Ogg Vorbis: what does mode1, mode1+, mode2 etc. mean?

[karl]

I hope this is the right forum (couldn´t decide between this one here and New A/V Formats - Codecs (http://forum.doom9.org/forumdisplay.php?s=&forumid=54) )
I had a Google search and one in this forum, but didn´t find an answer to this.

When I open the "Stream List" dialog in VDubMod and choose "Full processing mode" I get the following choices for "Ogg Vorbis":
Ogg Vorbis (mode1)
Ogg Vorbis (mode1+)
Ogg Vorbis (mode2)
Ogg Vorbis (mode2+)
Ogg Vorbis (mode3)
Ogg Vorbis (mode3+)

Can anybody tell me what´s the difference between them? And what would be the best choice for an OGM-file with XviD video? Or does it make a difference at all? :confused:

THX in advance for any answer :)

[celtic_druid]

It means that you shouldn't be using a vorbis ACM encoder for OGM files.

Encode the audio seperatly with say oggdropXP or whatever and then add it to the streams menu.

Sorry, got no idea what the actual modes mean. Seam to recall that all the docs for ACM codec were in Japanese.

[karl]

That´s a pity :( I wanted to reencode several MPEG-Files with sound and to simply choose audio compression in VDub would have saved me one step (= extracting audio and encode it seperatly)

But thanks for your answer :)

[Neo Neko]

If you read Japanese here is a link to Freddie-fish's site along with the original archive that the Vorbis ACMs come from. IIRC the modes have to do with bitrate controll and allocation to try and overcome the VBR nature somewhat. It does not really work though. The ACM framework can output VBR data but does not track anything like time codes etc to allow synch after the fact.

[karl]

Hmm, I can´t read Japanese :D

Can it be that the MP3 Codec that appears in VdubMod is also not good for use and I should always encode audio seperatly?
I tried to encode the MPEG audio with some files as MP3 (128kb, Radium MP3 codec) in Vdub and had some problems: audio was shorter than video in some cases although they matched perfectly in the source MPEG1 file.

THX for all the answers so far :)

[jkwarras]

Originally posted by karl
Hmm, I can´t read Japanese :D

Can it be that the MP3 Codec that appears in VdubMod is also not good for use and I should always encode audio seperatly?


The ACM MP3 version that appears in VdubMod is CBR only. Try Lame ACM version can be installed downloading official Lame binaries. The advantage is that it allows diret ABR encoding (much better quality than CBR). Anyway, i recommend you that you encode separetly with Besweet to MP3/OGg or whatever, since it allows using optimized VBR presets:

- MP3: standard (+- transparent)
- OGG: q5 or q6 (+- transparent)

[arpcpro]

yeah, yeah call me a grave digger for replying to this after 5 years but I had this same question and this post was one of the first results that appeared on google. It was difficult to find an answer but probably it will help quite a few.

2000/11/21 Ver 0.0.1.0
Modification to mode1 of the name of Original stream compatible
Modification to mode2 of the name of Have independent header
Modification to mode3 of the name of Have no codebook header

2000/11/23 Ver 0.0.1.2
Added Pseudo CBR mode (mode1+,mode2+,mode3+)

Now what this means, and which gives more quality beats me! This isn't even mentioned on vorbis.com FAQ.

source: _http://svn.xiph.org/tags/vorbis/vorbisacm_20020708/readme-eng.txt

[Blue_MiSfit]

... just don't use it :)

Vorbis CBR is fail. If you must use vorbis, use a proper encoder.

~MiSfit

[arpcpro]

I noticed vorbis is a fail when I try to use via virtualdub. Vdub always launches and exception and crashes.

I didn't want to separate the pcm audio from my videos to allow the use a proper encoder, so I had to select Lame MP3 in vdud. Although I prefered to compress the sound with a codec from this generation like aac.