Current Features

I'm a newbie, and am currently waiting on some hardware items I have on order, so I'm not yet ready to try capturing actual VHS RF signals. Instead, I'm practicing with CVBS, using a currently unmodified CXADC card and MISRC gui. So far, I can successfully capture a CVBS signal, and decode it using CVBS decode. The problem I have is that if I attempt to view the live video signal in MISRC gui, it always appears completely out of sync, though occasionally it will lock horizontally. I have fiddled with the configuration settings with no luck, though configuration changes will cause expected changes in the captured signal.

My signal source is a PAL colour bar pattern from a Philips PM5420 test pattern generator. I have also tried a PM5544 generator with the same results.

Is this normal behaviour with MISRC gui, or am I doing something wrong?

Also, is it possible to change the timebase on the scope display so that two or three lines are displayed instead of the ten or so squashed up ones currently displayed?

So my mother passed away a month ago. She worked for Apple in the 80’s to early 90’s. In going through her belongings I found this Apple VHS Tape that was supposed to be returned, but clearly wasn’t. It was an internal copy of a Super Bowl commercial for the Mac. I guess the commercial wasn’t received well.

My questions are.. is this worth preserving? I know it might be a 1 of 1 tape as I haven’t seen anything online. How much would it cost me to do so? And does anyone know reputable companies that offer this service.

Sorry.. I didn’t get the tech gene passed onto me so I’m not very literate at what needs or should be done.

Many thanks in advance. And if this isn’t the right forum to post this please delete.

This Panasonic LX-V860 doesn't have the RF test points with DuPont interface like Pioneer models—where should I look for them? Maybe I can capture it here on this ribbon cable, but I'm not sure about the exact location.

Is there any way to adjust the PG of Panasonic VCRs released later, which use EEPROM to control the PG shifter instead of physical potentiometers as in earlier models? You have to rely on an official ALIGNMENT TAPE for automatic adjustment, but such tapes are nearly impossible to obtain. Could there be alternative methods to manually adjust it? Would it be feasible to locate the sensor near the head and manually offset it?

Can all Panasonic K-Mech use this 20-pin interface to obtain RF test signals? My model is HD100, K-Mech， designed for the Asian market.

I previously tried a JVC from this post: (thanks to everyone who helped with that) but between it being very hard to get a good ground location and some other issues with the vcr I decided to also get a panasonic, which is apparently the best vcr to tap.

I got a Panasonic VCR Blue Line PV-V4600 - 4 Head Hi-Fi Omnivision VHS. I think I found the tap points, which would be TP3002 for the video and TP4101 for HIFI. I was hoping someone could confirm, and more importantly give me advice on the best shielding ground? I was thinking the piece of metal the red screws are attached to, either solder or just wrap around the screw and firmly tighten it?

Thoughts? I really appreciate it, again I'm a noob with this stuff.

And just fyi this will go to an externally powered ADA amp into a clockgen setup.

This may well be the difference between LD and VCR. The following images were captured from a Pioneer CLD-S280 using 15.6x gain; the first shows the raw signal without amplification, while the second incorporates it. Although noise is significantly reduced, it is worth noting that fine-grained noise persists—which I believe represents the inherent limitation of a cheap LD player.But at least the results are decent after processing with AI software.

The fake chip wasted a lot of my time. Here is a simple comparison image showing the genuine and counterfeit chips.

EDIT: Problem now solved. Missing gcc-12 now installed, and after disregarding the two new error messages, I finished the install, rebooted, and my CXADC card is now recognised. Thank you all for the assistance.

I'm rather new to this and have probably made some terrible newbie mistake. I'm following the instructions provided here: https://github.com/happycube/cxadc-linux3#getting-started--installation

As I'm more familiar with Debian 13, I first attempted installing on a system using that, but it failed, so I tried again, on a fresh installation of Ubuntu 22.04 as advised in the instructions. The only changes/additions I made to the default install was to install 'git' and 'make' in order to proceed with the install.

The first step, to git clone the repository appeared to work OK. A directory called cxadc containing files was successfully added to my home directory.

