Smpte

[guitarfreak12]

I have always read about SMPTE, and it's uses, but I still don;t understand. Can someone explain in what specific cases I would benifit from SMPTE. I have the capapbilities, just don't know what to use it for.

 

[phaqu]

SMPTE is a time code used to sync up machines like audio to video or to sync older tape machines to other equipment like ADATS or a computer through a sync box ( something that can translate and use the different time codes with each other).

 

[Robert D]

I have the capapbilities, just don't know what to use it for.

It's not something you really *want* to find a use for. It's a non-sample accurate way to synchronize different equipment together so that you can either use them synchronously, or transfer several tracks from one to the other - more tracks than you can transfer in one pass. SMPTE locked at 30 fps (frames, not feet) is tight enough except for splitting stereo tracks, where it's non-sample accurate lock will become apparent. I've used it for transferring projects from ADAT to disk based MDM's. For transferring into a computer, I've usually used MTC (midi time code). SMPTE is usually striped onto an extra track on equipment that doesn't have a dedicated sync functionality.

Hope that helps, but that you never have to use it.

 

[bennychico11]

well, technically speaking SMPTE is actually an association of engineers who create internationally recognized standards. It stands for the Society of Motion Picture and Television Engineers.
SMPTE time code is just that....time code and was developed by those guys who are a part of SMPTE. In the music world it's an analog audio signal (you can actually patch it into some speaker and hear it) and in the video world it can be interleaved within the video itself. It's primary use is to label individual frames of video. It is not something to be afraid of and is used everyday in lots of studios...particularly post houses. Computers need the SMPTE code converted over to MTC (MIDI Time Code) in order to understand it.

 

[brendandwyer]

the way that it works (this is the non tech but works version) is that a device that generates SMPTE time code outputs it via 1/4" jacks to a recorder. In my case, i use a Mackie SDR2496 to generate time code and i record it onto track 8 of my Tasam 1/2" 8 track. Then, i put the Mackie into slave mode and set it to chase time code. It waits for me to press play on the 8 track, it *listens for the time code, and after a short 2-3 sec delay it locks up with the code that is being played into it. In that way, 7 tracks on the tape machine and 24 tracks on the Mackie are playing and recording in sync. This is one of the number of uses of SMPTE time code.

 

[felipousis]

The SMPTE time code was created to do sync between the image and the sound, so the idea is to have a VTR and a audio player running in sync, not at the same speed. The SMPTE time code divides a time unit (a second) into frames:

NTSC 30 or 29.97 frames per second (fps)
PAL 25 fps
Film 24 fps

If you need to do audio for video, you need to check the fps rate of the video footage to set your session or project to match that fps rate, if not, all the audio will be out of sync when they put the image and the audio together.

 

[Robert D]

OK, for bonus points....... what's the diff between 30fps drop frame and non-drop frame?

 

[petermiller]

in actuality 30fps is normal frame rate for black and white pictures. drop frame rate is 29.97 due to the distorions in framerate vs time in color video.
drop frame rate in relation to actual time is not directly divisable buy any unit of real time
thus if you played at 30fps you would have 108,000 frames for 1 hour. that played in 29.97 would translate to 1 hour 3.6 seconds. all NTSC video is in 29.97

 

[soundchaser59]

well, technically speaking SMPTE is actually an association of engineers who create internationally recognized standards. It stands for the Society of Motion Picture and Television Engineers.
SMPTE time code is just that....time code and was developed by those guys who are a part of SMPTE.

Actually, the SMPTE adapted a time code that was developed at NASA. It has been streamlined into "Litzi" (LTC), "Vitzi" (VTC) and "Mitzi" (MTC). LTC is "Longitudinal" time code for straight audio, VTC is vertical interval time code for video, and MTC is midi time code. 30 fps with 100 subframes per frame gives an accuracy of 1/3000th of a second.

Computers need the SMPTE code converted over to MTC (MIDI Time Code) in order to understand it.

It's the programmers and the software that needs it converted. The computer can handle it just fine if a programmer takes the time and trouble to write code for it. I have and still use a 1985 Atari 1040 STE that reads and writes true bit accurate binary smpte time code. This is an 8mhz processor with 4mb of ram and no hard drive. The smpte code is not interpreted or translated at all. My sequencer (Hybrid Arts SMPTE Track) reads and writes smpte using machine code in the hard-wired Atari os. I used to do exactly what brendandwyer describes below......

the way that it works (this is the non tech but works version) is that a device that generates SMPTE time code outputs it via 1/4" jacks to a recorder. In my case, i use a Mackie SDR2496 to generate time code and i record it onto track 8 of my Tasam 1/2" 8 track. Then, i put the Mackie into slave mode and set it to chase time code. It waits for me to press play on the 8 track, it *listens for the time code, and after a short 2-3 sec delay it locks up with the code that is being played into it. In that way, 7 tracks on the tape machine and 24 tracks on the Mackie are playing and recording in sync. This is one of the number of uses of SMPTE time code.

I did the exact same thing with my Atari, the Hybrid Arts sequencer, and a Teac TSR-8. SMPTE time code to track 8, then synch the Atari to the tape. I replaced the TSR-8 with a Tascam 2488, and now I do the exact same thing on that machine......SMPTE time code to track 1, then pipe it back to the Atari to drive the sequencer. I do this because the Hybrid Arts sequencer is so old it doesn't know what MTC is.....but I kept using it because it is otherwise a very powerful and friendly sequencer. It only recognizes clock and song pointer, but it runs on true binary smpte time code. I can random locate my 2488 to any point in the song, hit play, and the Atari will synch up perfectly in a second or two. Works great! And it has a midi-plexer that gives me 4 banks of 16 midi channels each......1-16 on banks A-D, or 64 midi channels. It controls my drum machine, my synths, my guitar amp, all my fx units, and the 2488 levels and mixer. The only thing it cant control is the 2488 transport.