DVD Quality

cinz1974 · Post by **cinz1974** » Fri Mar 16, 2007 7:13 am

I am a newbie

I have burned my first 3 dvd's and have encountered the following issues:

Picture Quality is not great
Sound and Picture are out of sync
Sound is of very poor quality

I have a 16.9 plasma tv and dolby 5.1 surround sound home theatre system. The volume just seems to come out of the centre speaker.

I followed the tutorial which states to click particular boxes to oxmpensate for the above but doesnt seem to be working.

Can anyone offer some help?

Thanks

Post by **Ken Berry** » Fri Mar 16, 2007 8:19 am

I don't think anyone will be able to help you until you give us some hard information to work on...

Where did the original video come from?

How exactly was it captured?

What were its properties? (Right click on one of the captured files within Video Studio and copy the Properties to here.)

What editing did you do to it? (Give us details.)

What work flow did you follow? (Ditto.)

What were the properties you used to burn the DVD?

And that's probably just for starters!!!

cinz1974 · Post by **cinz1974** » Fri Mar 16, 2007 9:01 am

Where did the original video come from? torrent file download

How exactly was it captured? not sure how to answer this mpeg video compression xvid bit rate 159

What were its properties? (Right click on one of the captured files within Video Studio and copy the Properties to here.)

What editing did you do to it? (Give us details.)

MPEG files
24 bits, 720 x 576, 25 fps
Frame-based
(DVD-PAL), 16:9
Video data rate: Variable (Max. 7000 kbps)
Audio data rate: 256 kbps
Dolby Digital Audio, 48 KHz, 2/0(L,R)
HQ 16.9 Dolby Digital

What work flow did you follow? (Ditto.) none

What were the properties you used to burn the DVD?
the file was large so I used the automatic compression built into videostudio 8x burn

I hope this info helps

i am so new to this

Black Lab · Post by **Black Lab** » Fri Mar 16, 2007 1:10 pm

And what version of VS are you using?

DVDDoug · Post by **DVDDoug** » Fri Mar 16, 2007 9:32 pm

The Xvid file is the root of the problem. These highly compressed MPEG-4 variations sometimes cause trouble when you try to edit them, convert them, or make a DVD from them. They can cause all kinds of weird problems - A/V sync problems, crashing & locking-up, failure to convert, etc.)

Really, these formats are all meant to be watched on you computer. They were not designed to be edited, or converted (again) to some other format. (BTW - MPEG-2 video and MP3 audio are not really designed to be edited or converted either. They are supposed to be "final" formats for viewing & listening.)

You might try a 3rd-party conversion program to convert them to MPEG-2. before importing the video into Video Studio. SUPER (FREE) is a universal conversion program.

Or, you can try SVCD 2 DVD (~$40 USD) which claims to convert almost anything to DVD.

And, you can check the Xvid websites to see what software they recommend.

I doubt that your video is anywhere near "DVD quality". Xvid is more efficient than MPEG-2 (DVD), but I wouldn't expect a 159kbps Xvid file to look as good as a 4000kbps DVD! It may look OK on your computer, but on a plasma screen, you will notice the difference.

There will be some quality loss every time you convert between one lossy compression scheme to a different lossy compression scheme. If the movie/program was originaly from a DVD, there was some quality loss when it was first converted to DVD, more loss when converted to Xvid. There will be more loss when it is converted back to DVD. Since you are not making an identical digital copy, it's something like making an analog copy, or like making a Xerox of a Xerox. (A high bitrate will minimize the loss, and the additional loss may not noticeable if you convert from 159kbps Xvid to 4000kbps MPEG-2.)

The same is true of the audio. There is loss with each conversion.

If the original soundtrack was stereo (or 2-channel "Dolby Surround"), you are better off leaving it as 2 channels. As far as I know, Video Studio does not have a Dolby Surround decoder, so it can't properly convert 2 channels to 5.1. Leave it as 2-channels, and let your Pro Logic receiver do the decoding. ...I think that's what you are doing. (If you want to "pan" the sound to a particular speaker, Video Studio can do that with it's 5.1 digital encoder.) If the Xvid contains a mono soundtrack, of course, all of the sound is going to come from the center speaker. It's also possible that Video Studio simply cannot decode the Xvid audio. (I don't know what type of audio compression is normally used with Xvid.)

cinz1974 · Post by **cinz1974** » Fri Mar 16, 2007 10:02 pm

im using vs 10

Post by **Ron P.** » Fri Mar 16, 2007 11:40 pm

While VS10+ can create Xvid or DivX video (provided you have the codec installed), it does not fair well trying to edit them.

To add to DVDDoug's excellent explanation, I recently talked to a programmer friend, who also does video editing (HD) using some of the expensive hardware and software. He has looked at specific algorithms of various formats. The simple reason as I understood it, why the conversions fail is because of the different algorithms that must be used for the conversions. Once a file is converted to a highly compressed format, to convert back to the previous less compressed format, it causes the data to fall outside the lessor-compressed's memory range. So it has no idea what to do with this data. Everything on your PC must use "ranges in memory" to work. Your memory (RAM) is divided up into numerous numerical sections or ranges. Programs, files, data will reserve ranges of the memory so they can work. If some data gets outside it's range then it starts causing problems.

