size of my VOB reduced after re encoding

[mathmax]

Hello

When I re encode a VOB file with HCenc VBR 2-pass, the size is decreased to 877Mb (it was 1048Mb originally). I set auto bitrate calculation, but maybe I should fix it 9000 kbps. I use AVStoDVD and I see no other option for encoding. I would like to keep the original size and preserve quality, if possible.

Thank you in advance for any advices.

[Baldrick]

Why convert? You can reauthor vob files without any reconversion. If the authoring app doesn't support vobs you can demux the video and audio with tsmuxer for example.

[mathmax]

no.. I removed a logo. I need to re encode.

[davexnet]

Interesting... AVStoDVD always encodes to the highest average bitrate it can, up to 8500k by default.
It sets max to 9000k. Use Bitrate Viewer to compare the old and new.
https://www.videohelp.com/download/BitrateViewerSetup23.exe

[mathmax]

Interesting... AVStoDVD always encodes to the highest average bitrate it can, up to 8500k by default.
It sets max to 9000k. Use Bitrate Viewer to compare the old and new.
https://www.videohelp.com/download/BitrateViewerSetup23.exe

thank you.. I set the min to 9000k, but the result is the same.

see, here is the original:


and here is the re encoded file:


why can't AVStoDVD encode up to 10500k like the original?

[davexnet]

See this, it explains the DVD legal limits:
https://forum.videohelp.com/threads/284993-Maximum-Bitrate?p=1721860&viewfull=1#post1721860

I think you're going too high.

[mathmax]

See this, it explains the DVD legal limits:
https://forum.videohelp.com/threads/284993-Maximum-Bitrate?p=1721860&viewfull=1#post1721860

I think you're going too high.

well... maybe the source was too high.. I just wondered why I couldn't encode in the same quality.
And also why AVStoDVD doesn't encode at a constant bitrate 9000 k since I set the min to that value ?

[davexnet]

See this, it explains the DVD legal limits:
https://forum.videohelp.com/threads/284993-Maximum-Bitrate?p=1721860&viewfull=1#post1721860

I think you're going too high.

well... maybe the source was too high.. I just wondered why I couldn't encode in the same quality.
And also why AVStoDVD doesn't encode at a constant bitrate 9000 k since I set the min to that value ?

Well the QUenc is supposed to be CBR. Did you try that?

The re-encoding of an mpeg-2 could get pretty close to the source mpeg (subjectively).
How did you remove the logo?
Did you produce an intermediate file, or are you doing it in the avisynth script dynamically
as the new mpeg-2 in encoded?

Here's a test I did, 1080p MKV > HCenc,
HCenc mpeg-2 > AVStoDVD (Quenc)
http://www.mediafire.com/download.php?zau76d1lamqedq7

[mathmax]

Well the QUenc is supposed to be CBR. Did you try that?

no, I didn't... I will try it? is it supposed to be better?

The re-encoding of an mpeg-2 could get pretty close to the source mpeg (subjectively).

mmm... but my source was mpeg-2, not mpeg..

How did you remove the logo?
Did you produce an intermediate file, or are you doing it in the avisynth script dynamically
as the new mpeg-2 in encoded?

I produced an intermediate file encoded with MSU lossless codec.. I can't render dynamically in avisynth script with AVS2DVD if the script is too slow. I don't know the reason of this limitation..
I also deinterlaced the file.. maybe it explains the size reduction..

Here's a test I did, 1080p MKV > HCenc,
HCenc mpeg-2 > AVStoDVD (Quenc)
http://www.mediafire.com/download.php?zau76d1lamqedq7

Thank you for this test.
QUenc seems indeed to encode in constant bitrate. Couldn't you get higher ? (up to 10000k)

[davexnet]

NO Quenc is not supposed to be better, but it does do CBR, where HCenc does not...
You can open QUenc and try it. You'll find a shortcut in the AVStoDVD program group.

If you deinterlaced your footage, this is almost certainly where you lost some quality.
How does the mpeg-2 you produced from the intermediate file compare to each other ?

Perhaps you should look into dealing with the logo in avisynth and re-interlace. If you can get the script right,
open it directly in the mpeg-2 encoder. Skip the intermediate file.
When the m2v is created author it with AVStoDVD.

[mathmax]

How does the mpeg-2 you produced from the intermediate file compare to each other ?

I don't understand the question..

Perhaps you should look into dealing with the logo in avisynth and re-interlace. If you can get the script right,
open it directly in the mpeg-2 encoder. Skip the intermediate file.
When the m2v is created author it with AVStoDVD.

I can't because the script is too slow to run.. AVStoDVD doesn't accept slow script.
What is the problem to use an intermediate file, since it's lossless?

[davexnet]

I was just wondering if you could retain the interlace. Encode it outside of AVStoDVD - in HCenc directly.

Beyond that, to get much further with this, perhaps you could provide some sample of the source, and the intermediate file.

Regarding this question, which I worded rather me badly :
"How does the mpeg-2 you produced from the intermediate file compare to each other ?"
I'm trying to get a feel for where the quality loss is. I was trying to ask how does the final mpeg-2 (or DVD ) compare to the
intermediate file in terms of the quality?