Cannot create interlaced 25 fps MP4 file

JonP01 wrote on 1/14/2015, 7:01 PM
Hi,

I am having an issue whereby I cannot correctly render to an output MP4 file any interlaced source material. Instead of the output file having the same frame rate and being interlaced as per the source, the output file has double the frame rate, but each frame is one of the actual original fields. So for example, with the project set in both project parameters and rendering options as 25 fps (PAL), I still end up with a 50 fps progressive file. But, the output looks horrible because each full frame is actually a field from the original. So it really looks beyond awful.

It does not seem to matter what combinations of project settings and options I set when rendering, the output always ends up with a completely separate progressive frame with each frame showing one of the two fields of the original material full frame.

This problem only occurs when using and / or modifying the MainConcept AVC/AAC option. Although there are other ways I can produce the output that I want (and at the correct 25 fps interlaced output), I wish to use the above option as it produces the best output for my purposes (playing back material on an LG TV via a USB hard drive). The other thing with this option (that the other useable options do not have) is that I can set a custom frame size. This is useful in the case of my LG TV where playing back 4:3 material via the USB drive causes overscan artefacts at the edges of the 4:3 screen. With this option, I can set the frame size to 1024 x 576 and avoid the overscan problem. Not that this has anything to do with my issue which happens regardless of frame size - I am just mentioning it if someone wonders why I want to use this option.

So, basically my workflow is I am taking my original source material, which is 25 fps 576i (so 50 fields per second). My project parameters are:

Template (as per requirements, but say PAL DV 720 x 576, 25 fps as that is the main one I have been testing.

Width: 720
Height: 576
Field order: either Upper field first or Lower field first (makes no difference)
Pixel aspect: PAL DV
Frame rate: 25 (PAL)
Rendering quality: Best
Deinterlace method: None

Render options:

Template: MainConcept AVC/AAC
Frame Size: Allow source to adjust frame size (or you can pick one of the defaults, it does not matter, it still does not work)
Field order: As per field order that I have set for the main project - either upper or lower frame first)
Pixel aspect: 1.0000
None of the other options make any difference - you can set them however you like.

So as I say, I put any delinterlaced input file into this of any type and it will always end up as a progressive frame file with twice the number of frames of the original and each frame showing alternatively the upper or lower fields of the original.

I've even tried using "incorrect" options and trying things like setting different frame rates (like double / half), etc, checking /unchecking all other checkboxes, etc, in the hope that there might be some sort of interface related bug.

But it doesn't matter - this template seems to be completely incapable of handling interlaced source material correctly. It might make more sense if the template did not have the adjustable options such as first / lower / progressive as well as the PAL 25 fps frame rate but it does. And since some of the options on the right hand side of the Advanced screen include things like Blu-ray 50i and 60i, it should be able to process interlaced material correctly and produce an interlaced output file.

I can "cheat" and change the project parameters to blend or interpolate for deinterlacing but all that does is create extremely poor looking video compared to the original. The whole idea is that I want my output to be 25 fps interlaced using this option.

I am starting to think there is a bug in the Movie Studio program or otherwise it must be generally known by everyone but myself that this template cannot produce proper interlaced video and I am just not aware of the fact.

Any help would be appreciated please.

Thanks

PS: You don't need any specific source examples for me to supply - you can try anything in any format that Movie Studio recognises so long as it is 25 fps interlaced to begin with.

Comments

EricLNZ wrote on 1/14/2015, 9:20 PM
It could be because in your Project settings you have Deinterlacing Method set to "None". Try "Interpolate Fields" instead. I note you've probably tried it but None is probably creating problems.
JonP01 wrote on 1/15/2015, 4:04 AM
Thanks for the reply. As I mentioned in my original post, I had already tried both the blend and interpolate options and it was not a viable option. It does eliminate the original problem but the resultant video quality is so appalling that it is unwatchable. Yes, it is a 50 fps progressive video, but it really looks abysmal. Even the cheapest LCD TV sets I have seen around do a much better job of deinterlacing than either the blend or interpolate options in Movie Studio (and my LG 3D TV does a far better job yet again), hence my strong desire to retain the interlaced format).

