Change video stream resolution in YoloV4 demo

Question

Here's what shows when loading the live stream demo for Yolov4:

Webcam index: 2 [ WARN:0] global ../modules/videoio/src/cap_gstreamer.cpp (935) open OpenCV | GStreamer warning: Cannot query video position: status=0, value=-1, duration=-1 Video stream: 2304 x 1536 Objects:

Then it starts finding objects with 2 fps.

How do I change the video stream resolution to 1080p or 720p? The frame rate is very slow and this appears to be the fix.

Can't find it within the makefile or cfg folder. Any thoughts? Is this an opencv problem?

Thanks!

cfg settings:

[net]
batch=64
subdivisions=8
# Training
#width=512
#height=512
width=320
height=320
channels=3
momentum=0.949
decay=0.0005
angle=0
saturation = 1.5
exposure = 1.5
hue=.1

learning_rate=0.0013
burn_in=1000
max_batches = 500500
policy=steps
steps=400000,450000
scales=.1,.1

I tried with the built-in camera and connected my phone(IP) and got 1080 on both with smooth results. I didn't find anywhere to change the webcam settings which are stuck on 2304x1536. Where would camera settings be located?

If your camera is supporting different resolution, you can change by camera hardware. Otherwise you can resize the input — Yunus Temurlenk, Jun 06 '20 at 17:51
can you show the config file of yolo v4 network? Probably it is doing inference with 416x416 or 512x512 or sth. — Micka, Jun 06 '20 at 20:43
Thanks, Guys! Edits above for camera hardware and config file — Jaguar84, Jun 06 '20 at 23:35

score 0 · Accepted Answer · edited Oct 14 '20 at 08:27

After searching around for a solution to this issue myself I finally found it!

In the darknet/src/ folder is a file named "image_opencv.cpp". At lines 597 and 598 you will find the following 2 commented commands:

//cap->set(CV_CAP_PROP_FRAME_WIDTH, 1280); 

& 

//cap->set(CV_CAP_PROP_FRAME_HEIGHT, 960);

After trying out these commands a lot more errors showed up, this is due to yolov4 (and my install) using OpenCV 4.1.1. Which has a different syntax. Your resolution should change to 1920x1080 if you replace the two aforementioned commands with these:

cap->set(cv::CAP_PROP_FRAME_WIDTH, 1920);

cap->set(cv::CAP_PROP_FRAME_HEIGHT, 1080);

Notice that the comment slashes have been removed as to activate the commands.

Change video stream resolution in YoloV4 demo

1 Answers1