Oddity Archive: Episode 232 - PCM Audio on Videotape (Betamax, VHS & U-Matic)
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- Опубліковано 12 січ 2022
- Hey buddy, wanna hear my (horribly impractical) mixtape?
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I never knew PCM and digital recording went back to the sixties. This was fasinating. Good job Ben.
well, PCM was used during wwii
Actually the concept goes back to the 1930s!
@@tomservo5007 Yep, It goes bac to the 1930s!
You should have hear a certain Tech moaning about it.
Okay maybecI need to do some studying
Techmoan would probably snatch that up ASAP if he doesn't have it. It's exactly as esoteric as he wants.
He did cover a system that used VHS tapes made by Technics; a sort of predecessor to ADAT.
Haha. I immediately thought of him as well when hearing this.
I love and Hate Techmoan.
Love the videos...
But the bastard keeps buying shit I want damnit
@@joshuarichards2421 lmao! At least we know why he has the name: "He reviews *Tech* we didn't know we wanted, and then we *Moan* when we see the prices on eBay within hours of him posting a video." lol
Yes very much my sir
This is actually really cool! It's basically a giant cartridge CD
Video cipher satellite tv encryption from the 80’s used to send digital audio via the baseband video signal as well.
I don't know how much bitrate's worth of audio you could send in the vertical blanking interval...you probably won't get much better than 2,400 bps LPC-10 speech codec or so...
This reminds me of a system they had to use VHS tapes as a backup system for Windows computers in about the 3.11 / windows 95 era
I know that with biphase mark code an a 9 bit as 11 cell recording code you can get about 400 8-bit characters per second on a 1-7/8 ips ferric compact cassette tape in mono...I got to the point were I was playing audio cassette of JPEG images at 240x160 pixels into my Sony PSP using the aux cord input...you could see each macroblock get clearer slowly and the become colorized, with further down in the image flashing the DC color the signal left off on...
When I was a kid, I used to record my CDs onto VHS Hi-Fi tape in SLP mode. On the right sound system, it sounded worlds better than most tapes, comparable only to type III.
Yes, because the audio signal was first fm-modulated and then recorded. Sounds better than the much more expensive reel-to-reel tape. But PCM played a few leagues higher, CD quality on cheap videotape.
I've done quite a lot of work on the PCM-F1/PCM-501/PCM-601/PCM-701 Beta based machines and PCM1630 U-matic format on my channel.
By the way your PAL PCM-501 will decode NTSC recordings just fine. I've added S/PDIF outputs to my 501 and 701.
thast what i was thinking, why cant a spdif port be added to the original 701? glad to know its possible tbh moding is always better
I need help accessing a VHS that can only be used on a PCM VCR. Can you help?
If you ever find yourself needing to capture a spdif signal, some video capture devices do feature such an input. You can probably feed in a dummy video signal (black video, test pattern, etc.) and then extract audio from the resulting file. My Happauge HDPVR unit has an optical input (there are adaptors for RCA->Optical), though I only used it once to transfer a DVR recording I really wanted 5.1 audio for.
I know for SURE that the RTL-SDR radio dongle will pass the EFM CD Pit dark/light laser spot signal completely if you solder it for direct sampling input and use the 2.4 megasample per second recording speed. I wrote a quick zero crossing detector program to convert the wave shape into an EFM file with the numbered pit lengths and loaded it into the open-source LD-Decode/ld-process-efm program and was able to recover the audio from pressed CDs...CD-Rs don't have a good enough signal to use...you need to open up a portable CD player and look at the chips and download the datasheets and find the pin with the EFM CD eye pattern signal, and the negative is the negative battery terminal. The biggest problem I had trying to get it to decode is the DC-restoration...
And another thing...if you are good with a soldering iron you can make a 2N2222 buffer amplifier that will take the coaxial RCA SPDIF signal and pulse a visible red LED if you need to drive an optical digital input....
You don't even necessarily need a dummy signal. Many PCM processors have a monitor output so that you can extract it and the audio.
Thank you, Ben, for your mini history lesson and demonstration on a video/audio subject that I never knew existed. Thanks also for making it interesting to a layman such as myself.
This is where 44.1 kHz originally came from.
BTW, it's "digital data through analogue means", not vice versa.
