50p video to NTSC authored blu-ray

[Ennio]

Hi everybody


I recorded a concert-stream via european satellite. The video is 1280 x 720 with 50 fps.

We want to burn this on BD which can be played on a US player. Trying to author with MultiAVCHD, I suppose I have to choose NTSC format in the author tab, am I right?

I get the "PAL video on NTSC warning" from MultiAVCHD. I am not sure to just ignore and continue. How will US players deal with 50p video? I don't have a US model to test this.

The resolution being ok for blu-ray, I'm thinking is it possible to do a framerateconversion / serving without re-encoding the video?

If so, what tool and settings do you recommend? Reading the blu-ray framesizes I suppose the framerate has to go to 59,94p?

Any advice would be appreciated. We wanna make sure the disc is problem-free in the US.


Thanks in advance

Ennio

[mail2tom]

As a starting point, here's what I do when I find a PAL video that I'd like to "convert" to NTSC, YMMV.

The tools I use are:

1. TFM Audio Tool
2. MKVMergeGUI
3. Transcoding tool, primarily MultiAVCHD.

My steps:

1. First, convert the audio. Start up TFM Audio Tool and add your original 50fps file.
Select your ouput folder location.
Select "Enable Framerate Conversion."
Select "PAL to NTSC (25 to 23.976 fps)
Select AC3 under "Output format."
(Optional: Select "Auto Gain Control" for extra audio boost if required.)
Press "Convert."

2. Second, convert to new video framerate. Start MKVMergeGUI.
Add the original file to "Input files:"
Deselect the audio stream.
Add the converted AC3 audio stream from TFM.
(Optional: Highlight the TFM audio stream and change the Language to the desired language from the drop down box.
Highlight the video stream, change tabs to "Format specific options."
In the "FPS" box enter 48000/001 (as opposed to 24000/001 to double the 23.976 NTSC framerate).
In the "Output filename" change the title to something that is easy to recognize.
Press "Start muxing."

If all goes right your new Matroska file should be ready to transcode to Bluray with MultiACVHD since MultiAVCHD will respect the converted frame change and ignore the original 50fps. I usually scan through the Matroska file with VLC to ensure that the audio and video are synchronized and after transcoding to Bluray with MultiAVCHD. Just remember that there are a number of unexpected things that can go wrong, but I've used this process successfully many, many times.

Good luck.

[Ennio]

Thank you mail2tom. I'm gonna try this out, will get back.

Cheers

Ennio

[Ennio]

Hi mail2tom,

To create the mkv as you described works, but I encountered some issues.

When I play the resulting mkv, there is a PAL --> NTSC slowdown. Of course, this is expected when you change the playback rate from 50 to 48000/1001.

When I import the mkv into multiAVCHD, tsMuxer stops working. I ran the mkv through tsMuxer only, and I got an error: "Matroska parse error: invalid H264 NAL unit size. NAL unit truncated" I don't know what that means.

Being curious about the separate streams, I ran the mkv through MKVExtractGUI. Inspecting them with MediaInfo, strangely the H264 stream was still 50 fps? And when I play this video-only stream with VLC the speed is about half the pace (I suppose the exact percentage will be something like ( (24000/1001) / 25 ) x 50)

According to the blu-ray standards here: https://www.videohelp.com/hd and the source being 1280x720x50p, my guess would be to convert/serve the framerate to 60,000/1001p. I guess this (european) video was recorded by (TV-?) cameras @ 50fps or maybe 25. I doubt converting to 24000/1001 to be proper imho; I don't think the source was film. Anyways, my source is 50 fps.

Converting to 59,94 will result in a bigger speed-up. When it comes to music I even can't live with the "slight" PAL/NTSC related speed-changes. 4 % is a lot, when you listen. Not to mention the tone-changes that can occur.

When I think about it, wouldn't it be possible to use the same 50 source-frames of one second, within a 59,94 framerate? Or is this not recommended?

The easiest shortcut would be to author the blu-ray disk in PAL, but does anyone know a US player will play this?

For now,


Cheers

Ennio

[jman98]

Your post is not a surprise to me as mail2tom's suggestion strikes me as more of a "just get working" kind of idea than a "this is the best way to do it" kind of idea. I do not do PAL<->NTSC conversions at all nor do I convert HDTV type video. You'll need one of experts like jagabo or manono to hopefully respond with maybe a better idea via using AviSynth.

US BluRay players will almost certainly refuse to play HD video with 25 or 50 fps. If the person playing it is one of the very very few people who have a true region free BluRay player that can convert from PAL to NTSC too then such a player might be able to handle it. But the odds of some random US person having such a player are less than 1%. There are ways to deal with the audio tone change from a conversion. I only know how to do this via Cool Edit but I think Audacity (free) can also do this.

