Quantcast Mencoder: is Ratecontrol Not Working with Vrc_Minrate Yet? - digitalFAQ.com Forums [Archives]
  #1  
05-05-2004, 09:19 AM
digitall.doc digitall.doc is offline
Free Member
 
Join Date: Jul 2003
Location: Valencia (España)
Posts: 741
Thanks: 0
Thanked 0 Times in 0 Posts
I encoded a SKVCD with mencoder.
There's a scene that fades to black. In my standalone player it almost freezes, and what it's supposed to last a second, lasts 2-3 seconds, until player restarts. It looks like a too low bitrate problem. In bitrateviewer gives me a bitrate value of 99 in that point.
I thought the too low bitrate (in case it is my problem, I think so) was mainly with mpeg1, but here also with mpeg2 (SKVCD) .
That's why I ask if you know if the problem when using a vrc_minrate value is solved. If not, how do you think can I solve this?. I thought of setting a minrate value and see what happens, since I use 2pass, maybe the problem of ratecontrol would mainly affect first pass...
What do you think?
Reply With Quote
Someday, 12:01 PM
admin's Avatar
Site Staff / Ad Manager
 
Join Date: Dec 2002
Posts: 42
Thanks: ∞
Thanked 42 Times in 42 Posts
  #2  
05-06-2004, 03:58 AM
digitall.doc digitall.doc is offline
Free Member
 
Join Date: Jul 2003
Location: Valencia (España)
Posts: 741
Thanks: 0
Thanked 0 Times in 0 Posts
Well, I'll give myself an answer (and for everybody).
It's not THE answer, since I don't know yet if the rate control problem was corrected when using vrc_minrate, I'll have to dive into mailing lists to see what they say there,...
...but, I tried a 2 pass encoding with vrc_minrate=150.
Conclusions: in first pass, I got a final size that was less accurate than without minrate, an average bitrate was also higher than expected. So, a first answer would be that it seems that it's not working.
But in second pass, it respected final size and average bitrate.
So, for those of us who have standalone players that need a minrate not to get frozen (the image ), it can be used in 2 pass.
I'll post how does it affect quantizers, and if it solves the freezing problem (I just had time to do some little tests...)
Reply With Quote
  #3  
05-06-2004, 04:42 AM
incredible incredible is offline
Free Member
 
Join Date: May 2003
Location: Germany
Posts: 3,189
Thanks: 0
Thanked 0 Times in 0 Posts
Send a message via ICQ to incredible
Open that "2pass incl. VRC_Minrate" Sample in Bitrateviewer und you will see that the quantisation in general looks very different (shure if VRC_minrate is set the Q is an other than without but WITH I do speak here that it stand in no relation).
So we should check this generally out.

I also got a Cyberhome SAP like Kwag and in DVD mode where I also get some "below 200kbit" areas ... anyway these encodings do play fine burned as DVD-R on my Cyberhome SAP.

I didnt tried Ksvcds jet ... as Im in another project right now, and so my focus is actually mencoder -"from DVD to DVD-R".
Reply With Quote
  #4  
05-06-2004, 05:53 AM
yaz yaz is offline
Free Member
 
Join Date: Aug 2003
Posts: 40
Thanks: 0
Thanked 0 Times in 0 Posts
... and if u open your file in bv u will see neither max nor min bitrate is kept. (i've spent days finding a solution but ...)
adds.:
- when i set min bitrate, mencoder drops a warning & the final bitrate is always different than the target (other way is perfect!)
- afaik, the minimum bitrate (for pure black frames) is about 140kbs(should be checked), so there's not much sense of setting 150 (but for higher rates ... see above )
- all 1pass run & all 1st pass run is heavily undersized for me but 2nd pass is always perfect as regards target bitrate (not the limiting bitrates !)
- all 1pass/1stpass run starts with overflow errors which indicates a kinda buffer initializing problem.
the bests
y
Reply With Quote
  #5  
05-06-2004, 10:28 AM
digitall.doc digitall.doc is offline
Free Member
 
