The quality of preset slow is worse than that of preset ultrafast on H.265

Robotics & Edge Computing Jetson & Embedded Systems Jetson Orin NX
1

For H.265, the preset slow appears to have more blocking artifacts (mosaic) than the preset ultrafast, which makes the quality of preset_slow look worse.
We test it with the sample code:
/usr/src/jetson_multimedia_api/samples/01_video_encode#./video_encode car.yuv 1920 1080 H265 car_hpt1_presetUltrafast.265 -hpt 1 -ifi 50 --econstqp -qpi 45 45 45 -fps 25 1
/usr/src/jetson_multimedia_api/samples/01_video_encode#./video_encode car.yuv 1920 1080 H265 car_hpt4_prestSlow.265 -hpt 4 -ifi 50 --econstqp -qpi 45 45 45 -fps 25 1
According to the bitstream analyzer, the deblock filter is disabled for both preset slow and preset medium, which may be the reason for the increased blocking artifacts. Currently, the code does not allow enabling deblock. Is there any way to enable it?

preset
preset1824×1122 234 KB

car_hpt1_presetUltrafast.zip (111.2 KB)
car_hpt4_prestSlow.zip (100.4 KB)

4

Hi,

What is your BP version? Is it jp6.2, r36.4.3?

Thanks

5

Hi,
It is jp6.2, r36.4.3,
This issue is not unique to the current JP/BSP version; it previously occurred in JetPack 5.2 and other BSP versions as well.
Thanks

6

Hi,
We will check it. Would be great if you can help compare PSNR for reference. Please refer to the commands in
H264 vs H265 - #4 by DaneLLL

8

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.