Recommended way to convert interlaced MPEG2 to MP4

[alinescoo]

Hello,

I am really new to this. I have a few video files which I think are from DVD format. The info I could find using apps like DGIndex and MediaInfo is:

Video

Stream Type: MPEG2 Program
Frame Size: 720x480
Aspect Ratio: 4:3 [2]
Frame Rate: 29.970039 fps
Video Type: NTSC
Sequence: Field/Frame
Frame Struct: Frame
Frame Type: Interlaced
Coding Type: P
Colorimetry: BT.470-2 B,G
Field Order: Top
Bitrate: 7806 Mbps

Format Settings: BVOP
Compression Mode: Lossy
GOP: Open


Audio
PCM 48k 16bit 2ch

I think that because the video is interlaced, when seeing it on some players, there are some lines that look fuzzy when movement. I know that some players can interlace on play, but I want to convert the files into mp4 or mkv to be able to remove the interlacing.

Looking at Handbrake in Filters, I see that there are some options:

Deinterlace: Decomb
Preset: Default
Interlace decection: Default

For audio
1. Unknown LPCM (2.0ch)
Codec: AAC (avcodec)
Bitrate:160

What would be the best set of option to use for converting into a more modern format, without too much loose in quality because of encoding.

Thank you for your time, I really appreciate it.

[LigH.de]

MP4 is a container. It may even be able to contain MPEG-2 video, I guess; but that's not what you want.

You may want to convert to MPEG-4/AVC video (a.k.a. H.264). This supports interlacing, so one option is to retain this attribute. Playback on a modern flat screen TV set should be supported with good motion adaptive deinterlacing during display.

For playback on a PC, different converters support a variety of deinterlacers. Handbrake may not be one of the most versatile, though. And before we recommend you one, you really need to check your source whether it is really interlaced, or instead telecined: The latter can be converted back (almost losslessly) to an originally progressive content. That method is not at all related to "deinterlacing". But it also works only if your material is a result of a Telecine process. You need to test that.

[jagabo]

Handbrake's deinterlacing (and and inverse telecine) are ok. The best deinterlacer is QTGMC() in AviSynth, by far. But that involves a very steep learning curve.

Are you sure you need to deinterlace? If it's a film based an inverse telecine is called for, not deinterlacing.

[alinescoo]

Thank you both for your info and time.

The video is taken from a video camera, the ones with tapes used a few years ago.

I've been searching around and it seems that the info from various tools isn't always right on Interlace/Telecine. I'll need to dig a bit deeper to see, but I think I need to extract frames and check the pattern they repeat. Isn't a simpler way to do inverse telecine on the video and see if the output is fine or not?

[manono]

If it's home video then the chances are very good it's pure video and shouldn't be IVTC'd. A short sample would confirm that. So, you probably want to deinterlace in Handbrake. Someone else can tell you what setting to use if you can't figure it out for yourself..

[abolibibelot]

The best deinterlacer is QTGMC() in AviSynth, by far. But that involves a very steep learning curve.

Well, the hardest part is to get it to work, and get used to Avisynth syntax if that's completely new... Also, it's way slower than more basic deinterlacers. Beyond that, even at default settings it produces a much better result than the deinterlacers included in Handbrake, so it's well worth the trouble, especially for unique and important footage.

I've been searching around and it seems that the info from various tools isn't always right on Interlace/Telecine. I'll need to dig a bit deeper to see, but I think I need to extract frames and check the pattern they repeat. Isn't a simpler way to do inverse telecine on the video and see if the output is fine or not?

– Open the file in MeGUI (Tools > AVS Script Creator > Video input > [open] > File indexer > [DGIndex should be selected] > Queue > [then go to “Queue” on the main window] > Start [wait until the indexing is done and a preview window opens automatically]) ; then check the total number of frames on the preview window (“Current position: 0/XXXXXX” > XXXXXX is the total number of frames) ;
– then manually mark the “source type” as “interlaced”, check the “deinterlace” box and apply “Yadif (Bob)” (or any other “Bob” deinterlacer – “Bob” means, as far as I understand it, that each field will be interpolated as a complete frame, meaning that the total number of frames will be doubled), then click on “Preview AVS script”, which should reload the preview : now the total frame count should be doubled ;
– then if you examine the frames one by one with the “>” button (or the left/right keys), if your source is truly interlaced, they should all be different ; otherwise, you will see a pattern of repeated frames (which are actually repeated fields in the source).
It also means that if you use a filter like Yadif (without “Bob”) in Handbrake, it converts for instance 50 interlaced fields per second to 25 progressive frames per second, but loses a lot of motion information from the source (since each field is different). So ideally, deinterlacing should be done with a doubled framerate, “50i” should be converted to “50p”. QTGMC does that by default (although it does have the option of keeping only half of the interpolated frames). Once you've managed to install QTGMC properly, along with all its dependencies, you just need to replace the “Yadifmod2” line in the “Script” tab of the “Avisynth Script Creator” of MeGUI (damn that's a mouthful !) by “QTGMC()” to benefit from its superior deinterlacing quality. You can then tweak it a little, by choosing a slower preset if you want to further improve the quality of processing at the expense of speed, or a faster preset if using an older computer or if there are several such videos to convert and you have a deadline ; other tweaks are available but I couldn't tell much about them aside from what's in the manual, and that would fall outside of the scope of a quick startup guide...
(I hope I didn't say anything wrong, I'm not an expert in that “field” ! )

