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View Full Version : A question about speed correction of lossless files


starman714
2005-02-08, 10:15 AM
and actually the question is just about everything you could tell me about it as I'm clueless.
I d/l a show > "Michael Hedges 9/21/97 Great American Music Hall, San Francisco, CA (AUD/?) [SHN]" and it sounds like ol' Michael was suckin' on some helium before he sang....well maybe not that bad , but definitely a higher pitch than anything I've heard of him live/studio.
Also , this is how it sounds on my HDD , not an audio CD-R copy.
I realize this is a show that I've obtained from a different tracker , so it's not really your problem , but I don't think I'll get much help where I got it from , they're swamped with problems.
Even a link to a tutorial would be much appreciated , and any clues as to how I'd know the true speed and pitch , and any software I'd need to perform the correction.
Also , knowing the standard TTD sets for lossless sharing , would you personally share such a speed corrected file , so long as lineage and availability met your criteria ?
Thanks for any help and your time.

h_vargas
2005-02-08, 04:00 PM
here's a good link to start with...

http://www.thetradersden.org/forums/showthread.php?t=2432


personally, i probably would not "seed" the corrected version.

Five
2005-02-08, 04:11 PM
here's a good link to start with...

http://www.thetradersden.org/forums/showthread.php?t=2432


personally, i probably would not "seed" the corrected version.
haha you beat me to it!

I was just going to link that.

It's your choice if you want to seed the corrected version, just be explicit in you notes in the .txt file and only seed if you feel 100% satisfied and confident with the results.

I haven't made much progress on my show yet, I'll probably bump my thread when I get in the thick of it.

starman714
2005-02-08, 04:47 PM
Ok , thanks a lot . I was thinking of finding out for sure the key he plays certain tunes in and trying to harmonize that note on my own gtr. w/the sound of the subject files , and kind of go from there , which it seems you pretty much have to do or trust your ears , from what you've shown me. Sounds like a lot of work , and this guy makes up his own tunings , but I think I have a few pieces of gtr. tablature around that showed his tunings on one of the instrumental tracks on this show called "Ragamuffin".
No , I can't play it...very sparse imitation back when I practised day and night ! :lol
Thanks for the help fella's ! :wave:

uhclem
2005-02-08, 05:05 PM
In foobar2000 you can adjust the pitch and speed of a track in real time as you listen to it. I have used this feature for listening purposes. I would assume that you have to adjust both speed AND pitch if your source was on analog tape.

starman714
2005-02-08, 05:05 PM
Actuall I'm an imbecile , that track ain't on there but some of the others are available as tabs. Also , I'll try to do a better job of searching for a subject before I start a new thread on it in the future.... :redface:
thanks again...

starman714
2005-02-08, 05:12 PM
In foobar2000 you can adjust the pitch and speed of a track in real time as you listen to it. I have used this feature for listening purposes. I would assume that you have to adjust both speed AND pitch if your source was on analog tape.

thanks , uhclem , I missed that feature in foobar.
so far , the source I'd be working with is on my HDD , but if you mean originally the lineage is too unclear and that's the way the seeder recieved the the fileset and info.'s . thanks for the tip , should make things easier for myself , and Five , for the show he's going to be working on :cool: :thumbsup
but , yeah , I'd guess I'd have to do both corrections , speed/pitch , though really , the songs don't seem too fast....maybe someone corrected speed at one point and the pitch stayed the same in the digital conversion ?

starman714
2005-02-09, 12:22 PM
In foobar2000 you can adjust the pitch and speed of a track in real time as you listen to it. I have used this feature for listening purposes. I would assume that you have to adjust both speed AND pitch if your source was on analog tape.

ok , so i used sound touch in foobar and got it where i want it , but when i save it as a playlist , it doesn't save the sound touch effect unless i leave it on in the dsp manager in a way that would effect anything i play unless i manually disable sound touch...i'm not sure how this will or will not transfer into an audio cdr burn. some players you can save a cue sheet that will leave an effect in for that setlist exclusively, i don't know how to do that in foobar , any tips ?
p.s. sound touch is awsome , I had Michael Hedges sounding EXACTLY like Richard Thompson as far as the voice went in Hedges cover of Shell Shock Venus , he's even singing with a U.K./Scottish accent to it ! I almost thought the show was a fake until i pitch corrected again and MH starts talking about his home in Oklahoma...! and of course the differences in gtr. playing. Here's what it looks like for anybody who doesn't know this feature in foobar2000...

http://img168.exs.cx/img168/9057/foobar2000stouch4wu.jpg

starman714
2005-02-09, 01:08 PM
oh , and i forgot to add that i decomped into .wav first , as that is what i'll be burning from...and you go into preferences>playback>dsp manager>sound touch , to open it up , if you have advanced features enabled...

