Off Topic Banter

[mctom]

Most of these devices are USB 2.0, so cannot spit out more than 60MB/s.
I assume they output MPEG2 stream, compatible with DVD video, but we will see.

Fortunately my mom has a VCR that I could use as a backup if my grandpa's player is borked beyond repair. Perhaps it has some kind of digital output, but I can't recall any digital video interface before DVI.

[rooted]

I've never seen a VCR with any digital output, I used to have a JVC with S-Video but that is still analog. Looked noticeably better than standard composite though, I suppose most of Europe had SCART which is better than that I believe.

First digital interface I can recall is FireWire.

[mctom]

Yeah, S-Video transports two video signals separately, so it should work a tad bit better than composite.
I read some online reviews of those dongles and apparently some reported their S-video inputs didn't work correctly.

If only we could plug in a PCI card to any modern machine, I'd use one of those old school TV capture things, I bet they were of superior quality compared to contemporary $5 dongles.

[mad_ady]

Well, that dongle on Amazon reports it works with obs studio, so it must present itself like a uvc camera. That means you can use ffmpeg, no need for dd.

[mad_ady]

Sorry for the delay.

So - here are some ideas for encoding:
1. Using Handbrake with software encoding. Note that I remembered why I liked Handbrake - it had a deinterlace filter that could be used, which is very important for that type of video. Sadly, using deinterlace forces you to using the software encoder (ffmpeg has it too).

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nice HandBrakeCLI -i '$infile' -o '$outfile' -t 1 --angle 1 -c 1 -f mp4  --loose-anamorphic  --modulus 2 -e x264 -b $bandwidth -2  -T  -r $rate --cfr -a 1 -E ca_aac --audio-fallback ca_aac --x264-preset=slow  --x264-profile=high --h264-level='4.1' --verbose=1 2>&1

2. Software encoding with ffmpeg:

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nice ffmpeg -i '$infile' -c:v libx264 -preset slower -crf 22 -x264-params 'nal-hrd=cbr' -b:v ${bandwidth}k -maxrate ${bandwidth}k -bufsize 2M -c:a aac '$outfile'

3. Software encoding with ffmpeg and deinterlacing:

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/usr/bin/ffmpeg -y -i '$src/$file' -map 0:0 -codec:v h264 -b:v ${bandwidth}k -pix_fmt nv21 -vf 'yadif, scale=trunc(iw/64)*64:trunc(ih/64)*64' $audioMapping '$dst/${filetimestamp}_$metadata{name}.mp4' 

4. Hardware encoding with ffmpeg on xu4 - sadly no deinterlacing - not sure if you can enable it with the hardware decoder - I guess not:

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/usr/bin/ffmpeg -y -i '$src/$file' -codec:v copy -codec:a none -bsf:v h264_mp4toannexb -f rawvideo - | /usr/bin/ffmpeg -r 25 -vf 'scale=trunc(iw/64)*64:trunc(ih/64)*64' -i -  -i '$src/$file' -map 0:v:0 -vcodec h264 -b:v ${bandwidth}k -r 25 -pix_fmt nv21 -c:a copy '$dst/${filetimestamp}_$metadata{name}.mp4'

Note that this is working with files. In your case you would use "-i /dev/video0" instead of -i "$src/$file" and -i for the audio (from the audio input of the dongle) - something like what is described here: https://stackoverflow.com/questions/117 ... ing-ffmpeg

If I were you, I'd test the XU4's hardware encoder on some test files, to see what quality mapping you need to use (controled via the bitrate -b:v parameter) and then work on the command to do it for the camera.

Also note that the encoder should be supported by gstreamer as well. I know you have some experience with it. Maybe you can do software deinterlacing and hardware encoding with gstreamer...
Here are some details: viewtopic.php?t=24366
Also, if you want to look into handbrake and it's not available for armhf (not sure what the current situation is), you can compile it by roughly following this guide: viewtopic.php?f=98&t=16863&p=196303#p196303

[mctom]

Excellent, thank you!

One question though: Can I save the /dev/video0 stream to a file and process it later? Unless it's really a massive amount of data, I'm thinking about spliiting the job between two computers - one for copying, and another for encoding.

I think I used handbrake on RasPi4s some time ago, but it was awfully slow - took me a month to encode a 1h video. My Wyse terminal did the same in some 20h or so.
If I get super picky I might run the encoding jobs on a company server - it's idle all the time anyway.

