Does a movie compressed as AVI loose its quality too much both sound and video?

[ajayritik]

Nowadays we get lot of movies with AVI format. I have also heard people telling of burning 4 or 5 AVI format movies into one DVD. But by doing this will we loose quality? When a DVD is compressed into AVI does it really loose much of its quality? I have never played an AVI format movie on a DVD player. So I'm not sure whether it will make a difference! Will it make a difference if I take an AVI movie and play it directly on a DVD player that supports it rather than converting the same AVI movie to DVD Format and play on it? I guess once a movie is compressed if we try to decompress again we may not get the same quality that the original had! So converting from AVI to DVD (VOB) is only done coz some of the DVD players don't support AVI format or its done so that there is improvement in quality?

 

[ravi_9793]

There is very little loss in quality in .avi format

 

[[xubz]]

MPEG-2 compressed to any format will lose its Quality (if not much).

Original DVDs (English Movies) take up nearly 7-8GB for a single Movie! It also contains 6Channel AC3 Audio (with both Dolby and DTS Audio).

If you 'rip' the Movie, And want to keep the Multichannel, You'll need ~600MB-1GB for just the Audio!

So yes, You WILL lose much sound. (I can definitely show you the video artifacts in my original Saving Private Ryan DVD and the Ripped AVI (XviD) which takes 1.3GB)

(AVI is just a Container for Various Video Compression Formats, there are many like that, MKV, etc.)

 

[goobimama]

Well here's the thing. You can either make a good job out of it, that is, small size but good quality, or a crappy rip. Depends on your encoding skills. Also, if 5.1 matters to you, then yes, the AC3 will take up space (although, not more than 500MB for a normal movie).

It also depends on what you are going to watch it on. If it's a 15" monitor, then 1.3GB or 700MB or DVD will make almost no difference. But if you plan on watching on a widescreen HD TV, then the difference will be obvious.

Btw, x264 is the new DivX. You can get multichannel audio + good video quality within 700MB

 

[raksrules]

You may have found on net that there are 1CD and 2CD rips available. The basic difference in both of them are the 2CD ones have usually higher frame rate like say 29fps and 1CD will have 23.xxx fps. Another thing is that the 2CD rips may have 5.1 Channel Dolby Digital Sound while it is very difficult to have in a 1CD rip. 1CD rips may have less resolution while it may be more in a 2CD Rip. So if you want better quality. smoother picture then go for a 2CD rip rather than one.
But one more thing in case you have DVDs and plan to backup in Divx/XviD format then please dont waste time in doing this, rather copy the disc itself. It takes hell lot of time for the conversion and transcoding to happen. I once tried making a 2CD Rip of my Rang de Basanti Original DVD (Just to see) and it took more than 10 hrs !!!!

 

[ajayritik]

Well my main question is if I have an AVI file and if I convert into DVD using Nero Vision or any other software will that enhance its quality since the size of file is increasing from 700 MB to 4 GB. I dont mind wasting one DVD for one movie but will I get better quality of sound and picture if I convert a 700 MB AVI file to 4 GB DVD format?

 

[[xubz]]

^ Quality once lost during Compression cannot be regained!

 

[ajayritik]

So when I'm converting an AVI file to DVD I'm just making it in a format that is playable on DVD Player, that's it? In that case its better if I burn the same AVI file rather than converting into DVD. I thought by converting maybe I will get a better sound quality if not picture quality. So it really doesnt make sense to convert an AVI file to DVD thinking we will get surround system for home theatre!

 

[[xubz]]

No LOL! On the Original DVD, the Surround Sound is actually stored in 6 separate channels! (each for one speaker + sub). All those 700mb Rips are just stereo.

You're just wasting space on the DVD, because neither you'll get good video/audio

One more thing to remember is, those 5 in one pirated DVDs have extremely low quality video and audio.

And Yes, .AVI files are directly read on the DVD player ONLY if it supports DivX

 

[the.kaushik]

^ Quality once lost during Compression cannot be regained!

Its only for lossy compression.. i think avi(DivX) is loose less compression!

 

[ajayritik]

Kaushik what do you meanby loose less compression?

 

[goobimama]

@kaushik: Heheheh... That's a nice one....

 

[raksrules]

DivX/XviD are also lossy compression techniques but the loss is not that evident when seen on small screen TV or computer monitor. And yes the 1CD Rips (700 Mb) have stereo sound but in case the movie is short in length it may carry 2Channel AC3 sound. And yes the 5 in 1 Pirated DVDs have extremely low quality video and audio. In case you buy those i suggest go for the 3 in 1 or at least the 4 in 1 but some old movies since they must have been taken from their original source and hence you can expect better video and audio.
The 2CD Rips do have 5.1 Channel AC3 Dolby Digital Sound incase it is ripped that way. But if you have to accomodate this sound then compromise needs to be done to the video bitrate and/or the resolution of the video.

 

[the.kaushik]

@kaushik: Heheheh... That's a nice one....

Nothing funny bro! These are technology used for compressing a media.. ! something similar to gif compared to Progressive JPEG..

Kaushik what do you meanby loose less compression?

Get to know about then from here
*en.wikipedia.org/wiki/Lossy_compression

Cheers to happy learning!

 

[goobimama]

Are you seriously saying that Divx/Xvid is not lossy? Cause that is crazy. All video are lossy (at least the ones we come across everyday). The bitrate defines how much of loss is evident. You may not see the loss on a small screen, but that doesn't mean it is not lossy.