RainDawg
2005-02-11, 10:09 AM
As for making a true "speed corrected" version, this is not very easy. You have to find a note which you know what it is in the recording, and the adjust the speed until it matches a "true" frequency for that note. This requires very good pitch-accurate ears and quite a bit of time. If you're not experienced with this, pleae do not re-seed these recordings.

starman714
2005-02-11, 12:42 PM
Well , i've definitely got the ears as I tune up by them and am normally quite accurate , but before I'd recompress a set of these .wavs' to .flac for archiving , I'll pitch them to my gtr. ,as I stated above, which I'll tune with a digitally accurate tuning source , however ,I foresaw the concern that you of the Den would feel about such altered sources entering 'the gene pool' , so to speak , and so I asked that question as well. The lineage alone disqualifies it for seeding on this tracker , but I had much confidence that somebody here would be able to field this question for me , so I asked you guys.
Thanks for the time and space , have a great day. :wave:

starman714
2005-02-11, 01:16 PM
I guess really , to make a long story short I should have just asked if there was software that could achieve "true pitch" on a show for the user , rather than rely on the users flawed abilities , but I suppose even such a program would need an accurate source to work from and a studio source of the same song would really not be reliable enough unless one knows for a fact they don't change keys for ease of tuning in live performance etc. etc. :wave:

Five
2005-02-11, 06:54 PM
I'm still in the theoretical since I haven't done pitch correction yet... that having been said, my concept is that if you can find several isolated notes, then you can match them to the studio version of those notes. If the guitar happens to be out of tune at the show from time to time, by finding a few places to check your pitch correction "magic number" you could find the setting that gets the highest number of these to correct pitch.

as for generating tones, I haven't used this but I believe mostly any wav editor can do it. dig around in the menus, etc... I'm going to take a look around when I get a chance and see what I can find. If you're really stuck I'm sure I can dig up a couple links and/or send you test tones from my end sometime next week. let me know how it's going.

starman714
2005-02-16, 10:52 AM
Hi Five ( no pun intended)
I had fixed the pitch and tempo in foobar2000 , which allows you to adjust both those and the rate AS you listen , which was a big plus , but then you have to burn it with foobar which uses your Nero as it's burner,in order to keep the effects in place , it wouldn't create a cue sheet that retained the values I had set.
I was using Aerial Boundaries as my tuning guide as there are four versions listed right on Stropes web page ( http://www.stropes.com/index.php?glbm=1&fa=7&bkid=1) that all incorporate the same tuning C2C3D3G3A3D4 , the numbers being the octave of each note , not the string, of course , and by tuning my own guitar accordingly , so I could let the low C note ring in open position as I adjusted tempo /pitch with my mouse, etc etc .
However ,Nero only recognizes my lite-on CD burner which has been junked , and not my DVD burner so the project got shelved until I could get CED , Goldwave or Sound Forge going on it. However I've been spending the last two days flat on my back in 28 degrees farenheit weather working on my car !
Some guy over on EZT tried a fix but I think he got it wrong....as indicated by the mods comments...
http://www.easytree.org/torrents-details.php?id=28278&viewcomm=280675#comm280675

starman714
2005-02-16, 12:52 PM
My bad , he did in fact , actually use the correct function in Goldwave to
restore this particular show , but had failed to mention that part of his proccess until later.
I don't know how this may or may not help on the show you're working on ,
but others experiences and angles of approach are always a good thing when
theorizing on a fix , plus it opens up the question in more depth for the more experienced users to address ,right ?
I'll be checking back now and then to see how things go for you , Five.
Have a good one and thanks again :cool:

Five
2005-02-17, 03:03 PM
thanks for the info starman... please do keep me updated. When I finally get to my project I'll post all the info about it for anybody who's interested to check out.

btw, I'm curious about using foobar2000 for pitch correction. Can foobar play back a file in real time so that the final time of a WAV is just a little bit shorter? Can you tell me where these settings are and how they're used? I want to use this for yet another project (work-related).

ssamadhi97
2005-02-17, 05:49 PM
errrr... he actually already posted all the info you're asking for. in this very thread, even.

http://www.thetradersden.org/forums/showpost.php?p=68927&postcount=8

starman714
2005-02-17, 05:59 PM
thanks for the info starman... please do keep me updated. When I finally get to my project I'll post all the info about it for anybody who's interested to check out.

btw, I'm curious about using foobar2000 for pitch correction. Can foobar play back a file in real time so that the final time of a WAV is just a little bit shorter? Can you tell me where these settings are and how they're used? I want to use this for yet another project (work-related).