[Ennio]

Thanks for your quick reply jman98,


I did some audio-stretching and -shortening in the past with indeed good results concerning tones (voices being the most sensitive in my experience).
However, you can't beat the speed-up or down. That's why - in this case - I prefer trying to work the video and leave the audio as it is.

Without speedchanges, imho there maybe two ways to do video. One is trying to put the original 50 frames into a 59,94 framerate.

Looking ahead and thinking of this, frames have to be doubled here and there sometimes? And how to do with progressive video as my source is? For interlaced film-based video you can apply pulldown. And the numbers match. It's "easier" to pull down 24p to 30i and then slow down by 1000/1001 for NTSC, if I'm right with this.

But how to go from 50p tot 60000/1001p? The numbers confuse me a bit and I don't know if this is a possible or even recommended way to go. However, if it can be done, I'm eager to try and see what the outcome is.

The second option is to re-encode the video to a 59,94 framerate - if that's possible. I have no experience with encoding to 59,94p.

I indeed hope that one of the more experienced guys (with this, that is) will have a look a this thread.


Thanks

Ennio

[mail2tom]

Sorry to hear that you ran into problems. The source material will always present the greatest challenge, like variable audio/video bit/frame rates - GIGO, so the procedure doesn't successfully work in every case. For instance I have had very little success with Xvid videos and MultiAVCHD, so I stick to x264. And yes, TSMuxer is usually the weakest link.

My procedure is more like a "recipe" or "quick and dirty" solution using available tools that will provided the right characteristics to the audio/video to get something that worked, so it's a place to start, and really doesn't convert from PAL to NTSC (as you found out with MKVExtractGui and Mediainfo), but rather gives the appearance of conversion by slowing down the audio and synchronizing the video to the audio stream. The PAL to NTSC slowdown should be transparent to MultiAVCHD since it's manually performed before you add the video. Before posting I actually did a "conversion" of a 1280x720 50fps video (AVC/AC-3) to ensure it worked on a double framerate source and MultiAVCHD authored a Bluray file structure that played fine.

I have 2 computers running Windows7 x64 Ultimate. MultiAVCHD works for me in the majority of cases on both computers, but MultiAVCHD does not work the same way or successfully on the same source on both computers.

NB: As an after thought, if you're running the current version make sure that you disable Header Stripping in MKVMerge. It is reported to cause TSMuxer to stop working.

[johns0]

If your player can play mkv files through the usb or data disc format than just use mkvmerge to output as mkv with header stripping unchecked as mail2tom posted for that error you got.My sony bdp-s380 ntsc plays pal mkv with no issues.

[Ennio]

I have 2 computers running Windows7 x64 Ultimate. MultiAVCHD works for me in the majority of cases on both computers, but MultiAVCHD does not work the same way or successfully on the same source on both computers.

This is strange indeed.

I am still encountering the NAL unit error with Header Stripping disabled. Googling around I found that more people have this issue also even with the right header stripping setttings. Some guy reported that with some older version of mkvmerge there were no problems importing in tsMuxer. But also read a reaction that the problem lies with tsMuxer. However, my workflow can be a problem in this specific case. I must keep realising that with a work-around like this, or trying to "trick" things, good working apps maybe react faulty on tricky input.

Next step I tried is running the mkv through Meteorite. tsMuxer could now import and process. But the outcome couldn't be properly played back in VLC. Both video and audio played hitchy and jerky (maybe Meteorite repaired something that was deliberately set in mkvmerge to trick?)




Anyways, aside from all this,

Up front: thanks for everybody's posts and efforts to make it work.

mail2tom's input started me off having something to go on. And eventhough some ntsc players will play pal - from USB stick or BD - I do take jman98's statement about the 25/50 fps video behaviour of general us players seriously:

We do this for an elderly, oldskool (excuse my french) musician that lives in the US. Of course there is no 100 % guarantee that a self-authored and home-baked disc plays flawlessly in any us player. But we sure can try to create it as proper as possible.

Now already having - for my feel - to much issues, I hope that there are more options I can look into.


One thing I anyways wanna give-a-go is transcoding with x264. After importing the original 50 fps stream in multiAVCHD, the transcode section gives me the choice of framerate-change to 59.94. I'll play around with several qualitysettings and see. Can anyone tell me though why I can't choose 59,94 fps in both VidCoder and Handbrake? I thought they both used x264 encoder like MultiAVCHD.


Cheers

Ennio