V8+Cineform loses last line

fausseplanete wrote on 4/19/2008, 4:53 AM
Render an original track of PAL HDV (m2t) to AVI profile "HDV Intermediate PAL 50i" open it below the original track, difference them. In Preview (say) at sufficient resolution, look down to the lowest actual video line (careful not to confuse this with possible cropping by the preview window). The lowest line shows through!

I haven't tried it with NTSC, so don't know whether this is PAL-specific or affects NTSC as well.

This implies that the lowest line in the Cineform, as seen (or exported) by Vegas, is either missing or black, hence the difference we are seeing is the lowest line of the original. Easy to miss unless you look for it. So I wonder if this has been a bug in persistence for some time. Could be in Vegas, Cineform or the interface between them (blame neither).

I used the latest version of Vegas (8b) and Cineform NEO HDV (NeoHDVv325b159-080313.zip) but have also previously encountered this problem with Vegas 7 and earlier versions of Cineform.

If you do a similar check as I described above, do you get the same thing? Please add your experience here, specifying if you used PAL or NTSC (original footage and rendered Cineform to match) and being careful to see the bottom line of the full image, not cropped by the preview.

Comments

blink3times wrote on 4/19/2008, 11:01 AM
I'm on NTSC and I am not seeing this. Granted my input files are cineform intermediate from m2t and rendered over to uncompressed avi. I will say however that i do see a TIME difference between m2t files captured with HDVsplit and cineform. It's not a huge difference and I am not sure which program is at error..... but there is a difference.

Cineform has a free player on their site for their codec. Suggest you download it and see if the line is missing in their player.
fausseplanete wrote on 4/19/2008, 4:59 PM
Below I describe a simpler test involving no files, just Vegas-generated media. Still the bottom line goes black.

I realise now also that HDV is HDV, there is no PAL/NTSC difference apart from frame rate. And the same effect occurs regardless of frame rate.

@blink3times:

Not sure if you conducted precisely the same experiment I described. The bottom line is hard to identify let alone check on just a straight image. Also I'm not talking about capture, just exporting Cineform from Vegas and reimporting it to Vegas.

Cineform player - not a bad idea, though the problem is how to see clearly whether the last line is missing. The following is a simple benchmark test, not involving any m2t files etc., do do just that:

@ALL: Simpler way to demonstrate the problem:

In Vegas, HDV project (50i or 60i, doesn't matter), place a sky (pale) blue solid color in a track above a red solid color. In Track Motion for the upper track, set the size to 1440x1079 i.e. deliberately one line too short, to let the bottom line of the red solid color show through. In preview, full resolution, you should see sky blue with a red line at the bottom. I found this color combination makes it most visible. If your screen isn't big enough, use half resolution, then you can see the average of the bottom two lines, giving purple.

Now render this out to uncompressed or HuffYuv (doesn't matter which) and to Cineform.

Finally, view the Uncompressed (or HuffYuv) and Cineform on their own in Vegas or play it in AvsP+AviSynth (which lets you scroll down easily) or in QuickTime Player (which you can push upwards using the side of its grey frame). In all of these cases, the bottom line is red (as expected) for the Uncompressed or HuffYuv file, but not for the Cineform file. In Vegas and QuickTime Player the lowest line is black. In AvsP+AviSynth it is green (meaning something special maybe? - I thought it might mean transparent, but it doesn't act as such in Vegas, even with media property alpha enabled).

I note that Vegas calls on VfW codecs and in AviSynth I used the "OpenSource" command which is also reliant on VfW. I don't know what QuickTime uses, VfW or DirectShow.

I ran the installer for the latest Neo Player on my system (Compaq Presario R4065EA with 2GB and running XP) where I already had the latest NEO HDV installed and although it gave no error messages, no player application appeared in menu or folder, just a file called "LookInstaller.exe".
johnmeyer wrote on 4/19/2008, 6:36 PM
Preview (say) at sufficient resolution, look down to the lowest actual video line (careful not to confuse this with possible cropping by the preview window). The lowest line shows through!

Just to make sure, you have the preview window set to "Best" resolution, right? If not, you will get the problem you describe.
fausseplanete wrote on 4/24/2008, 12:47 AM
Back after a time of unavailability....and some further experimentation...

I had tried resolution at various settings including Best.

However I concede that the "simpler benchmark" does not produce the "black last line" effect (as stated in my original post) which itself definitely exists and is repeatable. The missing additional requirement (which I now appreciate, from experiments) is that the original file (m2t or dv) must have been captured directly from a camcorder, not one rendered out from Vegas. Possible explanatory factor: using AviSynth via AvsP, the clip.info command reveals that from-camera HDV (m2t) and (DV-containing) AVI files are YUY2 whereas those rendered from Vegas are RGB32.
fausseplanete wrote on 4/24/2008, 1:04 AM
Here I update the original test "recipe" for greater precision. Please can you (anyone) repeat this exactly? It would be really helpful to establish repeatability or unrepeatability before offering an explanation or solution. The same effect occurs not only with HDV sources and project-and-render resolutions but also with SD.

Please try this, it only takes a minute to do:

1) Obtain a DV or HDV file (dv-avi or m2t) captured from a proper camcorder (not generated artificially e.g. by Vegas, for reasons explained in my previous post) where the lowest part (hence lowest line) of the image is not black (preferably contains multiple shades/colors).
2) Add it in Vegas as the only track in a correspondingly DV or HDV project.
3) Render to one of the Cineform profiles, as appropriate to the Project. For instance if HDV then AVI profile "HDV Intermediate 50i" (or 60i). Or if for DV then custom settings as appropriate (e.g. 720x676 1.0926 50i LFF for PAL, but use whatever's appropriate to your project).
4) In Vegas, open the rendered file below the original track, then difference them. The result (difference) should be mostly black.
5) In Preview (say) at Best resolution, look down to the lowest actual video line (careful not to confuse this with possible cropping by the preview window). The lowest line shows through! Set Preview background black (right-click) to see it even more clearly. The visibility of the lowest line in this difference result implies that the lowest line of the Cineform-based image (as read-in by Vegas) has lost its information.

Control experiment: Render to a non-Cineform format such as Uncompressed, HuffYuv or (in the case of DV projects) DV. Then difference this against the original. This time you should see a purely black result, indicating no difference, implying that the lowest line has been repoduced faithfully.