Repeated Divx Compression

[Four_of_Five]

I'm using TMPGEnc to convert tv-captured "regular" .avi files into mpeg files (for VCD burning later). With the mpeg files I find that by using VirtualDub I can not only blur away the tv-logos (logoaway filter) but also compress the mpeg files into Divx-avi files. However, since there are several logos (3) on avi file that i have to filter out, I have to continously compress the DivX-avi file at least 3 times to complete the process. Plus, later on... turn the DivX file back to it's mpeg format to burn them into vcds.

Are there going to be "lousy" after effects on the quality of the resulting format (mpeg) with the above process? If so, is there a better way to go about doing it? If not, is there another way of shortening the process?

Thanks in advance for any advice.

[DigiToast]

DivX is a lossy compression, so everytime you compress, you're going to be losing data (read: quality). If you compress an already compressed file then you continue to lose more data/quality (or lack thereof) than you already had to begin with. IE: Input1->lossy compression->Output1, Output1 has less quality than Input 1. Output 1->lossy compression->Output2, Output has less quality than Output1, and this continues for as many times as you do a new compression.

Anyhow, virtualdub should allow you to add in more than one filter (even if it's the same filter) and compress once instead of filtering and compressing three times like you described. Simply keep on using the add button to put in all three of your blurring filters and you can take care of it in one pass. Doing this shortens the process, and will leave you with a higher quality result.

And about the losing quality everytime you compress thing. Here's a fun (and quick) thing to try if you have time.. Take an mp3, output it to wave, compress it @128Kbps, output the compressed file to a wave, recompress the new wave.. keep repeating about 10 times and then listen to your mp3 after 10 encodes. You'll definitely notice how much quality you've lost.

[Gazorgan]

Don't save the AVI as a DivX. Use Huffyuv(lossless) or MJPEG(virtually lossless) at 95%.

[DigiToast]

Four_of_Five, keep in mind that if you wish to try something like huffyyuv, you're going to need to make sure you have *plenty* of hard disk space free as it takes rougly 20 gigabytes to hold an hours worth of footage @ 720x480. Just making sure that you understand since your computer specs listed 40GB as your hdd space.

[Four_of_Five]

Thanks guys! I think i'll go for the continous filtering...i'll certainly keep that in mind even if do have the disk space