(WIP) Laserdisc software image decoder from raw signal

ld_out · Posted: 07 May 2023, 22:01

Thanks for that, I too am aware of VHS-Decode (something I want to visit eagerly)!

However I was referring to the PCBs and KiCad files (if i am correct) to manufacture them physically and make them fully functional.

But because of the vast amount on the github, I don't know what files to use if I ever were to approach a manufacturer online or abroad

9954tony · Posted: 07 May 2023, 23:16

If you look under the "capture hardware" section (specifically "Domesday Duplicator"), you should find what you need. There is even a link to order it from PCBway. You can order it populated or not populated.

https://www.pcbway.com/project/shareproject/DoomsDayDuplicator_Rev_3.html

You can also find some people selling premade and tested kits.

laserdisc.ws · Posted: 27 Jul 2023, 21:37

I have a doubt... reading this page (https://bitcrush.io/laserwiki/index.php ... ng_Process) it seems that the raw capture is limited only to video... as my memory lacks (a lot) I can't remember IF the laserdisc audio is included in the raw capture, and in case, WHICH one(s) - analog, PCM, AC-3, DTS...

9954tony · Posted: 27 Jul 2023, 21:40

laserdisc.ws wrote:

I have a doubt... reading this page (https://bitcrush.io/laserwiki/index.php ... ng_Process) it seems that the raw capture is limited only to video... as my memory lacks (a lot) I can't remember IF the laserdisc audio is included in the raw capture, and in case, WHICH one(s) - analog, PCM, AC-3, DTS...

that is not correct. All of the audio is captured and stored in the RF. Analog and PCM are for sure decodable, i think AC-3 is, and unsure about DTS.

laserdisc.ws · Posted: 27 Jul 2023, 22:43

Thanks!

Curious to know now if AC-3 and DTS are effectively decoded now, or if there are plans to decode them in the future.

9954tony · Posted: 27 Jul 2023, 22:52

laserdisc.ws wrote:

Thanks!

Curious to know now if AC-3 and DTS are effectively decoded now, or if there are plans to decode them in the future.

https://github.com/happycube/ld-decode/issues/622

looks like AC3 is done, although still some minor issues on some discs.

https://github.com/happycube/ld-decode/pull/772

and DTS as well.

DTS also mentioned on the wiki https://github.com/happycube/ld-decode/ ... rocess-efm

The ld-decode wiki hasn't been updated, but --AC3 is shown in the help:

Code: Select all

$ld-decode --help
usage: ld-decode [-h] [--start file-location] [--length frames] [--seek frame] [--PAL] [--NTSC] [--NTSCJ] [-m mtf] [--MTF_offset mtf_offset] [--noAGC] [--noDOD]
                 [--noEFM] [--preEFM] [--disable_analog_audio] [--AC3] [--start_fileloc start_fileloc] [--ignoreleadout] [--verboseVITS] [--RF_TBC] [--lowband]
                 [--NTSC_color_notch_filter] [--V4300D_notch_filter] [-d deemp_adjust] [--deemp_low deemp_low] [--deemp_high deemp_high] [-t threads] [-f FREQ]
                 [--analog_audio_frequency AFREQ] [--video_bpf_high FREQ] [--video_lpf FREQ] [--video_lpf_order VLPF_ORDER] [--audio_filterwidth FREQ]
                 infile outfile

Extracts audio and video from raw RF laserdisc captures

positional arguments:
  infile                source file
  outfile               base name for destination files

options:
  -h, --help            show this help message and exit
  --start file-location, -s file-location
                        rough jump to frame n of capture (default is 0)
  --length frames, -l frames
                        limit length to n frames
  --seek frame, -S frame
                        seek to frame n of capture
  --PAL, -p, --pal      source is in PAL format
  --NTSC, -n, --ntsc    source is in NTSC format
  --NTSCJ, -j           source is in NTSC-J (IRE 0 black) format
  -m mtf, --MTF mtf     mtf compensation multiplier
  --MTF_offset mtf_offset
                        mtf compensation offset
  --noAGC               Disable AGC
  --noDOD               disable dropout detector
  --noEFM               Disable EFM front end
  --preEFM              Write filtered but otherwise pre-processed EFM data
  --disable_analog_audio, --disable_analogue_audio, --daa
                        Disable analog(ue) audio decoding
  --AC3                 Enable AC3 audio decoding (NTSC only)
  --start_fileloc start_fileloc
                        jump to precise sample # in the file

admin · Posted: 21 Apr 2024, 05:48

Someone had fund adding a RF out to a HLD-X9 for the Domesday Duplicator!

https://page.auctions.yahoo.co.jp/jp/au ... 1132987673

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Julien

laserdisc.ws · Posted: 23 Apr 2024, 19:14

admin wrote:

Someone had fund adding a RF out to a HLD-X9 for the Domesday Duplicator!

Must need some guts to do that!

Anyway, a nice job, and the adesive label adds a touch of elegance; well done.

kamm · Posted: 26 Apr 2024, 18:20

That's the future of LaserDisc.
It seems realistic that in the forthcoming years we will probably have real-time capable ld-decode in an embedded/dedicated system.
"DD RF out mod" will be something like the AC3RF out mod now.
And we won't be arguing about comb filters anymore, but about spindle motors, tracking servos, "cleanest RF signal" etc. :roll:

So, this X9 is future-proof!

admin wrote:

Someone had fund adding a RF out to a HLD-X9 for the Domesday Duplicator!

spooky · Posted: 27 Apr 2024, 18:14

So someone is going to "Domesday duplicate" all 65,000+ LD titles? Doubt it.

(WIP) Laserdisc software image decoder from raw signal

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