Recording Video with Python

[googlemike@hotpop.com]

Is there a video module so that I can write a Linux Python script to
record video coming over USB video cams?

What about these side-thoughts:

* What about recording multiple streams over multiple USB ports? (Think
in the context of a security system.)

* What about lossy compression?

* What about recording only time slices?

* How would you provide real-time video to a security guard, but then
only write time-sliced, lossy compression to disk, saving disk space
yet providing something very suitable for a security guard to watch
live?

[Diez B. Roggisch]

Re: Recording Video with Python

googlemike@hotp op.com wrote:
[color=blue]
> Is there a video module so that I can write a Linux Python script to
> record video coming over USB video cams?[/color]

You can open the device and read the images - I've done that before. No
module needed. But I don't remember how things worked - just download the
source for a simple viewer like gcqam and look at what they are doing.
[color=blue]
>
> What about these side-thoughts:
>
> * What about recording multiple streams over multiple USB ports? (Think
> in the context of a security system.)[/color]

No deal, open several devices.[color=blue]
> * What about lossy compression?[/color]

Won't be doable in python in reasonable time - but there might be modules
available for that, or at least libs you can wrap. Make your name honor...
[color=blue]
> * What about recording only time slices?[/color]

Just wait the appropriate interval
[color=blue]
> * How would you provide real-time video to a security guard, but then
> only write time-sliced, lossy compression to disk, saving disk space
> yet providing something very suitable for a security guard to watch
> live?[/color]

Hrm - just _do_ it? But the problems are not on the python side - how is
your guard going to retrieve the images, which bandwidth can he use and so
on.

Basically it boils down to

- do the infrastructure and application functionality in python
- delegate the compression to some c-backend

Network and IO performance _shouldn't_ be too much of a concern using
python, as it uses the underlying system's calls for that. But in the end,
use a profiler :)
--
Regards,

Diez B. Roggisch

[tertius]

Re: Recording Video with Python

googlemike@hotp op.com wrote:
[color=blue]
> Is there a video module so that I can write a Linux Python script to
> record video coming over USB video cams?
>[/color]

http://videocapture.sourceforge.net/

HTH

T