tx2 encoding/decoding performance issue

Hello Jetson team and developers,

I asked some questions but I don’t think my intention have been well communicated.

so I reupload. I am sorry to bother you.

I am using tx2 and gstreamer to stream video

and I am investigating about encoding/decoding performance on tx2

I found the blog https://devblogs.nvidia.com/jetson-tx2-delivers-twice-intelligence-edge/

below infomation is part of table that i saw on the blog.

encoder : 4Kp60, (3x) 4Kp30, (8x) 1080p30
decoder : (2x) 4Kp60

I guess some numbers indicate resolutions and fps but I couldn’t understand (3x),(8x),(2x). what is that mean?

also I get similar things when I use pipeline like blow.

gst-launch-1.0 rtspsrc location=rtsp://169.000.00.00:8554/test ! queue ! rtpvp8depay ! omxvp8dec ! nvvidconv ! nvoverlaysink overlay-x=400 overlay-y=600 overlay-w=640 overlay-h=480 overlay=1 & gst-launch-1.0 rtspsrc location=rtsp://169.000.00.00:8554/test ! queue ! rtpvp8depay ! omxvp8dec ! nvvidconv ! nvoverlaysink overlay-w=640 overlay-h=480 overlay=2

and I got message

NvMMLiteOpen : Block : BlockType = 278
NVMEDIA: Reading vendor.tegra.display-size : status: 6
NvMMLiteBlockCreate : Block : BlockType = 278
Allocating new output: 1024x768 (x 11), ThumbnailMode = 0
OPENMAX: HandleNewStreamFormat: 3605: Send OMX_EventPortSettingsChanged: nFrameWidth = 1024, nFrameHeight = 768

in the message there is “Allocating new output: 1024x768 (x 11)” .

I know 1024x768 is resolution of my video but what is (x11)?

Thank you.

Hi,
Below is explanation:
Take (3x) 4Kp30 as an example, it means three simultaneous 4Kp30 encoding threads. And (2x) 4Kp60 means two simultaneous 4Kp60 decoding threads.

1024x768 (x 11) means eleven 1024x768 buffers are created for decoding task.

[x11] 11 buffers is allocated, can we modify the buffer depth? how to do?
Thanks

Hi,

The buffer number is required for decoding and not able to be customized.

Thanks for reply.
On my TX2 device,omxh265dec plugin default allocating 1920x1080[x10] new buffers for decoding. And using enable-low-outbuffer=1 property, allocating 1920x1080[x7] new buffers.
Cause we need to decoding 12 channels video streams. so we try our best to save memory space. we have no choice but to use enable-low-outbuffer property.