That's my understanding of his complex explanation. The reverse encoding of a format that is not meant to be reversed, will fail more times then naught.

If this is not correct (which is very probable) someone will correct me (I hope)..

heinz-oz · Post by **heinz-oz** » Sat Mar 17, 2007 12:59 am

Why someone would want to get a highly compressed file from the internet and then reverse its compression to mpeg2 is beyond me. It's like trying to reconstitute coffee beans from instant coffee.

The instant coffee is ok (just) to drink but everything else...

I have not heard of anyone doing this conversion successfully. If you are hell bent on watching this stuff on the TV, get yourself a DVD player which can play these formats.

DVDDoug · Post by **DVDDoug** » Sat Mar 17, 2007 1:09 am

Interesting!!!!

I've sort-of had a similar hypothesis.... Send some nonsense-data to a video card and you get a bad pixel or a bad video frame. Before you know it, the next frame comes-along, and maybe you don't even notice it. Send the same nonsense-data to a codec, and who knows what will happen!

I am an amateur programmer... very amateur, and I don't know anything about video compression algorithms. But, I do know that the most common way of crashing a program is to over-write an array. Say you have a chararacter-array that's supposed to hold somebody's name. If the programmer reserves 30 characters for the name, and somebody types-in 31 characters, you will over-write some unknown memory location, and the program will do "something unexpected". (The programmer is supposed to make sure his program checks for this and throws-away the extra data, or warns the user... something reasonable...)

The "buffer overflow exploits" used by hackers are based on a similar concept. The hacker gets access to memory space he's not supposed to. Beginning programmers often make an array of 30 variables and then try to write something into variable #30. They forget that, in programing, the array subscripts are numbered 0 thru 29.

However, it's up to the programmer to make his program tolerant of bad data, and IMHO the codec should be able to handle invalid data gracefully.

Sorry, cinz... I know that didn't help you.

Why someone would want to get a highly compressed file from the internet and then reverse its compression to mpeg2 is beyond me.

Because it free?

I'm not saying that cinz is a pirate... But, I assume most DivX and Xvid stuff is pirated...

I have not heard of anyone doing this conversion successfully. If you are hell bent on watching this stuff on the TV, get yourself a DVD player which can play these formats.

Right! Then, you just copy the Xvid file to a DVD as-is and pop it into your DVD player.

Or, you can get a video card with composite-video out, or get a VGA-to-composite adapter, and plug the computer directly into the TV.

cinz1974 · Post by **cinz1974** » Mon Mar 19, 2007 1:59 am

WOW!!!

all great feedback but very high tech stuff for me guys

FYI my dvd player does play all formats

ideally all i really want to the picture to be in sync with the audio it seems from the comments made that this cant be done.

is this the issue with just vs10 or is there another program that will alleviate this issue?

is this correct?

Black Lab · Post by **Black Lab** » Mon Mar 19, 2007 3:30 am

cinz1974 wrote:ideally all i really want to the picture to be in sync with the audio it seems from the comments made that this cant be done.

is this the issue with just vs10 or is there another program that will alleviate this issue?

You've completely missed the point. It's not a VS10 issue. You're taking a highly compressed format and you're trying to uncompress and burn it to a DVD with the hope that nothing will go wrong. Unlike AVIs or MPEGs, those types of files are not meant to be edited. They're meant to be shared over the Internet.

ggrussell · Post by **ggrussell** » Mon Mar 19, 2007 3:38 pm

Unlike AVIs or MPEGs, those types of files are not meant to be edited.

Actually, MPEG 2 is compressed and shouldn't be edited either, but that doesn't mean that people wont' try it. There are plenty of apps that will convert and burn DivX and Xvid so they can be burned to video DVD. As for quality, I wouldn't expect much though, but it can be done.

Black Lab · Post by **Black Lab** » Mon Mar 19, 2007 3:45 pm

ggrussell wrote:
Unlike AVIs or MPEGs, those types of files are not meant to be edited.
Actually, MPEG 2 is compressed and shouldn't be edited either, but that doesn't mean that people wont' try it. There are plenty of apps that will convert and burn DivX and Xvid so they can be burned to video DVD. As for quality, I wouldn't expect much though, but it can be done.

Although they shouldn't be, they can be with minimal problems, unlike DivX or Xvid.

daniel · Post by **daniel** » Mon Mar 19, 2007 5:08 pm

Yes it's all a matter of the complexity of the compression tricks.

Editing an MPEG2 is like editing a jpg photo in a image editor.
If the compression was not too tight (high bitrate in video) and the editing is reasonable (no fancy color treatments) it is reasonable to obtain good enough results, at best really difficult to tell from the original.

MPEG2 tries to describe the original picture in a given number of bytes, by comparing each frame to the relevant I-frame, itself compressed like a medium-quality JPG image.

MPEG4/divX is more like audio MP3, and besides compressing the description even more with intricated mathematical description, actually throws away lots of significant data that is "unnoticeable by casual observers". Big difference when you try to alter the result again...

For specialists: yes I know this is a (over)simplified description;
this is a user, not a tech forum.

DVDDoug · Post by **DVDDoug** » Mon Mar 19, 2007 9:01 pm

FYI my dvd player does play all formats

I that case, just copy the Xvid file onto a DVD (or CD) with whatever burning software you have. Pop it into your DVD player, and it should play!