NSTC DVD conversion for 29.97fps x264

[txporter]

I have written before on here about a problem that I had with playing x264 video back on my TivoHD and "shimmering" subtitles. I burn-in my subs. The problem that was happening was that sometimes the subs would display fine and other times they would appear to move up and down very quickly. It was actually the entire video stream, but it was just easier to see with static images.

I finally figured out what the problem was. I was TIVTC'ing my NTSC discs back to 23.976fps. Well, Tivo can't deal with that framerate well when playing back h.264 material. The "shimmering" subs go away at 29.97fps. So I need to keep those videos at 29.97fps. I am trying to figure out the best way to do this. If I simply encode the video (with telecined frames) in x264, the playback (as expected) is rather ugly on the telecined frames. I have tried forcing interlaced encoding (--interlaced) but the issue is the same. I guess the Tivo doesn't look at field order flags or whatever MBAFF does in x264.

I next just ran the clip through Yadif(). The output looks pretty decent. I know that no one recommends to deinterlace telecined material though. What is the proper way to achieve 29.97fps x264 video from 23.976fps source material?

For completeness, I use avisynth 2.5.8 and x264-r1416 to encode and mp4creator to mux the elemental streams together. I can provide a source clip if needed, but I don't think it is really necessary for recommendations.

[poisondeathray]

Sounds like a Tivo problem, have you checked with their user forums?

Is this HD or SD?

You can try DGAVCPulldown - it's still beta , but it's functionality would be analogous to DGPulldown for MPEG2 streams (soft telecine)

x264 has --pulldown switch (I think this would be hard telecine), but I don' t know if it's functional yet

h264info has a 3:2 pulldown switch, but I don't know if it works

[txporter]

Yeah, I am active on tivo community forum (tivo.com forum tends not to really push into the advanced uses of Home Media functions). There are a number of threads going on over there as well, but there are really only a few of us that do much with transcoding to x264. But yes, this is a Tivo decoder problem. I am just trying to do what I can to work with it.

Thanks for the ideas though. I will look into them. Didn't know about the pulldown switch or DGAVCPulldown.

[txporter]

Ok, so I can see DGAVCPulldown has changed the frame rate from 23.976fps to 29.97fps. The video races ahead of the audio though in MPC-HC (muxed at 29.97fps with mp4creator). When I mux at 23.976fps, they play back in sync...but at 23.976fps, so that seems wrong. I can try the 29.97fps file on my Tivo when I get home again, but is there a way to have MPC-HC follow whatever pulldown flags DGAVCPulldown adds?

update: Also --pulldown doesn't work in r1416.

[poisondeathray]

Sorry not sure.

You're basically asking the software to IVTC "on the fly" for playback. Telecined h.264 content is not very common, and I doubt many software would do this.

I would ask over at doom9

[txporter]

Yeah, had a thread over there that neuron2 locked because the names I give my DVD rips looks like a torrent name.

That place can be frustrating. At least folks here seem to actually try to help.

[jagabo]

You could IVTC back 23.976 fps then ChangeFPS() to 29.97 fps. But that will give you 4 little jerks every second.

A better solution would be to forget the Tivo for playback and use a media player instead -- like the WDTV Live, Popbox, Boxee Box. In the long run you'll be glad you did because you can avoid screwing up your videos.

[poisondeathray]

Might be a container issue too. Could try .m2ts using tsmuxer , but not sure if that will screw up your tivo workflow

EDIT: just did a quick test, and looks to work ok, at least with kmplayer

[txporter]

Thanks, jagabo. Is there anything wrong with just running like Yadif() like I did? Or is that basically the same as using ChangeFPS? I didn't really notice the jerking motion with the yadif run, but when I step through the video, I guess I do see 2 repeat frames every 5. I guess this is what the jerks would be that you are referring to when using ChangeFPS.

[txporter]

Might be a container issue too. Could try .m2ts using tsmuxer , but not sure if that will screw up your tivo workflow

Yes, it could be a container issue. Unfortunately, the Tivo will only accept the mp4 container, so I really don't have any options on what else to try.

[jagabo]

With film sources Yadif() will give you jerky video like IVTC+ChangeFPS(). But it will have deinterlacing artifacts as well.

To see the jerkiness watch a smooth, medium speed, panning shot. You'll see an obvious jerk-jerk-jerk-jerk -- four jerks every second.

[poisondeathray]

Yes, definitely seems to be a container issue.

It's "sped up" in .mp4, but works fine in .ts/.m2ts

[txporter]

Yes, definitely seems to be a container issue.

It's "sped up" in .mp4, but works fine in .ts/.m2ts

Thanks, pdr. I will see what can be done from the tivo side of things to allow pushing of .ts files with h.264 content.

[txporter]

Yes, definitely seems to be a container issue.

It's "sped up" in .mp4, but works fine in .ts/.m2ts

I couldn't duplicate this. I mux'd the streams with tsmuxer (both .ts and .m2ts). In MPC-HC, they played back in sync, but at 23.976fps. In kmplayer, they raced ahead like the .mp4. I haven't used kmplayer before. I don't know how to enable statistics to see what the framerate is.

[poisondeathray]

It's supposed to playback at 23.976 and in sync. The signal is 29.97 in order to match NTSC systems, that's what telecine is for. Upon playback, the software or hardware player will IVTC it back to 23.976 so you get nice progressive filmrate playback

I didn't check playback framerates, I just noticed right away the .mp4 was too fast (probably playing at 29.97) and the running time was shortened, but the transport stream was fine

Transport stream (with dgavcpulldown) worked fine in MPC, KMplayer for me (MPC was haali and ffdshow)

[txporter]

Ok, I understand now. So the results that I got in MPC-HC with .ts or .m2ts are what I should expect. The real test will be whether I can get those up to my Tivo and whether it will honor the flags. Thanks!

