Tapeless Question: Drop frames every 2gb?

[Darryn Carroll]

Researching cameras to go tapeless, I have read about the "2gb file size limit" and am wondering:

Are there dropped frames between each 2gb file?

In other words, lets say I inserted a 16 GB card, press record and recorded an hour straight, could I end up with a few files of 2gb in size and experience dropped frames between? With tape I am accustom to recording an hour straight without interruption.

Thanks all.

[Vince Pachiano]

I'm not sure what 2GB limit you are refering to. There used to be OS limits, but 2GB is outdated.

1. At its highest quality setting, a 16GB card should get you nearly 90 minutes of footage.
At a DV setting (as your used to now?), you should get 4:45 of footage.

2. My particular camera has a 12 hour limit for a single scene. After 12 hours, the camera will stop for about 3 seconds before resuming recording.

Either of these solutions are greater than your current 60 minute limitation of tape.

[Darryn Carroll]

Thanks Vince, I may have old info, I had thought that files had a 2gb size limit. So are you saying that in your scenario, if I recorded an hour long video, I would have one single file?

[Darryn Carroll]

Actually, I think my question may pertain to the SD cards used. I think most cards formatted to Fat32 which has a 2gb limit. Maybe its as simple as formatting to NTFS?

[Vince Pachiano]

Originally Posted by Darryn Carroll

Thanks Vince, I may have old info, I had thought that files had a 2gb size limit. So are you saying that in your scenario, if I recorded an hour long video, I would have one single file?

I can only go by my camera:
1. Every time you press Record, it creates a new file,

2. The SD Card is formatted FAT32; thus the largest file is 4 GB

3. If you record at a lower setting, such as SP, your entire hour video would be in one file

4. If you record on the HIGHEST quality setting, 4GB holds about 20 minutes, so recording for a solid hour would yield 3 or 4 files (00001.mts, 00002.mts...)

[Bruce Watson]

Originally Posted by Darryn Carroll

Are there dropped frames between each 2gb file?

No. There are not.

I had an old Canon HF200 (five years ago?), recorded many classes and lectures, continuous captures of many GB, over 16GB in several cases. It created many 2GB files during a single capture, but never a dropped frame between these files. Why would it?

[Jody Arnott]

I have a couple of AVCHD cameras that split the file every 2-3GB (can't remember exactly what the number is).

Anyway, if I stick the files back together in my NLE, it does drop a few frames where the join is. However if I use the software that came with my Canon camera to import the files, it joins them together with no dropped frames.

[Chris Harding]

AVCHD creates a new clip as soon as the previous clip hits the magic 2GB point so all the happens is that a new clip continues from where the old one left off ...this continues until you stop the camera so an hour of continuous recording make create 4 or 5 clips (depending on the bit rate) ... Does it drop any frames? Not at all BUT you need to use the camera's export software to recognise that you have a sequence that's over 2GB and it will gather up all the pieces and export as one seamless clip.

However IF you decide to skip the import from the camera software step and simply copy the files across to your computer YES it does drop 12 audio frames only ... video frames are not dropped so you will have a slight glitch in the audio if you decide to manually join split clips together. Using the software that comes with the camera you always get a clean clip so don't worry about it.

Chris

[Dave Blackhurst]

As you can see, there "can" be issues between subclips IF you don't use the software supplied by the mfr. Different users have reported different results, depending on their software/hardware/camera configuration.

As a practical matter, it's a NON-issue, and just a different workflow than tape...

[Chris Harding]

You can also get over the issue by making sure you stop and start the camera before it hits the 2GB mark. Sometimes it's just not practical of course but at long weddings there are plenty of opportunities to do it. If all your clips are under 2gb then you can just copy them straight to the drive.

The biggest issue I had moving from tape to card was the fact that every time you push start/stop a new file is created ..with tape you can do this and film a whole bunch of say, 30 second segments and they will be recorded seamlessly. Do the same on card and you suddenly have hundreds of clips ...On my first card wedding quite a few years ago I copied the data over and found I had close to 200 clips from my B-Cam .... sometimes you need to keep filming otherwise doing it the old tape way you will end up with a horrific collection of small files that you simply are not used to!

Chris

[Jeff Pulera]

There seems to be some confusion and misinformation on this issue.

First, it is not up to the user to format the SD card with one file system or another - cards should be formatted IN the camera for best results, and it does what it does. Not for me to decide.

As stated by another poster, some cameras offer dual card slots and when one card becomes filled, it will continue onto the next card, but you may lose a few seconds of recording during the changeover. That is normal and is advertised as such by the camera vendors. Not something most of us need to be concerned about unless using very small cards and with very long recordings.

But if you are just recording say an hour or two onto one card for instance without stopping, yes it does create new clips every so often, however there should be NO recorded glitches or missing frames. Period. Any such issues are typically the result of improper file handling and/or import method with the NLE after the fact.

Depends on the NLE being used, and how you handle the files. A lot of folks think (in error) that they can just dig down through the file structure of the SD card and locate the actual "video clips" for instance .mp4 or .mts and then copy ONLY those files to the computer for editing. Those clips by themselves might play just fine in a media player software, but when put into the NLE for editing, problems can arise.

There is metadata in the folder structure of AVCHD, XDCAM, etc. that is vital! With some formats, the audio and video may even be recorded as entirely separate clips. People have copied video off the SD card and then re-used the SD card and then they have problems editing, with no recourse since the original data is gone forever.

I can't speak for all NLE workflows, but in general, copy ALL the data from the memory card directly over to your computer hard drive. This means ALL folders, do not pick and choose. Do NOT change the names of any files or directories, and tempting as that might be. You will corrupt the critical relationship shared between data in those files. Do not use any conversion or transfer utility (other than perhaps something that verifies the data integrity, key being don't alter the files at all).

For Premiere Pro, do not use File > Import. If you have a bunch of short files that are part of a longer recording, this method will result in the dreaded audio hiccups in the timeline between each short clip.

Rather, use the Media Browser function in Premiere to import. This recognizes and respects the AVCHD file structure, and those short clips will be imported as one long clip for editing purposes. No data is changed or rewritten, it just imports with intelligence. I just did 6 dance recitals at 2.5 hours each recording as AVHCD and the many small files for each show imported as ONE single 2.5-hour clip for editing. No glitches, no sync isues, PERFECT.

I read another posting recently that suggested Sony Vegas operates in a similar fashion, but have not tried it.

In any event, whatever workflow you decide on, I would always keep a backup of the raw data from the SD card separately until the job is done, regardless of what method or conversion you decide on for your workflow. Good to have that unmolested video data in case something goes south in editing.

Hope this helps

P.S. - even if the camera comes with some software to "stitch" together the clips after recording, I would still not mess with that if you don't need to. If editing with Premiere for example which can properly handle the raw data, why start messing with and converting things? Keep it simple and straightforward for best results.

[Darryn Carroll]

Thank you everyone for all the informative replies. I think I have a grasp on everything now and will pursue to my tapeless changeover!

[Karl Walter Keirstead]

My Panasonic Ag-AC160A starts a new file every 4 gb. No frames are lost if you do the transfer properly.

Anyone trying to record musical concerts (or their clients) would not tolerate frame drops.

[Don Palomaki]

Binary concatination (the old DOS COPY command with the /B option) of the spanned (split) AVCHD files from the Canon camcorders generally works to rejoin the split files, but many folks may be uncomfortable with using it.