[jagabo]

– then if you examine the frames one by one with the “>” button (or the left/right keys), if your source is truly interlaced, they should all be different ; otherwise, you will see a pattern of repeated frames (which are actually repeated fields in the source).

One note here: this is only true when there is motion in the video. In a still shot every frame will be identical. So be sure to examine a portion of the video with motion. Medium speed panning shots are good for this.

[alinescoo]

Wow, very interesting info I find here. Thank you all.

@abolibibelot thank you for the detailed steps.
The video file is about 1 hour long, and the number of frames are 108223

After selecting Deinterlace Yadif (with Bob) and Preview AVS Script I get the number of frames as 216446, so double

Now the interesting fact, Previewing I get something like 10 frames different then 2 the same. It could be that some look like smaller number than 10, but in most cases I've previewed, it looks like 10 to 2.

I've seen that on some forums there are zip packages with all files needed for QTGMC (not sure if I can post the links here) but would that be a good idea to get started with it?

[abolibibelot]

I've seen that on some forums there are zip packages with all files needed for QTGMC (not sure if I can post the links here) but would that be a good idea to get started with it?

In fact I'd be interested myself... Where did you find this ? If it works indeed, by all means, use that, it'll save you a lot of trouble. Last time I tried to use QTGMC, after downloading each required and “additional” plugin one by one, it failed and I couldn't figure out why ; I've used it successfully in the past but it was an older version, with less or different plugin dependencies ; I haven't tried again recently, as I don't need it on a regular basis, but I have a few unfinished tasks which would require using it.

One of the first times I've seen QTGMC mentioned was in this thread, which contains a few samples comparing it with Yadif :
https://forum.videohelp.com/threads/354092-Converting-video-frame-rates

Yadif :

QTGMC :

Now the interesting fact, Previewing I get something like 10 frames different then 2 the same. It could be that some look like smaller number than 10, but in most cases I've previewed, it looks like 10 to 2.

That's seems unusual ; someone more experienced may chime in. Uploading an untouched sample can help for the “diagnosis” aspect ; you can do that with DGIndex, which is included as a standalone tool in MeGUI (MeGUI\tools\dgindex\DGIndex.exe) : open the file, set the begining and ending markers with the [ ] buttons (10 seconds should be enough, in a sequence with motion but not too jerky), then File > Save project and demux video ; then upload the m2v file. (DGIndex also displays information about the file, in particular whether it's “progressive” or “interlaced”, but it can be misleading since progressive footage can be encoded as interlaced, in which case going back to progressive involves a much simpler process than true deinterlacing, while applying deinterlacing on a source which is not actually interlaced can make it look worse.)

[jagabo]

Now the interesting fact, Previewing I get something like 10 frames different then 2 the same. It could be that some look like smaller number than 10, but in most cases I've previewed, it looks like 10 to 2.

That's an unusual pattern. Do you see frames that look like double exposures? As was suggested, use DgIndex to demux a short sample which shows that pattern and upload it here.

I've seen that on some forums there are zip packages with all files needed for QTGMC (not sure if I can post the links here) but would that be a good idea to get started with it?

That's been done here several times in these forums (finding the posts may be difficult). One problem you may have is that some of the filters are specifically for processors with SSE2 or SSE3. If you have an older processors without those features you'll still have to track down the versions you need.

[Sharc]

…..I've seen that on some forums there are zip packages with all files needed for QTGMC (not sure if I can post the links here) but would that be a good idea to get started with it?

A package can be found here, for example. Maybe it helps.

http://forum.doom9.org/showpost.php?p=1806162&postcount=382

[amaipaipai]

Handbreak it's a very neat tool if you know what you are doing. About QTGMC, try Hybrid.


It offers more control to people that like to have control.