Music Video Conversion

[dominus]

This is, in a funny way - something I can't find anywhere help with.
I'm a user of virtualdub for several years now, but my main conversion files are Music Videos, rather than full length files (1 hr / 1:30 hrs).
What I want to know is whether there are specific guidelines to convert Music Videos to DivX/Xvid, and receive the best quality possible, for files that are originally 50 mb or so, into about 25 mb ...
I am trying all sorts of settings, but mostly the picture comes up pixelated. I admit I don't have expert knowledge of the divx codec, but there must be a way to reduce the amount of pixelization...
I used several bitrate calculators, that said I need to put a value of about 503 for that video, but that didn't help.
Any help would be appreciated, as I have several GB's of music videos I want to reduce...
Thank you.

[paglamon]

What format are the original videos in ? What are the bitrates of the originals ? Please use Mediainfo to provide relevant information about the original files.

[dominus]

Nice. I wasn't aware of the existence of media info, I'm using G-spot.
Anyhow, most of the files are mpeg files, with different bitrates.
Let's take the file I attached for example, it's an mpeg (MPEG-PS) with a bitrate of 1,071 Kbps video stream, and a resolution of 352x240 , 29.97 fps and 4:3 aspect ratio.
Enough info?

[paglamon]

it's an mpeg (MPEG-PS) with a bitrate of 1,071 Kbps video stream

VCD quality is 1150 kbps. Your mpeg has even less bitrate. So the source video is already pretty compressed and not of too good a quality. Compressing it further will surely have its untoward effects(like pixelation). For a low bitrate(as 503 kbps) you MUST do a 2-pass encode. Also,if the original video has any black borders, you should crop them before encoding. And see if you can squeeze out some more bitrate from the audio.

And lastly,at low resolutions(like 352 x 240) pictures will have pixelations on a computer full-screen. Should look somewhat better on your TV.

Some help with XviD configuration in Virtualdub:http://www.doom9.org/xvid-vdub-final.htm

[dominus]

Mpeg conversion

Hey,
Thanks for the reply.
When I used media info on the file it actually said
Bit rate : 1 071 Kbps
Nominal bit rate : 1 150 Kbps

Does this mean it isn't vcd quality?
I actually tried Xilisoft's video converter on the file and it didn't come out pixelated... it just came out bigger.... <g>
The double pass I never tried, perhaps that is my problem. I shall try it and report back.
Thanks for the answers.

[dominus]

Nope. No help there, 2nd pass didn't help.
The Xvid tutorial you referred me to had Gordian Knot prefix instructions I couldn't find, and referred to a dvd rip / 700 mb files... Which is exactly my problem - nowhere can I find small files conversion tutorials....
Any other ideas ?

[paglamon]

Sorry. At 503 kbps bitrate, you will never get a satisfactory Xvid/DivX avi. You can just try to get the best out of it by going for VBR and 2-pass. How does your avi look on TV ?

[gonwk]

Hi dominus,

If your SOURCE is low quality ... you can only do so much ... may be if you use FILTERS in VDub you can get it a little cleaned up but not much!

G!

[dominus]

actually the source isn't very low quality.
I mean, it's not s-vcd quality but it doesn't have the pixelization before I convert it.
But my question is generally for all of my 206 music videos, some of which are better quality and some of which are less.
Paglamon - The vbr/2-pass would mean that I set the audio to vbr, right? How does the audio affect the video conversion? And what would you suggest I set the bitrate to if not to 503?

[paglamon]

VBR for video,not audio.In any case,2-pass, IIRC, will automatically choose VBR. If you want the size to be about half the original, obviously the bitrate you can set is also about half the original. So,if you increase the video bitrate the size of file increases.The only other option is to decrease the audio bitrate and increase the video bitrate to keep the target file size same. Now those 1-CD encoding of a standard sized movie(this is the lowest quality acceptable to most) usually keeps the video bitrate at around 800kbps.Which means that the total bitrate(vid+aud) will be about 900+ kbps. That is why reencoding a vcd quality(1150kbps video)video will not be of much help since you are not saving too much bitrate. Try encoding small clips(1 min) of the original video at different bitrates and decide the minimum rate at which you get rid of the pixelation.

[dominus]

I feel like I'm struggling against windmills here... I took another file for reference and the pixelization continues.
I even tried 1100 bitrate setting for comparison, and it continues... is it a codec thing? I mean, if I try with Xvid should it better? And the Xvid codec has it's own settings... Arrgg....

[paglamon]

I took another file for reference and the pixelization continues.

This is the third time I ask the question : How does the encoded file look on TV ?

[dominus]

Sorry, I haven't answered this question because I haven't tried it on a tv. I didn't have access to one with the divx... but I'll try it later.

[paglamon]

Can you possibly upload a very small(say about 10 MB) sample of the original video and let me see what I can make out of it with XviD/DivX ? Here is a free site for uploading.

[dominus]

Okay, took me about a day to find and test a good video splitter (used ezsplitter eventually) that won't change the bitrate/ratio/anything else in the split file.
This is another file, rather than the first one I wrote to you about.
It's original size is 40.2 mb, and as with the rest of my to-b-converted files, I'd be content with up to 75% of it's size after conversion...
<a href='http://www.sendspace.com/file/8uord0'>http://www.sendspace.com/file/8uord0</a>
THanks.