its options using the -list_options switch it shows the supported frame rates and resolution information 5 times. (more then on my cheap c210 webcam there are only 3 repetitions) My guess is that it shows the different streams/colour profiles it can offer because the last 2 repetitions on the list show less entries and end at a lower resolution.

Is there a way I can tell the dshow utility which stream to use?

Best Regards,
Gijs Hulscher

rogerdpack
Posts: 1882
Joined: Fri Aug 05, 2011 9:56 pm

Re: DirectShow Capture support

Post by rogerdpack »

There is a patch to enable selection of features. I suppose I should work on it sometime...is this a high priority item for you?
-roger-

ramiro
Posts: 157
Joined: Tue May 10, 2011 12:56 am

Re: DirectShow Capture support

Post by ramiro »

Updated patches sent to ffmpeg-devel =)

gijsendamir, we'll let you know once the patches get in and zeranoe issues a new build, then I'd like you to post the output of list_options to see if there's anything I can do about it.

gijsendamir
Posts: 2
Joined: Thu Aug 23, 2012 10:10 am
Location: the hague

Re: DirectShow Capture support

Post by gijsendamir »

Hello Rogerdpack and ramiro,

Thanks for the quick reply, it's important we are recording on a remote computer and since there is limited disk space available and the cpu utilization is high when processing the raw stream(60%*4cores on intel i5m) capturing the already encoded stream makes much more sense.

I can post the output of the list but maybe it would be better to attach it as a txt since its quite long and the post becomes less readable?

On the listed output topic; it shows 2 resolutions above the actual camera specification(min s=2304x1296 fps=2 max s=2304x1296 fps=2; min s=2304x1536 fps=2 max s=2304x1536 fps=2) at a low frame rate. I cant select these however(using -s and -r) since they are not on the last pin.
I thought maybe since they are different the forced resolution might pick them up.

Best regards,
Gijs

rogerdpack
Posts: 1882
Joined: Fri Aug 05, 2011 9:56 pm

Re: DirectShow Capture support

Post by rogerdpack »

Ok if you want to try it out earlier, here is one with ramiro's patches:

http://rogerdpack.t28.net/incoming/ffmp ... .ramiro.7z

and here's an experimental one that might be more aggressive:
http://rogerdpack.t28.net/incoming/ffmp ... and_one.7z

Let me know how it goes...
-r

mobi1300
Posts: 14
Joined: Tue Aug 28, 2012 4:44 am

Re: DirectShow Capture support

Post by mobi1300 »

Hello Rogerdpack and ramiro,

I am in the exact situation as Gijs i.e. using C920 with Directshow capture. I tried the experimental release and could see the streams with pix_fmt, video_codec = mjpeg and video_codec = h264. However, how do I select these streams ?

Using the following command gives me an error for the 'video_codec'

ffmpeg -f dshow -video_codec h264 -s 160X90 -i video="Logitech HD ProWebCam C920" ...


On a different note, if I try the ffmpeg's soft encoder (libx264) and do a local streaming session ( 127.0.0.1:6000) on a i5/Windows 7, I get about a 3 sec lag between the source and the playback image. Even with the capture and playback happening on the same machine, the CPU utilization never exceeds more than 50%. Is this normal ?

Thanks for your support.

Meierhans
Posts: 1
Joined: Tue Aug 28, 2012 5:53 pm

Re: DirectShow Capture support

Post by Meierhans »

Hi everybody,

did anybody here manage to capture/stream from decklink cards in any kind of HD resolution?

I refer to:
[dshow @ 0000000001e8f300] Unknown compression type. Please report verbose (-v 9) debug information.

Adding -v 9 just makes it crash before returning any error message.
I need to stream this weekend and would really love to stay with FFMPEG for this.

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