Latency, Accuracy and Repeatability - Test Files

Computers have been standard equipment in post production for some years now. Not all have real time operation systems so that latency can be a problem. When synchronizing the major problem is not accuracy but repeatability, it does not matter if there is a one frame sync error provided that there is always a one frame sync error!

Recently I was asked to add phase compensation to the P2MMC, Jun Yamazaki who works with Tac Systems (our Japanese agents) discovered that different DAW's had a different offset error when synchronizing to MTC. To measure offset Jun recorded timecode and looked at the recorded waveform, Jun is a timecode geek like me but this is not a suitable method for everyone!

I asked Chris Braclik (I worked with Chris when at Audio Kinetics) from Soundtrack Productions to make 3 stereo WAV files, each has one track with continuous timecode at 24, 25 or 29,97fps, starting at 00:59:55:00 and ending at 01:01:05:00. The other track has 1KHz bursts one frame long, once per second stating at 01:00:00:00 and ending at 01:01:00:00. The bursts are positioned exactly at the start of each second.

You can use these files to check the timecode latency and more importantly the repeatability of both record and replay.

I checked the Record on a Sadie system, there was a consistent 1/5 of a frame error when locking to LTC , I have not checked the playback yet.

I will publish a chart of your results if if receive enough information- DAW, Platform, and Results.
Click here to download the test files

Using the TG-2 with Avid Media Composer

On Tuesday this week I visited Anthony Sachot at Eurosport Paris with Daniel Gollety from RS422 our agent in France. I was supposed to visit in December but the flights were cancelled due to snow. I was lucky this time as on Wednesday the flights were again cancelled due to snow!

Eurosport is using a 50i Media composer (25 fps EBU timecode) to import selected takes directly from a 60i HDCAM (SMPTE Drop or Non Drop timecode). This requires a standards converter in the video and the TG-2 to convert the timecode and RS422 communications. A similar setup can be used with a 60i Media Composer and 50i/48i HDCAM. The problem is how to set up the TG-2

This is one of the simpler jobs for the TG-2 as there is it requires no Pullup or Pull down but simply standard translation. On looking at the default setup of the TG-2, I discovered that an number of setting changes were required to make this work. The next software update on the web will include an update to the default setup that will simplify the settings. The setup is as follows:-


1) Connect HDCAM TC Output to TG-2 input
2) Connect HDCAM RS422 input to Serial B on the TG-2
3) Connect Media Composer RS422 output to Serial A on the TG-2
4) Connect 25fps video syncs to the TG-2 , Tri / Bi Level.

The main TG-2 Settings are as follows
1) Input Auto and Output Auto ON
2) Output frame rate selected to 25
3) Serial B Config set to Chase Enable (current Default is Chase Always)
4) Unit Config Set to Ser Auto
5) Gen ref Set to Video

Once the setup was correct the system worked flawlessly and we left a happy customer!

CBServer2

Today I added a CBServer2 page to the colinbroad.com web site. Alpha version of both software and web page! Currently only available by the following direct link - CBServer2

It should be similar to CBServer with the following enhancements
1) Runs on Mac, Windows and Linux. I have tested the software on MAC OS-X version 10.4 and on Windows-XP but not on Linux (Intel-86).
2) One or two RM-6/SR-4 synchronizers may be used allowing control over multiport systems.

I will post updates to this blog, I would appreciate comments on look and feel at present, it is to early to comment on things that do not work - there are to many!

CBServer

I am in the process or rewriting the CBServer software so that it will run on Mac, Windows and Linux. At the moment I am designing the components required and the individual windows.

Now is a good time for customer requests for improvements or special functions. Although CBServer was originally written as a display for the hardware keyboard but has developed into a full user interface in its own right.

The first release will probably not do as much as the current version, but all future improvements will be made on the new version.

VCube - v3

VCube is a Windows based video player capable of playing a number of different formats in both Standard and High Def. Its great strength is its flexibility, however this flexibility makes it easy to make a mistake during setup.

You can find a setup guide on the merging site
VCube_sync_setup_guide_v3.pdf

Daniel Gollety (rs422.fr) has updated this for 24/25 operation and corrected some errors, you can obtain an updated copy from from CB Electronics.

PARIS: L'Aniversaire de Daniel Gollety

Tonight there is a surprise for party for Daniel's 60th Birthday, I will make this post tomorrow.

I have worked with Daniel for 32 years, when I started CB he became our French agent. Daniel was also the agent for Timeline but used CB for Biphase and Sony 9 pin. Daniel now runs RS422 with Jean Pierre Barbottin, Daniel makes the French translations and Jean-Pierre makes the better drawings for our web site.

One of the most important services that Daniel performs for CB is as Quality Control, when possible software is not released until Daniel has checked it and made me fix any bugs that he finds.

Nuendo SyncStation

This week we shipped the first 45 production units to Stienberg, what a relief. The units have been finished awaiting final software for a long time. We can now start on the next batch,

I am expecting to make a lot of small software updates after they arrive with actual customers, but as both the software and most of the hardware is field programmable this should not be a problem. I will try and build a support page for the colinbroad.com web site, more details on that later.

Syncstation connects to Nuendo via USB using an extended midi protocol. You can also connect System Link for bit accurate lock. System Link connects differently, SyncStation receives system link from Nuendo instead of sending system link to Nuendo. This allows the audio to be looped through so that you do not lose an audio channel.

My preferred way of using SyncStaion is by making the virtual machine the "Master". In this mode Nuendo follows the MTC via USB and both LTC and MTC are available from SyncStation. Connect both Wordclock/aes clcok and video syncs to SyncStation and run the audio from wordclock/aes clock.


Timecode: To ensure that the timecode is locked it uses the wordclock O/P or I/P to generate timecode. The wordclock(audio) and timecode should always be locked.