slicing to avi or mp4 for making sequence

[jcalcina]

Hi,

I'm making a compilation, slicing about 30 or so 4-5 second bits from various videos I took of my cat with a smartphone. Before I import and sequence them back into AE should they be saved as .mp4 vs. .avi or something else.  Is there an easier way to go about this?

Thanks.

[Warren Heaton]

Ideally you'd be using a video format and CODEC that's good for editing, like Apple ProRes, Avid DNxHD or GoPro Cineform.

That said, your AVI and MP4 files will probably work.

As far as assembling an edit goes, while you can get this done by sequencing layers in an After Effects Comp, but Premiere Pro or Rush are a better suited for this.

[jcalcina]

I really just wanted confirmation that .avi or .mp4 are the best options for a PC user using the Adobe platform, which must constitute a large audience base here. I knew that Premier Pro is better for video than AE, but does it rely on video formats other than, or better than the two aforementioned?

Of course I can find out elsewhere, but ultimately this answer irked me a bit. Yesterday I imported into AE an old .avi file I created about a year ago, I had also deleted it's original mp4. The quality was poor now, flickering and even the green screen. I suppose this is one example of why one codec/format/platform is better than the other.  

[Warren Heaton]

MP4 and AVI are easily prone to compression generation loss.

For exmple, you start with a handful of MP4 files that you edit in Premiere Pro and then export to MP4.  Even if you don't see the generation loss in the picture right away (that is, it still looks good), the resulting video has lost the abitlity to hold up to being edited again.  So, you bring that file into a new Premiere Project at a later time and exprot it again and it loses another compression generation.  This time maybe you do see degredation in the picture.

Maybe you're working with high bit-rate MP4s. If so, the compression generation loss may be not be obvious right away.

Maybe you're working with low bit-rate MP4s.  If so, the compresssion generation loss may be obvious immediately.

Maybe you're working with uncompressed AVI files (they would be huge, taking up most of your hard drive space for very short video durations and probably would not play smoothly), but these could be used and re-used over and over and over again as uncompressed AVIs and never suffer compression generation loss because they're  not compressed to begin with.  Important note: if the AVI file is easy to copy and play, then it's probably compressed.

There's also low color sampling with MP4 and likely with AVI.  MP4s use 4:2:0 color sampling (that's low).  Depending on which CODEC is being used in an AVI, it may also have 4:2:0.  Again, if your AVI happens to be uncomprssed, it's likey has higher color sampling (4:2:2 or 4:4:4:4).  When doing color correection and color grading, working with 4:2:0 formats tends to quickly reveal the compression in the picture that you were not seeing.

If you have source footage that's MP4 or compressed AVI, one strategy is to always convert to a CODEC that's good for editing (that is, it minimizies or eliminates compression generation loss).  Better yet, your source fotoage would be a CODEC that's good for editng from the beginnnig and only your delivery files are MP4 or AVI.  So instead of MP4 and AVI, you have MOV files or MXF files that use Apple ProRes or DNxHD.  

With the "good for editing" formats, it's probably worth mentioning that it's not as simple as just using a ProRes MOV or MXF or just using a DNxHD MXF.  Those formats have to be used correctly as they each have higher end and lowerer end variations.

Now that Adobe has licensed ProRes, I'd recommend it for most users, specifically ProRes422 LT.  It has good color sampling and good peak signal noise ratio (PSNR) for minimizing compression generation loss while keeping storage requirements modest with farily easy to meet sustained data rate requirements for smooth playback on most computers.

But ProRes422 LT is just one of a family of CODEC options.  I highly recommend reading the Apple White Paper on Apple ProRes.  It explains everything very well.  All it's missing is telling you which flavor of ProRes is best suited for your specific workflow (but I just did, so you're good to go!):  Apple_ProRes_White_Paper.pdf

-Warren

[jcalcina]

Thank you, just seeing this now, very interesting. I create vector-based animations using AE. The idea of pixel loss and degredation was not something I wanted to deal with in editing all my cat videos.  It's something anyone editing videos should be aware of though. I guess I'm stuck w .mp4 for now.

[Mylenium]

If you really want to play it safe, then your only option is using a publicly documented image sequence format like PNG, JPEG, TIFF. All technical issues in AE aside, video formats and CoDecs simply don't age well and support for them will ultimately be all over the place. I have 20 year old MOVs that will only open in alternate players these days due to Apple and adobe no longer supporting them. that's just how it is. Of course there's a bit of irony here, as H.264, ProRes and DNxHD are just as well publicly documented video formats, but the simple answer is that Adobe are just not getting it right and are screwing around with their nonsensical hardware acceleration stuff and other things. It's an endless cycle of going from broken to fixed and back in every version. Anyway, most definitely don't do anything with AVI. Even Microsoft has abandoned it at this point and it would be foolish to rely on CoDecs that won't work two years from now. Everything else is up to your own judgement.

Mylenium

[jcalcina]

That's interesting.

Now I have just read that an avi is "A lossless file will not lose quality over time, regardless of how many times you open or save the file"  Source: https://www.howtogeek.com/365627/what-is-an-avi-file-and-how-do-i-open-one/ 

I am more apt to trust Adobe than howtogeeks. There many aspects to this subject, trying to learn a bit more about it. 

[jcalcina]

This article better put things into context as well.

https://bytescout.com/blog/2014/08/avi-file-format-and-its-advantages-and.html 

[Mylenium]

AVI is a container format just like MOV, both of which at that point are deprecated media architectures. Beyond that all that matters is what internal CoDec they use. As long as those are "visually lossless" you can of course re-edit and re-encode your footage as often as you want, but given the limitations of e.g. the standard "Lossless" CoDec or for that matter "Animation" in MOVs, that ultimately becomes a workflow hinderance itself as you have to deal with chunky huge files that won't play smoothly anywhere...

Mylenium