TMPGEnc - Best Settings for MPEG2

[Cunhambebe]

I've been encoding with TMPGEnc Plus for over a year and I really consider it as the best encoder available nowadays. On the other hand, after reading all the guides around here, I guess I still don't know how to configure TMPGEnc Plus to get better MPEG2 files

(I'm encoding to VBR DVD).

I used to encode within this range:
- 200 (2 hundread) for minimum bitrate (no problems here, I guess the value could be 2 thousand);
- 6.000 for the average bitrate;
- 7.000 for the maximum bitrate.

Unfortunately as I've noticed the video was full of banding (low quality video/poorly encoded), I've decided to change these values to:
-200 (2 hundread - same thing here);
-8.000 for the average bit.;
-9.000 for the maximum bit.

Once again, since the video seemed poorly econded and some banding could be noticed, I've decide to change these values once more:
-200 for minimum bit. (same thing here);
-8.000 for the average bit.;
-9.500 for the maximum bit.;

I had some problems here, since I had forgotten the video would have a soundtrack + subtitles, things that in fact would increase the final bitrate, therefore upsetting the top player. I've noticed that in some sections where the video had visual effects (that would increase the bitrate), the subtitles would not be shown correctly (they were out of sync.). The video quality was almost the same: some banding and it seemed poorly encoded. "Talking" to some friends at Sony's forum (for DVD Architect), some users told me to rise the average bitrate to at least 8.200, so I thought about that and decided this time I would encode with these settings:

-200 for the minimum bit;
-8.500 for the average bit;
-9.000 for the maximum.

Now things definitely work. Video is perfect, the banding is gone and the image is crytal clear. On the other hand, as I started GSPOT to check the real bitrate, GSPOT showed me bitrates that were too far away from the average 8.500 (some at 7.700; 7.500; 7.300 and even at 6.700). I guess this is happenig because I'm setting the minimum bitrate at 200. It could be, what do you think?
Now I am currently encoding a video at this very moment to 8.500 CBR since it's a small intro, but I would really like to hearing form all the experts around here, what would be the best values for VBR minimum; average and the maximum bitrate, as well as the best setting to CBR (what do you think of 8.500)?

Thanks in advance.

[reboot]

Set min to 6000, max to 8000, and avg to 7000 and you should see a difference.
Try CQ-VBR at 7500, with a Q of 90.

[Nelson37]

You say there are bitrates that are "too far away from the average". Not only do I not understand what you mean by "too far", but I don't see where this is a problem.

The goal is not to use the maximum bitrate Possible, the goal is to use the maximum bitrate Necessary.

[Cunhambebe]

thanks to all who took time to respond here..

Not only do I not understand what you mean by "too far", but I don't see where this is a problem.

- GSPOT showed me bitrates that were too far away from the average 8.500 (some at 7.700; 7.500; 7.300 and even at 6.700).

Well, I guess the average here is 8.500 isn't it? So, 7.700 and the othr values includding 6.700 are too far away from the average 8.500. Got it? OK...

Set min to 6000, max to 8000, and avg to 7000 and you should see a difference.
Try CQ-VBR at 7500, with a Q of 90.

- I guess I would set min to 7.000, avg to 8.500 and max to 9.000. Or I would leave the way it is; min to 200, and the same for the rest. Hope this won't upset some top players.

[filipdebie]

My settings are always:

pal DVD
2 pass vbr
min = 0
average = 6000
max = 8000
and I always have very good results

[bugster]

If final filesize is not an issue, try TmpGenc's CQ mode with a value of 80 or 90. It produces excellent quality results and is much faster than 2 pass VBR.

If you need to know the final filesize, it is the average bitrate value that determines that, so you should set this according to your filesize requirements. A bitrate calculator should help here. If you do this and the video is still poor you have only the option of putting less playing time on your DVD.

If you are encoding 2 pass VBR with an average of 8500, you might as well use CBR and save some time.

Remember to set motion search precision to high (highest may help, but I have never seen any improvement using it, it just increases encode time a huge amount!)

