Handbrake Newb: Same as Source + Variable Frame Rate

[EmptyMorale]

Hi guys, i'm new to the forum, and I'm somewhat of an amateur when it comes to video encoding, i've been doing it for awhile now. I have about 200 blu rays, it took me over a year to eventually finish adding my collection into a digital library. But recently, i've learned that perhaps the settings I've used in handbrake have not been good enough (i never aimed to get them the best or perfect, but just good enough) i naively trusted another users guideline. Now, i'm worried all my work is completely flawed. I will ask a few questions in new topics around here but the first one i want to ask is just this frame rate set up I've been using on all my blu rays: Is "Same as Source" + VFR ruined the original frame rate of my Blu-Rays?

thats the most important thing to me now, i currently use iTunes as my Library and Apple TV (3rd gen) stream box. I've never noticed issues with my blu rays through the Apple TV or PC playback (which, along with ipad/iphone are the target devices, i never wanted to replace my blu rays, i just wanted a convenient way to enjoy my collection casually since i really enjoy rewatching some scenes.)

what have i done to my blu rays really? MediaInfo still recognises 23.976 fps in all my blu ray encodes.

i know they are all genuinely variable frame rates now, but my main concern is: Have my encodes lost frames, has it genuinely changed the original content as far as what was there? or is all the frames/original content still there, but simply being played back by my players differently? i guess I'm not sure what I'm asking, but i would Really like to not have to re do my collection. hope you guys understand. I respect most of you will know much more about this than i do.

for anyone who may be able to help me understand, why is Constant frame rate "safe" if , as suggested on handbrakes guidelines, frame rates can vary in films? why does Same as Source not make my frame rate the same as the original? i really thought that setting was all i had to care about because i knew frame rates can change in films but i just wanted handbrake to make exactly the same film, frame for frame, at exactly the same frame rate.

Thanks

[EmptyMorale]

thanks for the help guys

[_Al_]

VFR does not mean that you loose some frames, ... , I think thousands of users does or uses the same settings as you, I would not though, it is just somehow hanging omen over Handbrake, that VFR , its boogieman. You might have issues trying to edit those videos, to process them further but just playing it on screen I thing you are fine.
Did you try to jump ahead while playing, skip parts in video, go forth and back and you are still in sync with audio? Then it would be no problem for me.

[hello_hello]

I'm not a (regular) Handbrake user, but.....

I'm pretty sure Handbrake's VFR mode is used by the Decomb filter. For example, if it sees two successive frames as identical, it'll only encode the first one, but it'll have twice the duration, so nothing is lost as such. The idea would be to increase compression, but it's fairly minimal. It doesn't take much to encode a frame if it's identical to the previous one. The other objective is to enable encoding of "hybrid" video, where an NTSC DVD might contain progressive parts at 23.976fps and interlaced parts at 29.970fps etc. The way I understand it, VFR mode has the advantage of not requiring one of those parts be converted to a common frame rate (which generally lowers quality or makes motion jittery).

Without the Decomb filter enabled, I suspect, although you'd need to check, the output might always be CFR.

Anyway, most Bluray video is 23.976fps or 24fps progressive and it sounds like your encodes have a constant frame rate given MediaInfo sees them that way. If you need to be sure what's happening try re-encoding a video (or part of one) with your usual settings and check the Handbrake log file when it's done. It's quite detailed. It'll tell you how many frames it expected, how many frames it encoded, the output frame rate and how many frames were duplicated to achieve it, if it's constant.... that sort of thing. You could try a few different encodes with different settings and check the log file each time to see what changes. I doubt you have anything to worry about, especially for constant frame rate progressive video (ie most Bluray video).

[EmptyMorale]

VFR does not mean that you loose some frames, ... , I think thousands of users does or uses the same settings as you, I would not though, it is just somehow hanging omen over Handbrake, that VFR , its boogieman. You might have issues trying to edit those videos, to process them further but just playing it on screen I thing you are fine.
Did you try to jump ahead while playing, skip parts in video, go forth and back and you are still in sync with audio? Then it would be no problem for me.

