Topic: Portable with timecode capability

[Carlos E. Martinez]

I am on the look for a CF portable recorder that can record timecode too. And I would like to know how compatible the existing models are or how they differ from each other.

What I wonder is how you record TC in those machines. Is it an extra channel? How do you export the whole recording?

From what I could see, among the affordable machines (below $2,000) the Fostex FR2 and Edirol R4 Pro can record BWF files, which AFAIK can include TC info in the files. The other option, the Tascam HD-P2 seems to record TC too, but they use WAV files, which I don't know if accepts TC.

The Tascam, besides being the most affordable one (less than $1,000), seems to have excellent mic preamps and I think it's a very reliable machine. So it might be my entering door into the film & video double-system market. But I need total compatibility with what's already used.

[flintstone]

I think you identified the options under $2000: Tascam's HD-P2 ($850 plus cost of memory cards) and Edirol R-4 Pro ($2000, including hard disc).  The Sound Devices 702T ($2500) would be the next step up the ladder.

Marantz talked about making a time code module for the PMD671, but I don't think it's available at this point.  The Edirol R-44 has a useful sync port that lets it control a second R-44, but it doesn't accept true time code.

Does anyone know if the HD-P2 can address all of a 16Gb compactflash card?  It used to be limited to 8GB.  8GB = 4 hours of recordings using two channels at 24/96.

Flintstone

[JackoRoses]

last I heard (april 08) the hd-p2 can not address the full 16gb cards.
Still limited to only recording 7.99 gbs on them currently unless something has changed in the last 2 months.

[ghellquist]

A small diversion...

As for the digital boxes mentioned, timecode is only used to stamp the beginning of the sound. It is not recorded in any other way. It is not a special track or anything like that, only encoded into the header of the sound file (bwaw format). In older analog recorders (tape recorders, anyone remember them) time code was recorded running all the time on a special track.

If you are planning to run with time code, be careful to look into how you are going to synchronize the time of different units. On a film shot you will probably have a "master" time code box which you use to "jam" the time code of the different units over a cable. The boxes can then freerun half a day or so, if the shot goes longer than that you could jam again at a convenient break.

Generally, time code is only useful when you want to combine several sources all having, more or less, short takes. And only if your editing program handles it. Typical use may be several cameras and one or more audio recorders doing some kind of film shot. Each take is often short, a minute or maybe two. There are many takes to combine. In Avid you then simply import all the video and sound (now, this is simplification, but the idea is there) and they all end up the time line exactly where they were done and hence are already in synchronization. In a situation where you need to postprocess several hundred things each day it is easy to see the time and hassle saved.

One problem time code does not solve is the drift between different units. If you want to mix together sound recordings done on several recorders (sometimes called matrixing on this forum, others call it mixing) you will most probably end up having a problem with the drift  between the units. This might be heard as a kind of "phasing" sound. The only really reliable method is to run all the units from the same word-clock. Typical units we all can afford to buy are not stable or accurate enough to not drift in respect to each other so they need to use a common reference. There are ways to transfer word-clock on radio signals, not to had on the cheap though. In a typical film setting though this drift is not a problem as you do not mix together differen sound recordings. The synch needed is between sound and picture and it is then enough to resynch a few times a day.

As the whole purpose of time code is to make post-processing people happy, check with them how they want the material. Seems like sending the CF card with the dailys is a good way today. Any self-respecting person would keep his own backup copy though, at least for a while.

If you want to mix several sound sources, it can sometimes be done by carefully synching the start of a song and then "slip" one of them using some kind of time stretch. Many programs includes ways to do the time slip, and I guess some people has been succesfull in using them, alas I have never had such luck.

Gunnar

[Carlos E. Martinez]

You probably mean that the TC is stamped at the beginning of each take, right?

Do you know if all CF recorders work that way? That is the Sound Devices, Fostex, Deva, etc. do that stamp too? No continuous TC?

I am familiar with the "jamming" concept, as I already own two Denecke digital slates, both having jamming capability. What I am not so sure about is the drift degree a machine such as the Tascam or the Fostex might have as compared with the higher priced machines. If there's not a continuous TC, then you will depend on the transport internal precision.

When you mention a short take, how long do you mean? 15 minutes, 30, 60...? What I do know is that machines such as portable MDs and non-TC recorders can hold up to a frame in 15 to 30 minutes, which in film might never happen, as the roll can only be 10 minutes long.

