Windows Media Encoder max Bitrate Problem

JackSnap · 1st May 2008, 13:12

Hi,

Im having a problem using Windows Media Encoder, with it going over the max bitrate i specify, which causes the video to stall as my wireless network cant keep up.

Im using avisynth, to point to a MKV file, then using makeavi's to create the fake avi. I then point WME to this avi.

I select audio codec Windows media 10 pro, and i use a CBR of 440, its ac3 sound using ac3filter. (I wanted to use VBR, but understand the problem with ac3filter and WME being presented differeng sound streams on each pass, so i use CBR)

For Video im using WM9 with a capped bitrate. Ive done various tests and my wireless network can handle about 19M, so I set the average bitrate to 10M and the Peak to 16M (the audio shouldnt change with CBR so it should never reach over 17M and at worst with overheads 18M)

Unfortunately when encoding the stats screen shows the max bitrates i entered, but on complex parts of a film shows the current bit rate up as high as 28M , if i let this finish and play it back it obviously encounters bandwidth problems in these scenes and stutters.

Ive tried changing the peak bitrate to other values, and the output file always ends up the same (exactly the same size) with the same problems,

Is there some reason it's ignoring the peak bitrate i specify, Ive linked to a screenshot showing the display whilst encoding high action scenes, notice the combined and video output, the current is way over the max.

video encoding is pretty new to me so sorry if its an obvious mistake,
Any help would be appreciated.

benwaggoner · 1st May 2008, 19:15

What buffer duration are you using? If it's something long, like 8 seconds, you might have a section within that buffer that exceeds your network's throughput. I'd try a 1-2 second buffer and see if that helps. Reducing the max bitrate a bit would also be worth trying.

JackSnap · 1st May 2008, 21:09

Hi thanks for the answer,

my buffer was set at 5 seconds,

ive changed the max to 15M and buffer to 3 and im giving that a try.

I also notice that i dont have the WM9 advanced profile, how can i get this, i have the latest media player, i thought it was included, but the drop down list doesnt have the advanced option?

Thanks

benwaggoner · 1st May 2008, 21:27

Quote:

Originally Posted by JackSnap

Hi thanks for the answer,

my buffer was set at 5 seconds,

ive changed the max to 15M and buffer to 3 and im giving that a try.

Great. Let us know how it goes.

Quote:

I also notice that i dont have the WM9 advanced profile, how can i get this, i have the latest media player, i thought it was included, but the drop down list doesnt have the advanced option?

You need to be on Vista, or XP with WMP 11 installed, to get the current .dll files.

JackSnap · 1st May 2008, 22:48

that test worked well, so im doing the full film now,
Ive managed to reinstall wmp11 and I have the advanced profile.

Looking from your sig, i was already on your site, i've also changed the registry settings you recommended using the WMV powertoy, so hopefully it will be even better.

Many thanks for your help, ill let you know the outcome.

Update 1... JEEZE, whats caused the slowdown. the advanced profile, or your registry settings? been going a day, and still a day to go!! I hope this one works.

Update 2....****, its still going! 14 Hours to go. Such a bitch that this virtual machine only uses one core of my dual processor.

JackSnap · 6th May 2008, 15:48

Well, after 4 days and 4 hours, its a bit of a disapointment. I have the same problem I started with.

I set the buffer to 2 seconds, the average bitrate to 9M and max bitrate to 14M, and still in the fast action sections the network maxes out at about 20M for periods of over a minute. It was showing this during encode time but I was hoping for the best. This is also confirmed if I use wmsnoop to look at the WMV output, and by monitorig the network on playback.

Im at a loss of what to try now, as if it ignores the limit I set, what can I do?

I really suspect it's to do with the CBR audio, my next step is to try and exclude audio altogether and see if I get a similar problem.

Thanks for your suggestions on this, and if you think of anything else , let me know.

PS. The parts of the film that dont stutter did look awsome!

