? about divx to svcd conversion

[johnny quest]

Let's say that I load a divx clip into Vdub and look under file info to get the bitrate. Let's say the bitrate is 1500. If I am converting to svcd or mpeg2 dvd compliant, will it make any difference in picture quality if I increase the bitrate when encoding, i.e. 2520 or 6000. The reason I ask is that I always thought that the quality of the clip could not exceed its original parameters when first captured or compressed.

If this is wrong, please let me know, thanks.

[ghoster]

that is correct the picture will not get any better then the source you are encoding from.

[Gazorgan]

The bitrate of the source and the bitrate of the final product aren't directly related. The final product can never be 'better' than the orignal ( some noise filtering not withstanding for captures ). Re-encoding is like this; take the original (film) and make a copy (DVD), now take the copy and make anotehr copy (DivX), now take that copy and make another copy (SVCD). You have a copy of a copy of a copy, and it's like a photcopier, not like digital copies of digital material. Each re-encode introduces loss of quality.

So, as to conversions, a good 2 CD backup in DivX can often times produce an excellant quality DVDR or SVCD final product. However, DivX tends to come in nonstandard reolutions, so you will have to crop/letterbox.

[johnny quest]

I understand you both. My question is this, is it worth it to up the bitrate from the original source. In other words, say I'm going to dvd compliant mpeg2 and can increase the bitrate because I have enough room on the disc, will I see any quality changes or should I just use whatever bitrate the divx file was captured with?

[bugster]

I understand you both. My question is this, is it worth it to up the bitrate from the original source.

It seems you dont actually understand. There is little if any relationship between the bitrate of a divx movie and the bitrate used to encode an SVCD (or any other mpeg) from it.

Assuming a decent quality source, the best quality mpeg will be achieved by using the highest bitrate you can, at least up to a point. As to where that point is you can only guess or use experience to guide you.

If you Divx is a good quality DVD rip, say a two hour movie occupying 2 CD's worth disc space, then it is probably good enough to convert to DVD with a bitrate high enough to fill the DVD-r. As for converting it to SVCD, best quality will come with the highest psossible bitrate again, though a few other techniques such as custom matrices can sometimes help. Basically experiment and find out what you are comfortable with.

[johnny quest]

Ouch! I guess I didn't understand. You post more than adequately answers my question and I thank you for the quick response.

[erikur]

My question to you people is this: Must the bitrate be from 4-8000 in a DVD file, or can it be lower ? if lower, will the dvd player accept it as a DVD ?

[mats.hogberg]

Even if the Video DVD standard doesn't seem to say anything about a lowes bitrate (only max: Up to 9.8 Mbit/sec ), the individual make and model may have its own idea on what's the lowest acceptable bit rate.
More info found here.

/Mats