LaserDisc Database
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(WIP) Laserdisc software image decoder from raw signal
https://forum.lddb.com/viewtopic.php?f=32&t=2671
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Author:  happycube [ 16 Feb 2019, 05:36 ]
Post subject:  Re: (WIP) Laserdisc software image decoder from raw signal

Yup, I didn't say it was easy... ;)

Author:  segasonic91 [ 16 Apr 2019, 16:43 ]
Post subject:  Re: (WIP) Laserdisc software image decoder from raw signal

I was REALLY impressed with LD Encode v4 demo on youtube. It really is hard to believe some of those pictures are from LDs. The dropout removal is a feature I eoukd sure as hell like to use in my LD captures.

Will this be a good way to go for people wanting to "rip" their LDs and encode for AVI, DVD, BD etc? I am really excitted by the results and would love to try it out. I have a second R7G I could use or a D99. Are the boards themselves being sold by you guys or is it a "DIY" thing?

Thanks!

Author:  titan91 [ 14 Jul 2019, 02:58 ]
Post subject:  Re: (WIP) Laserdisc software image decoder from raw signal

I've done a lot of reading and research on this project and am quite fascinated with these tools! I'm trying to decode nemesis's Sonic 2 sample for use with ld-analyse. I'm trying to compile the Qt project using the tutorial on the tools GitHub wiki page but am getting an error:

In file included from ../ld-comb-ntsc/comb.h:37:0,
                 from mainwindow.h:51,
                 from main.cpp:25:
../ld-comb-ntsc/opticalflow.h:34:10: fatal error: opencv2/core/core.hpp: No such file or directory
 #include <opencv2/core/core.hpp>
          ^~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
Makefile:635: recipe for target 'main.o' failed
make[1]: *** [main.o] Error 1
make[1]: Leaving directory '/home/andrew/Downloads/ld-decode-master/tools/ld-analyse'
Makefile:155: recipe for target 'sub-ld-analyse-all' failed
make: *** [sub-ld-analyse-all] Error 2


Can someone tell me how to fix this or provide a pre-built download for ld-analyse?

Author:  atsampson [ 15 Jul 2019, 09:50 ]
Post subject:  Re: (WIP) Laserdisc software image decoder from raw signal

titan91 wrote:
In file included from ../ld-comb-ntsc/comb.h:37:0,
                 from mainwindow.h:51,
                 from main.cpp:25:
../ld-comb-ntsc/opticalflow.h:34:10: fatal error: opencv2/core/core.hpp: No such file or directory
 #include <opencv2/core/core.hpp>
          ^~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.


Do you have the OpenCV development headers installed? On Debian/Ubuntu, install libopencv-dev.

If you've already done this, your distribution might be installing the headers in a directory that ld-decode's build system doesn't know about (e.g. I build against a later OpenCV that puts the headers in /usr/include/opencv4/opencv2). You can either edit the .pro file, or make a symlink from the current directory to where they actually are since . is in the search path, e.g.

ln -s /usr/include/opencv4/opencv2 opencv2

Author:  simoni [ 15 Jul 2019, 09:52 ]
Post subject:  Re: (WIP) Laserdisc software image decoder from raw signal

Quote:
Can someone tell me how to fix this or provide a pre-built download for ld-analyse?


Follow the installation instructions on the wiki and you will get the correct dependencies for compilation:

https://github.com/happycube/ld-decode/wiki/Installation

Author:  titan91 [ 20 Jul 2019, 13:51 ]
Post subject:  Re: (WIP) Laserdisc software image decoder from raw signal

Thank you both, I installed the prerequisites and the tools are working now. I missed the initial "installation" article.

Author:  titan91 [ 20 Jul 2019, 20:01 ]
Post subject:  Re: (WIP) Laserdisc software image decoder from raw signal

I encountered another issue, ld-decode does not detect any sync pulses. I tried both the Fantasia RF sample and the Chicago Blues sample, renaming the .bin files to .lds files. Using the command in the basic usage article on GitHub:

ld-decode-master$ python3 ld-decode.py input.lds output -s 1 -l 25
/usr/lib/python3/dist-packages/numpy/core/fromnumeric.py:2909: RuntimeWarning: Mean of empty slice.
  out=out, **kwargs)
/usr/lib/python3/dist-packages/numpy/core/_methods.py:80: RuntimeWarning: invalid value encountered in double_scalars
  ret = ret.dtype.type(ret / rcount)
Unable to find any sync pulses
Unable to find any sync pulses
Unable to find any sync pulses
Unable to find any sync pulses
Unable to find any sync pulses
Unable to find any sync pulses
saving JSON and exiting
Info: Processing complete

Author:  simoni [ 20 Jul 2019, 21:54 ]
Post subject:  Re: (WIP) Laserdisc software image decoder from raw signal

Hi

.lds is a specific format generated by the Domesday Duplicator (packed 10-bit samples) - if your source samples aren't in .lds format, you can't just rename them. The output from ld-decode is typical of an invalid input sample.

