Why does files expand!?

[vikung]

Why does a 500mb mpeg file, become 4GB! mpeg file in burning software?

I know that files have to be decoded if I want to make dvd from avi etc. But I miss a: Leave-The-Damn-Files-As-They-Are-And-Just-Burn-The-Files Button!

[guns1inger]

avi is not dvd compliant. Depending n the codec used to compress the avi file, you can expect at least a 3 - fold increase in size as a minimum. Mpeg 2 is not as efficient at low bitrates, so higher bitrates are required to maintain quality. This is the main reason the files get bigger. Secondly, most burning software will try to fill the disc, again in order to keep the quality up. If you want control, encode with a standalone encoder where you can set the bitrate.

If you don't want bigger files, get a player than can play divx/xvid format avi files, and put6 - 7 full movies to a disc. The quality won't be DVD quality (and in most cases, not even near DVD quality) unless you push the bitrate up to around 2000kbps mark, but then you won't fit it in 500 - 700 mb either.

[Baldrick]

Buy a divx/xvid dvd player if you want too keep the file size and just burn as a data dvd.

DVD-Video requires much higher bitrate to keep similiar quality. If you still want too keep down the size you must use lower video bitrate = lower quality...

[Abond]

Why does a 500mb mpeg file, become 4GB! mpeg file in burning software?

This is the question.

I know that files have to be decoded if I want to make dvd from avi etc.

This is the answer

But I miss a: Leave-The-Damn-Files-As-They-Are-And-Just-Burn-The-Files Button!

AFAIK it has a name Data-DVD-DivX/XviD-DVD Player!

[KBeee]

What programs are you using to author and burn your mpeg file? If your 500 M mpeg file is already DVD compliant, then it shouldn't need re-encoding, though Nero seems to like re-encoding just about everything for the Hell of it.

[Abond]

Interesting, I am quite sure the question was about 500 mb avi file. Even if one look at the answer of guns1inger. How it appear now 500 mb mpeg file??
If your burning program does this, you should seriously consider to change it.

[jtoolman2000]

It's really based on length and not file size. A 2 hour movie can be delivered as a highly compressed 700meg file in DIVX ( crappy ) or as 4000 meg barely compressed DIVX (very good).

Same goes with Mpg2. Highly compressed mpg is small but crappy and slightly compressed is large and very good. Whether they are large or small they are still all the same length.

When you convert some avi of whaever to mpg2 for ultimate DVD authoring, the minimum bit rate required for adequate quality will take that 700 meg and increase it many fold. The higher the bit rate the larger ( size ) will the file become. With this extra size comes higher quallity. There is a limitation of bit rate so read up on that and you will learn more aabout that subject.

There are many tricks and techniques to allow you to cram more video onto a DVD and maintain at least adequate qualtiy.

So don't be shocked when you see that huge increase. They are two differenct formats.

[jtoolman2000]

Forgot to add another factor. What will you be watching your video on. A TV / big or small? A PC monitor, a portable player. All will dictate how you go about preparing your files.

[thecoalman]

Why does a 500mb mpeg file, become 4GB! mpeg file in burning software

Providing the mpeg files are DVD compliant you can. For most applications matching your output specs to the specs of the video is all you need to do otherwise most reencode to whatever the project specs are. Really depends on what software you are using... which you fail to mention...

As far as the AVI's as mentioned above there is no way around that besides buying a Divx player if they are divx files.

[guns1inger]

What I said still holds - if you throw a 500 mb overcompressed non-compliant mpeg file into a one-click-wonder, you will get something big in return. For a lot of software, it could even be compliant and still get re-encoded.

[vikung]

Thank you all for anserws.

Ok Im a noob. But I still wonder why a 3Gb file looks worse than the 700mb file it was made from. Or what the added 2.3Gb data to the file is.

[guns1inger]

In most cases it doesn't. The 700 mb file is full of image flaws. Most of them you don't see watching on your PC, but if you had a divx capable player you would see them on your TV. Then you used a second rate encoder to resize and encode to mpeg2. If you want to convert an avi to dvd and keep some semblence of quality you need to use avisynth with the right combination of ilters, encding with a good quality stand alone player. Assuming you have a 90 minute avi compressed to 700mb, you will have to fill a DVD disc (4.38gb) to maintain quality. This is the difference between mpeg4 compression and mpeg2 compression. Conversly, if you want to take a DVD and maintain DVD quality using mpeg4 compression, the resulting file would still be around 2gb in size. Any less and you are compromising on quality somewhere.

If you want to understand this stuff, then you have a lot of reading to do. If you don't want to do the reading required, buy convertxtodvd and live with the results.

[donnyj]

Ok Im a noob. But I still wonder why a 3Gb file looks worse than the 700mb file it was made from. Or what the added 2.3Gb data to the file is.

One way is to use a crappy encoder, or using the wrong settings in a non-crappy encoder.

Use a good encoder with good settings and good quality source material to get good results

[thecoalman]

But I still wonder why a 3Gb file looks worse than the 700mb file it was made from.

The first thing to look at is the resolution of the original. Scaling video up produces bad results, most likely that is what your encoder is doing. You have to set the resolution at the same or below. Since most Divx files are less than the maximum resolution allowed for DVD you have to use a lower resolution, 352x480. Thias will slightly decrease detail but eliminate many of problems introduced by scaling up.

[donnyj]

But I still wonder why a 3Gb file looks worse than the 700mb file it was made from.

The first thing to look at is the resolution of the original. Scaling video up produces bad results, most likely that is what your encoder is doing. You have to set the resolution at the same or below. Since most Divx files are less than the maximum resolution allowed for DVD you have to use a lower resolution, 352x480. Thias will slightly decrease detail but eliminate many of problems introduced by scaling up.

I am probably putting my foot in my mouth, but I strongly disagree. Scaling a 640x480 movie to 352x480 is VERY unneccessary. Either use a better quality resizer (preferrably) or add black bars to expand the frame to 704x480. Don't throw out half the width...

But, to each his own

[thecoalman]

I am probably putting my foot in my mouth, but I strongly disagree. Scaling a 640x480 movie to 352x480 is VERY unneccessary. Either use a better quality resizer (preferrably) or add black bars to expand the frame to 704x480. Don't throw out half the width...

It's been my experience that scaling a amovie up always produces bad results... Of course you can try both and decide for yourself. Your second suggestion is good but will introduce problems with AR.

Personally I never have these issues because I use 720x480 from astart to finish.