[txporter]

I ended up just doubling the framerate of the FILM source to 47.952fps and the playback is fine on my Tivo. I tried 25fps and 29.97fps and just couldn't live with the duplicated frames. The file size isn't as small as it could be, but I still get some savings over MPEG2. I filed a bug report with Tivo. Hopefully they will find a way to fix 23.976fps h.264 playback issues. Thanks for all your help.

Also, I cannot push .ts or .m2ts files up to my tivo, so I couldn't test the pulldown flags there. And it ignored the pulldown flags on mp4 containers just like MPC-HC.

[jagabo]

I ended up just doubling the framerate of the FILM source to 47.952fps and the playback is fine on my Tivo.

Weird.

[txporter]

I ended up just doubling the framerate of the FILM source to 47.952fps and the playback is fine on my Tivo.

Weird.

Yes, very odd. Framerates of 25fps or higher seem to decode and playback fine. I tried both 23.976fps and 24 and both had playback issues. I didn't try anything in between 24 and 25. At least I found a solution that I can live with for the time being. Hopefully they can fix it with software.

[txporter]

A new wrinkle to this one. I rebuilt the original 23.976fps stream from one of my 720p episodes of Lie to Me last night. I hardsub'd it and encoded it with x264 and pushed it up to my TivoHD. The 1280x720 23.976fps plays back with no issues!? I really don't understand this. Guess I need to try something with resizing. Do you think this could be caused by resizing with Lanczos4resize to 720, 400? Should I try different resolutions or resizers or maybe just leave the stream at 720x480 and set the SAR to something like 6:5?

[jagabo]

The Tivo can't know what resizing algorithm you used. It's possible the frame size could make a difference, although it shouldn't. It might be the difference between the 23.976 approximation and the true value 24000/1001 (23.0976023976023976...).

[txporter]

The Tivo can't know what resizing algorithm you used. It's possible the frame size could make a difference, although it shouldn't. It might be the difference between the 23.976 approximation and the true value 24000/1001 (23.0976023976023976...).

Yeah, I was starting to wonder about the framesize (720x400 is 1.8 instead of 1.77777....), but I don't understand why doubling the framerate (or just increasing it to 25+) would fix the issue. Not sure. Going to try a variety of different resolutions (and tossed in spline36 & bicubic, just for good measure). I also encoded one with a 720x480 frame with a 6:5 SAR. Will see what happens.

[jagabo]

If I was you I would avoid using unusual properties just to make the Tivo play your files. Find one of the standard sets of video properties that the Tivo will handle and use that. You are much less likely to run into problems in the future that way.

[txporter]

Yeah, my goal is really to see if Tivo can fix it from their end. What are you referring to as unusual properties though? SAR of 6:5 (guess I really should have used 32:27 to get HD display) or oddball resolutions?

[poisondeathray]

If the chip in the tivo is anything like those for blu-ray , you use mpeg4 specs for the --sar signalling ie.
10:11 for 4:3
40:33 for 16:9

this is instead of the mathematically correct
8:9 for 4:3
32:27 for 16:9

for blu-ray, everything SD needs an interlaced signal to meet NTSC specs, hence the requirement for 3:2 telecine for film content. I'm guessing if the hardware chip on the tivo is related , it might need similar treatment as you would for blu-ray

[txporter]

If the chip in the tivo is anything like those for blu-ray , you use mpeg4 specs for the --sar signalling ie.
10:11 for 4:3
40:33 for 16:9

this is instead of the mathematically correct
8:9 for 4:3
32:27 for 16:9

for blu-ray, everything SD needs an interlaced signal to meet NTSC specs, hence the requirement for 3:2 telecine for film content. I'm guessing if the hardware chip on the tivo is related , it might need similar treatment as you would for blu-ray

Thanks! I will try the SAR settings as well. Not sure if anything can be done about the interlaced signal requirement or not. As far as MPEG2 encodings go though, it plays 23.976fps progressive streams just fine. Telecined as well. The playback of hard telecined h.264 material is ugly...

[txporter]

For what it's worth, the TivoHD uses a BCM7401 decoder chip. Here is the product brief. It looks like it should handle 480p24. Maybe my non-standard resolution is causing the problem. Will check tonight.

[txporter]

Well, my statement about 720p @ 23.976fps not showing the problem was not correct. I attempted various resolutions and SARs with SD content and still saw the problem. So I went back to the 720p clip and I can see the same issue, it is just not quite so obvious (maybe because the amount of shift is proportionally smaller since there are more vertical lines?...say if it is shifting up and down by 1 line between frames which is what is causing the shimmering effect?). Hopefully something can be done from the software side of things by Tivo. At least I am back to a framerate issue...even though that isn't precisely obvious, it seems better than framerate and framesize.

[jagabo]

Post a small sample of your 720p video.

[txporter]

You can download the source for the 720p film here. The mp4 file I created from it will be uploaded in a few minutes.

Source - Lie.to.Me.S01E06-clip.mpg
x264 file @ 23.976fps will be called 720p-test.mp4

Again, this is only a problem being displayed on my TivoHD. It looks fine playing back on my computer.

update: x264 file is uploaded now