Den 11.02.2023 07:30, skrev Andrew Randrianasulu:
I think this detailed description reflect nicely how high-speed
non-uvc data capture work
https://github.com/simoninns/DomesdayDuplicator/wiki/Hardware-Guide
for better or worse you can't just connect usual analog output to it.
I have strived to get an overview of the workflow and found it best here
in the "VHS-Decode Wiki":
https://github.com/oyvindln/vhs-decode/wiki/Diagram-Visuals#basic-workflow-breakdown
"The final standard for tape archival"!
Concept of VHS-Decode
Bypass all non-essential hardware, and process it all in software
directly.
Capture today decode tomorrow!
Summary
Thanks to low-cost CX Cards alongside the DomesDayDuplicator today
digitisation and archival of tapes can be done not only properly but
affordably with tapes' original FM (Frequency Modulated) signals
being captured and preserved for software decoding and digital archival.
Unlike baked-in standard S-Video/Composite and line-out audio
capture, FM RF capture offers the full original tape signals making
a true digital master copy of your analogue media removing the need
for expensive time base correctors and even working physical players
in the future.
A simplified workflow
Practically Any VCR --> FM RF Capture --> RF File of Tape's FM
Signal -> Software Demouldation & Timebase Correction --> Lossless
TBC Files --> Video Files
Correct me if I am wrong, but it seems to me that the second part "FM RF
Capture" is the "Domesday Duplicator" (hardware/sw) to create the third
"RF File of Tape's FM Signal".
So the "VHS-Decode" executes"Software Demouldation & Timebase Correction
--> Lossless TBC Files --> Video Files
I found it useful to continue reading with
FAQ
https://github.com/oyvindln/vhs-decode/wiki/FAQ
Why FM RF capture and software decoding instead of normal video capture?
A: Its just better!
No It's a little more advanced, yet very simple in practice.
Is this the best way to preserve analogue media?
A: Yes, as the method of capture preserves the original tape signal
just after initial tracking and amplification there is no alteration
of content in any way.
Capture today, decode forever!
The RF capture process provides an exact copy of the original
modulated signal content and then using FLAC compression this data
(basically a zip file) can be made 40-60% smaller this is smaller
than any lossless compressed video format available.
VHS-Decode features the world's first software-defined digital TBC
for analogue video media and its 100% free and 100% open-source
developed
What are the costs?
A: It costs 60-300USD* depending on the level of setup you wish to
invest in and what hardware you already have available, the white
PCIe 1x CX Cards are 20-35USD per card and basic tools/cabling and
even amplifyers is under 50USD depending on how budget restrictive
you need to be or if you preferer to make cables from the ground up etc.
The DomesDayDuplicator (DdD) can cost upto 300USD* is each ware as
China has 1000's of CX cards and amplifier boards available so if
you already have a VCR/Desktop you are just 2 steps away.
How complex is using vhs-decode and its tool suite?
Setup normally takes under an hour for hardware and software.
Continue with
Quick Setup Guide
https://github.com/oyvindln/vhs-decode/wiki/Quick-Setup-Guide
Yet, I am still in doubt if DomesdayDublicator + VHS-Decode is end-user
or developer solution?
Somewhat related:
https://www.windytan.com/2019/08/capturing-pal-video-with-sdr-and-few.html?m=1
(no code).
older fx2 experiments, there by now seems to be whole library of
programs for those older devices in digital instrumentation sector
http://www.triplespark.net/elec/periph/USB-FX2/
Some documentation on earlier sgi board called Sirius, you can see
board was 10-bit internally but small font around analog inputs said
they are 8bit really!
http://www.sgistuff.net/hardware/video/documents/007-2238-003-siriusvideo.pdf
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