Question Record mp4 file without splitting (Panasonic v770 and sdxc card)

asd84

Member
Hi,
I've looked all over the internet to try and find an answer to this and I'm struggling - hoped someone here might be able to help!

I'm recording video on Panasonic v770 in mp4 onto SanDisk Extreme Pro sdxc card to then edit on iMovie. I'm recording clips up to about 35mins long.

First time I did it I recorded using AVCHD which was then a pain to edit in iMovie. (Although clips were recorded in full length)

Second time I switched to record in mp4, but clips cut (and automatically restarted) around 15 minute mark. Wasn't a huge problem as can just run one clip after the other, but there's a slight skip and I'd rather it was all just one mp4 file. I understand that this happens on SD cards, but my research/googling seems to suggest that sdxc (which the v770 is compatible with) should be able to record the full length clips. The mp4 format was definitely easier to use on iMovie

Any suggestions?
Thanks, Ali
 

Emerton

Active Member
I have never noticed a limit with .mp4 files. If you are formatting the card in camera there shouldnt be a continuous recording limitation afaik.
 
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dosdan

Active Member
I have never noticed a limit with .mp4 files. If you are formatting the card in camera there shouldnt be a continuous recording limitation afaik.
There is an individual filesize limit with Panasonics.

I'm mainly done 1080p60 MP4 recording at "50M" which actually has an average bitrate of approx 45Mbps with a peak bitrate of 49.2Mbps. With the "50M" setting, the Panasonic HC-V750 records a new file every 3.47GiB (11m), while the HC-V770 records a new file every 3.99GiB (12m36s). This is at 60p. 1080p50 would be different: 60/50=1.2, so 20% longer recording duration when using 50p before the individual filesize limit is reached. The camera automatically starts a new file when the max. filesize is either reached, or you pause and then restart recording. There is a slight pause in the audio at the very end of the file, but this switch-over gap is not normally noticeable. You can edit it out, if necessary.

The max. duration I've recorded was just over 10h31m, unattended. These cameras can be run off of an ext. 5V source, and I was testing the actual capacity of a "20,000mAh" 5V/9V/12V powerbank when using it only supplying 5V. This was in 720p60 mode which is supposed to be about 9Mbps. I was using this mode so I could record for a longer duration on a 64GB SD UHS-1 card. In 1080p60 50M mode the camera is supposed to fit 3h09m onto a 64GB card, but I've never tested that.

Note: a "64GB" card is 64 * 10^9 bytes because 1GB = 10^9 is used by the media storage industry. In "true GB", where 1GiB = 2^30 bytes, this is 60.3GiB.
Note2: after formatting, a small portion of the space is taken up by the filesystem's structural files.

I just switched to "PAL" mode, (a misnomer for digital video; these are analogue-TV-specific terms, but "PAL" and "NTSC" are the choices offered in these cameras' Service Menu), and shot a test 1080p50 clip in 28M mode. "28M" is actually 25.3Mbps overall. With this format, a 3.99GiB file equates to a 22m36s recording. Normally, since I shoot action and edit it heavily, I use 50M, but 28M is OK for general shooting.

Generally, either MP4 or AVCHD is fine, as long as it's a progressive mode. MP4 is all progressive. Unfortunately AVCHD is mostly interlaced. I'd suggest avoiding these interlaced modes completely: they're obsolete. The V750/V770 do offer 1080p50/p60 @ 28M AVCHD v2.0 so, if you want to use AVCHD, this is the only mode to consider.

Note3: both the MP4 & AVCHD M2TS container formats, (the .M2TS file extension changes to .MTS if you use a transfer program to transfer it to your PC instead of just copying it across in Windows Explorer, but the contents are the same as in the .M2TS file), use the same video stream compression format: H.264. So the size and quality of 28M MP4 and 28M M2TS files from these cameras, (both are offered), are similar. (The audio stream format in these two containers is different, and AVCHD includes a bit extra metadata.) But 60p/50p 50M is only offered in the MP4 container format.

Dan.
 
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Emerton

Active Member
I had assumed that camcorders that format their cards to FAT32 would have a file size limit and the ones that formatted to ExtFAT they would not need breaks.
 

Terfyn

Well-known Member
I had assumed that camcorders that format their cards to FAT32 would have a file size limit and the ones that formatted to ExtFAT they would not need breaks
I would go with that also. I have an SDXC card, formatted in the camera, in my 800 and have never had a problem with file cut off.
 

dosdan

Active Member
I had assumed that camcorders that format their cards to FAT32 would have a file size limit and the ones that formatted to ExtFAT they would not need breaks.
I've tested two 64GB SD cards formated in the V750 and in the V770. Both Windows CHKDSK & TestDisk (TestDisk - CGSecurity) reported that the filesystem on these two cards is exFAT. These two cameras definitely do segment long recordings. So this limitation on <4GB media files in the V7nn series may have been specific to Panasonic at that time.

Dan.
 
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asd84

Member
Thanks for the help guys. The SD card does appear to be formatted to exFAT, but still getting the breaks. It's not a major issue as the change over is pretty much imperceptible - would just be simpler to have one file!

Otherwise, is there a reliable (and preferably free!) way on converting AVCHD files to mp4 on a mac for easy editing in iMovie? Don't know if anyone has any experience with 'AVCHD to Mov lite'? (‎AVCHD to Mov Lite)

Thanks again for the help,
Ali
 
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