Video compression seems to be the likely culprit for the DVD transfer going wrong. Even at the XP setting, with all that video noise there's just too much detail that the MPEG-2 format can't handle, causing too many artifacts. It would be interesting to see if MiniDV (via the A/V input function on a number of Sony camcorders) could handle the PCM video stream.
DV video uses the same basic compression method used in JPEG, and it has to fit into a constant bitrate... maybe, maybe not. DV video uses a far higher bitrate than DVD though (25 mbit). I know I once got some visible artifacts with an HD DV camcorder (720p) filming a CRT screen of a DOS prompt with that halftone character (▓) all over the screen.
@@thegreatcodeholio123 HDV uses MPEG2 video compression, just like DVD and D-VHS, except at a higher bitrate. Standard definition DV uses DCT compression which is much closer to lossless quality. HDV also has MP2 (MPEG Layer II) compressed audio while DV has lossless PCM audio.
@@vwestlife There is also a high definition version of the DV codec that captures at a 4:3 aspect ratio (which is stretched to 16:9), so while it is displayed for example as 16:9 720p, it's not 1280x720 but 960x720. A friend of mine used to do video production in the very late 2000s with a high definition video camera that recorded everything to "P2" cards (proprietary flash in a PCMCIA form factor, apparently) using some variant of the DV codec, in MXF files (or you could record the same to MiniDV tape). We have gotten files from others that use the "HDV" codec in the QuickTime MOV file format, though.
@@thegreatcodeholio123 DVCPRO HD has 960x720. It's progressive though, and it'd be upconverting the 480i signal, so no idea what that would do to the signal. The irony is that if you're using a DV format, you're better off just using the digital audio channel for audio recording.
Probably the only way you can get PCM adapter audio onto a DVD+R DL disc is to use a computer program to synthesize the animated barcode pattern at 50 % modulation and send the frames image pixels directly into a software MPEG-2 encoder such as yuv4mpegpipe mode on FFMPEG.
First and only PCM setup I saw in person was a Bose presentation for introduced the acoustic wave. The presentation was a set of slide projectors (at least 6, maybe 8) to do the "video". I'm guessing the slides were controlled by audio cues on the video tape's normal audio track. Using an audio track to control multiple slide projectors was common enough. I had setup and run two-projector versions in my A/V job.
I seem to recall a Sony consumer Beta VCR. I don't remember the model number, but it was a top loader with a push button preset tuner. There was a switch in the back to go between video and PCM. There was another switch in the back to switch playback from Beta II/Beta III to Beta I. Crazy place to put it. This was around 1980-81 or so.
I know that the beta tapes used in Showbiz Pizza contained PCM audio. Creative Engineering inc is still around and actually sold one of the tapes to a collector.
Channel 44 in Boston used to sometimes broadcast this. I guess like maybe a dozen people had systems that could process it in realtime?
TiVo, back when they used modems, would buy infomercial time to send bulk data to their units. It looked similar to this.
Great video - really enjoyed learning about this recording format. Had no idea Sony Beta was used for digital audio.
There were actually a handful of titles released on this format by Mobile Fidelity in Betamax and VHS formats. They were made to order only and I believed limited to 500. I happened across one on Ebay many many years ago in the Betamax format. Which I then purchased a used PCM -701ES and a Sony pro Betamax deck. Over the years I've only played the tape maybe 3 times total as to not damage it. My last play back I captured the video signal and now there's computer software that can decode the video signal and reconstruct the digital audio.
i wonder how this would play out with subtle video effects added to it. what the result of the sound would be. could be an idea to import a high resolution NTSC AVI recording into video editing software and see what happens. of course, to monitor the effects during editing in real time, you would need to output the source from the PC as NTSC unless someone has developed software that alternatively read PCM in video.
I do recall that being the audio method of choice on my Sony CCD-V3 camcorder in 1987
Video tape becomes super audio tape.
Also, PCM audio was incorporated on sony 8mm decks I have some recordings i made and are good also
Upload Pavanned as a lossless video so I can record it to VHS! I doubt my 1/4" VTR would record it properly even if it were working perfectly.
I wonder if modern smart phones could interpret and play back the audio in real time just by pointing the camera to the signal output on a monitor.