1st May 2008, 13:12	#1 \| Link
JackSnap Registered User Join Date: Jan 2007 Posts: 22	Windows Media Encoder max Bitrate Problem Hi, Im having a problem using Windows Media Encoder, with it going over the max bitrate i specify, which causes the video to stall as my wireless network cant keep up. Im using avisynth, to point to a MKV file, then using makeavi's to create the fake avi. I then point WME to this avi. I select audio codec Windows media 10 pro, and i use a CBR of 440, its ac3 sound using ac3filter. (I wanted to use VBR, but understand the problem with ac3filter and WME being presented differeng sound streams on each pass, so i use CBR) For Video im using WM9 with a capped bitrate. Ive done various tests and my wireless network can handle about 19M, so I set the average bitrate to 10M and the Peak to 16M (the audio shouldnt change with CBR so it should never reach over 17M and at worst with overheads 18M) Unfortunately when encoding the stats screen shows the max bitrates i entered, but on complex parts of a film shows the current bit rate up as high as 28M , if i let this finish and play it back it obviously encounters bandwidth problems in these scenes and stutters. Ive tried changing the peak bitrate to other values, and the output file always ends up the same (exactly the same size) with the same problems, Is there some reason it's ignoring the peak bitrate i specify, Ive linked to a screenshot showing the display whilst encoding high action scenes, notice the combined and video output, the current is way over the max. video encoding is pretty new to me so sorry if its an obvious mistake, Any help would be appreciated.

1st May 2008, 19:15	#2 \| Link
benwaggoner Moderator Join Date: Jan 2006 Location: Portland, OR Posts: 4,770	What buffer duration are you using? If it's something long, like 8 seconds, you might have a section within that buffer that exceeds your network's throughput. I'd try a 1-2 second buffer and see if that helps. Reducing the max bitrate a bit would also be worth trying. __________________ Ben Waggoner Principal Video Specialist, Amazon Prime Video My Compression Book

1st May 2008, 22:48	#5 \| Link
JackSnap Registered User Join Date: Jan 2007 Posts: 22	that test worked well, so im doing the full film now, Ive managed to reinstall wmp11 and I have the advanced profile. Looking from your sig, i was already on your site, i've also changed the registry settings you recommended using the WMV powertoy, so hopefully it will be even better. Many thanks for your help, ill let you know the outcome. Update 1... JEEZE, whats caused the slowdown. the advanced profile, or your registry settings? been going a day, and still a day to go!! I hope this one works. Update 2....***, its still going! 14 Hours to go. Such a bitch that this virtual machine only uses one core of my dual processor. Last edited by JackSnap; 5th May 2008 at 20:03.*

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1st May 2008, 21:09	#3 \| Link
JackSnap Registered User Join Date: Jan 2007 Posts: 22	Hi thanks for the answer, my buffer was set at 5 seconds, ive changed the max to 15M and buffer to 3 and im giving that a try. I also notice that i dont have the WM9 advanced profile, how can i get this, i have the latest media player, i thought it was included, but the drop down list doesnt have the advanced option? Thanks

6th May 2008, 15:48	#6 \| Link
JackSnap Registered User Join Date: Jan 2007 Posts: 22	Well, after 4 days and 4 hours, its a bit of a disapointment. I have the same problem I started with. I set the buffer to 2 seconds, the average bitrate to 9M and max bitrate to 14M, and still in the fast action sections the network maxes out at about 20M for periods of over a minute. It was showing this during encode time but I was hoping for the best. This is also confirmed if I use wmsnoop to look at the WMV output, and by monitorig the network on playback. Im at a loss of what to try now, as if it ignores the limit I set, what can I do? I really suspect it's to do with the CBR audio, my next step is to try and exclude audio altogether and see if I get a similar problem. Thanks for your suggestions on this, and if you think of anything else , let me know. PS. The parts of the film that dont stutter did look awsome!