Quality Loss when Con. from mpeg1 to avi...

[Pink Floyd]

Dear All

I have a few VCD Resolution MPEG1 files that I need to convert to avi for editing. AVI is not the final format to which I intend to encode after editing. I am using DGDecode to decode the MPEG1 stream and converting the MPEG1 file to avi using the following AVISynth script:

---------
LoadPlugin("X:\DGDecode.dll")
LoadPlugin("X:\mpasource.dll")

video=MPEG2Source("X:\MPEG1_File.d2v")
audio=MPASource("X:\MPEG1_FIle.mpa")

AudioDub(video,audio)
---------

In Virtualdub, I set the Video to Fast recompress and the Compression to HuffYUV 2.1.1 CCS SP Patch 0.2.5, and save the MPEG1 file as an avi.

Now the problem is that the resulting avi file becomes Visibly blocky. I was not expecting this Quality loss.

Am I doing something wrong here? I there a better way to do the same. Do I need to use a different Codec for the AVI. I

neeeed to convert to avi. I dont mind the big file sizes that HuffYUV produces.


Thank You.

[guns1inger]

Have you changed the resolution at all - in virtualdub, for example ? I find even commercial VCD releases to be noticably blocky, and this will only be enchanced by any resizing.

[daamon]

I've used the following to great effect with VOBs containing MPEG2 files to get DV AVI for editing. There's no real difference for you, except you've got MPEG1.

1) Load the MPEG1 into VirtualDubMod (this variant works with MPEGs).

2) Video -> Compression: Choose your DV AVI Codec. You may need to download and install the Panasonic DV Codec (it's free and known to work with VirtualDubMod and other variants).

3) Save the MPEG1 as DV AVI.

I don't believe VirtualDub works with MPEGs as source files - this may be the problem (that's why I specifically stated VirtualDubMod). Or, perhaps the "Fast recompress" is causing the problem?

I hope that helps. Good luck.

[guns1inger]

These are VCD resolution. To save them as DV avi requires they be DV resolution, which means a big upscale and a lot of potential image issues. You are right that virtualdubmod may be the easier option, but I wouldn't take VCD to DV is there were other options available.

[daamon]

These are VCD resolution. To save them as DV avi requires they be DV resolution, which means a big upscale and a lot of potential image issues. You are right that virtualdubmod may be the easier option, but I wouldn't take VCD to DV is there were other options available.

Good point - I overlooked that. I used MPEG2 at full D1 (full DVD) resolution.