Join Date: Jul 2003
Location: Valencia (España)
Posts: 741
Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by yaz
... and if u open your file in bv u will see neither max nor min bitrate is kept. (i've spent days finding a solution but ...)
adds.:
- when i set min bitrate, mencoder drops a warning & the final bitrate is always different than the target (other way is perfect!)
- afaik, the minimum bitrate (for pure black frames) is about 140kbs(should be checked), so there's not much sense of setting 150 (but for higher rates ... see above )
- all 1pass run & all 1st pass run is heavily undersized for me but 2nd pass is always perfect as regards target bitrate (not the limiting bitrates !)
- all 1pass/1stpass run starts with overflow errors which indicates a kinda buffer initializing problem.
the bests
y
I've been lucky in my encode, then.
In BitrateViewer max and min bitrate have been respected:
without minrate: max 3219 avg 1089 min 99 filesize 717498
with minrate: max 3014 avg 1089 min 154 filesize 717155

It would be OK for me that minrate would have been 140 kbps, but BV says it is 99 (or less, this figure I took from the graphic)

No buffer under/overflow during encoding, nor when muxing

You're right, 1st pass is less accurate than without minrate, but 2nd pass worked perfect... and in my case respected min/max rate. But I'm afraid I just was lucky (I just did 1 SKVCD film)
Those of us with "delicate" standalone, need a way to solve the too low min bitrate...
Do you know if they are working in solve this (since it looks like they didn't solve it)?. If not, I will just be able to do KDVD, and for 1CD encodings I'll have to drop mencoder and keep with TMPGEnc
Reply With Quote
  #6  
05-06-2004, 11:35 AM
digitall.doc digitall.doc is offline
Free Member
 
Join Date: Jul 2003
Location: Valencia (España)
Posts: 741
Thanks: 0
Thanked 0 Times in 0 Posts
I tested to burn as SKVCD the encoded film (mencoder, 2pass, with vrc_minrate=150).
It now plays smoothly in my SAP (I still have to see the hole film, but it doesn't freeze where it did before).
It looks like it was a too low bitrate problem (didn't change anything else).
I hope they'll solve the vrc_minrate problem soon (post if you know a thing. I didn't go to mailing list to read yet ).
Cheers
EDIT: the hole film plays well... and looks great!
Reply With Quote
  #7  
05-07-2004, 05:00 AM
yaz yaz is offline
Free Member
 
Join Date: Aug 2003
Posts: 40
Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by digitall.doc
I've been lucky in my encode, then.
In BitrateViewer max and min bitrate have been respected:
without minrate: max 3219 avg 1089 min 99 filesize 717498
with minrate: max 3014 avg 1089 min 154 filesize 717155
maybe i just can't follow. i didn't state that menc did not accept these options but i did state that it couln't keep them. i mean, maxrate is always higher than i set & minrate seems to make the whole bitrate control collapse (neither the target nor the minrate is kept ) in add., any time i set minrate, mencoder drops the warning
Quote:
Warning min_rate > 0 but min_rate != max_rate
isnt recommended!
it seems as if it were only for constant bitrate, or what
anyway, your results do not seem to comply with the 'svcd standard'. afaik, you can't exceed 2725kbps as maxrate. u got much higher. that's my basic problem.
Quote:
Those of us with "delicate" standalone, need a way to solve the too low min bitrate ... Do you know if they are working in solve this (since it looks like they didn't solve it)?. If not, I will just be able to do KDVD, and for 1CD encodings I'll have to drop mencoder and keep with TMPGEnc
afaik, nobody deals with it, or at least i haven't seen any indication. i've just dropped (almost) the same note to nic (ye know, quenc) & he promised to have a look. that's all i have.
under some conditions i'm able to redirect maxrate to where i want but i haven't got a general solution. with minrate i'm fake completely
the bests
y
Reply With Quote
  #8  
05-07-2004, 07:24 AM
digitall.doc digitall.doc is offline
Free Member
 