Ive since been experimenting and unless Sony can determine there is a bug in the program or some other reason the MainConcept MP4 options are not working with interlaced source material, I am using the MPEG-2 option and just creating PAL DV widescreen output files employing a massively high bitrate. It is not my most preferred option but at least the giant files play perfectly and look extremely good. Obviously I have to use an extremely high bitrate to get the same quality from the MPEG2 files that I have been getting using the H.464 type codecs, but at least the solution I am using is a workaround and just requires massive storage space (I can live with that).

Hopefully my issue is just due to a bug in the program that is fixable or otherwise the MainConcept MP4 option is simply not meant to be able to deal with interlaced material and the user interface does not "lock out" the relevant interlace/ progressive options.

Incidentally, I have also been experimenting with the MainConcept MP4 option when using 25 fps progressive source material and the results are excellent. Near perfect output compared to the original. Superb results indeed. So it is a pity that I simply cannot use this same process for interlaced material as well.
musicvid10 wrote on 1/15/2015, 6:48 AM
Match media settings
Select a deinterlace method
Render quality Best
Works fine here. Has for years.
JonP01 wrote on 1/15/2015, 9:58 AM
But the whole point is that I don't want to deinterlace. The MP4 option works fine for progressive in and progressive out and it also works (horribly) for interlaced in and progressive out. But it does not work for interlaced in and interlaced out no matter what the interlaced source material is and regardless of what options are or aren't selected.
musicvid10 wrote on 1/15/2015, 1:07 PM
It's a safeguard in case something else is going on, such as even minor resizing.

I think there is something going on you haven't told us yet.
Is there Track motion or Pan/Crop on the timeline?
Is the output aspect the same as the source?
Did you try it without "Adjust source to match output"?

Post some before and after results with complete MediaInfo for each (not on Youtube!) and we'll see what's going on.
JonP01 wrote on 1/15/2015, 6:36 PM
As I stated in my original post, I have tried absolutely every single possible setting combination - I spent literally two days doing nothing else other than going through all the permutations - even counter intuitive ones. This issue occurs no matter what settings you try and no matter what type of source material you use. So long as it is interlaced and you want the output to remain interlaced, it simply doesn't work.

With respect it isn't necessary to give before and after examples or to give my settings because EVERY possible combination of settings under the sun fails to produce a result.

It would thus be far easier for anyone trying to understand the problem to simply try it themselves. For whatever reason the MainConcept MP4 template cannot cope at all with interlaced material and because I believe this should not be the case for these codec packages, I believe there is a bug in Movie Studio (well at least build 190 - I can't speak for earlier builds).
EricLNZ wrote on 1/15/2015, 7:28 PM
I normally use vob and m2ts files from my disc images to play on my TV from a thumb drive. My only mp4 are what I do for Vimeo and they are progressive. But I'll give interlaced a try but firstly Jon I need to know:

1 - What type of files are your source material
2 - What bitrate are you exporting at?
JonP01 wrote on 1/15/2015, 8:53 PM
My source material is exactly the same as yours - I am transcribing and editing my DVDs so they can be played straight to the TV via a USB HDD.

The DVDs are usually 4:3 content at 576 interlaced, though I have a couple that are 576 progressive at 25 fps. The progressive ones work perfectly - no issues whatsoever. It's the interlaced ones that don't work. The only results I get are terrible combing artefacts on the output file because each individual field becomes a full frame on the output file or I have to select blend or interpolate as a deinterlace method in the project itself - which totally defeats the purpose of wanting to remain interlaced and results in a terrible picture anyway (since blend and interpolate are massively inferior to the vastly superior bob deinterlacing used on progressive LCD TV displays).

Anyway, output bitrate doesn't matter - as do none of the parameters available. I have probably tried this rendering about 200 times, changing parameters here there and everywhere in order to try and get what I want. For testing you will need to use a sufficiently high output bitrate so that you can see the artefacts (combing) or see that the output video is of horrible quality compared to your source. For that reason, I suggest you use 14,000,000 constant bitrate option as that will give you an output closest in quality to the original input.

If people want example input files I will be happy to provide them (both an interlaced and progressive test files so that you can see progressive input works perfectly fine but interlaced is a disaster. I can create a 10 second except from two of my motorsport DVDs (one interlaced and one progressive) which will make the artefacts very obvious.