That's a good question...wish I knew !
If you go into preferences > playback>DSP Manager > Sound Touch , the controls are there.
( first you have to make sure you've got all that stuff enabled by going into DSP Manager and putting them from the right column into the left column , and remove effects you don't want the same way...my simplest explanation... :hmm: )
In Sound Touch are the controls for 'Apply Slider Changes In Real Time' , 'Tempo' , 'Rate' and 'Pitch'.
There's a screen shot of the sliders that also pretty much includes the path to them on the previous page of this thread.
They are very sensitive...I had to move the mouse cursor a hair at a time before clicking to get it just right. If I move the slider by holding my left click down , I get what I want but it takes awhile to get used to , especially while hitting a guitar string with my left hand(one time being a lefty came in handy , my left is my natural pick hand).
There may be ways of doing what you're saying in foobar , but I'm not aware of how to use them.
I just managed a rudimentary , but I believe , tonally-accurate way of fixing the pitch on this one show I encountered , using foobar.
See , I'm not sure what tempo he played this show at...he could've rushed through the numbers a little , but the guitar would still be in the right pitch that he tunes in, if it was him hurrying and not the tape recorder/player...know what I mean ? So I just focused on getting the note right and left the timing of the beat to my ear and my pretty much embedded memory of how fast his tunes go....not the mathematically accurate way , I know , but you've given me a new idea :idea2: as far as how to get that corrected using a studio recordings timing as a guide.
If you're shooting where I think you are (took me a minute to catch on !), we'd probably be better off trying to do it with CED or Sound Forge 7.0, which I've got a cracked copy of , but admittedly , the controls on SF might as well be in Greek to me at this point !

ssamadhi97
2005-02-17, 06:57 PM
Audition's speed/pitch correction filter has always unimpressed me.. SoundTouch or whatever Sound Forge has to offer might be the better option.

By the way, no need to pull off mouse acrobatics. You can move sliders (like those in the SoundTouch config) around using the arrow keys as well.

starman714
2005-02-18, 12:11 AM
On second look at your comment , Five , are you just asking basically to shorten the play time of a file ? That's what I thought at first , then I thought you meant to change the time without having to listen to it , so I modified my comment and came to think you were saying we could change a tempo by submitting a pre-determined value for the software to use as a template of sorts to adjust the speed of the track. However looking again I'm thinking real time is what enables us to hear the track/adjust the track 'on the fly' , so to speak , and that my original interpretation of the question was correct...
This terminology is new to me and I'm not sure what you mean....look forward to your comments , I'm gettin' hooked on trying to learn this....!

Five
2005-02-18, 02:32 AM
I need to shave 50ms off of a separate WAV file to wild sync it with a 12 minute cartoon from pro digital tape. ugh! This is just temporary until we get a SMPTE system wired up. I hope foobar has fine enough controls.

Well, here's the story of pitch shifting, as I know it:

Tape decks always have a pitch control (usually buried somewhere in the circuit board, sometimes can be controlled from the front panel). For years this was the only pitch shifting available. Dead simple, it's a control that adjusts the speed of the motor. Playback at a faster speed, pitch is also increased. Play back at a slower speed, pitch is decreased. Also of importance is that time (& thus tempo) are made shorter or longer sympathtically.

On an analog multitrack machine, all of the tracks run at the same speed. So to affect the pitch of one track means also changing the pich of the other tracks (equally). So, to pitch shift an overdub up a bit the multitrack would have to be run at a slightly slower speed during layering, or vice-versa for pitch shifting down. I'm sure some other more labor-intense strategies were used as well.

Then sometime in the 70's an outrageous new invention called the "Pitch Shifter" was invented. It could digitally alter pitch without altering time with just a tiny lag for processing time. Prices were incredibly high, it still costs around $5000 for an Evantide Ultra-Harmonizer.

Now we have all this and more in software.

So, in the case of a tape of a show, when you can hear the speed is all wrong, it means your deck isn't playing at the same speed the original tape was recorded on. Ideally and by far the best option is to adjust the pitch of your analog deck right at the stage the tape is being played into the digital recorder.

If this is impractical, digital speed correction is necessary.

Preserving tempo is useful for pitch correction of a single wrong note (on a discrete track).

Preserving pitch is useful for a television documentary where you want to adjust spoken passages to the exact right lengths to sync with the timing of the film. In this case you want the pich of the announcer's voice to stay the same and the tempo (and therefore length of time) will be stretched or squashed.

Since we want to simulate the analog deck running at a different speed, we don't want to preserve pitch or tempo.

The really big complication comes if an analog deck runs at varying speeds during recording or playback. Now that's a challenge to fix!

starman714
2005-02-18, 05:59 PM
Ha Ha , looks to me you don't need my help ! :lol
You know way more than I could tell you.
I knew about speed changing pitch way back when I'd have to adjust my turntable to play along with a record , since I was tuned correctly but the record was usually too fast , and I see how it applies to tape , but all that other stuff....
I can understand your meaning but I don't really 'know' all that. I know Clapton did some of that on the Let It Rain solo in the studio , which was a big disappointment to me , to read him say they sped it up and synced it with the backing track before they layered it in to the final mix , but as far as foobar shortening a wav and then being able to sync that with a vid , I really don't know , would their read-outs even be the same even though digital is supposed to be mathematically perfect ? Are most softwares on the same page with that ?
You'd know better than I would ,
but thanks for the fascinating conversation , anyway , and wish I was up to speed enough to help with something like that.
I'll just sit back and listen for awhile ! Have a good one , Five :wave: