VirtualDub improper audio encoding: solution and other questions.

[Aeolis]

- I hope this post is in the right place -

Hi folks,

I have some .avis and VirtualDub report that they have improper audio encoding. So I think I will extract the audio tracks to .wav and then multiplex the extracted .wav using Lame MP3 codec to compress. But I have a few questions:

1. Is that process absolutely 100% video quality lossless? I will use Video in Direct Stream Copy in all the steps I mentioned. I mean doing that way will every byte of video be preserved?

2. What is a good Lame MP3 setting for compression? 48000 Hz, 192 kbps CBR, Stereo is a good one to preserve quality?

Another situation: Vegas 6.0 only recognize .avis with DIVX fourCC code, it can’t read XVID fourCC. Any ideas?

3. Changing fourCC code is a 100% video quality lossless process?

4. Is there a good and reliable solution to change fourCC code?

5. Does VirtualDub work on that change of fourCC codes?

Now comes the last situation: Maybe I could leave behind all codecs and install only ffdshow.

6. Is that a real advantage in using ffdshow instead of the real codecs? I mean will speed really increase when processing thru it (Encoding, decoding and playing)? And about stability? I’ve heard here a lot of people complaining about the instability of the newer versions? I used an old version of ffdshow (ffdshow-20041012-sse2.exe) that was SSE2 instructions capable the last version (ffdshow-20051129.exe) is SSE2 capable too? Is that last version stable and reliable?

Thank you for your attention.

See you later,

Aeolis

[guns1inger]

1. If you use Direct Stream Copy then the stream (be it audio or video) passes through unchanged.

2. Personally, I don't think any level of MP3 encoding is good. If you are going to use 192kbps you might as well use AC3. The encoding quality is substantially higher, and it will take the same amount of space. MP3 is a butchers codec.

3. The FourCC codes a small indentifier tag in the file. Changing does not alter the video content.

4. It's a simple process. I suspect most changers are much of a muchness. If in doubt, look at the scores and comments in the tools section.

5. Haven't really played around enought o answer this one.

6. I have Divx, Xvid and FFDshow installed, and use each of them indifferent situations. So long as they don't interfere with each other, there are advantages to having them all there.

[mats.hogberg]

1)Yes
2)Yes - But for DVD, I'd go AC3 instead.
3)Yes
4)Yes
5)Yes
6)Undecided

/Mats

[Aeolis]

Hi folks,

I really appreciate your help and want to thank you guns1inger and mats.hogberg.

guns1inger: Could explain better how do you use the three codecs you mentioned before? I mean could you explain in which situation and why you prefer to use these or that codec? I know they are probably personal reasons but it would be of a great help to learn a little more about these codecs and its particularities.
The only tool I found so far to change fourCC code is AVI FourCC Code Changer and it worked great for me. I used it with a little intuitive approach and want to know if you know that tool and have a good tutorial or site that could help understanding better its functionality?

mats.hogberg: You answered yes to question 5 so I presume that VirtualDub can change fourCC code. Could you tell me how to do that? Or point me a tutorial or site that could explain how to do that?
You answered yes to question 4, which tool do you use to change fourCC codes?

See you later,

Aeolis

[mats.hogberg]

I presume that VirtualDub can change fourCC code.

No, I misunderstood the question, therefore answered in error. What I meant was that VirtualDub uses the fourcc to determine codecs, so a change of fourcc alters the way VirtualDub handles the AVI. (I've used this to trick VD to accept XviD it has trouble with by changing the fourcc to DIVX). So, No, VD can't change fourCC (by other means than reencoding to another codec) in the same manner as the fourcc changers do.
I use Nic's Avic.exe, included with his XviD codec build.

/Mats

[Aeolis]

Hi folks,

Thank you again mats.hogberg for your help and your fast reply. Now I'm waiting for guns1inger reply.

See you later,

Aeolis

[mikiem]

"Another situation: Vegas 6.0 only recognize .avis with DIVX fourCC code, it can’t read XVID fourCC. Any ideas? "

There are some threads on this, or use frameserving.

"Is that a real advantage in using ffdshow instead of the real codecs?"

It works. & the other codecs aren't imaginary (un-real) BTW.

"I mean will speed really increase when processing thru it "

Never noticed a difference.

RE: FFDShow stability, personally don't use it on this machine because of compatibility problems, which *might* occur as gunslinger posted. Personally I suspect if others have prob. that's why. Do use it on other machines without problems.

RE: 4cc stuff, there are a couple of other prog if you google. Can also muddle around in the registry but using software to change the headers is safer/easier. An example of what 4cc does, if you have a .doc file it's assumed to be microsoft word format. Same with pdf & adobe acrobat. But, can't tell about avi files because they can hold different kinds of video, so the 4cc code in the file tells windows & software what kind it is. WIndows stores a table that says if this 4cc, it's this kind of avi, then use this software to decode it.

[guns1inger]

I rarelt encode to Divx/Xvid - occassionally to put something on the web, but never for archiving. I use the difference codecs for playback under different circumstances. The most common reason - depending on how the video was encoded, you can often be greeted by the annoying "b-frame decoder lag" message when frameserving and using the original codecs in avisynth or virtualdubmod. I have found that in these circumstances, loading the file as a DirectShowSource (which uses ffdshow) removes this problem.