Bottom line is this: MainConcept AVC/AAC only works with a progressive source in Movie Studio unless you want an absolutely terrible quality output file that is of abysmal quality and / or has horrible combing artefacts. And my research suggests that MainConcept should be able to handle interlaced source material correctly. Which means I believe there is a bug in Movie Studio.
JonP01 wrote on 1/15/2015, 9:24 PM
OK, here is a link (at the bottom of this post) to two source files for testing purposes. Both are MPEG2 format and were taken from two Chevron publishing DVDs I own. One is 576i, the other is 576p. You will find the 576p one works perfectly with MainConcept MP4 but you won't get a useable result with the 576i one. Each file is 10 seconds long.

By the way, I am fully ware that I can use MPEG2 conversion for my projects and get a "result", but I want to use MP4 because the quality is far better and the file sizes are smaller. I also know I can get a result using the Sony MP4 option, however it does not have the flexibility I need (in terms of being able to create a proper 16:9 output file for use on a modern TV display). All I can do with the Sony option is produce a 4:3 576i file which has problems on many displays because of overscanning issues.

I can avoid all of that by using the MainConcept option or the MPEG-2 option, but as I say, the MainConcept option produces noticeably superior output quality and with files sizes significantly smaller.

https://www.sendspace.com/file/2b6sdo
EricLNZ wrote on 1/16/2015, 1:31 AM
Thanks Jon, An interesting experiment.

Exporting your interlaced clip (with my MS12 Build 1183) as mp4 interlaced gives me a file which appears to be giving mixed information over its frame rate and interlacing.

Dragging the mp4 clip into MS gives its properties correctly as 25 fps interlaced.

Playing it on my pc media players gives problems as some won't play it or play it with bad edge combing unless they provide the option for me to force deinterlacing when it plays okay. They appear to be reading the file as 50 fps progressive.

Putting the file on a USB thumbdrive and playing it on my Panasonic TV with its built in media player I get the edge combing as my TV clearly isn't deinterlacing

But if I put the USB thumbdrive in my Panasonic Blu-ray player USB input it plays perfectly. My player feeds a 1080 50p signal via HTMI to my TV. My BR player appears to recognize the file as 25i and is deinterlacing and upsizing.

Until your post I was under the wrong impression that mp4 files were always progressive and I had never come across an interlaced one. But I note from the mp4 specs that interlaced is included.
JonP01 wrote on 1/16/2015, 3:09 AM
Thanks for trying it. So you had the exact same issues. Your Panasonic TV does have a delinterlacer built in unless it is an old CRT machine. If it did not have a deinterlacer then every time you fed it with interlaced content (i.e anything where the res ends in an "I" and 90% of every sports DVD out there), you will get the horrible combing effect as you saw. Plus, companies like Foxtel here in Australia deliver the content at 1080i out of their boxes.Basically every "digital" display out there that uses LCD technology is progressive and has to have a deinterlacer.

The 50 fps thing you note is the other symptom which you also describe - yes, the output does now have 50 frames, but each frame is one of the fields of the original. Even if you did not know which input file was interlaced and which was progressive, you'd know just checking the frame rates of the output files. The frame rate doubles if it was interlaced and is correct as per the original if it is progressive.

Like you, after my experiments I was wondering whether it was possible to have an interlaced mp4 file. But as you see yourself, the specs say it is possible and checking the MainConcept website also confirms it is fully supported.

I suspect that Sony have forcibly made the MainConcept option progressive either accidentally (through a bug not passing the parameters properly to the codec) or on purpose because they want every possible output file to be internet "ready". But people play DVDs on computers all the time and that includes sport DVDs like I own that are 99% interlaced. I have contacted Sony support so hopefully they will confirm a bug or it is done on purpose but the interface is not configured properly to reflect that.

I also came across a post made some time back by someone running the Pro edition that mentioned something about a MainConcept interlaced option. I sure hope you don't need to pay $700 or whatever it is just to be able to use an interlaced input file!

I've been using Sony software for years (I am actually an audio person and am new to video stuff) so hopefully support will help me / us out. Also, you might have noticed that the Blu-ray presets for MainConcept - the interlaced ones (50i and 60i) also stuff up. They also double the frame rate and produce one frame per input field. Now that cannot possibly be right by any stretch of the imagination!!!
musicvid10 wrote on 1/16/2015, 8:42 AM
"

Well, that's far from being source. It is 4:3 miniDV that's already been run through some kind of deinterlacer during transfer to a 16:9 PAL DVD that's flagged as interlaced. If that wasn't enough, it's been wrapped as .m2t (not .mpg?), indicating you are actually working with a third generation sample.

