On Wednesday, February 5, 2014 6:02:02 PM UTC+1, Jon Smirl wrote: > On Wed, Feb 5, 2014 at 9:01 AM, Enrico <-> wrote: > > > Il giorno martedì 4 febbraio 2014 16:29:24 UTC+1, Jon Smirl ha scritto: > > >> > > >> Does anyone have a setup which works for viewing a live image from the > > >> csi camera on the display? Something like cheese? > > >> > > >> I tried doing this on the A20 with non-accelerated video drivers and > > >> the system is not fast enough to keep up with the output from the CSI > > >> camera. Cheese just gives me a black rectangle and lots of errors out > > >> of the camera drivers. > > >> > > >> I want to work on the CSI driver but I need to be able to see what I > > >> am doing. When the display system isn't fast enough everything gets > > >> complicated because of dropped frames. > > >> > > >> It also doesn't work to save the video stream to SD Card or the > > >> network, neither is fast enough. > > >> > > > > > > Did you try saving it to a tmpfs (usually /tmp or /dev/shm) ? That's the > > > fastest place you can save to. > > > > Uncompressed video is gigabytes in size
I might be blunt. You want unencoded video output. Cedar and or Cedarus can only help with scaling. When compressed video is played it get's uncompressed resulting in the same amount of gigabytes. So those shouldn't be the problem. I guess the problem is in the path between input and output. If the video player taps directly into the CSI stream there shouldn't be a problem. I guess the issue that the stream gets copied to userspace and than send back to kernalspace. Which gets limited by CPU and RAM speed, these perform the copy actions and need to track delays, dropping frames, etc. Generic copy free would require something like DMA access. But such a generic userspace connected framework is quite new, DMA-BUF. For now I guess you are limited to directly encode the output stream before playback. Usually the encoders are dirctly, copy free, connected to the inputstream. Which limits memory en cpu strain by only needing handle the compressed stream So you need a player that can directly tap into the video stream and deliver it copyfree to the output device. Or a DMA-BUF capable CSI+Display driver and player to match. Good luck > > > > > > > > > > Enrico > > > > > > -- > > > You received this message because you are subscribed to the Google Groups > > > "linux-sunxi" group. > > > To unsubscribe from this group and stop receiving emails from it, send an > > > email to [email protected]. > > > For more options, visit https://groups.google.com/groups/opt_out. > > > > > > > > -- > > Jon Smirl > -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
