[Ffmpeg-devel] Could not find video grab device

[Michel Bardiaux]

Martin van Es wrote:
> Hi,

Please dont top-post, even when replying to yourself...

> 
> I might have done wrong starting my last post of with a big 'Hurray',
> cause I don't seem to get any response to this problem anymore...
> oops.

No, I think the problem is that ffserver is in the mix, and there are 
not as many people knowledgeable about ffserver as about the rest. I 
suggest you try grabbing from the camera to a file, using ffmpeg only. 
Then we'll know whether your basic grab setup is working.

> 
> I am able to get some grablike activity from my camera with ffmpeg,
> but (as you can read below) I'm still not able to grab (from the same
> camera) for an asf stream?
> 
> Is there anybody that could give me a hint why ffpmpeg quits by
> telling me it can't find the video grab device in this setup?
> 
> Grtz.
> Martin

HaND,

> 
> On 8/26/05, Martin van Es <mrvanes at gmail.com> wrote:
> 
>>Hurray, I got ffmpeg to grab some stuff, so it's probably my
>>ffserver.conf and/or commandline that gets in the way:
>>
>>The commandline I use is:
>>ffmpeg -vd /dev/video0 -ad /dev/dsp1 http://host:8090/webcam.ffm
>>
>>On 'host' I have ffserver running with this configuration:
>>
>>Port 8090
>>BindAddress 0.0.0.0
>>MaxClients 10
>>MaxBandwidth 1000
>>CustomLog -
>>
>># Suppress that if you want to launch ffserver as a daemon
>>NoDaemon
>>
>><Feed webcam.ffm>
>>File /tmp/webcam.ffm
>>FileMaxSize 512K
>>
>># Only allow connections from localhost to the feed
>>#ACL allow 127.0.0.1
>></Feed>
>>
>># ASF compatible
>>
>><Stream webcam.asf>
>>Feed webcam.ffm
>>Format asf
>>VideoFrameRate 10
>>VideoSize cif
>>VideoBitRate 128
>>VideoGopSize 30
>>VideoCodec msmpeg4v2
>>#VideoBufferSize 40
>>AudioCodec mp3
>>AudioBitRate 32
>>AudioChannels 1
>>#NoAudio
>>VideoHighQuality
>>StartSendOnKey
>></Stream>
>>
>>
>>This is the output I get (all local testing on 1 machine).
>>first ffserver:
>>minivanes:/usr/src/media/streaming/ffmpeg# ./ffserver
>>ffserver started.
>>127.0.0.1 - - [Fri Aug 26 19:50:37 2005] "GET /webcam.ffm HTTP/1.0" 200 4165
>>127.0.0.1 - - [Fri Aug 26 19:50:37 2005] "GET /webcam.ffm HTTP/1.0" 200 4165
>>127.0.0.1 - - [Fri Aug 26 19:50:38 2005] "POST /webcam.ffm HTTP/1.0" 200 0
>>
>>Then in another console ffmpeg:
>>minivanes:/usr/src/media/streaming/ffmpeg# ./ffmpeg -vd /dev/video0
>>-ad /dev/dsp1 http://localhost:8090/webcam.ffm
>>ffmpeg version CVS, build 3211266, Copyright (c) 2000-2004 Fabrice Bellard
>>  configuration:  --prefix=/usr --enable-mp3lame
>>  built on Aug 26 2005 19:49:58, gcc: 4.0.1 (Debian 4.0.1-2)
>>Could not find video grab device
>>
>>What am I overlooking or what option changed from 4.8.0 so that this
>>results in a 'Could not find video grab device' for what that's worth?
>>
>>Martin
>>
> 
> 
> 


-- 
Michel Bardiaux
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