I wonder if you can store digital PCM audio onto UA-cam by having software decode the patterns in the UA-cam videos
I love the "deep dives" that we get here on the Archive. I am into "old school" audio, Hell just "recapped" and got good "new" tubes for a 1939 Zenith 8-S-463 (That I STILL use to get active SHORTWAVE stations!) along with using it's "TELEVISION"
Oh..come on..you don't need an audio input on an AM radio...you've never heard of the 1 MHz 4-pin crystal oscillator trick? I did that and was even able to use a 96 kHz sound card to generate a sine and cosine wave at 20 kHz and play C-QUAM AM stereo into my 1980s receiver when you tune to 1020 AM on the display using a C program. If you only need mono, you can use a TIP41 transistor amplifier so you can not have to touch any antenna leads. I got mono AM 1000 signal to fill a small room this way. Basically what you do is play music into the 4 pin crystal oscillator with a 4.5 volt DC offset provided from a LM741 op-amp with some gain.
we use to have a pair of these at work! They worked really wonderfully... excellent sound quality!
17:33 I had the pcm-f1 and also found the emphasis to be a pain in the ass. I didn't understand why sony didn't put a switch in to shut it off. I disabled my emphasis by removing the input filter caps that give the f1 the frequency response it had and rejumpered the board for no emphasis on playback. After that with a test cd it recorded perfectly flat 20-20,000 hz.
The VHS suffered from background noise. The MOOG clip didn't sound that bad but treble shot up a little compared to source. The Betamax was pretty much the same quality as expected from higher bandwidth and "fresher" media being used.
Ah! So THAT'S where the "DIGITAL" on my Sony MDR-V6's came from! XD
DragonTime: The "M.D.R." on a pair of Sony headphones stands for Micro Dynamic Receiver. Enjoy much better sleep now.
There's a Russian dude who goes as VCD on youtube he fiddles around a *lot* with VTRs and VCRs of all sorts; I believe he has an entire livestream or few of fixing this Technics VHS PCM machine, as well as some Hitachi (?) one.
There's also a software PCM processor in the making: ua-cam.com/video/q1pasjA9C-I/v-deo.html
Might be of interest.
Whoah! Didn't expect anyone to mention me here. Indeed, if Ben needs any information or help with PCM devices, I'm ready to help. Me and my friends have researched just about everything on the history of early digital audio. I also have probably the largest collection of PCM processors.
the warm up sounds like a bad capacitor that takes time to reform.
How did I miss this on its upload? Great ep, man the YT algorithm must hate you.
To paraphrase George Carlin: It’s a big club and I ain’t in it.
The issue with the cloner alliance box is that it may actually be de-interlacing the video, which breaks it.
Same thing with the DVD recorder, actually.
You had me at "NHK"...
The obvious next step is to get a raspberry pi to output audio through composite video to feed into this kind of thing. :D
And i feel like the DVDR version sounded so poor was because of the MPEG compression on it...
and old Raspi generating CVBS from an MP3 for this converter would certainly make it to hackaday....
Not only the MPEG compression, but the presence of a Chroma (color) signal. In order to see if it is the chroma signal or the compression, a re-test would need to be done with special cables to the S-Video input (center conductor of the encoder's video output to Y, shield to ground, and on the S-Video end C to ground via a 72 to 75 ohm resistor). With the video output set to 480i, the component output of the DVD recorder could be used to return the video to the encoder by connecting the Y (green RCA jack) to the input of the encoder or connecting the Y from the S-Video out as before (this is where the 75 ohm resistor comes into play in the adapter I mentioned).
@@jrmcferren I kid you not...I have an HDMI to CVBS adapter that refuses to put out a video signal if the input it feeds into has too high of an input impedance...it need to have a load connected to function....
the DVD-R tries to do some MPEG1 on the PCM-audio-CVBS... that's even worse than youtube's video compression artefacts....
Thank you for giving me a reason not to skip the intro this time
Wait....You SKIP Benny Boys intos? 😳
Why would you do that?
Last night doing some typical boredom fleabay browsing, I came across a few 45IPS digital reels for the 3M recorder, dating to 1980… maybe somebody can play them, but that somebody isn’t me. They’re probably still up if any of the audio nerds here might wanna try anything with ‘em. I’ve never seen anything like that come up for sale before.
It would be really cool if someone figured out how to read them with a computer image document scanner and magnetic developing fluid the same way they do credit cards....
Nice to see Martha Davis and the Motels get some love
I guess as the image is black an white only, you could patch the composite out to the luminance in of an svhs recorder.
Nice concise history of PCM and early devices. What about Video8? on a camcorder!
I'd rather have one of the little units that were intended (at least cosmetically) to be used with a portable Video8 deck--one of those kinda early field recording unit deals.
