Re: need help on using ffmpeg for video grab

[Camaleón <noelamac@gmail.com>]

On Sat, 19 May 2012 05:51:51 +1200, Chris Bannister wrote:

> On Wed, May 16, 2012 at 12:59:52AM -0400, Long Wind wrote:
>> I have bt848 card and watch TV with xawtv As another application shows:
>> 
>> Device 00: BT848A video (Lifeview FlyVideo /dev/video0)
>>     Port 00: Television
>>     Port 01: Composite1
>>     Port 02: S-Video
>>     Port 03: Composite3
>> 
>> I select "Composite1" in xawtv
>> I try ffmpeg with this command:
>> 
>> ffmpeg -s vga -f video4linux2 -i /dev/video0 t2.mpg
>> 
>> then I "ffplay t2.mpg", it shows green screen maybe I didn't specify
>> "Composite1" in ffmpeg command, but how to do that? or maybe I didn't
>> specify PAL, but how to do that?

FFmpeg is very powerful but you have to carefully read the docs and 
search for command line samples when something goes wrong, e.g.:

http://ffmpeg.org/ffmpeg.html#Examples

>From there it can be read:

"(...) Note that you must activate the right video source and channel 
before launching ffmpeg with any TV viewer such as xawtv by Gerd Knorr. 
You also have to set the audio recording levels correctly with a standard 
mixer."

Maybe is that you missed the "-channel" argument?

Anyway, you can also consider in using a different application such as 
VideoLAN which is simpler to use and can also grab the video from the TV 
card.

> Wrong list! Please direct your question to a ffmpeg users list.

I don't think so. It could be somehow [OT] but this list is okay for that 
kind of questions.
 
Greetings,

-- 
Camaleón