1. Time Code and Word Clock
Syncing Audio with Video and MIDI
And syncing digital devices

2. What is Time Code? It is a way of SYNCRONIZATION
It allows different kinds of devices to communicate and sync together
This can be useful with:
Audio for Video
MIDI systems
Various digital devices

3. SMPTE Time Code
When audio is added to video, they need a way to be perfectly in SYNC
VIDEO is made up of individual frames
DIGITAL AUDIO is made up of SAMPLES

4. What is SMPTE? The Society of Motion Picture and Television Engineers
They decided on a UNIVERSAL standard.

5. Frame Rates The time codes depend on the frame rate of the video
It is usually one of the following:
24 FPS (Common for film)
25 FPS (PAL European format)
29.97 FPS (NTSC American)
30 FPS (HDTV)

6. Audio/Video Communication
The audio and video streams are generally produces from different devices
Using a universal SMPTE format allows for the audio to stay perfectly in place with the frames
For example:
Take 24 video FPS and 48k audio
That’s 2,000 audio samples for every frame of video!

7. Telecine and 3:2 Pulldown
TELECINE is the process of converting motion picture film to a video format
3:2 pulldown makes 24 FPS film look proper on a TV broadcasting NTSC FPS.
Luckily, audio is not affected by this process

8. MIDI Time Code (MTC) Remember that MIDI is simply data information
MTC is simply another form of syncing audio and video
These are called ‘Quarter-frame’ messages

9. Word Clock Word Clock is DIFFERENT than timecode
It is for syncing digital devices to avoid data errors
This can also be useful with:
Tape machines
CD Players
Multiple digital devices

10. Master Word Clock These devices are used to sync it all perfectly
Antelope
Drawmer
Lucid
Digidesign

11. Jitter Jitter is distortion of high-frequency signal
It is caused during transmission between digital devices
This is often caused by clock errors and can be avoided by:
Using a Master Word Clock
Using quality A/D converters with Jitter reduction
Jitter reduction built in to digital units

12. Syncing in the modern studio
Syncing is often now done “In the Box”
Software is designed to sync internally
Modern digital devices have technology to sync properly and avoid jitter

13. Surround Sound Most common format is 5.1
7.1 is also supported on Blu-Ray
The ‘.1’ refers to the LFE channel (Low- Frequency emmissions)
Generally, this is a crossover for the subwoofer, incorporated by the engineers

14. Uncompressed Audio for Video
PCM: Pulse Code Modulation
This is a completely uncompressed file, just like we would save from Pro Tools
Blu-Ray TrueHD: Linear PCM 8 Channels fully uncompressed! Wow.

15. DTS and Dolby Digital
Support surround sound, but are compressed audio formats
They are considered a ‘CODEC’ almost always found on DVD discs
About 640 kbps compression rate

16. Some Other Formats DVD Audio SACD Up to 192k stereo, 96k full surround
24-bit audio
SACD
Sampling rate up to 2822 khz! (CD is 44.1)
120dB Dynamic Range (CD is 96)
Nearly 8GB capacity