topic Re: vpu encoding/decoding parallely in i.MX Processors

vpu encoding/decoding parallely

gautammanam — Thu, 23 Jul 2015 09:31:36 GMT

HI,

I am trying to encode camera buffers to H264 and stream the rtp packets and at same time i am recieving the H264 rtp packets and decoding it. I am using VPU through openmax layer for encoding and decoding .

Stream is 720P and at 15 FPS it works fine, but at 25fps i see decoding becomes slow. And CPU usage becomes 80-90% . As per documents VPU is capable of decoding 60 FPS

Any suggestions where to look into the issue. Does imx6 capable of 720P video conferencing ?

Re: vpu encoding/decoding parallely

igorpadykov — Thu, 23 Jul 2015 10:43:33 GMT

Hi GAUTAM

one can look at presentation below p.6 it shows multistream performance:

2 simultaneous instances of 720p@30fps encode/decode, so seems for

encode+decode more realistic is 30fps

Q&A: MX6 VPU H.264 Dual Stream Encode Limits

For increasing vpu performance one can increase vpu frequency up to 352MHz,

Disable DFVS

echo performance > sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

some suggestions can found below

GStreamer i.MX6 Multi-Overlay

for testing it is recommended to use imx-test/ mxc_vpu_test, included in BSP:

L3.14.28_1.0.0_iMX6QDLS_BUNDLE

http://repository.timesys.com/buildsources/i/imx-test/imx-test-3.14.28-1.0.0/

Best regards

igor

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Re: vpu encoding/decoding parallely

gautammanam — Mon, 27 Jul 2015 10:20:24 GMT

Hi Igor,

When doing encoding/decoding simultaneously, i am getting around 30fps total for 720P H264 encode+decode. [15pfs for decoding and 15 fps for encoding] .

This is way less when compared to the above mentioned document. I can see i am getting enough rtp packets from network, but vpu decoder is slow in decoding .And i am using VPU through fsl_imx_omx layer. I am not sure if i am missing some thing. Can you suggest any VPU settings that i am missing.

IMX6Q sabre-Lite board

kernel 3.0.35

Re: vpu encoding/decoding parallely

igorpadykov — Mon, 27 Jul 2015 10:40:51 GMT

Hi GAUTAM

these figures are given for vpu standalone performance, that is without

additional applications (which may consume bandwidth) like rtp network,

please try with unit-test (imx-test) mxc_vpu_test

Index of /buildsources/i/imx-test/imx-test-3.14.28-1.0.0

Best regards

igor