DirectShow Capture support

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rogerdpack
Posts: 1877
Joined: Fri Aug 05, 2011 9:56 pm

Re: DirectShow Capture support

Post by rogerdpack » Tue Aug 30, 2011 7:27 pm

It also would be nice to fix the cleanup code
to avoid this failed assertion with debug builds:

Executable: ffplay.exe Pid 1214 Tid c1c. Module PushDesktop.ax, 2 objects left active!

(just pointing out that I ran into it and it surprised me).
Thanks!

sirhaden
Posts: 4
Joined: Tue Sep 20, 2011 5:10 pm

Re: DirectShow Capture support

Post by sirhaden » Tue Sep 20, 2011 6:32 pm

I have an extensive background in DirectShow and I've integrated the libav libraries into various DirectShow filters over the years. I'd be willing to participate as long as there is tolerance for my limited linux and cross-compliation skillsets, which I would like to enhance.

I did a test with the latest static builds using the Hauppauge USB Live-2 capture device. This type of device utilizes both a crossbar filter (Hauppauge Cx23100 Crossbar) and a capture filter (Hauppauge Cx23100 Video Capture), where both types of filters support audio and video. Unfortunately, the test failed first an error 'Could not find audio device' and after removing audio from the command line, an error 'Could not run filter'.

Looking at the code, there is no support present for capture devices which use a crossbar filter. It also appears that the implementation is very basic, not taking into account any additional DirectShow filters that may be required to support the integration of a larger group of capture devices into the libav libraries.

Is anyone working on any enhancements in this area? Are you still looking for volunteers?

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

Re: DirectShow Capture support

Post by ramiro » Tue Sep 20, 2011 10:02 pm

volunteers are always welcome =). we will help you out with linux/cross-compilation/etc.
As a start, create a virtualbox install of ubuntu and run zeranoe's script to make a cross-toolchain. Then use the cross-toolchain to build FFmpeg. Start a thread for any issues you find.

sirhaden
Posts: 4
Joined: Tue Sep 20, 2011 5:10 pm

Re: DirectShow Capture support

Post by sirhaden » Fri Sep 23, 2011 12:01 am

Sounds like a plan. I had a bad week, with my raid 10 crashing and lossing nearly everything from about 4 months back. Still trying to recover before I rebuild, so it may take a bit for me to get started. I'll be in touch...

bongprof
Posts: 2
Joined: Wed Oct 26, 2011 11:06 pm

Re: DirectShow Capture support

Post by bongprof » Wed Oct 26, 2011 11:17 pm

Hi there,

I am trying to use FFMPEG to stream directly to RTMP from a "KWorld USB Tuner" - which shows up internally as Conexant Polaris Video Capture Device. I am using :

ffmpeg -r 25 -f dshow -s 720X576 -i video="Conexant Polaris Video Capture":audio="Conexant Polaris Video Capture" -vcodec libx264 -b 500k -vpre slow -acodec libfaac -ab 96k rtmp://<rtmpaddress>

When using Adobe FMLE it takes in both the Video and Audio on the same device - assuming it is using a Crossbar Filter.

However running this command throws an error: Unable to enumerate Audio Devices.

Any thoughts?

Thanks in advance.

sirhaden
Posts: 4
Joined: Tue Sep 20, 2011 5:10 pm

Re: DirectShow Capture support

Post by sirhaden » Thu Oct 27, 2011 1:00 am

More than likely the capture filter provides both audio and video with the help of a crossbar filter. See above...

sirhaden
Posts: 4
Joined: Tue Sep 20, 2011 5:10 pm

Re: DirectShow Capture support

Post by sirhaden » Thu Oct 27, 2011 1:02 am

sirhaden wrote:Sounds like a plan. I had a bad week, with my raid 10 crashing and lossing nearly everything from about 4 months back. Still trying to recover before I rebuild, so it may take a bit for me to get started. I'll be in touch...
Got my system rebuilt and should be ready to proceed this weekend. I'll start setting up everything needed for the virtual linux environment and give a heads up when ready.

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

Re: DirectShow Capture support

Post by ramiro » Thu Oct 27, 2011 3:13 am

good luck and don't be shy to ask for help if you get stuck =)

bongprof
Posts: 2
Joined: Wed Oct 26, 2011 11:06 pm

Re: DirectShow Capture support

Post by bongprof » Thu Oct 27, 2011 7:35 am

So, is there a way to get around Cross-bar filters - especially using 3rd party DirectShow filters in conjunction with FFMPEG?

Regards.

cbassdeyfinenow
Posts: 4
Joined: Thu Dec 08, 2011 5:57 pm

Re: DirectShow Capture support

Post by cbassdeyfinenow » Mon Jan 02, 2012 9:17 pm

I'm also using dshow.c and am running into the crossbar issue ("Could not run filter." from the dshow_read_header function). With most consumer level video capture devices they offer S-Video and composite video input. It seems by adding a pin/input/crossbar option the those already possible it would make dshow more useful and robust across more devices.

Vladimir built something very similar or a wrapper (not sure) that allows for these needed options in mencoder: http://doors.univer.omsk.su/~voroshil/ .

Flash Media Live Encoder also allows the selection of which video input to choose in their Crossbar options under the selected device.

I looked at the source of dshow.c (copyright Ramiro Polla - same Ramiro posting here?) and it appears the functions are already there to accomplish selection of pin/input, just appears that the options in the cli need to be expanded to account for the crossbar. I could be way off, I don't know C very well and am not familiar with ffmpeg source.

More than happy to test with the several different input devices I have here if that would help.

Very useful software for my needs. Thanks.

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