[mad_ady]

As far as I know no, you can't use /dev/video0 like a block device and dump it with dd (because it's a character device):

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 adrianp  ~  $  ls -l /dev/video*
crw-rw----+ 1 root video 81, 0 Jul 18 17:01 /dev/video0
crw-rw----+ 1 root video 81, 1 Jul 18 17:01 /dev/video1
crw-rw----+ 1 root video 81, 2 Jul 27 19:56 /dev/video2
crw-rw----+ 1 root video 81, 3 Jul 27 19:56 /dev/video3
 adrianp  ~  $  sudo dd if=/dev/video0 of=/tmp/test bs=1000 count=1000
dd: error reading '/dev/video0': Invalid argument
0+0 records in
0+0 records out
0 bytes copied, 0.0025775 s, 0.0 kB/s
 adrianp  ~  ⚑ 1  $  

But you can query its capabilities:

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 adrianp  ~  $  v4l2-ctl --all -d /dev/video0
Driver Info:
	Driver name      : uvcvideo
	Card type        : FJ Camera : FJ Camera 
	Bus info         : usb-0000:00:1a.0-1.6
	Driver version   : 5.15.39
	Capabilities     : 0x84a00001
		Video Capture
		Metadata Capture
		Streaming
		Extended Pix Format
		Device Capabilities
	Device Caps      : 0x04200001
		Video Capture
		Streaming
		Extended Pix Format
Media Driver Info:
	Driver name      : uvcvideo
	Model            : FJ Camera : FJ Camera 
	Serial           : 
	Bus info         : usb-0000:00:1a.0-1.6
	Media version    : 5.15.39
	Hardware revision: 0x00009783 (38787)
	Driver version   : 5.15.39
Interface Info:
	ID               : 0x03000002
	Type             : V4L Video
Entity Info:
	ID               : 0x00000001 (1)
	Name             : FJ Camera : FJ Camera 
	Function         : V4L2 I/O
	Flags            : default
	Pad 0x01000007   : 0: Sink
	  Link 0x02000013: from remote pad 0x100000a of entity 'Extension 4' (Video Pixel Formatter): Data, Enabled, Immutable
Priority: 2
Video input : 0 (Camera 1: ok)
Format Video Capture:
	Width/Height      : 1280/720
	Pixel Format      : 'MJPG' (Motion-JPEG)
	Field             : None
	Bytes per Line    : 0
	Size Image        : 1843200
	Colorspace        : sRGB
	Transfer Function : Rec. 709
	YCbCr/HSV Encoding: ITU-R 601
	Quantization      : Default (maps to Full Range)
	Flags             : 
Crop Capability Video Capture:
	Bounds      : Left 0, Top 0, Width 1280, Height 720
	Default     : Left 0, Top 0, Width 1280, Height 720
	Pixel Aspect: 1/1
Selection Video Capture: crop_default, Left 0, Top 0, Width 1280, Height 720, Flags: 
Selection Video Capture: crop_bounds, Left 0, Top 0, Width 1280, Height 720, Flags: 
Streaming Parameters Video Capture:
	Capabilities     : timeperframe
	Frames per second: 30.000 (30/1)
	Read buffers     : 0
                     brightness 0x00980900 (int)    : min=-64 max=64 step=1 default=0 value=0
                       contrast 0x00980901 (int)    : min=0 max=95 step=1 default=0 value=0
                     saturation 0x00980902 (int)    : min=0 max=100 step=1 default=64 value=64
                            hue 0x00980903 (int)    : min=-2000 max=2000 step=100 default=0 value=0
 white_balance_temperature_auto 0x0098090c (bool)   : default=1 value=1
                          gamma 0x00980910 (int)    : min=100 max=300 step=1 default=100 value=100
                           gain 0x00980913 (int)    : min=1 max=8 step=1 default=4 value=4
           power_line_frequency 0x00980918 (menu)   : min=0 max=2 default=0 value=1 (50 Hz)
				0: Disabled
				1: 50 Hz
				2: 60 Hz
      white_balance_temperature 0x0098091a (int)    : min=2800 max=6500 step=1 default=4600 value=4600 flags=inactive
                      sharpness 0x0098091b (int)    : min=1 max=7 step=1 default=2 value=2
         backlight_compensation 0x0098091c (int)    : min=0 max=3 step=1 default=1 value=1
                  exposure_auto 0x009a0901 (menu)   : min=0 max=3 default=3 value=3 (Aperture Priority Mode)
				1: Manual Mode
				3: Aperture Priority Mode
              exposure_absolute 0x009a0902 (int)    : min=3 max=1250 step=1 default=166 value=166 flags=inactive
         exposure_auto_priority 0x009a0903 (bool)   : default=0 value=1

You could presumably encode on xu4 to a simple/fast format (mjpeg, but there's no native container that can keep also sound), and transcode it elsewhere.
Or you can try a software encoding to mpeg2 (mpegts): http://www.waveguide.se/?article=creati ... ing-ffmpeg, maybe with deinterlacing, and later you could encode the files even further to save disk space. I too think that with a reasonably high bitrate (2-3Mbps @576p) the XU4 could encode in real-time. Not sure if deinterlacing could be done in real-time...

