Re: [Mlt-devel] Git: Fix video4linux in avformat producer.

[Dan D. <da...@de...>]

On Mon, Feb 21, 2011 at 3:12 PM, Hungerburg <pc...@my...> wrote:
> Am 2011-02-20 06:39, schrieb Dan Dennedy:
>> New commits:
>> commit a71c827644ff0acc38da80e080b0ed596acb3308
>> Author: Dan Dennedy<da...@de...>
>> Date:   Sat Feb 19 21:39:54 2011 -0800
>>
>>      Fix video4linux in avformat producer.
>>
>>      melt video4linux2:/dev/video0
>>
>
> Works for me.
>
> Currently I only have a very cheap device that is limited in its
> abilities. Two points to correct for that:
>
> 1) The MLT_PROFILE has to specify a setting that the device/driver can
> successfully use. Otherwise melt reports: Failed to load "video4linux2".

The requirement for an explicit profile is by design at the moment as
there is no support for probing the v4l2 device capabilities. Also,
one can use -profile on the melt command line instead of environment
var.

> 2) LD_PRELOAD=/usr/lib/libv4l/v4l2convert.so and
> LD_PRELOAD=/usr/lib/libv4l/v4l1compat.so are my friends.
>
> Below command line gets me some kind of delayed mirror:
>
> $ LD_PRELOAD=/usr/lib/libv4l/v4l2convert.so MLT_PROFILE=quarter_15 melt
> video4linux2:/dev/video0 -filter frei0r.flippo:"X axis=1" "Y axis=0"

You need to drop that colon after flippo because it prevents "X axis"
from applying. Only filters that accept "constructor args" take the
colon, but frei0r does not process constructor args.

I find "X axis"=1 is very handy when looking at one self in the webcam.

-- 
+-DRD-+