Mpeg Render problem at DVinfo.net

Brian Mitchell Warshawsky · September 7th, 2004, 01:53 AM

I haven't seen this mentioned previously, but I just encountered the following issue:

I rendered a sequence as an Mpeg-2 and the playback speed is noticeably faster than the normal Vegas preview speed. The audio is a music track.

I then tried an Mpeg-1 render which rendered at the correct speed.

The footage was shot in 23.967 speed (DVX100) and I have previously rendered Mpeg-2's the same way without issue.

From my perspective, it appears that the speed increase may reflect the difference between the (approx. ) 24 fps and the 29.970 fps rate.

There must be some switched I selected which needs to be de-selected but so far I haven't found it.

Might be sleep deprivation.

Thanks for any suggestions,

Brian

Rob Lohman · September 7th, 2004, 05:51 AM

Can't you select 23.967 when exporting? Otherwise perhaps
set the project to 24.0 to see what that does? I think someone
else had a similar problem a while ago. Perhaps try a search?

Brian Mitchell Warshawsky · September 13th, 2004, 11:36 PM

The solution: I installed a new Mpeg2 decoder... Problem solved.

I discovered that my too-fast Mpeg2 renders played just find on other PC's, so if anyone has a speed problem, it might not be Vegas or the render settings within Vegas.

Brian

Peter Jefferson · September 14th, 2004, 04:23 AM

no its not vegas, as vegas uses whatever codecs are installed in ur OS, it wont install mpg codecs unless theyre licensed/registered, and some codecs have issues upsampling (which is what ur doing..

aufio is standard 44.1khz 16bit, dv and dvd is 48khz at 16 bit some decoders render to the bitrate of choice but sometimes changing the sample rate is done literally (instead of resampling) and interpolating

its a common issue for those who are new to the audio sampling game, but heres a lil test.

get a 44.1 file and import it into soundforge, now change the sample rate in the project properties (WITHOUT resampling) now hit play, and youll notice the audio is much faster.

BUT if u go to your processes tab, then selet resample, it will retain the origianl pitch, however it will interpolate or "fill the gaps" betwen 44.1 and 48khz

the same goes for lower bitrates..

Rob Lohman · September 14th, 2004, 04:37 AM

Peter: Vegas should use the MainConcept MPEG engine for both
decoding and encoding of an MPEG stream. It also uses their DV
codec per default. So I'm not eniterely sure where your "vegas
uses whatever codes are installed in your OS" comes from.

It can ofcourse encode/decode AVI or MOV files with any codec
that you have installed.

Peter Jefferson · September 14th, 2004, 07:21 AM

oh, sorry i wasnt clear.. vegas ALLOWS you to access any codec (encoder/decoder) available to you.. for rendering that is..

for decoding it uses MainConcept of course. but with regard to .mov, you MUST have quicktime installed..

quicktime 5 for v4 or QT6 or later for V5.. else it wont import those files.

another reason i keep V4, is that i dont want to pay for an upgrade of my QT, so im taking my .movs to V4 and rendering to avi to input into V5..

Peter Jefferson · September 14th, 2004, 07:22 AM

one thing i forgot to mention to encode to mpg with vegas u must purchase the MPG encoder plugin ... i had to do that with v4.. else i could onlyoutput to avi or by using another codec already on my system..

Edward Troxel · September 14th, 2004, 08:06 AM

Vegas has always come with the MPEG2 encoder. It just needs to be registered separately. If you have DVDA, it gets registered when DVDA is registered. But even if you do not get DVDA, you still have the MPEG2 encoder. The first time you do a File - Render As, pick MPEG2, and you will be asked to register the MPEG2 codec and, once registered, will be able to use it freely.

Peter Jefferson · September 14th, 2004, 09:26 AM

i did it the other way around.. :( still works though :)

Brian Mitchell Warshawsky · September 14th, 2004, 12:40 PM

Peter Wrote:

>>>>>>>>>>>>>>>>>>no its not vegas, as vegas uses whatever codecs are installed in ur OS, it wont install mpg codecs unless theyre licensed/registered, and some codecs have issues upsampling (which is what ur doing.. >>>>>>>>>>>>>

Actually, that wasn't the issue: Vegas always played the file back properly ....

It was WMP, Real One, and others which had the speed issues which were remedied with the decoder.

Sorry for the confusion.

Brian

Peter Jefferson · September 14th, 2004, 09:54 PM

so basically THOSE players werent running the correct codec??

thats what it sounds like...

