How can you check the exported file's integrity? (AKA the project rendered fine, without lags)

[rambomhtri]

Hi, I was just testing Adobe Premiere, imported some 4K videos from my camera, made a collage and exported the project as a 4K 60fps video. I'm pretty sure the first few seconds of the exported video lag/frame skip, and the original video file didn't have this problem. Then I asked myself:

Isn't there a way to check that the export process was successful and there weren't any frames skipped/lags/sloppy passages...?

How can you tell with your bare eye that the frames were all exported successfully and without problems during the renderization? How about a video that's 2 min long, or 2 h long?

Thank you

[Phillip Harvey]

Well, in most professional settings somebody is always going to QC (Quality Control) the video after it's encoded.

Another thing you can do is re-import the sequence to Premiere and put it over the top of the timeline and set the blending mode to Difference. It should turn black and basically be black for the entire video. If you scrub through and see areas where it's not black, that means there is a difference between the top video and the original video in your timeline, which could be a render issue.

[rambomhtri]

Yeah, but that's checking technology with your bare eye. Totally inefficient. If it's a 6 min video, you can totally miss this scene in which frames dropped from 60 to 23, until you notice a few days later once the project is done and closed and it bugs you forever. If you export a film, 2 h long, how are you going to check its integrity by sitting and watching?

There must be some kinf of tool that tells you the export waa completed successfully and without errors. Imagine you do 3-4 min videos every 2-3 days, you can't sit a check if there was a hang out in the CPU in minute 1:23 and the scene froze for 1 second.

[Phillip Harvey]

Weird. Well I wrote a big reply but it won't actually let me post it. Apparently I have to wait an hour to try to post it again.

[Phillip Harvey]

I'm going to try again to post this:

I'm not familiar with any tool that does that. It would be nice. But there are certain things it may not catch. I think it's pretty rare that an issue arises from the encoding, if you're talking about the CPU hanging or something, it's not typically going to burn that into your video, it's just going to slow down the process of encoding. More often there is an issue somewhere on your timeline that needs to be addressed whether it's user error or an unintended result on some VFX, or maybe an issue in the original media itself. A tool like this would be a third party thing and it's hard to imagine that it would be able to account for all the combinations of effects, grading, etc., since even those can be third-party. It's also hard to imagine a world where you just run it through a tool and then send something on air without a person actually QC'ing it, so I don't think it would ever replace that part of the process.

Don't get me wrong. It sucks. I hate QC'ing because I've usually seen the video so many times by that point, and honestly it can make it difficult to catch things because you start to tune it out. For that reason I always try to make sure another person gets eyes on it, and many production companies will have that in place already, whether it's a dedicated QC person or producer(s)/director/CD. In an agency it will change hands probably 10 times for approvals before it ever reaches the client or if it goes to broadcast. And if it goes to broadcast they do have automated QC software/hardware (I don't really know what that looks like) that will check for legal color and luma values, audio loudness, and framerate. So in those situations you actually can fail their QC algorithms and have to fix it.

[Kevin-Monahan]

That's kind of a cool idea. I've never done that to QC a program. I do that sometimes in graphics production, though.

Regards,
Kevin

[salvo34]

I imagine if you do what Philip suggested ( difference ) and increase speed of scrubbing you'll see flashes of light if it's out and you can stop it there and check it more closely...

I never heard of some software program other than an editor ( where you use your ineffficient bare eyeball ) that can show you what worked or not.

[Kevin-Monahan]

R,

I think it's a great question. I'm not aware of any tool that my colleagues use for this purpose, unless something has flown under my radar.

However, there's this. Even if you've got the greatest QC tool known to mankind, there will probably be anomalies it simply won't catch. Editors cannot avoid the task of watching down the program with an eagle eye. I've never really seen many errors brought about by rendering previews, most of them are my own errors: typos, flash frames, and stuff like that. I see QC'ing  my own show as a very important part of the job.

Regards,
Kevin

[rambomhtri]

I'm reading some things that are out of the boundaries of my question. By "checking its integrity" I only mean just that what you see in the project (including typos, flash frames, black frames...) when you play it back is what the exported file stores. Basically, in the exported file there are no black frames, frozen frames, lags, sloppy scenes... due to some kind of problem with the CPU or PC in general while it was rendering it.

[Kevin-Monahan]

Rambomhtri,

We do have dropped frame on playback detection. Duplicate frame detection, but nothing to check the integrity of an output file. Sounds like a great idea for a feature request: https://adobe-video.uservoice.com/forums/911233-premiere-pro

Thanks,
Kevin

[salvo34]

===

Isn't there a way to check that the export process was successful and there weren't any frames skipped/lags/sloppy passages...?

=====

NO

[salvo34]

maybe do something else for a living

[rambomhtri]

Weird. Thanks anyway for the replies.