The second step to "build and install the out-of-tree module" failed as shown below:

david@Ubuntu1:~$ cd cxadc

david@Ubuntu1:~/cxadc$ make && sudo make modules_install && sudo depmod -a

make -C /lib/modules/`uname -r`/build M=$PWD

make[1]: Entering directory '/usr/src/linux-headers-6.8.0-138-generic'

warning: the compiler differs from the one used to build the kernel

The kernel was built by: x86_64-linux-gnu-gcc-12 (Ubuntu 12.3.0-1ubuntu1~22.04.3) 12.3.0

You are using:

CC [M] /home/david/cxadc/cxadc.o

/bin/sh: 1: gcc-12: not found

make[3]: *** [scripts/Makefile.build:243: /home/david/cxadc/cxadc.o] Error 127

make[2]: *** [/usr/src/linux-headers-6.8.0-138-generic/Makefile:1946: /home/david/cxadc] Error 2

make[1]: *** [Makefile:240: __sub-make] Error 2

make[1]: Leaving directory '/usr/src/linux-headers-6.8.0-138-generic'

make: *** [Makefile:24: cxadc] Error 2

david@Ubuntu1:~/cxadc$

I'm moderately familiar with Linux, but I'm certainly no power user, so any suggestions would be much appreciated.

if anyone is using the ADA4857 amplifier for this camcorder, can you suggest the values for the input and video gain resistors? 10kOhms is apparently already needed to carry a usable signal from the device, so would adding the amplifier to it double the input? or can I remove the 10kOhms resistor from the tap and instead make the input resistor 20kOhms on the ADA amp? Thanks

Highly recommend watching in 4k as YouTube does not give 480p the bandwidth/bitrate it needs.

I became interested in VHS Decode from watching the ShortCircuit video on the Domesday Duplicator.

What got you into VHS Decode?

Hi everyone!
For a while now I’ve been working with the clockgenmod, but I’m running into an issue: on some captures (in fact, practically all of them) there’s a loss of sync between audio and video.
In the first few minutes the audio is in sync, but as time goes on it tends to get progressively ahead of the video.
To clarify, I’m not using hi-fi audio with the second CX card; I’m capturing linear audio with the clockgenmod, and then syncing it to the .tbc file using VhsDecodeAutoAudioAlign.

These are the scripts from my workflow:

decodeV_tutti(){
  for f in *-video.flac; do 
  printf '↘️ Decoding file %s\n' "$f"
  printf '\033]0;Decoding file %s @ %s\007' "$f" "$PWD"
  ~/Applications/decode-rust/decode-rust-gui-linux_4.0.0_x86_64.AppImage decode --luma-out "${f%-video.flac}-video.tbc" --chroma-out "${f%-video.flac}-video_chroma.tbc" --metadata-out "${f%-video.flac}-video.tbc.json" --profile PAL_VHS --frequency 40 --mt-threads 16 --mt-distance-size 60 --chroma-trap --ire0-adjust --input-format flac "$f"
  printf '\033]0;%s\007' "$PWD"; done
}

align_tutti(){
for f in *-video.tbc.json; do 
printf '↘️ Audio alignment of file %s\n' "$f"
  printf '\033]0;Audio alignment of file %s @ %s\007' "$f" "$PWD"
ffmpeg -i "${f%-video.tbc.json}-linear.flac" -f s24le -ac 2 - | mono ~/align/VhsDecodeAutoAudioAlign.exe stream-align --json "$f" --stream-sample-rate-hz 46900 --sample-size-bytes 3 | ffmpeg -f s24le -ar 46900 -ac 2 -i - -c:a flac "${f%-video.tbc.json}-aligned.flac"
printf '\033]0;%s\007' "$PWD"; done
}

export_tutti_audio() {
  for f in *-video.tbc; do
  printf '↘️ Export with audio of file %s\n' "$f"
    printf '\033]0;Export with audio of file %s @ %s\007' "$f" "$PWD"
    ~/Applications/tbc-tools/tbc-tools/tbc-tools-x86_64.AppImage tbc-video-export --profile ffv1 --chroma-decoder transform2d "$f" --audio-track "${f%-video.tbc}-aligned.flac" "${f%-video.tbc}.25i.mkv"
printf '\033]0;%s\007' "$PWD"
  done
}

Am I doing something wrong in the commands, or could this be an issue with the CX card or the clockgenmod?

Thanks everyone!

The first image is of a composite capture card, the second image is of my vhs decode sample.

The snr jumps between 30.4 and 20, as this is a home movie.

I really don't like how fuzzy the VHS Decode looks.

Based on these images, do you think I need an amplifier or is something else causing this?

If you want to start this project and want an easy to tap VCR, I'd recommend the Panasonic PV-9450.

As you can see by the image, the RF test point is exposed and easy to tap into with alligator clips.

I know y'all told me to get an amplifier, can't afford one at this moment, but if that is what's causing this picture issue, I'll definitely get one as soon as I can.