[Kdenlive-devel] Direct filming to computer using video4linux

[Dan Dennedy]

On Mon, Dec 8, 2008 at 11:05 AM, Jean-Michel Pouré <jm at poure.com> wrote:
> On Mon, 2008-12-08 at 09:18 -0800, Dan Dennedy wrote:
>> Do you have any more information about this - what is "USB streaming?"
>> Have you used it before with another V4L app?
>
> I already used USB streaming with a webcam.

I am sorry, but that is meaningless. There is no specification called
"USB Streaming." That is a marketing term for something potentially
non-standard. You can not assume that since one thing called "USB
Streaming" worked therefore anything called "USB Streaming" should
work. OTOH, there is a specification called "USB Video Class" and
there is a V4L2 kernel module for this called uvcvideo. However, there
are different payload types defined by that standard and not all V4L2
apps are prepared to handle all the various payload types and pixel
formats. FFmpeg ought to to be able to support all of them; however, I
am not certain it is prepared to. A brief scan of its code leads me to
believe it only supports uncompressed. More interestingly, the
uvcvideo module does not yet support MPEG2-TS, which I expect to be
second most common after uncompressed, but that is just a guess. More
info here:

http://linux-uvc.berlios.de/

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+-DRD-+