topic Re: H265 Decoding consumed more cpu load on iMX8M Plus in i.MX Processors

H265 Decoding consumed more cpu load on iMX8M Plus

Hariharan1 — Thu, 09 Oct 2025 04:22:45 GMT

Hi all,

I was trying to get clk_summary of vpu. i was getting vpu_g1 set has Y but vpu_g2 set has N. What could be the reason. Is that the reason i am getting more cpu load like 85% when i was decoding H265 whereas H264 decoding was taking just 7% CPU Load.

H265 decoding command: ./g2dec -tbs encoded.hevc -Oout.yuv

H264 decoding command: ./hx170dec-arm -Otest_hxdec.yuv DOP_Animation_W_.H264

cat /sys/kernel/debug/clk/clk_summary | grep vpu

vpu_g1 0 0 0 800000000 0 0 50000 Y deviceless no_connection_id
vpu_g1_root_clk 0 0 0 800000000 0 0 50000 N 38300000.vpu_g1 clk_hantro
vpu_pll_ref_sel 0 0 0 24000000 0 0 50000 Y deviceless no_connection_id
vpu_pll 0 0 0 700000000 0 0 50000 Y deviceless no_connection_id
vpu_pll_bypass 0 0 0 700000000 0 0 50000 Y deviceless no_connection_id
vpu_pll_out 0 0 0 700000000 0 0 50000 N deviceless no_connection_id
vpu_g2 0 0 0 700000000 0 0 50000 N deviceless no_connection_id
vpu_g2_root_clk 0 0 0 700000000 0 0 50000 N 38310000.vpu_g2 clk_hantro

Thanks,

Re: H265 Decoding consumed more cpu load on iMX8M Plus

Zhiming_Liu — Thu, 09 Oct 2025 05:32:27 GMT

Hi,

There is no cpu load issue on i.MX8MP EVK using gstreamer.

root@imx8mpevk:~# gst-launch-1.0 filesrc location=test_MediaCoder_HEVC_demo_video.mp4 typefind=true ! video/quicktime ! aiurdemux ! h265parse ! queue max-size-time=0 ! v4l2h265dec ! autovideosink Setting pipeline to PAUSED ... ====== V4L2DEC: 1.26.0 build on May 7 2025 08:46:20. ====== Pipeline is PREROLLING ... ====== AIUR: 4.10.0 build on May 10 2025 01:33:22. ====== Core: MPEG4PARSER_06.22.14 build on Apr 28 2025 08:50:53 file: /usr/lib/imx-mm/parser/lib_mp4_parser_arm_elinux.so.3.2 ------------------------ Track 00 [video_0] Enabled Duration: 0:00:59.958333000 Language: und Mime: video/x-h265, parsed=(boolean)true, alignment=(string)au, stream-format=(string)hev1, width=(int)1920, height=(int)800, framerate=(fraction)24/1, codec_data=(buffer)01016000000080000000000078f000fcfdf8f800000f03a00001001840010c01ffff0160000003008000000300000300789dc090a100010021420101016000000300800000030000030078a003c080321659de491b6bc0400800a2000100064401c173d189 ------------------------ ------------------------ Track 01 [audio_0] Enabled Duration: 0:01:01.347120000 Language: und Mime: audio/mpeg, mpegversion=(int)4, channels=(int)1, rate=(int)22050, bitrate=(int)28992, stream-format=(string)raw, codec_data=(buffer)138856e5a54880 ------------------------ Redistribute latency... Redistribute latency... Pipeline is PREROLLED ... Setting pipeline to PLAYING ... Redistribute latency... New clock: GstSystemClock ^Chandling interrupt. (37.5 %) Interrupt: Stopping pipeline ... Execution ended after 0:00:23.068026502 Setting pipeline to NULL ... Total showed frames (556), playing for (0:00:23.067971879), fps (24.103). Freeing pipeline ... root@imx8mpevk:~# cat /sys/kernel/debug/clk/clk_summary | grep vpu vpu_vc8000e 0 0 0 500000000 0 0 50000 Y deviceless no_connection_id vpu_vc8ke_root_clk 0 0 0 500000000 0 0 50000 N 38320000.vpu_vc8000e clk_hantro_vc8000e vpu_bus 0 0 0 800000000 0 0 50000 Y deviceless no_connection_id vpu_root_clk 0 0 0 800000000 0 0 50000 N 38320000.vpu_vc8000e clk_hantro_vc8000e_bus 38310000.vpu_g2 clk_hantro_bus 38300000.vpu_g1 clk_hantro_bus vpu_g1 0 0 0 800000000 0 0 50000 Y deviceless no_connection_id vpu_g1_root_clk 0 0 0 800000000 0 0 50000 N 38300000.vpu_g1 clk_hantro vpu_pll_ref_sel 0 0 0 24000000 0 0 50000 Y deviceless no_connection_id vpu_pll 0 0 0 700000000 0 0 50000 Y deviceless no_connection_id vpu_pll_bypass 0 0 0 700000000 0 0 50000 Y deviceless no_connection_id vpu_pll_out 0 0 0 700000000 0 0 50000 N deviceless no_connection_id vpu_g2 0 0 0 700000000 0 0 50000 N deviceless no_connection_id vpu_g2_root_clk 0 0 0 700000000 0 0 50000 N 38310000.vpu_g2 clk_hantro

The issue should from your g2dec application.

Best Regards,
Zhiming

Re: H265 Decoding consumed more cpu load on iMX8M Plus

Hariharan1 — Tue, 14 Oct 2025 10:22:00 GMT

Hi,

How did you run top command while executing gst-launch command.

Thanks,
Hariharan

Re: H265 Decoding consumed more cpu load on iMX8M Plus

Zhiming_Liu — Wed, 15 Oct 2025 00:42:32 GMT

Hi,

I didn't use any other command before using gst-launch.

Best Regards,
Zhiming