[mctom]

Alright, I think you guys gave me more than enough to start tinkering with.

Too bad there are no PCI - USB adapters so I could use an old video capture card. I'll gamble with one of those cheap dongles instead.

[L67GS]

Medieval fair today, I've wanted a Damascus steel dagger for 20 years and today I found one that felt just right in my hand.
Sure, it cost 4× as much as my Gerber Machete Jr. that's infinitely more practical, but that folded steel just warmed from my heart right down to my wallet.

20220814_195703.jpg (434.75 KiB) Viewed 100 times

[rooted]

Very nice, now you can open packages in style.

[mctom]

Never heard of Damascus steel before, I've never seen one in a museum. Different place and time than medieval Poland, clearly.
Have you bought it from an actual blacksmith?

The medieval lifestyle and battle reenactment groups are popular around here.

[rooted]

For $100'ish I can't imagine this is a custom piece, "Damascus" steel is labor intensive.

[L67GS]

I'm sure it's mass market, more or less decorative. Probably made in India or something.

[rooted]

I'm sure it's mass market, more or less decorative. Probably made in India or something.

I'm sure the blade is plenty strong, just made on a large scale.

[L67GS]

I'm sure it's mass market, more or less decorative. Probably made in India or something.

I'm sure the blade is plenty strong, just made on a large scale.

It's a fantastic piece, well balanced, Damascus steel by nature has good edge retention, nice to hold, and beautiful. I thought "nope" when I saw that handle but when I held it the spiral handle was actually really nice. I might have a black sheath made for it that's a little more period specific.

[phaseshifter]

phase wrote....


droid@server:~$ lsb_release
No LSB modules are available.
odroid@server:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu Kinetic Kudu (development branch)
Release: 22.10
Codename: kinetic
odroid@server:~$ uname -a
Linux server 5.18.0-odroid-arm64 #1 SMP PREEMPT Ubuntu 5.18.0-202205181718~jammy (2022-05-18) aarch64 aarch64 aarch64 GNU/Linux
odroid@server:~$


droid@server:~$ uname -a
Linux server 5.18.0-odroid-arm64 #1 SMP PREEMPT Ubuntu 5.18.0-202205181718~jammy (2022-05-18) aarch64 aarch64 aarch64 GNU/Linux
odroid@server:~$ neofetch
`:+shmNNMMNNmhs+:` odroid@server
.odMMMMMMMMMMMMMMMMMMdo. -------------
/dMMMMMMMMMMMMMMMmMMMMMMMMd/ OS: Ubuntu MATE Kinetic Kudu (develo
:mMMMMMMMMMMMMNNNNM/`/yNMMMMMMm: Host: Hardkernel ODROID-M1
`yMMMMMMMMMms:..-::oM: -omMMMMMy` Kernel: 5.18.0-odroid-arm64
`dMMMMMMMMy-.odNMMMMMM: -odMMMMMMd` Uptime: 7 mins
hMMMMMMMm-.hMMy/....+M:`/yNm+mMMMMMMMh Packages: 2596 (dpkg), 7 (snap)
/MMMMNmMN-:NMy`-yNMMMMMmNyyMN:`dMMMMMMM/ Shell: bash 5.1.16
hMMMMm -odMMh`sMMMMMMMMMMs sMN..MMMMMMMh Resolution: 1920x1080
NMMMMm `/yNMMMMMMMMMMMM: MM+ mMMMMMMN DE: MATE 1.26.0
NMMMMm `/yNMMMMMMMMMMMM: MM+ mMMMMMMN WM: Metacity (Marco)
hMMMMm -odMMh sMMMMMMMMMMs oMN..MMMMMMMh Theme: Yaru-MATE-light [GTK2/3]
/MMMMNNMN-:NMy`-yNMMMMMNNsyMN:`dMMMMMMM/ Icons: Yaru-MATE-light [GTK2/3]
hMMMMMMMm-.hMMy/....+M:.+hNd+mMMMMMMMh Terminal: mate-terminal
`dMMMMMMMMy-.odNMMMMMM: :smMMMMMMd` Terminal Font: Ubuntu Mono 13
yMMMMMMMMMms/..-::oM: .+dMMMMMy CPU: (4) @ 1.992GHz
:mMMMMMMMMMMMMNNNNM: :smMMMMMMm: Memory: 1214MiB / 3734MiB
/dMMMMMMMMMMMMMMMdNMMMMMMMd/
.odMMMMMMMMMMMMMMMMMMdo.
`:+shmNNMMNNmhs+:`

[phaseshifter]

@rooted
@ odroid
@ mad_ady

[mad_ady]

Always living on the edge, eh?

[phaseshifter]

what can i say

[rooted]

what can i say

Life's short eh