YUV420p->RGBA conversion is broken

[okkobroderson]

Detail

well, i connected my android13 phone via droidcam to my linux laptop.
as it works with stopmotion application, i expected the same with pix_video.
unfortunately there seems to be some issues, because the output of pix_video is garbage. the device is available, the connection is made...

hope i was clear:)
greetings

Gem Version

v09.4

Pd Version

plugdata 0.7.1

Operating System

Linux

OS Version

xubuntu 22.4.3

Which CPU are you using?

amd64/x86_64 ("64bit Intel")

[umlaeute]

hmm.
no, you were not very clear.

• try again with Pd-vanilla
• check other video devices (a "real" webcam)
• show us your "garbage" (there are many different levels of "garbage", i have no idea whether you get static, a half-broken feed or scrambled colors)
• give us the configuration of the videodevice (v4l2-ctl --all -d /dev/videoX)

[umlaeute]

also, the exact version of droidcam might be useful

[okkobroderson]

ok, thanks for answering!
here we go...

a screenrecording of the "garbage":)
https://github.com/umlaeute/Gem/assets/79641361/c39ca6c2-967d-4cf8-8664-eebd16697dc8
edit: seems the videupload failed?

the same result in pd-vanilla

droidcam client 2.1.2

other webcams (internal, usb) are working.

~$ v4l2-ctl --all -d /dev/video3
Driver Info:
	Driver name      : v4l2 loopback
	Card type        : Dummy video device (0x0000)
	Bus info         : platform:v4l2loopback-000
	Driver version   : 6.5.8
	Capabilities     : 0x85200003
		Video Capture
		Video Output
		Read/Write
		Streaming
		Extended Pix Format
		Device Capabilities
	Device Caps      : 0x05200003
		Video Capture
		Video Output
		Read/Write
		Streaming
		Extended Pix Format
Priority: 2
Video input : 0 (loopback: ok)
Video output: 0 (loopback in)
Format Video Capture:
	Width/Height      : 640/480
	Pixel Format      : 'YU12' (Planar YUV 4:2:0)
	Field             : None
	Bytes per Line    : 640
	Size Image        : 460800
	Colorspace        : sRGB
	Transfer Function : Default (maps to sRGB)
	YCbCr/HSV Encoding: Default (maps to ITU-R 601)
	Quantization      : Default (maps to Limited Range)
	Flags             : 
Format Video Output:
	Width/Height      : 640/480
	Pixel Format      : 'YU12' (Planar YUV 4:2:0)
	Field             : None
	Bytes per Line    : 640
	Size Image        : 460800
	Colorspace        : sRGB
	Transfer Function : Default (maps to sRGB)
	YCbCr/HSV Encoding: Default (maps to ITU-R 601)
	Quantization      : Default (maps to Limited Range)
	Flags             : 
Streaming Parameters Video Capture:
	Frames per second: 30.000 (30/1)
	Read buffers     : 2
Streaming Parameters Video Output:
	Frames per second: 30.000 (30/1)
	Write buffers    : 2

User Controls

                    keep_format 0x0098f900 (bool)   : default=0 value=1
              sustain_framerate 0x0098f901 (bool)   : default=0 value=0
                        timeout 0x0098f902 (int)    : min=0 max=100000 step=1 default=0 value=0
               timeout_image_io 0x0098f903 (bool)   : default=0 value=0

[umlaeute]

I cannot reproduce the problem with Gem-0.94 (e.g. as packaged in Debian, and thus (x)Xubuntu).

however, i can reproduce the problem with current git (c6eff7f).
there's a reason why i ask for the (exact) Gem version :-)

[umlaeute]

i've recently updated the color-conversions, and obviously broke the I420->RGBA conversion.

until this is fixed, you should be able to get a working video feed by sending a [colorspace yuv( message to [pix_video] before opening the device.

[okkobroderson]

the [colorspace yuv] message does the job!

i swear, i would have given you the exact gem version, if i knew where to read it!:)

thank you very much for your help!
greetings

[umlaeute]

i swear, i would have given you the exact gem version, if i knew where to read it!:)

well, the bug-reporting template spells it:

What is the exact version of Gem you are using (as printed in the Pd-console)?

the Pd-console should say something like this (when loading Gem):

GEM: Graphics Environment for Multimedia
GEM: ver: 0.94.git v0.94-845-g4f88c7ac9

[okkobroderson]

the console here says:
GEM: Graphics Environment for Multimedia
GEM: ver: 0.94.
GEM: compiled on Feb 5 2024

in both plugdata and pd-vanilla

[umlaeute]

Interesting.
How did you get/compile Gem?

[okkobroderson]

i guess not in the most recommended way...
some mixture of from within pd/plugdata and from the repository.

i encountered lots of crashes/freezes in the beginning, so i tried this and that