> I´ve looked at the V4L2 API description about this capturing; looks good, > but I´m missing one detail: what happens when program can´t dequeue fast > enough (or deliberately throttles the framerate). More specifically: when > the queue is full, do you drop the last frame captured, or the oldest? bttv never ever throws away a captured frame. If there is no free buffer to put data in, bttv stops capture (i.e. it keeps the old data). > I ask > because originally in my webcam driver I simply dropped the last frame; > however, this quickly leads to stale data in the buffer (I used a few > internal buffers to queue data); Well, bttv has no internal buffers but uses only the ones queued by the application... > be nice to write a few words about it. Or turn it into an option. Sometimes, > all an application is interested in is the latest frame, and don´t care > about queueing, or dropping a few frames (maybe using only one buffer > will do the trick?). That's the way to go IMHO. If the app don't need queued frames, it simply should'nt use multiple buffers. Gerd -- Gerd Knorr <kraxel@xxxxxxxxxxx> -- SuSE Labs, Außenstelle Berlin