September 7th, 2004, 01:53 AM	#1
Brian Mitchell Warshawsky Major Player Join Date: Aug 2003 Location: Bay Area Posts: 216	Mpeg Render problem I haven't seen this mentioned previously, but I just encountered the following issue: I rendered a sequence as an Mpeg-2 and the playback speed is noticeably faster than the normal Vegas preview speed. The audio is a music track. I then tried an Mpeg-1 render which rendered at the correct speed. The footage was shot in 23.967 speed (DVX100) and I have previously rendered Mpeg-2's the same way without issue. From my perspective, it appears that the speed increase may reflect the difference between the (approx. ) 24 fps and the 29.970 fps rate. There must be some switched I selected which needs to be de-selected but so far I haven't found it. Might be sleep deprivation. Thanks for any suggestions, Brian

September 7th, 2004, 05:51 AM	#2
Rob Lohman RED Code Chef Join Date: Oct 2001 Location: Holland Posts: 12,514	Can't you select 23.967 when exporting? Otherwise perhaps set the project to 24.0 to see what that does? I think someone else had a similar problem a while ago. Perhaps try a search? __________________ Rob Lohman, visuar@iname.com DV Info Wrangler & RED Code Chef Join the DV Challenge \| Lady X Search DVinfo.net for quick answers \| Buy from the best: DVinfo.net sponsors

September 14th, 2004, 04:37 AM	#5
Rob Lohman RED Code Chef Join Date: Oct 2001 Location: Holland Posts: 12,514	Peter: Vegas should use the MainConcept MPEG engine for both decoding and encoding of an MPEG stream. It also uses their DV codec per default. So I'm not eniterely sure where your "vegas uses whatever codes are installed in your OS" comes from. It can ofcourse encode/decode AVI or MOV files with any codec that you have installed. __________________ Rob Lohman, visuar@iname.com DV Info Wrangler & RED Code Chef Join the DV Challenge \| Lady X Search DVinfo.net for quick answers \| Buy from the best: DVinfo.net sponsors

September 14th, 2004, 08:06 AM	#8
Edward Troxel Sponsor: JET DV Join Date: Dec 2001 Location: Southern Illinois Posts: 7,953	Vegas has always come with the MPEG2 encoder. It just needs to be registered separately. If you have DVDA, it gets registered when DVDA is registered. But even if you do not get DVDA, you still have the MPEG2 encoder. The first time you do a File - Render As, pick MPEG2, and you will be asked to register the MPEG2 codec and, once registered, will be able to use it freely. __________________ Edward Troxel [SCVU] JETDV Scripts/Scripting Tutorials/Excalibur/Montage Magic/Newsletters

September 13th, 2004, 11:36 PM	#3
Brian Mitchell Warshawsky Major Player Join Date: Aug 2003 Location: Bay Area Posts: 216	The solution: I installed a new Mpeg2 decoder... Problem solved. I discovered that my too-fast Mpeg2 renders played just find on other PC's, so if anyone has a speed problem, it might not be Vegas or the render settings within Vegas. Brian

September 14th, 2004, 04:23 AM	#4
Peter Jefferson Inner Circle Join Date: Apr 2003 Location: Aus Posts: 3,884	no its not vegas, as vegas uses whatever codecs are installed in ur OS, it wont install mpg codecs unless theyre licensed/registered, and some codecs have issues upsampling (which is what ur doing.. aufio is standard 44.1khz 16bit, dv and dvd is 48khz at 16 bit some decoders render to the bitrate of choice but sometimes changing the sample rate is done literally (instead of resampling) and interpolating its a common issue for those who are new to the audio sampling game, but heres a lil test. get a 44.1 file and import it into soundforge, now change the sample rate in the project properties (WITHOUT resampling) now hit play, and youll notice the audio is much faster. BUT if u go to your processes tab, then selet resample, it will retain the origianl pitch, however it will interpolate or "fill the gaps" betwen 44.1 and 48khz the same goes for lower bitrates..

September 14th, 2004, 07:21 AM	#6
Peter Jefferson Inner Circle Join Date: Apr 2003 Location: Aus Posts: 3,884	oh, sorry i wasnt clear.. vegas ALLOWS you to access any codec (encoder/decoder) available to you.. for rendering that is.. for decoding it uses MainConcept of course. but with regard to .mov, you MUST have quicktime installed.. quicktime 5 for v4 or QT6 or later for V5.. else it wont import those files. another reason i keep V4, is that i dont want to pay for an upgrade of my QT, so im taking my .movs to V4 and rendering to avi to input into V5..

September 14th, 2004, 07:22 AM	#7
Peter Jefferson Inner Circle Join Date: Apr 2003 Location: Aus Posts: 3,884	one thing i forgot to mention to encode to mpg with vegas u must purchase the MPG encoder plugin ... i had to do that with v4.. else i could onlyoutput to avi or by using another codec already on my system..

September 14th, 2004, 09:26 AM	#9
Peter Jefferson Inner Circle Join Date: Apr 2003 Location: Aus Posts: 3,884	i did it the other way around.. :( still works though :)

September 14th, 2004, 12:40 PM	#10
Brian Mitchell Warshawsky Major Player Join Date: Aug 2003 Location: Bay Area Posts: 216	Peter Wrote: >>>>>>>>>>>>>>>>>>no its not vegas, as vegas uses whatever codecs are installed in ur OS, it wont install mpg codecs unless theyre licensed/registered, and some codecs have issues upsampling (which is what ur doing.. >>>>>>>>>>>>> Actually, that wasn't the issue: Vegas always played the file back properly .... It was WMP, Real One, and others which had the speed issues which were remedied with the decoder. Sorry for the confusion. Brian

September 14th, 2004, 09:54 PM	#11
Peter Jefferson Inner Circle Join Date: Apr 2003 Location: Aus Posts: 3,884	so basically THOSE players werent running the correct codec?? thats what it sounds like...