I have a Sony EV-S700UB Video8 unit with PCM, it's a bit of a funny system though, it's quite compromised due to the wrap angle of the heads, it can still sound very good though.
The ratio of 8mm videotape camcorders that can only record through the lens versus the ones that permit you to record a line-in signal is like that of female faeries to male faeries...like 146,000,000 to 1.
I need a music visualizer that looks like this
would be interesting to hear your take on NICAM
Video artist perspective: 📼🦓The Patterns are interesting to watch! and think about how they represent the sound
I notice you mention Ry Cooder alot. You ever get into Al Cooper and Mike Bloomfield? Supersession? Moby Grape Wow "Grape Jam" bonus l.p.? The Electric Flag? Paul Butterfield Band?
I do have the Super Session album. Also have the first two PBB albums, plus a second copy of the second one on vinyl.
@17:12 that’s a 1980’s version of a qr code on the lower left - for those that don’t know. lol
The DVD-r mangled drums are kinda sick
0:25 sounds like the wow and flutter from a compact cassette.
One of the first times I manage to tune-in to an episode so early! Horray :)
Did Benny Boy just have a "Simpsons Already Did It" Moment?
Ben, I really liked your music in this video. Re-edit of “Battle At Elderberry Gulch” in particular. Have you heard an album, Painted Desert by Ikue Mori, Robert Quine, & Marc Ribot? Also look up “Incident At Cima” by Scenic. I think you’ll like these for more Western-tinged instrumental rock.
Thanks for all your videos man. We really enjoy your content, and hope to see OA go on for a long time. It’s an awesome channel.
*VHS recordings of Sega Genesis games with voice samples*
I have a number of PAL betamax tapes with PCM encoding from a PCM device that ive never been able to get working. If you would like high quality transfers of them maybe we can sort something out? my PCM-501es is not working at the moment. Always wondered what was on them.
I have the Sony 601ESD with digital output I sure can dump your tapes to files losslessly with no analog involved.
Perhaps I may help you. A friend of mine has developed a software PCM decoder which you can use with an ordinary TV tuner and VCR to digitize your recordings.
@@VCD-Channel I posted links to those software solutions but the author kept deleting my posts.
@@Capturing-Memories It's not the author, it is the absurd system of UA-cam pre-moderation sadly =\
@@VCD-Channel I had posted links on other videos at the same time and they are still up, but again algorithms do weird things, Sorry if I wrongly accused Ben.
Somebody needs to make this ffmpeg compatible... encodable/decodedable in software. (I haven't googled. It might exist.)
I wonder if you could rip the audio with a (uncompressed!) video capture and software. This doesn't sound like it would be that hard.
Save for whatever voodoo UA-cam does, this'd be it. ua-cam.com/video/FkvBSF-Gv8U/v-deo.html
So what's actually being displayed in the image? Is it just the black-white of the seven bands? Does the rest of the image have any bearing? Also why do the bands seem to get "eaten" on the right side? There seems to be simple binary sequence patterns going on in those "bites" as well.
I hope this will satisfy your curiosity. ua-cam.com/video/Mw3IZ_y1DIw/v-deo.html
@@VCD-Channel Is the PCM Coder box available for sale?
@@Capturing-Memories The first release is sold out, perhaps another batch of coders will be assembled soon.
@@VCD-Channel Where should I check if it's available again? Any ideas on the pricing? Also does it decode video from tape and send it as digital output like the Sony 601ESD does?
Ytube audio (watermark?) is putting "swishing noise" your tests...
Should be ok if you're playing at the full 1080p setting.
Silly question myhap, but what is "ADPCM," compared to PCM?
Very simplified: PCM = low sample rate (kHz) and higher bit resolutions. ADPCM is high sample rates (in the gHz) and low 1-bit/variable resolution. ADaptive PCM. en.wikipedia.org/wiki/Adaptive_differential_pulse-code_modulation
The ones used on desktop PCs use a 4 bit per sample lossy time-domain compression algorithm. It does not require much kerosene to run it, so you can play them back in high fidelity on even a Game Boy Advance console....
A VHS video a day keeps the NFTs away
Wry Cooter!?
...only if it's Record Ripoffs. And I don't think we're in any great danger of seeing Ry on a knockoff record.
