bttv and saa driver: buffer question

[Franz Reinhardt <fre@xxxxxxxxxx>]

Hi,

after looking through the code of bttv-0.9.10 and saa7134-0.2.7, I have 
still some questions about streaming and reading the video resource.

If I've understood it correctly, this is how it's done.

Framebuffer   --------------------->  System Memory (cacheable)
Video-Card     DMA Transfer                   many buffers
                       (steered by interrupt)

Do the driver use double buffering for the framebuffer to separate the 
frames properly ?

Is streaming done all the time, or does it stop after filling up all the 
enqueued buffers ?

TIA,

Franz