Where did those samples come from?

Edit: if those samples are 16-bit signed samples you can use ld-lds-converter (available in tools/ in the rev6 repo) to convert 16-bit .raw to 10-bit packed .lds)

Author:  titan91 [ 20 Jul 2019, 23:17 ]
Post subject:  Re: (WIP) Laserdisc software image decoder from raw signal

Thank you. Still learning the different formats, and appreciate the input. I will use ld-lds-converter from the Rev6 branch to generate the proper .lds file.
I got the samples from these two posts. Evidently the duplicator .lds format used by ld-decode has changed from signed 16-bit to packed 10-bit since then and I did not realize it. I saw an interview conducted by RetroRGB which mentioned only 10 bits per sample needed.

nemesis wrote:
happycube wrote:
@nemesis - can you send me an RF sample of that so I can tweak my (old) TBC... and to have another 28mhz DD sample ;) Thanks!

Here you go:
https://mega.nz/#!AANmHQzA!zuN-9-bm1tuK ... Qz8kw9BPh8
That's in the original 16-bit signed format from the Domesday Duplicator software.

Quote:
Also that cable looks great, but I can't find any US stock of it. Ah well. My crimp game's getting a bit better at least.

It looks like they're out of stock at RS (AKA Allied Electronics), but I found some US stock here: https://www.altechproducts.com/accessories/933844001/


Also, from what I understand the accepted sample rate for use with ld-decode is now 40MSPS. Here is where my second sample came from.

nemesis wrote:
To help out anyone else who might be interested in experimenting with the software who isn't able to generate their own captures right now, I've uploaded the raw RF capture I used to generate the above Fantasia clip at the following location:
https://mega.nz/#!EQtwVJxC!Mlx5rzTZ-aGg_-kYmWXZSEqq3XdYMhtUQDsEkIJQMgM
This is a 10-bit 32MSPS capture of an NTSC CAV disk.

Author:  titan91 [ 21 Jul 2019, 01:21 ]
Post subject:  Re: (WIP) Laserdisc software image decoder from raw signal

Ok, I was able to convert Nemesis's Chicago Blues 28MSPS 16-bit signed RF sample to 10-bit packed format. ld-decode does not recognize it when trying to decode a 25 frame sample, I am guessing due to the sample rate. I also know these captures are pretty old and may not be compatible with Rev6.

~/Downloads/ld-decode-rev6/tools/ld-lds-converter$ ./ld-lds-converter --input 16bitsigned.raw --output  output.lds --pack
~/Downloads/ld-decode-rev6$ python3 ld-decode.py output.lds output -s 1 -l 25
ERROR:root:Unable to find any sync pulses, jumping one second
ERROR:root:Unable to find any sync pulses, jumping one second
ERROR:root:Unable to find any sync pulses, jumping one second
ERROR:root:Unable to find any sync pulses, jumping one second
saving JSON and exiting
Info: Processing complete

Author:  simoni [ 21 Jul 2019, 05:02 ]
Post subject:  Re: (WIP) Laserdisc software image decoder from raw signal

Those samples are probably very old :) I suggest that you get on the project's IRC channel #domesday86 on freenode. There will be people with Domesday Duplicator boards available there that can make you a test sample.

Author:  titan91 [ 24 Jul 2019, 02:19 ]
Post subject:  Re: (WIP) Laserdisc software image decoder from raw signal

Thanks for the suggestion.

Author:  lordnahte2 [ 25 Nov 2019, 21:15 ]
Post subject:  Re: (WIP) Laserdisc software image decoder from raw signal

I've recently acquired a seemingly unused Pioneer DA-V1000 LD-ROM adapter. Once I track down a LD-V8000 I can use the EFM port to grab data from the disc, I have a copy of the Albegas/Cybernaut prototype I can test dump. Is the general consensus that these adapters will be useful as well for Mega-LD/LD-ROM^2 discs? If so I'll be glad to offer any help I can in the effort to dump and preserve these games!

Author:  kuncendorfs [ 26 Nov 2019, 08:25 ]
Post subject:  Re: (WIP) Laserdisc software image decoder from raw signal

Its basically what turns CD player into CD-ROM reader. I would guess its DA-1 with an extra chip. It will read digital audio and decode CD-ROM layer from it. Regular arcade games doesn't have those, LD-ROMs do. So you should be able to read Laseractive game data encoded as CD-ROM on audio track. Won't help with video data. You can do same thing through SPDIF or by hooking Arduino to DAC chip.
edit:
So Domesday thing works on lower level - you pull whole signal out together as it comes from laser and do all decoding in software.
With this signal goes through player and is processed and separated and you pull out just digital audio part. Analogue audio and video are unaddressed. You can still capture those as usual.