Most the time yeah, but sometimes the video stops playing and the audio continues, if that happens then i press pause and play again and it resumes normal playback.

I'm not a (regular) Handbrake user, but.....

I'm pretty sure Handbrake's VFR mode is used by the Decomb filter. For example, if it sees two successive frames as identical, it'll only encode the first one, but it'll have twice the duration, so nothing is lost as such. The idea would be to increase compression, but it's fairly minimal. It doesn't take much to encode a frame if it's identical to the previous one. The other objective is to enable encoding of "hybrid" video, where an NTSC DVD might contain progressive parts at 23.976fps and interlaced parts at 29.970fps etc. The way I understand it, VFR mode has the advantage of not requiring one of those parts be converted to a common frame rate (which generally lowers quality or makes motion jittery).

Without the Decomb filter enabled, I suspect, although you'd need to check, the output might always be CFR.

Anyway, most Bluray video is 23.976fps or 24fps progressive and it sounds like your encodes have a constant frame rate given MediaInfo sees them that way. If you need to be sure what's happening try re-encoding a video (or part of one) with your usual settings and check the Handbrake log file when it's done. It's quite detailed. It'll tell you how many frames it expected, how many frames it encoded, the output frame rate and how many frames were duplicated to achieve it, if it's constant.... that sort of thing. You could try a few different encodes with different settings and check the log file each time to see what changes. I doubt you have anything to worry about, especially for constant frame rate progressive video (ie most Bluray video).

Yeah, i don't like that idea/manipulation. I just wanted everything to be identical to the source, and i really thought "Same as source" was all that mattered. I kinda overlooked the "VFR" as something that doesnt try to force irregular frame rates into a fixed frame rate. so based on that, I'm probably going to re do my collection. I won't lose too much sleep over it, I'm getting a new machine soon (8 cores) and that should help me get through those blu rays much quicker than i did on my old machine.

i'm going to make a series of topic (and attempt to link/index them together) so i can get my handbrake settings optimal this time. I hope to see you guys there.

[hello_hello]

I don't know if I'd necessarily get too excited about re-encoding if MediaInfo says the encodes are constant frame rate and the same as the source.

I did though, try a quick experiment. I re-encoded the first minute of an AVI I had handy. It's 23.976fps.

With the output set to VFR, same as source, it didn't encode a frame or three at the beginning. The first few frames are just black and I assume it didn't encode what it considered to be duplicates. It encoded the rest. When I set the output to constant frame rate it encoded the "duplicates", but it's interesting the way the Handbrake log file describes it:

[01:59:05] sync: got 1437 frames, 1462 expected
[01:59:05] render: 1439 frames output, 0 dropped and 2 duped for CFR/PFR

Kind of implies it drops the frames it considers duplicates anyway and then replaces them with duplicates. Not that it matters.
There was no similar info in the log file for a VFR output.

There's ways to tell if a video is really VFR. You might want to check before re-encoding everything, and I wouldn't take MediaInfo's word for it. I use AVIsynth because a couple of decoders output the average frame rate if it's not constant, so it makes VFR video even easier to spot. Especially if you then tell the decoder to output the "correct" constant frame rate. If the frame count changes, it's also a sign it's VFR.





I did find it interesting MPC-HC reported each of my VFR encodes as the "correct" CFR. It doesn't seem to care whether the duplicate frames are encoded or not, which makes me wonder if it matters, at least in the case of CFR video encoded as VFR. It might be different if the frame rate changes (ie from 23.976 to 29.970 etc) but in this case you could look at it as still being CFR only without the duplicate frames encoded. It's kind of like "display this frame for 40ms" then the next for 40ms, then another, then "display this one for 80ms", then back to 40ms durations. And if it's only a few "duplicate" frames over an entire movie I don't know if it's worth worrying about.



Anyway..... just offering some info in case it helps. I might have a bit more of a play with Handbrake's VFR encoding later. Encoding NTSC DVDs.... that sort of thing..... as a learning experience.