dvd size

[zak_swan]

when i encoded an avi file to dvd and use the same bitrate as the avi it comes out all blocky.
to make a dvd out of avi and make it the same quality does the final dvd size have to be bigger than the avi? and why?

also when using any encoder is it better to use something like gold wave to do the audio before using it with encoder rather than having video source and audio source from same file?

[Gees]

It'd probably be a good idea to go back to the What is DVD and the How To Convert Guides to get a grasp on what is actually going on when you go from avi to (DVD) mpg.

No offense, but the questions you ask seem best answered that way rather than to retype the whole theory around video file types and their uses.

You will benefit greatly by reading through all that rather than to just get handed an answer which means nothing outside of "the big picture".

[zak_swan]

no offence taken i will read the guides again but here is my confusion if i encode a small test with mainconcept as a vcd and watch it with windows media player it appears to be the same quality as one i encoded as dvd format but dvd format uses a lot more memory.
if i have an avi file of say 700mb can i encode it to 700mb dvd without loss of quality?
before i start looking for a needle in a haystack can anyone help with my questions?
if every answer was to read the guides there would be no point in having this help forum.

[housepig]

Zak -

that's like asking "can I take a cd and play it on a record player? both of them have music on them..."

dvd video has specific acceptable formats for the video files (mpg1 or mpg2) - by contrast, most software players have a much wider range of formats they will accept and play (mpeg, avi, wmv, mov, asf, etc).

so if you want to play these avi files on a dvd player, you either need to get a player that will play avis, or you need to convert them to a (usually less-compressed, and therefore larger) more acceptable dvd format.

[RabidDog]

quick explanation ... divx/xvid (AVI) files use the power of your computer to compress (and playback) the video and make it look reasonable. A dvd player has a puny little mpeg2 decoder which cannot use the highly compressed files of avi.

[zak_swan]

kind of understand but if i encode a 700mb file to vcd it will work on my standalone dvd, if i encode a 700mb file to dvd it will work on my standalone dvd player will be excactly same quality (well to the human eye) but at least twice the size

[dcsos]

Simple Answer
If the AVI is really an MPEG-4 file in an AVI wrapper
(That is -not a AudioVideoInterleave file- but MPEG-4 like divx , xvid or V4)
then its compressed with a more advanced kind of COMPRESSION than the DVD could be

This is- MPEG-4 was developed after MPEG-2
and it therefore provides better quality at a lower file size..
In order to play in a SET TOP you''ll need to go back to the older format
MPEG-2

[tgm4883]

kind of understand but if i encode a 700mb file to vcd it will work on my standalone dvd

No

if i encode a 700mb file to dvd it will work on my standalone dvd player will be excactly same quality (well to the human eye) but at least twice the size

yes

[jaxxboss]

To answer your main qustion simply.. Yea the dvd file has to be bigger than your avi file as it will be uncmpressed. Blocky? maybe the source file (avi) is crappy.

[tgm4883]

i read somewhere a long time ago that the dvd should be like 10 times bigger than the divx file. but its probably closer to only 6 times bigger considering most movies will fit a 700 meg divx file and dvd's will fit on a 4.7gb disk, so thats roughly 6 times bigger

[SaSi]

kind of understand but if i encode a 700mb file to vcd it will work on my standalone dvd, if i encode a 700mb file to dvd it will work on my standalone dvd player will be excactly same quality (well to the human eye) but at least twice the size

The VCD MPEG-1 file has a picture size that has each dimension half of what the normal DVD dimensions are: 352 x 288/240 vs 720 x 576/480.

This means that each DVD "picture" has 4x the area of the VCD picture.

This increase in frame area takes it's toll in bitrate. Theoretically, you should quadruple the bitrate to achieve the same quality. In practice, because MPEG-2 is so good you practically can achieve quite acceptable quality with only twice as much bitrate.

Now, if your original AVI converted to VCD appears to look acceptable and same as the AVI, it implies that you don't need a full DVD resolution to encode. Additionally, DVD VIDEO can happily accept MPEG-1 (i.e. VCD) MPEG fles.

Furthermore, if your source AVI has a small frame size (320x240), it makes no sense to scale it up for a DVD. Just use the same resolution and encode as MPEG-2 (or MPEG-1) using a 1.5Mbps bitrate.

I suppose that most of the above are covered in the guides, but I bet some of these are not quite clear for a novice.

Scan the postings and search for articles.

[Gees]

if every answer was to read the guides there would be no point in having this help forum.

Yes. Not for every question. But from the nature of your question I will always maintain that was the best advice.

A main function of the forum in my, and many others', opinions is to direct people to all the resources this site has to offer beyond just the forum. Lots of good people have worked hard to put it all in handy places.

A quick read or search here will answer lots of the types of questions you asked.

Best of luck with everything. :c)

[zak_swan]

Sasi your signature seems to apply to me just now.
Is this correct, an avi file can be played on a pc because it is compressed and the pc decompesses it (codec) and to view it on a standalone dvd it has to be decompressed enough so the player can read it so therefore the size of dvd is larger than the avi file?
ok think i've got that one figured out but the vcd one im still not sure of and i'm not going to bother figuring it out tonight as i need a break from figuring out DVD making, its making my brain hurt lol

[Jukka]

I go for a really simple rule if I am converting AVI to DVD/VCD - use the highest bitrate possible to make it still fit one disk. That way you can avoid all the questions above.

Good luck.

Jukka