Help with 720p video to 576i DVD (Only 25fps?)

[Killer3737]

Hi guys,

I've got a video saved from the web which is 720p, I'm a little confused though as MediaInfo doesn't give me a framerate:

Video
ID : 256 (0x100)
Menu ID : 1 (0x1)
Format : AVC
Format/Info : Advanced Video Codec
Format profile : Main@L3.1
Format settings, CABAC : Yes
Format settings, ReFrames : 1 frame
Codec ID : 27
Duration : 2h 36mn
Width : 1 280 pixels
Height : 720 pixels
Display aspect ratio : 16:9
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive

Audio
ID : 257 (0x101)
Menu ID : 1 (0x1)
Format : AAC
Format/Info : Advanced Audio Codec
Format version : Version 4
Format profile : SSR
Muxing mode : ADTS
Codec ID : 15
Duration : 2h 36mn
Bit rate mode : Variable
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 44.1 KHz
Compression mode : Lossy
Delay relative to video : -22ms

And when I load it into DGAVCIndex to create a project file for encoding it says 25fps. Shouldn't it be 50fps? Or does that mean it's actually 25fp and each frame is just doubled?

Is there a way I can check exactly what this is, and then get the best method for converting it to DVD? I know it's PAL video so 576i would be my target but how would I handle the interlacing? I would be encoding via an AVISynth script.

Thanks in advance.

[manono]

And when I load it into DGAVCIndex to create a project file for encoding it says 25fps. Shouldn't it be 50fps?

Why would it or should it be 50fps? FPS means frames per second. If you mean 50 fields per second, then say it.

Is it interlaced? You've seen the interlacing? You know 720p means progressive, don't you? If it's not interlaced, just resize it and encode.

[Killer3737]

I think I am getting a bit confused here to be honest, I know it's progressive which I thought meant 50fps? I was looking at this thread for reference - https://forum.videohelp.com/threads/273233-HDTV-720p-50-fps-SDTV-PAL-576i-p-25fps

I don't see any interlacing at all, no.

[manono]

You downloaded it, right? So who knows what's been done to it already. The other link to which you referred had a real 50fps capture for a source, not a reencoded video. Progressive just means progressive and has nothing to do with the framerate. As for confirming the framerate, since you'll be using an AviSynth script, open the script in VDub or whatever and check the framerate and see what it says. I'd be inclined to trust what DGAVCIndex says about it. When advancing a frame at a time, is every other frame a duplicate? No, eh? And this is film sourced isn't it, a movie maybe?

[Killer3737]

It's a live music video stream downloaded from iTunes so the only people that have done anything to it are iTunes. Not film sourced, HD video cameras. I was stood next to them in the venue when it was shot.

So I created a script with just a resize and colorimetry change and VirtualDub does say 720x576 25.000fps when I load the avs into it.

So that is correct and will output a DVD compliant stream?

[manono]

I don't think I've ever heard of a two and a half hour music video. That's why I thought it must be a movie.

Yes, there's no reason you shouldn't get a DVD compliant video out of it. Technically, you'd resize to 704x576 and then, if you wish, add borders to fill it out to 720. It's a minor point, though:

LanczosResize(704,576)#or your favorite resizer
Addborders(8,0,8,0)

[Killer3737]

Well it's a live show to get technical.

What is the reason for those borders, TV overscan?

[manono]

No, closer to the correct aspect ratio (assuming the source was done properly). But, as I said, it's a minor point as there's only about a 2% difference between the two.

[Killer3737]

Ok, thanks for the information.

[jagabo]

I disagree with the resizing. The DVD spec refers to the MPEG 2 spec for aspect ratios. The MPEG 2 spec is very clear: the full frame constitutes the indicated display aspect ratio (unless overridden by a Sequence Display Extension -- which I've never seen used for that purpose). That is at odds with the BT/rec digital video spec where the central 704x576 (or 704x480) subsection constitutes the indicated DAR -- which is where the confusion comes in. I've seen DVDs done to both specs (by measuring what appears on-screen during playback). In any case, the ~2 percent difference isn't worth worrying about.