Join Date: Jul 2003
Location: Valencia (España)
Posts: 741
Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by yaz
...i mean, maxrate is always higher than i set & minrate seems to make the whole bitrate control collapse (neither the target nor the minrate is kept )
yaz, I understood you well. But in my (only) test average bitrate was respected (2pass) and also minrate didn't drop below 150.
Quote:
Originally Posted by yaz
in add., any time i set minrate, mencoder drops the warning
Quote:
Warning min_rate > 0 but min_rate != max_rate
isnt recommended!
it seems as if it were only for constant bitrate, or what
Don't take this advise too seriously. It just says (bilu told me) that if you set minrate=maxrate, that's constant bitrate It's just informative.
Quote:
Originally Posted by yaz
anyway, your results do not seem to comply with the 'svcd standard'. afaik, you can't exceed 2725kbps as maxrate. u got much higher. that's my basic problem.
As Inc said, we cannot completely accept BV as a truth. In fact, my avg bitrate goal was 1118 and not what BV said. I just posted results in BV with and without minrate to show that they are similar. And my delicate player play it...
Hope Nic can help us...
Reply With Quote
  #9  
05-07-2004, 07:43 AM
incredible incredible is offline
Free Member
 
Join Date: May 2003
Location: Germany
Posts: 3,189
Thanks: 0
Thanked 0 Times in 0 Posts
Send a message via ICQ to incredible
Also I hope you keep your builds updated

So maybe u got a version (maybe newer (makes sense) or older) which works better at minrate settet?

PS: Builds updated in here, so check it out
Reply With Quote
  #10  
05-07-2004, 10:01 AM
digitall.doc digitall.doc is offline
Free Member
 
Join Date: Jul 2003
Location: Valencia (España)
Posts: 741
Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by incredible
...PS: Builds updated in here, so check it out

Do you mean that Builds are updated here Inc?

Yep, I go "there" regularly to update mencoder/mplayer... BTW, thanx for keeping us uptodate
I'm using your last pentium4sse2 version. It's not faster, nor slower.
And the SKVCD I did was done with mencoder version that came with mencodeme023
Reply With Quote
  #11  
05-07-2004, 11:10 AM
incredible incredible is offline
Free Member
 
Join Date: May 2003
Location: Germany
Posts: 3,189
Thanks: 0
Thanked 0 Times in 0 Posts
Send a message via ICQ to incredible
Quote:
Originally Posted by digitall.doc
Do you mean that Builds are updated here Inc?
Ok, "the Downloadlinks to the newest CVS compilings of mplayer/mencoder have been updated in that Thread"
Reply With Quote
  #12  
05-07-2004, 11:48 AM
digitall.doc digitall.doc is offline
Free Member
 
Join Date: Jul 2003
Location: Valencia (España)
Posts: 741
Thanks: 0
Thanked 0 Times in 0 Posts

Inc, highest precission in the answer is not possible
Reply With Quote
Reply




Similar Threads
Thread Thread Starter Forum Replies Last Post
Mencoder: Color Problems on Mencoder outputs? Koekies Video Encoding and Conversion 60 06-15-2004 06:40 AM
Mencoder: Vrc_minrate and vratetol maurus Video Encoding and Conversion 1 05-27-2004 07:24 AM
Mencoder: Changing/Setting field order in mencoder tuco1979 Video Encoding and Conversion 1 04-17-2004 09:06 AM
Mencoder: Extensive tests without vrc_minrate bilu Video Encoding and Conversion 21 04-13-2004 03:54 AM
Mencoder: Mencoder ratecontrol bilu Video Encoding and Conversion 11 04-11-2004 05:56 AM

Thread Tools



 
All times are GMT -5. The time now is 02:30 PM  —  vBulletin © Jelsoft Enterprises Ltd