[Cin] offtopic: Digitize and record Video with A/D USB adapters

Terje J. Hanssen terjejhanssen at gmail.com
Tue Oct 12 01:24:43 CEST 2021

Den 11.10.2021 22:41, skrev Marco Ciampa via Cin:
> Hello people,
> first time I'm writing here and not native English speaker.
> So forgive me if I'm not that good at expressing myself.
> That said I want to share the content of an article I read somewhere that
> (unfortunately) I do not remember anymore but I remember the guts of if
> and think it could be much useful for someone.
> The writer tested a lot of (not so) inexpensive PAL/NTSC USB and PCI
> converters and a few of expensive ones too. Suddenly he remembered that
> its Digital TV with PAL/NTSC input was _much_ better at displaying video
> that the video grabbers. To make a long story short he discovered that
> that was because of an internal analog to digital _and_ the FHD to HD
> digital downconverter that did the trick. The principle here is "always
> sample much more that what you want to obtain".
> The result is this: forget the explensive and inexpensive grabbers and
> buy:
> - one cheap HDMI to USB3 grabber (you can find models compatible with
>    linux for ~10-20 euros / dollars)
> - one cheap PAL/NTSC (SCART) to HDMI converter (you can find models for
>    ~10 euros/dollars)
> and that's all. It will also come handy for aquisition of video from
> reflex/mirrorless cameras and so on...
> Hope someone find this handy...
> --
> Saluton,
> Marco Ciampa

This looks like a captivating, simple solution, if and when everything work.
What I think I've read previous, is that playback of interlaced video 
looks better on Televisions than on PC displays.

1. My TV has built-in ports for analog video playback (S-Video and 
RCA/Phono), beside additional SCART and HDMI ports

2. If I understand your description right, the HDMI to USB3 grabber 
should be used to record from a TV HDMI port to a Linux PC?

While my HDV camera supports HDMI video out, I wonder if TV HDMI ports 
do that as I have really never tested it.
(At least my HD PVRK could not record HDTV via the HDMI cable, only a 
limited format from the antenna cable. Analog VCR could record SD video 
via SCART or S-video adapter)

3. If HDMI video out works, what type of digital signal is expected 
(format uncompressed and chroma level?)?
And if works, it has to be recorded as compressed  (lossless) on the 
Linux PC? Among other 4:3 aspect ratio from analog SD video has to be 
taken care of.

Terje J. H

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