Author Topic: Normalizing high speed recorded track (video & audio)  (Read 778 times)

Offline vhsexplorer

Normalizing high speed recorded track (video & audio)
« on: October 26, 2019, 05:09:29 PM »
Hello everyone,<br>
I have a continuous recording on a VHS tape and at playback on a PAL Samsui VCR a part of it plays at a faster speed with fast video and chipmunk audio output and then after 1 hour of play it goes back to normal speed with video and audio (still same continous recording of programme, thus there was no stopping I could see of REC button when it was originally recorded years ago). I am not sure how that could have happened, perhaps the VCR at that time changed automatically the recording speed while it was recorded). <br>
Now my aim is to have this part of the recording like the rest of the tape to use it for conversion to digital. Even if I can just isolate this part, change to normal speed (video and audio) and have seperate digital file for it. Could anyone tell me how to &quot;normalize&quot; this type of recording and also stabilize video? Definately about recording on the tape, not the VCR, since other parts of same tape and same recording play fine. Thinking I should try following, please give me your comments:<br>
1. Find another VCR machine which can playback at other speeds. Im not sure which speed or format required.<br>
2. Convert this fast part as is and then once in digital format try to manipulate the video and audio speed. Which software out there could be used?<br>
Many thanks for any advise from the conversion/editing expects :)

Offline chrisc

  • Trade Count: (+142)
  • AVForums Grandmaster
  • *****
  • Posts: 11,285
  • Total likes: 560
  • Cape Town Hi-Fi Club - we're getting better sound
Re: Normalizing high speed recorded track (video & audio)
« Reply #1 on: October 26, 2019, 05:13:56 PM »
Somebody used a half-speed (aka Long Play) VCR for the chipmunk section, so you will need to find a similar machine
Music is the shorthand of emotion

Offline vhsexplorer

Re: Normalizing high speed recorded track (video & audio)
« Reply #2 on: October 26, 2019, 05:55:58 PM »
Thank you Chris for the reply!
I just wonder why at a certain point the video and audio (which is a continuous recording) starts normalizing with still intermittent chipmunk sound and then totally fine, so had to have been done with the same VCR that would  have halfspeed/long recorded one part and then switched to full speed/standard during the same recording cycle (without stop pressed or recording speed changed manually). Is that possible?

Offline vhsexplorer

Re: Normalizing high speed recorded track (video & audio)
« Reply #3 on: October 26, 2019, 11:29:32 PM »
It still a mystery to me how could a 2 hour non stop recording on tape (it the same continuous single program without recording having been stopped) could have part of it as LP mode and part if it SP mode. Never having done it myself back in the day, but do you know if it was/is possible to, while a recording is in progress, change the recording speed from LP to SP without stopping the recording by pressing stop?

Offline Hi-Phibian

  • Commercial Member
  • Trade Count: (+48)
  • *****
  • Posts: 12,642
  • Total likes: 285
  • I really prefer email, see my banner for address..
    • Croak Audio Exploration
Re: Normalizing high speed recorded track (video & audio)
« Reply #4 on: October 26, 2019, 11:39:51 PM »
I seem to remember mid flight speed change was possible and text in this link seems to confirm this. 


https://www.techwalla.com/articles/what-is-sp-lp-and-slp



Best bet is to find a compatible machine to play it.  It will sense the speed needed for the tape from the “video sync pulse interval”.  Sorry.   I am no video expert so may be using wrong terms. 


.
Proprietor of Croak Audio Exploration.
Fair, not crazy, cash paid for turntables and tonearms from Rega, Linn and Thorens.          http://www.croak.co.za

Offline vhsexplorer

Re: Normalizing high speed recorded track (video & audio)
« Reply #5 on: October 27, 2019, 12:11:23 AM »
Thanks Hi-Phibian, i will try to find a compatible machine.
I have been doing the playback using a Sansui VC-R254EI model. I see in its manual that it can do tape speed (SP/LP) recording (to get more space on tape) using the SP/LP button and also picture searching depending on tape speed, but not sure if it is capable of doing normal playback of a recording in LP mode (see no reference in manual or any button to adjust the playback in LP versus SP). Since the rest of the tape playback is all fine, it must be that VCR can only reproduce SP mode in normal playback. I will then search for a VCR that specifically can do normal playback of tapes in LP mode (not just able to record or picture search in LP mode). I have seen a 2nd hand Philips VCR for sale which has "long play" written on the front panel. Will that mean it can playback normally any recordings in LP mode, or it means just that it can record/do image search in LP mode? If perhaps anyone you know any other makes to recommend?

Offline MR.C

Re: Normalizing high speed recorded track (video & audio)
« Reply #6 on: October 27, 2019, 09:54:51 PM »
I used to use the SP/LP function on my LG Stereo VCR.

Proudest moment back in the day ? Recording the top 40 or was it Top 100 songs of the century (iirc) on my video machine on Long Play connected to my hifi. Think it was Mark Pilgrim that presented it. Dont think I will find that tape.

Sent from my SM-N970F using Tapatalk

I can help you to post pics for your ads.