- August 16, 2019 at 3:54 pm
Will I lose resolution or camera information by importing Mp4 – 4K, re-cordered on a Sony A7iii into FCP X, ProRes 422, Rec 709. And then exporting the file as Master File (default) ProRes 422 4K.
What I am trying to do is clean up my camera files to trim unwanted footage or split long segments into multiple shorter segments. I am not doing any correction at all, just bringing the footage into FCP X trimming and exporting file by file.
The same question as above but the workflow changes to opening the Original File in Quicktime and using the Trim option to remove unwanted footage.
If I use ” Save ” after trimming, the file stays as a mp4 at 121 MB. if I use “Export As ~4K, the file changes to .mov and the file sizes drops to 27 MB.
The Original Sony mp4 ( camera original ) file before trimming is 264 MB, after trimming from 21 sec to 10 sec in FCP X and exporting to ProRes 422, it now becomes 557 MB
If I take everything together, Logic seems to say that using Quicktime to trim and then using “Save” I will end up with a trimmed version of the Original file without any Loss of quality.
This would save on the large ProRes file generated if I do the trimming and exporting in FCP X.
Does all this make sense..????
The Sony Codecs is H.264, Linear PCM
Color Profile HD (1-1-1)
Thanks for any help
- August 16, 2019 at 11:01 pm
Yes- you are recompressing an already highly compressed format. That said you might not notice any visual difference in quality except on a high-end monitor. That said- MP4 is such an already compressed format I would suggest keeping the entire take. Or shooting less long takes in your workflow. You can get very cheap hard drives to back that up.
- August 17, 2019 at 8:45 am
When I was “filming” government footage this was standard. You get the idea: talking head talking a lot followed by another talking head rebutting the previous talking head. (Honestly I love the policy debate, ergo C-SPAN.)
When it’s time to edit, treat the camera archive as digital tape. That means it is an old school work flow. The mp4 capture is just a “tape”; first step, then, is to convert the selects into edit formats. FCPX has a great workflow for this. However, it will require storage space.
(This is a real issue that we should talk about more.)
- August 17, 2019 at 7:29 pm
The only time you truly preserve the cam original is when you concatenate a file. But whenever you re-export that to a different codec or same codec, it would have to go to another cycle of transcoding and you’ll not the same bit for bit data of the footage. The lost is small but for those who insists on the highest quality, there is a small degradation every time the footage is transcoded.
I’m reluctant to Optimimze media in FCP X because it transcodes everything to Pro Res codec. I mostly shoot in native AVC Ultra 4K 12-bit on the Varicam series cam and use the Ultra 4K codec for lower disk space consumption vs Pro Res 4444 that can be recorded directly to the Express P2 media if selected. Even though 16 Tb and soon 18-20 Tb hdds will be out, the data and storage costs saving are quite substantial for camera native formats vs Pro Res.
I’d always preserve the original cam footage at all costs. It preserves full metadata values including TC, cam info, shutter speed, ND filter settings, lens info, GPS data, audio tracks layout, shot marks, text memo, etc… When you re-export to another codec, I don’t think all of those rich metadata will get transferred. In fact, only the new codec metadata showing the current bitrate, depth is shown. All others cam metadata are completely lost. The H.264 codec is quite compressed already and file size is reasonably small. I don’t see any added benefits by trying to perform a lossy trim the raw cam media further. The time spent on saving a few hundred gigs may far outweighs the costs of storage media that’s keep increasing in size and decreasing in cost per Mb.
- August 19, 2019 at 2:35 pm
FCPX “likes” to work in ProRes422 and related ProRes, and normally I would let it… but it’s not mandatory: if you want to edit in MP4, you can alter the preferences to skip the transcoding and work with the original files as they are… performance may take a bit of a hit, is all.
You can also save space by telling FCPX to leave the source files wherever they are, and not import them into the library… only, I find this to be risky, since it makes it more possible that the connections to the originals might get lost at some point.
If you insist on transcoding footage, and you want the maximum quality, be sure you’re outputting at the maximum bit rate, at least. It’s gonna cost you drive space, of course.
Fast-good-cheap: pick any two, but ONLY two.
- August 19, 2019 at 3:22 pm
[Mark Suszko] “You can also save space by telling FCPX to leave the source files wherever they are, and not import them into the library… only, I find this to be risky, since it makes it more possible that the connections to the originals might get lost at some point. “
In my experience FCPX regular media links on an HFS+ volume are very reliable. In addition to storing pathnames to those files in SQL tables inside the library, it also stores the inode of each file as a backup locator.
You can shut down FCPX, rename each media file, then move each media file to a different folder on that disk, then open the library package and delete all symbolic links to those files, then when FCPX restarts it will automatically and transparently use inode lookup to find each renamed/relocated media file and rebuild the path pointers and symlinks to those files.
This unfortunately does not work for proxies, only regular media. It only works within a single disk volume, but for a changed or renamed volume FCPX can scan the entire volume and relink those.
Of course the media files could just plain get lost or accidentally discarded, in that case nothing will help.
- August 19, 2019 at 4:39 pm
Thanks everyone for your thoughts.
My understanding of codec’s, bit rates, resolution etc.etc, is that once you film it, it’s not going to get any better.!!!! ( If I’m wrong can anyone suggest a workflow for upresing Hi8 640 x 480 to at least 720p.)
So the only difference is in workflow, if I work in ProRes 422 is it only because it is easier on the processing power of my mac..?? especially if Color Grading, effects etc. ?? What are the detriment of not transcoding and just editing the H264 mp4 files.??.
Considering that I film in 4K, and output to youtube at 1080p, as I like the opportunity to crop in when editing. How noticeable would any image loss be.??
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