Will the quality increase if the bitrate is higher after conversion?

[Choppa]

Just a quick question...
Say if I have a movie 126kbps Video and I convert it to mpg1 with TMPGEnc, using VBR, and make the kbps higher like 1000 with the quality increase? Or will it reach a maximum then just increase the file size?

[daamon]

Say if I have a movie 126kbps Video and I convert it to mpg1 with TMPGEnc, using VBR, and make the kbps higher like 1000 with the quality increase?

No, unfortunately the quality won't increase. To increase the quality, you need to add what's missing or been thrown away. Increasing the bitrate doesn't do this - you're quality is only ever as good as what you start with.

[Choppa]

Hmm... How come if I choose the same bitrate to convert to as .mpg the quality is a heck of alot worse rather then the same?
(video bitrate).

[thecoalman]

Because different codecs do not perform the same. You're original video is most likely divx or some other codec that performs very well at low bitrates. MPEG needs about 4x to produce the same quality. If your original was MPEG and you reencoded at the same bitrate beside the inevitable loss of quality during from reencodeng the quality would be the same. Increasing it won't make it better. Also be aware that making the resolution larger generally produces poor results.

Aside from doing restorative work on high quality captures suitable for such things the best quality you'll ever have is the original, . Any conversion loses quality.

Or will it reach a maximum then just increase the file size?

Relative to the resolution yes it will. Bitrates should also be adjuted to fit the resolution. For a basic idea for MPEG2:

720x480 8000 to 4000
352x480 4000 to 2000
352x240 2000 to 1000

You can go outside of these guidelines depending on your source and it's content but for the most part going higher just creates a larger file with no discernible benefit, going lower and you'll start to see macroblocking. Especially with a clips with a lot of action.

[Choppa]

Hmm... I see now, most of my bitrates are below 1000 and around 500-400x200-350 resolution eek...
Thankyou both for helping me.

[thecoalman]

Hmm... I see now, most of my bitrates are below 1000 and around 500-400x200-350.

Be aware the bitrates listed above are for MPEG2, as i stated above different codecs do not perform the same. I'm not familiar with divx that much but WMV is quite comparable and 1000kbps for a 500x350 fivx file would be right in the sweet spot or above.

[GideonK]

Before encoding/converting a video file, I use the following link which works very well for me:

http://dvd-hq.info/Calculator.html

[daamon]

Relative to the resolution yes it will. Bitrates should also be adjuted to fit the resolution. For a basic idea for MPEG2:

720x480 8000 to 4000
352x480 4000 to 2000
352x240 2000 to 1000

@ Choppa: Note that those resolutions are for NTSC-land. You're in NZ and so in PAL-land. Therefore replace "480" with "576", and replace "240" with "288".

[thecoalman]

@ Choppa: Note that those resolutions are for NTSC-land. You're in NZ and so in PAL-land. Therefore replace "480" with "576", and replace "240" with "288".

, Yes what he said. :P

[Choppa]

Ah I see... Speaking of NTSC and PAL I have a question on this that has bothering me.
If I have a NTSC movie and I convert to MPG-PAL will this mess it up? Or say if...
I have a NTSC and when I go to burn with Nero I choose PAL will this also distort it?
Because I'm not really sure about this, should I choose the NTSC setting the whole time or is there a way I can make it PAL?

[thecoalman]

Distortion is not a problem, however framerates are. Your best option in this case is to keep NTSC and Pal material seperate. You "PAL landers" are fortunate in that most PAL DVD players will play NTSC discs. No need for conversion ,just create seperate NTSC and PAL discs.

[Choppa]

I see, because some of my movies are either at the top of the screen (sometimes a bit is cut off) and the movie is somewhat longer then wide, I use the widescreen option on my TV to get it... Decent I guess.

[thecoalman]

Aspect has nothing to do with resolution, a 4:3 video whether NTSC or PAL resolution will look the same played on 4:3 TV. Same goes for 16:9, 16:9 and 4:3 video both share the same resolution of 720X480(PAL 576) .

[Choppa]

Wow, I never knew there was so much to all of this, with TMPGEnc, it has an option for aspect ratio, which one should I choose? The video is NTSC, the TV is PAL, and I think, well Sky says to have sky settings at 4:3 center cut. Any recommendations?

[thecoalman]

Wow, I never knew there was so much to all of this, with TMPGEnc, it has an option for aspect ratio, which one should I choose? The video is NTSC, the TV is PAL, and I think, well Sky says to have sky settings at 4:3 center cut. Any recommendations?

You should encode and author whatver the aspect of the source is, that's providing you want everthing to look normal. Here's the way it works, if the disc is 4:3 material that sets a flag on the DVD, the DVD player will read this flag and adjust the aspect accordingly.

Let's assume we have a 4:3 and 16:9 flagged all the stars align and you have your DVD player set to output the correct siganl to your 16:9 or 4:3 TV and you don't have thew TV doing anything with the signal....

If you play the 4:3 disc on 4:3 TV it will display full screen, the same DVD played on 16:9 TV will be pillarboxed adding balck bars left and right. The black bars left and right are added by the DVD player. It knows this 4:3 material because of the flag and if the stars align.... Also knows it's sending it to a 16:9 disply so it adjusts the signal to maintain the aspect. The opposite is true for 16:9, on a 4:3 TV black bars are added by the DVD player top and bttom and it will play full screen on 16:9 TV.

By doing this you maintain the aspect of the video, e.g. balls will still be perfect circles instead of egg shaped.

You can display or set the flag however you want, it's not that imporatant if it's unimportant to you. Whether you flag a video as 16:9 or 4:3* is not going to produce a different vide, the only thing that is different is the flag.

Note that I said flag, the seettings in encoders can be alittle confusing, for example you can set them to 16:9 on 4:3 matte. In other words the black bars are part of the video. This should be avoided.

[Choppa]

How can I tell what the source aspect ratios is?

[thecoalman]

Eyeball it, you only have 16:9 or 4:3. If you open it up in something like Virtualdub that diplays it at the resolution size 16:9 will look tall and skinny. 4:3 will look relatively normal. Here's a sample from 16:9, i will be more noticeable with PAL because of the increased vertical resolution.