HC Encoder Minimum Bitrate?

[ron spencer]

Is it possible to use vbr bias to have HCenc have a MINIMUM bitrate like CCE does? Just curious...if not, would this be hard to add?

[hank315]

Is it possible to use vbr bias to have HCenc have a MINIMUM bitrate like CCE does? Just curious...if not, would this be hard to add?
No, it's not hard to add but I won't do it because if it's used wrong results are pretty bad.
BTW, do you want a higher or lower minimum bitrate than the default one used by HCenc?

[ron spencer]

it really is used in a wrong way if a person does:

min. 3000
avg 5000
max 7000
(throttled range)


in a case like this then yes, poor results CAN occur.

But if I use CCE and use:

min 1500-2000
avg 6000
max 8500
(nice range)

then I find I can often get some nicer results than HC on DV fade in and outs to black if there is some action going on (my kids sports) on the fade out. Not so much on a small 27" TV, but on panels you do notice it.

Problem with the Bias thing is that I never really know what I am going to get. Sometimes with it at, say, 35, I still get some issues (rare) on such fade outs (and other rare occasions). I have alot of this fading stuff for school sports, hockey, etc. I have used the zones thing in the past with HC, but it is extra work.

I for one would love it if you added such a feature, which a warning perhaps that poor results can occur if the user throttles the range too much. I think Mainconcept has it as well.

Thanks for listening (reading).

Love your proggy....

[freebird73717]

Actually I can understand why hank doesn't want to implement that function. If someone uses it incorrectly and it does produce a bad output they would think that hcenc is a bad encoder and not realize that it was their operator error that produced the bad video.

Having said that I too wish for an option to enter a minimum bitrate that I have control over myself. :sly:

Again hank thanks for such an amazing encoder!
:D

[manolito]

@ron spencer

For CCE I always use a minimum bitrate of at least 1000 to avoid these "fading to / from dark" issues. For HC I found that using the LUMGAIN and AQ features gives me results which are at least as good as from CCE. I use LUMGAIN 2 and AQ 2 for all my encodes, and for problematic encodes you could even use higher values.

Cheers
manolito

[ron spencer]

well...it is a free program (well donationware) so if you complain about your own mess up, then, well, you are SOL and will be told so on this board I think....


maybe with your vote too hank will add it LOL

@manolito

I had thought about that, but never really understood those options...is there a general guide for those? I thought lumigain had some issues?

[freebird73717]

maybe with your vote too hank will add it LOL


:lol:

Always good talking to ya ron.

[ron spencer]

is that videohelp freebird?? Ha Ha

glad to see you here mucking around....new HC seems good...lets hope for min bitrate

[Sharc]

@ron spencer

.... For HC I found that using the LUMGAIN and AQ features gives me results which are at least as good as from CCE. I use LUMGAIN 2 and AQ 2 for all my encodes, and for problematic encodes you could even use higher values.

Same experience here. I would suggest to try and take advantage of the available settings, before introducing new parameters.
I am not sure how the "minimum bitrate" should be defined: over a 1 second interval, for one frame or a couple of frames ....

[ron spencer]

@Sharc

thanks but:


1. What do lumigain and AQ accomplish exactly? They are more conufsing than a minimum bitrate. Where is a guide on this to explain what exactly they do at various levels.

2. If you have used CCE you know that minimum bitrate can work well...I am sure Hank could implement this easily with minimum fuss without worry about esoteric stuff like lumigain and AQ.

3. Why worry about whether it would be used for 1 sec or 1 min? On a two pass encode encoder would know ahead of time where bitrate needed. If at a point where came in at say 300 but min. batrate was 1000, just stick in at 1000.

Of course all up to Hank

[Sharc]

@Ron

The experts could probably give more details, but you will find more about these settings that have been introduced in version .21 and .23 respectively by browsing through this thread. Here some info from the pdf which ships with HCenc:

*AQ
parameter strength (0 - 4) type integer
Default -
Example *AQ 3

This command activates adaptive quantization, flat parts are given a lower quantizer.
Strength 0 means no adaptive quantization, strength 4 generates the lowest quants for flat parts
but it may create artifacts around sharp edges.

*LUMGAIN
parameter sensitivity (0 - 4) type integer
Default 0
Example *LUMGAIN 2

This command adapts the quantization matrices on dark scenes so the bitrate will be raised.
• 0 no change
• 1 mild change
• 2 moderate change
• 3 heavy change
• 4 hit dark scenes real hard

You can select these settings in HCgui. I usually set both to the value 2. They definitely help in dark and fading scenes.

[ron spencer]

Thanks!!!

[freebird73717]

is that videohelp freebird?? Ha Ha

glad to see you here mucking around....new HC seems good...lets hope for min bitrate

yep it's me. just haven't uploaded my avatar yet. I actually use aq2 and lumgain 2 myself and it does make a noticable difference...but being able to set my own minimum bitrate would be nice.

Saw this thread and thought I'd add my vote. Take care ron. Off to work on my own long neglected project now.

Once again hank many thanks for such a great encoder!

[blutach]

@ron spencer

LUMGAIN = 2 might solve your problems - I had a DVD that had a couple of dark scenes that were quite bad, but with LUMGAIN (and AQ) it was fine. I use 2 on both.

Of course, if the whole movie is set in the dark, LUMGAIN might not be useful, but you'd have high BRs anyway.

Regards

[ron spencer]

those settings DID help..thanks!!!

Still hope for maybe min. bitrate, but that is up to Hank.

thanks again...