Poor framerates on iMX6 Solo when decoding H264

cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

Poor framerates on iMX6 Solo when decoding H264

5,236 Views
ralph__
Contributor IV

I'm using gstreamer to playback some H264 videos - one is 720p60 and one is 1080p30. The framerates are much worse than expected (the iMX can do 1080p30 and 720p60 allegedly....) and I am certain the hardware is doing the decoding as it only has 1-2% CPU utilisation.

Here are the commands I run to test the video. Either:

gst-launch-0.10 filesrc location=/usr/sample.mp4 ! qtdemux ! vpudec ! mfw_isink

or:

gplay /usr/sample.mp4

Both lines give me the same end result which is this:

1080p30 clip runs at 23fps (reported)

720p60 clip runs at 27fps (reported)

Why are the clips running so slowly? If I play back either clip in VLC on Windows the framerates are as expected; i.e. 30fps for the 1080p30 and 60fps for the 1080p60.


Thanks for your help,

Ralph

Tags (2)
0 Kudos
25 Replies

294 Views
ralph__
Contributor IV

Thanks for the link. That looks like it may in fact fix things however after applying the patch in the link, I flashed U-Boot and have currently bricked my board. I'm attempting to unbrick it over USB however it doesn't show up on my PC over USB.... :-(

0 Kudos

294 Views
xizhouwang
Contributor II

Sorry to hear that and hope you will get it going again soon.

0 Kudos

294 Views
ralph__
Contributor IV

Hi, I've unbricked my device now and flashed a U-Boot that has all functions that return the CPU revision return 0x61011. The patch in the link did not apply very well at all so I manually edited arch/arm/cpu/armv7/mx6/soc.c so that the revision was returned as a fixed number.

When I rebooted the unit, I found that the hardware revision was only set correctly in /proc/cpuinfo when I booted *my* kernel image. When I tried booting the Freescale DEMO kernel image it came up with a "hardware revision" of 0000.

Why would this be? Both kernel images are booting from the same bootloader.

Thanks,
Ralph

0 Kudos

294 Views
xizhouwang
Contributor II

Returns from one of my Solo kit. Hope other expert may have advice on the issues.

root@:~# cat /proc/cpuinfo

Processor       : ARMv7 Processor rev 10 (v7l)

processor       : 0

BogoMIPS        : 1581.05

Features        : swp half thumb fastmult vfp edsp neon vfpv3

CPU implementer : 0x41

CPU architecture: 7

CPU variant     : 0x2

CPU part        : 0xc09

CPU revision    : 10

Hardware        : 

Revision        : 63000

Serial          : 0000000000000000

0 Kudos

294 Views
ralph__
Contributor IV

Your Bogomips score is double what mine is. Maybe the CPU clock could be affecting the VPU clock. Any idea how I can increase the CPU clock?

0 Kudos