QuEnc : how to encode XVCD (non standard mux) ?

[Jackzeripper]

hello :)
how to encode with QuEnc in MPEG-1 with a non standard mux (for XVCD = bitrate less than 1150 kbps).
Mux is always standard (file size matches like for a CBR 1150 kbps VCD, and I must demux and remux files with TMPGEnc to have the right size).

thanks for your feedback(s). :)


[edit] in fact the problem is only with non-standard CBR mpeg-1 that are muxed as if they make 1150kbps bitrate

[Jackzeripper]

PS : the problem is the same in MPEG-2 ...

- edit : no it doesn't : (X)SVCD mux is quite good. :)

[Nic]

@Jackzeripper: I'm not sure I understand what you mean. Could you give me a little more information. By demuxing and remuxing what are you changing exactly.

If you can give me as many details as possible, i'm sure I can solve the issue :)

-Nic

[Jackzeripper]

hi, thanks for your quick answer :)

For example : I encode in MPEG-1 @ 625 kbps (an X-VCD) with MP2 @ 128kbps. I calculated a file size about 440,5 Mb.

QuENc made a 753 Mb file (625Mb + 128Mb). BUT :
- if I demuplitiplex audio and video (with TMPGEnc 2.5+). mp2 audio is 128 Mb (OK) and m1v video is 312,5 Mb.
- or if I make separate files (no audio / no videdo) with QuEnc with exactly the same params : m1v is 312,5 Mb
and if I multiplex m1v with mp2 I will have a little bit more than 440,5 Mb (312,5 + 128 Mb).

QuEnc mux m1v and audio like it was 1150 kbps (m1v) standard MPEG-1 files, even if the bitrates of the video files are lower.

What would be great in QuEnc is a MPEG-1 mux profile for X-VCD (aka "non-standard VCD" in TMPGEnc).

Thanks in advance :)

[Jackzeripper]

And other little question :rolleyes:

What's the use of QLB matrix ?

thanks :)

[Nic]

Hmmm, Interesting. I wouldn't have expected that. I'll look into it.

Does it definitely happen with SVCD? I can see the code that makes it happen with VCD....it's called vcd_padding_bitrate. But I can't see anything similar for SVCD yet.

Thanks for the info,
-Nic

ps
QLB matrix is a matrix that should help low bitrate encodes. Try it and see if it helps your VBR XVCD streams. (it's created by Dragongodz)

[Jackzeripper]

I'll try QLB matrix soon. Thanks. ;)

Originally posted by Nic Does it definitely happen with SVCD?
Well, I must have dreamed it... :( :rolleyes:

I retry X-SVCD and I've got what I want (good file size, good mux for the requied bitrate) :) :) :)

The problem is only for (non-standard) MPEg-1 mux

[Jackzeripper]

hello :)

in fact the mpeg mux problem with XVCD seems to appear only with CBR mpeg-1 that are muxed as if they make 1150kbps bitrate. For VBR XVCD there is no mux problem.