Vegas is doing what it should.

Sorry, you "source" is a red herring. So, all bets are off and you're completely on your own here. Yes, there were a few things you weren't sharing with us, no matter where you got it. Do let us know how your project turns out.

Oh, did you know that your PLAYER must be set to deinterace if you are playing interlaced footage on a computer monitor?


JonP01 wrote on 1/16/2015, 10:07 PM
No, the two sources were from a 576i DVD and a 576p DVD. But if you had read my posts you would have noted this. It is nothing to do with MiniDV. The reason one is flagged as interlaced is because it is actually interlaced. The fact that they are allegedly third generation examples is also completely irrelevant. They could be fourth, fifth sixth or tenth as far as I am concerned. It makes no difference.

The fact is that Movie Studio 13 build 190 cannot handle interlaced input using MainConcept as an MP4. If you can't or won't believe that I am obviously not going to persuade you one way or another. Not that it matters as you aren't going to solve the problem anyway.

Also, if you had even bothered to read my posts properly you would have noted I am creating this output for use on a TV connected to a USB hard drive. As you may (or may not) be aware, all modern LCD HD TV sets have a deinterlacer built into them. The user does not have to get into the esoterics of "selecting" it or not.

Please do not contribute any further to this thread as your posts have not only been unhelpful, but also time wasting and in my opinion counterproductive.
EricLNZ wrote on 1/16/2015, 10:29 PM
Having given this further thought I suspect there may not be anything wrong with the MS created output mp4 interlaced files.

Instead the problem may be with your (Jon), and my, TV's software for playing mp4 files. They just don't handle mp4 interlaced correctly. Note in my post I mentioned that MS12 correctly reads the file as 25 fps interlaced and more importantly my Blu-ray player correctly handled the file. It doesn't surprise me as my BR Player software does a better job deinterlacing and upsizing than my TV's inbuilt player.

It might pay you to check with LG whether the TV's software can deinterlace mp4 files. That's if you can find someone knowledgeable enough to answer.
JonP01 wrote on 1/17/2015, 2:49 AM
No, it's definitely a problem with MS and not a device's ability to play it back. I get the same results on playback with any device, from Windows media player, other software media players to my TV sets - even when playing back the output in MS itself. The problem is there in the output file itself - not the playback mechanism.

And don't forget that MS is doubling the frame rate when you push an interlaced file through it with the MP4 option - it is incorrectly producing 50 fps progressive output from a 25 fps interlaced input with each frame being an original field (half frame, hence the combing effect that has nothing to do with your display not being able to deinterlace). That being the case, it won't matter whether the playback device can deinterlace "correctly" or not because the output is always progressive when using the MP4 option. Thus, what you are seeing isn't a reflection of an incapable playing device - it is a reflection of the individual fields of the input file being incorrectly turned into individual frames on the output file.

In any case I have found a workaround over the last day. I am now using the Sony AVC/MVC option with the Project set at 720 x 576 PAL 25 fps lower field first PAL DV Widescreen. Then I use the cookie cutter twice (once for the left and right black borders and a second time to account for the fact that the old analogue transfers of interlaced PAL material end up taking up 713 lines instead of 720 at 576i (this can cause artefacts with HD TV displays that display all 720 lines such as my LG). I then make sure the pixel aspect ratio for rendering is 1.4545 and this produces a file that plays back correctly through a modern 16:9 progressive display (and of course the output file is critically still interlaced as I wanted - the whole basis of the issues I have reported - any attempt to deinterlace using MS - I.e "blend" or interpolate" just loses a huge chunk of quality unless you are using professional level software that has highly sophisticated deinterlacing options and algorithms).

As I say it is a workaround but it is currently the only way to create interlaced output from an interlaced input file using MS 143 build 190 unless you go the MPEG-2 route, which is not a very good codec even at extreme bitrates.

I would still prefer for this issue to be addressed by Sony as the MainConcept option is more flexible and can produce a genuine 16:9 aspect ratio output (1024 x 576) rather than the pseudo 16:9 output I get with this windscreen flagged PAL 720 x 576i material. Plus there are more encoding options and the potential for better quality. But at least the workaround does use a codec much superior to the MPEG-2 one.