[SaSi]

When setting an average bitrate between 8000~8500 then quality issues should go away. The MPEG group tests have shown that with most material, encoding at 8000bps produces output with no real visible difference to the source.

An aspect that sometimes go un-noticed is that different bitrates require different quantization matrices for efficient encoding. Additionally, interlaced and progressive video require different scanning order for best quantization. And a bad quantization will decrease quality no matter what the bitrate is.

If you check CCE (any latest version demo), you will find that it has different Quantization matrices for high bit rate, low and very low bitrate encoding. For DVD MPEG2 files, very low bitrate is considered to be anything below 3000~3500 and low is something in the range of 4200~4800.

You can copy the suggested QM values from CCE to Tmpgenc and save them. I have noticed significant differences in encoding quality depending on the QM used.

Finally, focusing on bitrate alone, I would tend to use single pass CBR when encoding at 8500bps. A trap with VBR in Tmpgenc - pointed out in several older posts here - is that if you set the min bitrate too low, Tmpgenc will not make good use of bitrate. A good rule of thumb suggested is that you select your average (say 7000bps) and set min and max at 6000 and 8000.

[Nelson37]

If you set an average at 8500, and some scenes get 6700, why is this a problem? If you want no deviation, then use CBR.

I don't get it. The whole point of VBR is "less in some places, more in others". Going lower than 8500 means that you can also go higher, when needed. This is how it is intended to work. The bitrate is Variable.

Did you see visible PQ degradation in the "low bit-rate"scenes"? Many scenes do not require hi bitrates to encode properly.

[MrMoody]

The only reason to use 2-pass VBR is to make the output file hit a certain size. Otherwise it's a waste of time. Try using CQ set to 90-100.

[Cunhambebe]

Thanks to all who took time to help me...
Hi bugster, nice to "see" you again...

try TmpGenc's CQ mode with a value of 80 or 90. It produces excellent quality results and is much faster than 2 pass VBR..(...)If you are encoding 2 pass VBR with an average of 8500, you might as well use CBR and save some time.

-Thanks so much for the input. I was so involved with Xvid that I was almost forgetting how to encode to MPEG2

Remember to set motion search precision to high (highest may help, but I have never seen any improvement using it, it just increases encode time a huge amount!)

-I always encode as highest.

SaSi, thanks for the excellent ideas...

You can copy the suggested QM values from CCE to Tmpgenc and save them.

-Do you have them? Can you paste them around here, please? Thanks!

Nelson 37

I don't get it. The whole point of VBR is "less in some places, more in others". Going lower than 8500 means that you can also go higher, when needed. This is how it is intended to work. The bitrate is Variable.

- You're absolutely right - Degradation? Yes, the video has some "banding".

Mr.Moody

The only reason to use 2-pass VBR is to make the output file hit a certain size. Otherwise it's a waste of time. Try using CQ set to 90-100.

- thanks a lot for the input. Are you sure this kind of bitrate won't upset the top players?

Thanks!

[Nelson37]

MrMoody's assertion is incorrect.

2-pass VBR results in improved Motion Search Precision, due to the second pass.

Also, bitrate allocation is more efficient than a single pass. To achieve same quality with CBR, Constant Bit Rate must be set equal to Maximum Bit Rate for the 2-pass VBR.

[MrMoody]

TMPGEnc Plus does not motion search on the second pass. It does exactly 1 no matter what mode you use. And CQ is not CBR.

CQ has a maximum bitrate setting just like the other VBR modes, which should be about 9500 depending on what audio you're adding.

[Nelson37]

Not sure about TMPGenc, reasonably certain CCE and others do utilize second pass for motion search precision.

Do NOT wish to begin the whole CQ vs 2-pass VBR debate again. Been there, done that 3 or 4 times.

[SaSi]

The CCE QM Matrices are as follows:

1. The Standard CCE set (what most users use) - not good for low bitrate or VCD encoding.



2. The Low bitrate settings - what I use for 3400bps encoding are:



3. The Ultra Low bitrate settings - good for VCD or very low bitrate and small frame size:



It will take some effort to hand-copy them to Tmpgenc.

[Cunhambebe]

Thanks so much for your help!
C u around!