[Ffmpeg-devel] [PATCH] Set input channel on vide4linux withchannel parameter

Silvano Galliani kysucix kysucix
Sat Oct 7 12:38:21 CEST 2006

Luca Abeni wrote:
> Hi Silvano,
> On Fri, 2006-10-06 at 17:13 +0200, Silvano Galliani (kysucix) wrote:
>> Here is a simple patch to video4linux (grab.c) letting input to select 
>> video source (composite or s-video, ...) with channel option.
>> ffmpeg help has been updated too. It was just for DV1394.
> I think the video source selection code should not be in libavformat,
> but in a separate program (like v4lctl), that you run before ffmpeg to
> setup the video device.

Imho it makes no sense at all using an external program to control your 
video4linux behaviour. User would be obliged to install xawtv just to 
select the s-video input of its v4l card. One external package Vs ~15 
lines of code.
And also, if that's the policy of video4linux in ffmpeg, all the code 
concerning channel and normalization in grab.c shouldn't be there.
If libavformat allow the user to read from a v4l device why deny the 
capability to switch tuner, input, normalization and so on. ?

More information about the ffmpeg-devel mailing list