topic Re: /dev/fb0 relation to IPU in i.MX Processors

/dev/fb0 relation to IPU

robertspriggs — Wed, 19 Apr 2017 20:34:42 GMT

Hi,

I'm using a custom i.MX6dl board with Linux. I have found using GStreamer sometimes that if I pause playback, then capture /dev/fb0, the image I get is a frame before what I see paused on the screen coming out of the IPU. Can anyone give me an idea what might be happening?

-Rob.

Re: /dev/fb0 relation to IPU

igorpadykov — Thu, 20 Apr 2017 05:19:20 GMT

Hi Rob

what bsp/gstreamer used in the case, please try with nxp bsps described on

http://www.nxp.com/products/software-and-tools/software-development-tools/i.mx-software-and-tools/i.mx-6series-i.mx-7series-software-and-development-tool-resources:IMX_SW

http://git.freescale.com/git/cgit.cgi/imx/linux-imx.git/tree/?id=rel_imx_4.1.15_2.0.0_ga&h=imx_4.1.15_2.0.0_ga

and gstreamer usage in sect. 7 Multimedia attached Linux Guide

Best regards
igor
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Re: /dev/fb0 relation to IPU

robertspriggs — Thu, 20 Apr 2017 13:11:21 GMT

A new BSP is not an option. I built the i.MX GStreamer plugins from source code I found here: GitHub - Freescale/gstreamer-imx: GStreamer 1.0 plugins for i.MX platforms

After further investigation, I've found that pausing video often causes a jump of several frames ahead (sometimes 5 or 6) for what is on screen, but /dev/fb0 seems to contain the correct frame where the video SHOULD be paused. I think unless someone has an answer, my best recourse is to analyze the i.MX plugin source code. For our application we need a pause to be a true playback freeze.

Re: /dev/fb0 relation to IPU

igorpadykov — Thu, 20 Apr 2017 13:45:38 GMT

gstreamer-imx plugins are not nxp software, it is supported through community,

please check maintainer of gstreamer-imx plugins mentioned on
https://community.nxp.com/thread/445732

difference between community gstreamer-imx plugins and nxp gstreamer plugins

described on

trac.gateworks.com/wiki/Yocto/gstreamer

Best regards
igor