As we have all source codes what do you advice ?
On Tue, Apr 9, 2013 at 10:38 AM, Hans Verkuil <hverk...@xs4all.nl> wrote: > On Tue 9 April 2013 09:58:33 Michal Lazo wrote: >> I want to make API that will provide hw video decoder on Amlogic SOC >> it is ARM cortex 9 >> >> with some proprietary video decoder >> >> amlogic provide me with working example that generate output frames in >> amlvideo driver. >> It is v4l2 driver >> and it did memcpy to mmap userspace memory >> >> buffer_y_start=ioremap(cs0.addr,cs0.width*cs0.height); >> for(i=0;i<buf->vb.height;i++) { >> memcpy(vbuf + pos_dst, buffer_y_start+pos_src, >> buf->vb.width*3); >> pos_dst+=buf->vb.width*3; >> pos_src+= cs0.width; >> } >> >> I did it with one memcpy with same cpu load >> >> https://github.com/Pivosgroup/buildroot-linux-kernel/blob/master/drivers/media/video/amlvideo/amlvideo.c#L218 >> >> top get me 50% cpu load on this driver for 25fps PAL >> >> it is really too much >> >> and funny is that vivi driver(amlvideo is completely base on vivi) get >> me same cpu load > > Well, yes, because it is the memcpy that gives you all the load. > Of course, in a well-written driver the amlvideo buffers would be available > to userspace directly using mmap() and no memcpy would be needed. > > Basically amlogic gave you a crappy driver. > > Regards, > > Hans > >> >> it looks like memcpy isn't cached or something but I don't know how to >> identify problem >> Any idea how to identify this problem. >> >> On Mon, Apr 8, 2013 at 2:46 PM, Hans Verkuil <hverk...@xs4all.nl> wrote: >> > On Mon April 8 2013 14:42:32 Michal Lazo wrote: >> >> Hi >> >> 720x576 RGB 25, 30 fps and it take >> >> >> >> 25% cpu load on raspberry pi(ARM 700Mhz linux 3.6.11) or 8% on x86(AMD >> >> 2GHz linux 3.2.0-39) >> >> >> >> it is simply too much >> > >> > No, that's what I would expect. Note that vivi was substantially improved >> > recently >> > when it comes to the image generation. That will be in the upcoming 3.9 >> > kernel. >> > >> > This should reduce CPU load by quite a bit if memory serves. >> > >> > Regards, >> > >> > Hans >> > >> >> >> >> >> >> >> >> >> >> On Mon, Apr 8, 2013 at 9:42 AM, Peter Senna Tschudin >> >> <peter.se...@gmail.com> wrote: >> >> > Dear Michal, >> >> > >> >> > The CPU intensive part of the vivi driver is the image generation. >> >> > This is not an issue for real drivers. >> >> > >> >> > Regards, >> >> > >> >> > Peter >> >> > >> >> > On Sun, Apr 7, 2013 at 9:32 PM, Michal Lazo <michal.l...@mdragon.org> >> >> > wrote: >> >> >> Hi >> >> >> V4L2 driver vivi >> >> >> generate 25% cpu load on raspberry pi(linux 3.6.11) or 8% on x86(linux >> >> >> 3.2.0-39) >> >> >> >> >> >> player >> >> >> GST_DEBUG="*:3,v4l2src:3,v4l2:3" gst-launch-0.10 v4l2src >> >> >> device="/dev/video0" norm=255 ! video/x-raw-rgb, width=720, >> >> >> height=576, framerate=30000/1001 ! fakesink sync=false >> >> >> >> >> >> Anybody can answer me why? >> >> >> And how can I do it better ? >> >> >> >> >> >> I use vivi as base example for my driver >> >> >> -- >> >> >> To unsubscribe from this list: send the line "unsubscribe linux-media" >> >> >> in >> >> >> the body of a message to majord...@vger.kernel.org >> >> >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> >> > >> >> > >> >> > >> >> > -- >> >> > Peter >> >> >> >> >> >> >> >> >> >> >> >> -- Best Regards Michal Lazo Senior developer manager mdragon.org Slovakia -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html