Why the Panasonic GH4 Splits Video Clips Into Multiple Files

Data Management for the Panasonic GH4
By Sol March in Resources

You just shot a long video clip with the Panasonic GH4, but instead of a single file, you find multiple files on the memory card.

What gives?

It might not make sense at first, but there is a simple reason for this. We’re going to dispels some myths, explain why the GH4 splits clips into multiple files, and show you what you can do about it.

Note: This post specifically refers to shooting in MOV or MP4 formats with the GH4. AVCHD creates files in it’s own mysterious and convoluted way and should be avoided whenever possible.

The Red Herring: Recording Time Limit

If you’ve ever shot video on a DSLR camera like the Canon 5D MKIII, you’re painfully aware of the recording time limit most of those cameras impose. This might lead you to think that this is why the GH4 splits video clips into multiple files, but that’s not the reason.

Simply put, the reason this is not the case is because the GH4 does not have a recording time limit.

While some cameras need to stop recording every 12 to 30 minutes to avoid overheating, the GH4 has no issues with cooling. In fact, even Panasonic’s GH1 from way back in 2009 keeps it’s cool when shooting for extended periods of time.

There is a caveat: If you purchased your camera in Europe, then all hybrid cameras– including the GH4– are limited to recording for 30 minutes at a time due to regulations on imported cameras.

Nonetheless, a European GH4’s 30 minute recording time limit, does not explain why video clips are split up into multiple files on the memory card. In fact, even a 30 minute 4K recording would be split into about 6 separate files on the card.

Bottom line: The GH4 does not have a video recording time limit, but even if it does (European model), the limit has nothing to do with video clips being split into multiple files on the GH4.

The Real Reason: Disk Formatting

The real reason that the GH4 splits clips into multiple files is due to file size limitations of the FAT32 file system used to format SD cards.

Take a look at the GH4’s 4K footage and you’ll notice that it’s usually split into files that are each about 5 minutes in length. This is because the FAT32 file system only supports files up 4GB in size, which amounts to around 5 minutes of 4K (100mbps) footage from the GH4.

As a result, while the GH4 can record video continuously for over an hour straight, the video will be spanned across multiple files that are no larger than 4GB in size each.

Thankfully, nothing is lost when multiple files are created for a long clip. The entire video is available when the files are played back sequentially.

Bottom line: The GH4 splits clips into multiple files because the FAT32 file system used by SD cards does not support files larger that 4GB.

exFAT: The Solution?

exFAT is the successor to the FAT32 file system and was designed for high-capacity memory cards. FAT32’s 4GB file size limits are a thing of the past as exFAT supports file sizes up to 128 million gigabytes.

As the default file system for modern SDXC cards, surely exFAT is the solution to our multi-file problems…right?

Unfortunately, even when using an exFAT-formatted memory card, the GH4 still splits long videos into 4GB files.

After further testing, the GH4 appears to create 4GB files as a rule, regardless of whether the memory card’s file system supports larger files or not. Panasonic chose this approach to avoid extremely large files and to make handling files easier for post production.

Furthermore, by breaking clips into 4GB files, the GH4’s footage maintains compatibility with other file systems that– like FAT32– do not support files over 4GB in size. This can help to avoid unexpected issues when copying your footage from the memory card to external hard drives for editing and archiving.

Bottom line: The GH4 splits clips into 4GB files when using an exFAT-formatted memory card even though the card supports larger files.

Solutions for Working with Multiple Files

There’s no way around it– the GH4 is going to split your video clips into multiple 4GB files whether you like it or not. Thankfully, working with multiple files during post-production is rather straightforward.

Here are a couple options for dealing with multiple files per clip:

Option 1: The Line-up

The most straightforward option for working with video clips that span across multiple files is simply to line them up sequentially on the timeline.

When the files are lined up back-to-back on the timeline, they should play back seamlessly. Most NLEs software will automatically arrange multiple clips when you select them in the bin and drop them on the timeline .

Select multiple files in bin Spanned clips lined up on timeline

Option 2: Merge Files

To simplify media management from the beginning, you can also merge a clip’s multiple files into a single large file with software such as MPEG Streamclip.

Joining multiple clips into single file with MPEG Streamclip

The key is to use software that only merges the files together rather than reencoding the video and audio data, as this will maintain the clip’s original quality.

Important: The new merged file will be larger than 4GB, which means that it will be incompatible with certain file systems. Ensure that your hard drives support files larger than 4GB to avoid issues during post-production.

Inconvenient, But Workable

There you have it– the GH4 splits files to maintain compatibility with file systems that do not support large files and to keep individual file sizes from getting to large, not because of a recording time limit.

There’s no doubt that wrangling multiple files is inconvenient, but with a bit of forethought and organization of your project’s files, it is manageable.

Hopefully Panasonic will remove this limitation in future cameras, or even in the GH4 itself via a firmware update.


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