TMPGEnc: does the VBV Buffer Setting Effect Image Quality?

[muaddib]

Does the VBV Buffer setting affects image quality?

I'm asking because I made 2 samples of svcd video, the first with VBV at 112, and the second with VBV at 40. The result was that VBV 112 makes a 4MB bigger file in a 4min sample!!!

Both samples play smoothly, and I can't see any difference in quality, but this is a huge difference in file size!

[Jellygoose]

yeah, i'd like to know that too! i noticed that effect several times, but i thought it's just the media I AM USING...

why do i need a larger vbv buffer size for mpeg-2 ? and DOES it really affect the quality?

[kwag]

The higher the VBV value, the higher the quality, and also the file size and less compatibility with standalone players
That is, of course, referenced from the standard values used on VCD, SVCD, DVD.
Stick close to the default values used on each format.

-kwag

[muaddib]

Quote:

Originally Posted by kwag

The higher the VBV value, the higher the quality, and also the file size and less compatibility with standalone players
That is, of course, referenced from the standard values used on VCD, SVCD, DVD.
Stick close to the default values used on each format.

-kwag

I'm not sure if I understand...
Will the VBV value limit the amount of bitrate?
And in this case no matter how hight you set the max bitrate, cause the VBV will cut it off?

[kwag]

Quote:

Originally Posted by muaddib

Quote:

I'm not sure if I understand...
Will the VBV value limit the amount of bitrate?
And in this case no matter how hight you set the max bitrate, cause the VBV will cut it off?

No. The VBV is just a virtual hypothetical buffer, that tells the decoder ( DVD player or software player ) a pre-determined size to use when decoding the stream.
It's like a "pre-fetch" queue, where you have a buffer size to work with.
Makes sense right? no , here some info: http://www.bretl.com/mpeghtml/VBV.HTM

-kwag

[muaddib]

Quote:

Originally Posted by kwag

No. The VBV is just a virtual hypothetical buffer, that tells the decoder ( DVD player or software player ) a pre-determined size to use when decoding the stream.
It's like a "pre-fetch" queue, where you have a buffer size to work with.
Makes sense right? no , here some info: http://www.bretl.com/mpeghtml/VBV.HTM

-kwag

It’s really a NO! I'm completely lost... I read that info, but still lost
If it is like a "pre-fetch" queue… a buffer that the decoder will work with, I assume that the quality will be affected at the decoding processes . So, why it affects so drastically the file size?

[kwag]

I don't know, but if you talk japanese , you going to have to ask that one to Hori, the developer of TMPEG

-kwag

[muaddib]

Quote:

Originally Posted by kwag

I don't know, but if you talk japanese , you going to have to ask that one to Hori, the developer of TMPEG

-kwag

Hey man, I'm having a hard time trying to sepak english!!
You want me to speak japanese!
I think that I will stay out of jananeese talk, and just make more tests...

Thanks anyway kwag,
sayonara aryghato shynishywa