The program that will be used for editing will probably be Avid or Pro Tools, which I think already handle TC controlled shots.

The usual is to have only one audio recorder handling the sound, and several cameras for the image. They would certainly have to work from the same video reference, which I would have to jam myself to too.

Any variables I am forgetting?

From the Tascam manual, I don't think the HD-P2 can jam to anything, although it does accept external
TC sync.

Sending CF cards might be an expensive and delicate way for delivering the files. I think you can copy them onto an external CD or DVD, which is why I asked about the Tascam files being WAV and not BWF, and if that would be a problem.

[ghellquist]

All digital recorders work the same way as far as I know, including Sound Devices, Deva and Cantar. They simply stamp the beginning TC time of the sound. No continuos TC. And programs like Avid (and so on) are perfectly happy with this. The basic reason is that it is not needed, the stability of the internal word-clock is good enough to run the full 15 minutes (and more). It is not the "drive" that has to be stable anymore, but a crystal oscillator and it is very easy and cheap to make a crystal oscillator good enough for a "long roll".

The built-in TC generator of SD, Deva, Cantar are good enough to still be synched on more or less a full days work. That is good enough to be synched to video, ie with an error less than one frame.

How you deliver the sound files is all about what you have on the set and what the post people expect. They are after all only "computer data". You could burn them to CD or DVD (as data files), copy to CF-cards, copy to a hard disc, send over internet, whatever works. Some of the units can burn directly to a CD or DVD, example the Sound Device units. I guess what most people would do is to have a laptop computer, copy the files over firewire or USB to the laptop internal hard-disc and then make a data DVD disc.

It sort of depends on what work you are doing and how much extra time it will take to do the copy at the end of the day. As CF cards are coming down in price, they are becoming an alternative, especially if they are rotated back once the transfer is done. The Sound Devices units can record simultaneously to CD card and internal hard disc, so after the day you simply send the CD card away, the backup is on the internal hard disc. The day after the CD card is returned and you could reuse it.

Gunnar

[Carlos E. Martinez]

It seems you are right, Gunnar. I got the following answer from Sound Devices:

"The 702T, 744T, and 788T all handle time code in the same manner. When
recording with time code the recorders internal timecode generator is always
running and is available as an analog signal via the 5 pin LEMO connection.
When the file is written, the starting time code value is stamped into the
header information of the file. When the file is brought into a program that
can read the time code stamp, it usually can insert it at the appropriate
point on the time line. When the file is played back on the recorder the
recorders internal timecode generator is again triggered and SMPTE time code
is again present at the LEMO out. If one needed time code striped to an
audio track for say, transcription purposes, you could run a LEMO 5 to XLR
cable back around to an available input and route it to a track on the
recorder while recording audio on the others. Let me know if you have any
other questions.".

Now can someone tell me in what file system the Tascam HD-P2 records in? In the specs Tascam says it's a "Time-stamped Broadcast WAVE file format". That is BWAV.

From BBC I got the explanation that "Broadcast Wave Format File (BWF or BWAV) is a computer file format for audio, based on the Microsoft wave (.wav) file.".

So if BWAV is the same thing as BWF, why doesn't Tascam call the P2 files BWF? 

[rastasean]

Now can someone tell me in what file system the Tascam HD-P2 records in? In the specs Tascam says it's a "Time-stamped Broadcast WAVE file format". That is BWAV.

From BBC I got the explanation that "Broadcast Wave Format File (BWF or BWAV) is a computer file format for audio, based on the Microsoft wave (.wav) file.".

So if BWAV is the same thing as BWF, why doesn't Tascam call the P2 files BWF?  ??

I asked this question about what BWF to Wayne and he replied with this:

Broadcast wav files are simply normal wav files with two distinct differences. You can have poly BWF files (these contain multiple tracks, instead of the standard one or two that wav files have), and you have time code embedded in the file (or you can).  Some applications don't like poly files, so you have to break those up using standalone software if your sound application doesn't support multiple tracks in a single file. Time code is handled differently from application to application, but most video software sees it and places the audio on the timeline where it belongs (assuming that everybody is using timecode, and most consumer/prosumer cameras don't support time code jamming, only their internal free running timecode).

[ghellquist]

If you are technically interested, the actual definition of the file format might be of interest. I believe it can be found here:
http://www.ebu.ch/CMSimages/en/tec_doc_t3285_tcm6-10544.pdf

Gunar