Captain Khajiit's Basic Guide to Encoding with HCenc

[TV's Frink]

Not sorted yet. I think I have identified the problem (see my previous post) but no idea how to fix it.

 

[Captain Khajiit]

Post your script, Frink. I'll probably need a sample of your rendered AVI and your source file for the logo too.

Have you opened the script that you are feeding to HCenc in Virtualdub, to see how the logo looks?

 

[TV's Frink]

Avisource("C:AustinIMoMSanitized15.avi")
ConverttoYV12()
Spline36Resize(704,480).AddBorders(8,0,8,0)

I just loaded it into vdub, and it looks exactly the same as what HCenc gives me (logo works at beginning and end, garbled in the middle).

I can upload the files later.

 

[Captain Khajiit]

I just loaded it into vdub, and it looks exactly the same as what HCenc gives me (logo works at beginning and end, garbled in the middle).

If your script looks exactly the same when you view it in Virtualdub, then it's not a HCenc issue because it is present before encoding to MPEG-2. It sounds like a decoding error to me, but it's hard to tell without seeing it. Could you send me a link to this logo? When you do, I'll make you a script from which you can render a lossless-AVI version of the logo to insert into your Vegas timeline.

 

[TV's Frink]

Big ups to Captain K, who pointed me to an avisynth plugin and wrote me a script to resize the logo for 720p, and everything is a-ok now.

 

[RollWave]

I was looking to see what my color space was, and mediainfo tells me that it's "grey"

Working with a HD source this time. I'm trying to figure out what my color space is so I can write the correct second line of the script, but mediainfo reports the color space as "Grey."

As Reave mentioned, he had this problem recently. He sent me a sample, which read as RGB on my end in Mediainfo and in other programs.

I think I may know what happened to reave and frink, because it just happened to me - though i'm not entirely sure why or if it matters.

Process:
dvdfab to copy bluray to hard drive
hdbrstreamextractor to pull out the video as .mkv and the audio as .wav
megui to index the video and create an avs script
added a line to the avsscript to ConverttoRGB(matrix="Rec709")
virtualdub to get lagarith avi. "no audio", color was the default then rgb24bit, then lagarith mode was rgb

three cases: (all look correct, ie they are in color, not greyscale)
1. Render the entire clip - mediainfo says colorspace is Grey
2. Render a short test clip in the middle - mediainfo says colorspace is RGB.
3. Render a short test clip at the very start of the file - mediainfo says colorspace is grey.

I looked at the beginning of the clip and noticed that there's about 40 frames that are completely blank at the start of the video (cant count exactly since the video opens in a fade in, so not sure where the fade starts).

I suspect that mediainfo is counting the colorspace as grey by looking at only this first frame which is pure black. But when the first frame is any other part of the video it correctly indicates rgb for the colorspace. That's why reave's full clip told him it was grey, but the sample clip showed rgb - he probably made a sample from the middle.

So anyway - I plan on just going forward and assuming that everything is working as intended and that this is, well not necessarily a bug in mediainfo, but a case where it doesn't tell the whole story. If anybody who knows more about this can say whether they think i'm right or wrong and reassure as to whether or not this really matters, thanks. Or if frink/reave still have their old clips or remember - for the clips that showed as grey in mediainfo, were the very first frames entirely black?

 

[TV's Frink]

I barely remember what day it is. /old

 

[Captain Khajiit]

I suspect that mediainfo is counting the colorspace as grey by looking at only this first frame which is pure black. But when the first frame is any other part of the video it correctly indicates rgb for the colorspace.

So anyway - I plan on just going forward and assuming that everything is working as intended and that this is, well not necessarily a bug in mediainfo, but a case where it doesn't tell the whole story.

As far as I'm aware, all MediaInfo can do is read the metadata of a file: it does not perform any analysis as such. I would sooner guess that the NLE is miswriting the metadata, but you might be right about the reason.

Regardless, Frink and reave's encodings seemed to turn out well. I don't think you have any cause for concern.

 

[RollWave]

Note that I am not yet on the timeline, my files have never been in Vegas, the lagariths were generated by virtualdub and i checked them prior to placing them in vegas. This is slightly different than reave/frinks case (though i hypothesize that they may have been in the same situation as me, they just didn't check until after).

i hadn't really considered that virtualdub would be miswriting the metadata since it specifically has the settings to know what colorspace its trying to write, but that certainly could also be the issue.

 

[Captain Khajiit]

Make sure that you select fast recompress before rendering from VirtualDub. Apart from that, I don't know what to suggest. I can't recall ever experiencing this issue.

 

[RollWave]

I had been using full processing mode. Just tried instead doing a fast recompress from the same avs file to see if it changed anything, but the resulting lagarith appears to be identical, same size, and color space still indicates as grey in mediainfo.

oh well, probably doesn't matter. maybe next year somebody else will add another piece of the puzzle.

 

[RollWave]

4. Basic Resizing

If your source is HD, add the following line to your script. Then your script is done.

Spline36Resize(704,480).AddBorders(8,0,8,0)

N.B. I am not prepared to debate the resizing instructions given in this guide. If you feel you know better, then you do not need the guide. People who have corresponded with me over PM might have gone into more advanced cropping and resizing. I might write a guide for this at some point, but for now I want to keep this simple to avoid confusing people. If you want to discuss more advanced resizing, PM me; please do not post in the thread about it.

After following this step, my m2v file had narrow black bars on the left and right side. I thought maybe they'd go away after authoring, but no they are still there.

Rather than debate about more advanced cropping...how about less advanced? Is there some benefit to having these bars on the edges of the screen that I'm missing? Or did I screw up another step somewhere that should have removed these bars?

 

[Gatos]

Disregard. I should have read the guide more carefully.

 

[FreeTime]

Disregard this post.

Issued was solved in a different thread.