Wow, that DVD Recorder produces some very mild glitch-art. :D
Awesome video Ben! Can you do one on the 80s/90s demoscene? Amiga/C64/Spectrum graphics and MIDI audio, some fantastically talented groups/coders out there. There are some documentaries already on UA-cam but I'd love to see your take.
I'll take one of those PCM mixtapes!
...That'll be $1999.99 in Guyanese dollars, right?
So you'll telling me that all those CD jabronies lied? But... but... but... but... PCM is ultra modern kool!!!!
"You can't record a composite video signal with S-VHS or D-VHS"!?...Really?
Back before 2012 I was doing daily TV archiving and dubbing (to eliminate commercials to save tape) on S-VHS and it could record in S-VHS off composite input just fine...My JVC HM-DH30000U D-VHS deck will record 480i SD video from RF, Composite, S-Video, or DV/Firewire to D-VHS tape in D-VHS recording mode easily (though it only records HD over firewire which requires interesting workarounds that I'm planning to make a video about).
A lot of people make the mistake (that I think you're making) of confusing S-Video with S-VHS. S-Video is essentially a using a comb filter to split composite video in to 2 Separate (where the 'S' in S-video comes from) signals: Luminance (B&W video with sync) and Chroma (the color information). You can convert S-Video to composite simply by shorting the coax centers together and feeding that to a composite input.
S-video is not necessary for S-VHS or D-VHS recordings composite is fine... There's only 3 cases where S-video is an improvement over using composite: In deck to deck dubbing where maximum quality is desired, In cases where the source device has a better comb filter than the destination device, or devices that either store or are capable of generating the Luminance and Chroma seaprately.
If say it was 2005 and you were using an outboard analog tuner with composite and S-video out and a professional broadcast monitor with a better comb filter than the tuner the picture could actually look better through composite because the monitor knows to use it's own superior comb filter through the composite input and not rely on the S-video source device's comb filter as it would with an S-video input.
I suppose you could record S-VHS via composite, but a better question would be: Why? Since we’re dealing in audio (when all is said and done) and the basic format’s audio specs don’t factor in, it’s just an exercise in doing it because you can.
As for D-VHS, it’s no longer analog and you’re dealing in full-on data compression, so I’d imagine that’d end the same way the DVD-R test did. Whatever method of input you use wouldn’t matter.
@@OddityArchive I agree it shouldn't matter which tape format is used since the PCM digital encoding was designed to be robust against less than perfect VCRs of it's time.
With regards to D-VHS...The NTSC PCM video stream is effectively a digital signal carried over an NTSC analog video signal, digitizing the video signal should not effect the audio quality...At least if there's little to no video compression occurring. I suspect what is occurring with the DVD-R is that the PCM signal resembles Macrovision video copy protection (triggering the cannot record message). Macrovision is typically 4 vertical stripes in and just after the vertical sync pulse (if the 4 PCM signal bars go up that high (say into the first few lines of video reserved for closed captioning data) that could be the problem). I wish I had a PCM encoder to try it with, but last time I tried to get one (a PCM-1) from an estate sale someone managed to snag it out from under me when I wasn't looking.
I love how you seem to apologize about the geeky content when most of your viewers are like "Yummy geeky content! Yum!" We are your People.
The DVD one could be counted as a Glitched Mix lol
Didn't try 8mm film.
I don't think film would do much good.
35mm and 70mm films used similar technology to print audio digitally on the edge of the film frame in a barcode like manner.
Wait...do I know who you are?
I think DVD failed because it can't capture full video frame, only part of the video that can be seen.
DVD didn't fail - it was a highly popular video format, which absolutely took over in the mid-2000s. However, Blu-ray has gradually taken over its market share, simply because it's a better quality format that carries more data. (That, and many people simply don't see the point in owning movies in the era of streaming video, so home video has decreased in general in the market.)
@@elphive42 your comment is very funny. it sound like you didn't watch the video to the end. If you don't call that a failure, please make an appointment to get your hearing checked.
the PCM on DVDR failed due to the bad MPEG-1 (probably) and it's horrendous compression artefacts, far worse than todays VP9/H265 issues.
The resolution is not the problem, the compression is.
@@Capturing-Memories Definitely would want to make sure any quality setting is maxed out, but Ben probably took care of that.
For better results use timelapse vcr in b&w mode
Better results? PCM cannot magically increase bitrate out of nowhere.
I'm early
Hi, Early! I’m lame! XD
A you a flat earther ❤️