Author:  simoni [ 26 Nov 2019, 08:52 ]
Post subject:  Re: (WIP) Laserdisc software image decoder from raw signal

ld-decode has a functioning EFM processing stage these days; so it can extract both digital audio and data direct from the RF copies of the disc. Since all processing is from the laser RF, it can do this with any player that is tapped for RF capture - no additional LD-ROM hardware is required. The extraction also works for any EFM track; so, no matter the info on the source disc, you can get it back without a specialist LD player.

The EFM processing also works for CDs too (although this is lightly tested at the moment).

As a side note, even if you capture from an EFM output - you will still need to perform all of the EFM processing to get any meaningful data - ld-process-efm in the ld-decode-tools is designed for that task.

Author:  kuncendorfs [ 26 Nov 2019, 09:16 ]
Post subject:  Re: (WIP) Laserdisc software image decoder from raw signal

simoni wrote:
As a side note, even if you capture from an EFM output - you will still need to perform all of the EFM processing to get any meaningful data - ld-process-efm in the ld-decode-tools is designed for that task.

That's what his thing does. DA-1 decodes digital audio. DA-V1000 adds processing for CD-ROM layer (XOR with constant, basically)

Author:  titan91 [ 02 Apr 2020, 02:58 ]
Post subject:  Re: (WIP) Laserdisc software image decoder from raw signal

I know this isn't strictly LaserDisc related, but Oyvindln from Norway has made some great progress on VHS decoding. He forked the ld-decode git and heterodynes VHS's chroma signal up to 3.58MHz/4.43MHz. He recently implemented NTSC support and Simon's ld-analyse tool handles it well. Currently there is a need to blend the luma and chroma images in post-processing as there are two tbc files, but he is working on a script to combine them. Thanks to him, others for submitting RF samples, and the ld-decode project as a starting point, here's what we have so far!

Image
Image
Image
Image
Image
Image
Image

Author:  9954tony [ 24 Jul 2020, 17:54 ]
Post subject:  Re: (WIP) Laserdisc software image decoder from raw signal

FWIW, i have accomplished a "proof of concept" by successfully decoding "something" using an RF capture i made with a LimeSDR (USB version).
Image

This process required nothing too complicated. Following internet instructions for installing LimeSDR on ubuntu, then ld-decode on ubuntu, and using "pothos flow" (a visual SDR block flow tool) to capture an rf file. Happycube added the compatibility for the file type (float32, thanks). I only have "broad strokes" knowledge of all the concepts, so it could only improve from here. This setup can be obtained with zero soldering. EDIT: [I did have to remove one component from the limesdr board to improve HF performance, this can be done with a screwdriver]. I bought everything, hooked it up, and fiddled with the GUI settings of Pothos Flow for the SDR until i saw something in the ~7Mhz range. Image

While i realize for an actual archive capture, you would want to use the domesday duplicator board, for doing comparisons and tests, or to get your feet wet, this setup might provide a means to do that. the "domesday duplicator" is better and will provide the most fidelity, but this is an "off the shelf" solution that is available to anyone hesitant to put together the board.

I believe that the LimeSDR *may* be overkill at this point, because there are now cheap off the shelf frequency multipliers (shifter?) available (https://airspy.com/spyverter-r2/). Using such a device, you could use a cheaper SDR, and then just divide the signal in pothos flow.

DISCLAIMER: I can not confirm yet that this is a "full working solution". The "Ruckus" disc is in horrible shape, nothing in the setup has been optimized. I think that the capture the picture above is taken from, doesn't have a strong enough signal in the EFM, and possibly the analog audio.

Anyone reading this that has SDR knowledge, let me know. I literally just fiddled around with things until i got something ld-decode would accept. When i raised the gain past ~43 for the SDR, the signal actually disappeared!

Tony

Author:  titan91 [ 24 Jul 2020, 21:35 ]
Post subject:  Re: (WIP) Laserdisc software image decoder from raw signal

I'm looking at a 1994 Pioneer CLD-V2600 commercial/educational grade player. It turns on intermittently and has a tray issue but I want to try fixing it. If I can get it going would this be a good model for signal to noise ratio as it's not technically consumer grade?

Edit: Found this thread and I'm convinced. I took the plunge on this one and will report back if I can fix and mod it! It was definitely cheap enough.

https://www.hometheaterforum.com/commun ... ying.8312/

I have one or two old Radio Shack demo discs I want to capture.

Author:  happycube [ 26 Jul 2020, 19:11 ]
Post subject:  Re: (WIP) Laserdisc software image decoder from raw signal

The V2600 is really a CLD-S201 with a serial port. If you get a good deal on it and it's fixable, it's still nice :)

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