wmv render problems at DVinfo.net

Mark Howells · June 25th, 2007, 02:32 AM

I am using Sony Vegas 5. In the past I have rendered many files to wmv without any problems. These typically play at maybe 800 to 2000Kbits /sec in windows media player. I have now rendered a file to wmv and it comes out at >10,000 kbits /sec when played. The result is a great deal of posterising. My settings have not changed from previous successful attempts. Has anybody got any ideas what could be going wrong ?

Douglas Spotted Eagle · June 25th, 2007, 08:29 AM

Are you rendering to the same resolution? It would be odd if they play sweetly at 2Kpbs but are macroblocking at 10Kpbs.

Mark Howells · June 25th, 2007, 09:22 AM

Thanks for the reply Douglas. I'm not sure what you mean, though. All I know is that when I play the wmv in windows media player and it shows at the bottom "playing xxxx kbits/sec", the rate is well over 10,000. One render was 26,000. This seems extraordinary as most of the my wmv files and others I have viewed are a few thousand at best. And I have done nothing different from what I normally do ie select the default wmv settings, change to best and audio to 128.

I am completely confused. The result, as I mentioned, is a swirl of posterisation.

Mark Howells · June 26th, 2007, 02:21 AM

I have now found that it plays fine at home, where I think I'm using windows media player 10, but shows these major posterisation/blocky issues at work (windows media player 9). However, it can't be an issue with the version of windows media player as I have watched many of my wmv's at work before.

Could the problem be that my hard disk is close to full capacity ? Could this explain why the bitrate in the file properties is so ridiculously high ?

Mark Howells · June 27th, 2007, 02:30 AM

Latest update

I rendered my edited film in 2 minute segments to wmv using video VBR. This identified at what point the bitrate, when played, exceeded 10,000. I found that in most cases the playback bitrate was as expected, around 500 - 800 kbps. The problem area was right at the end of the film when the footage goes to a few seconds of tv static. This was achieved using the extreme noise and B&W filters. The bitrate shot up to 20,000.

I then changed the video settings for this segment to 2-pass cbr 1Mb. Result !! The bitrate came to a more acceptable level. All this was at home, using wmp 10.

I then re-rendered the whole film to 2-pass cbr 1Mb and was horrified when the playback bitrate again showed around 20,000. Demoralised, I copied the segments that worked using vbr onto a cdr together with this re-rendered whole film and took the disc to work.

Work uses windows 2000 and is therefore limited to wmp9. Playback here is where the problems have arisen. When I played the whole film, rendered with 2-pass cbr 1Mb, all the posterisation had gone, even though the playback bitrate was showing 20,000 kbps. When I played the vbr segments the posterisation was back, even though the playback bitrate was an acceptable 500-800 kbps.

I would really appreciate if anyone can rationalise these findings as I am stumped.

1. It appears that wmp9 does not like video vbr but I know all of my previous films have been rendered using video vbr and played back with no issues.
2. Why if the render is set at a constant rate of 1Mb does it result in a bitrate shown of 20,000 kbs.

June 25th, 2007, 02:32 AM	#1
Mark Howells Regular Crew Join Date: Jul 2006 Location: UK Posts: 99	wmv render problems I am using Sony Vegas 5. In the past I have rendered many files to wmv without any problems. These typically play at maybe 800 to 2000Kbits /sec in windows media player. I have now rendered a file to wmv and it comes out at >10,000 kbits /sec when played. The result is a great deal of posterising. My settings have not changed from previous successful attempts. Has anybody got any ideas what could be going wrong ?

June 25th, 2007, 08:29 AM	#2
Douglas Spotted Eagle VASST Join Date: Jan 2004 Location: Stockton, UT Posts: 5,648	Are you rendering to the same resolution? It would be odd if they play sweetly at 2Kpbs but are macroblocking at 10Kpbs. __________________ Douglas Spotted Eagle/Spot Author, producer, composer Certified Sony Vegas Trainer http://www.vasst.com

June 25th, 2007, 09:22 AM	#3
Mark Howells Regular Crew Join Date: Jul 2006 Location: UK Posts: 99	Thanks for the reply Douglas. I'm not sure what you mean, though. All I know is that when I play the wmv in windows media player and it shows at the bottom "playing xxxx kbits/sec", the rate is well over 10,000. One render was 26,000. This seems extraordinary as most of the my wmv files and others I have viewed are a few thousand at best. And I have done nothing different from what I normally do ie select the default wmv settings, change to best and audio to 128. I am completely confused. The result, as I mentioned, is a swirl of posterisation.

June 26th, 2007, 02:21 AM	#4
Mark Howells Regular Crew Join Date: Jul 2006 Location: UK Posts: 99	I have now found that it plays fine at home, where I think I'm using windows media player 10, but shows these major posterisation/blocky issues at work (windows media player 9). However, it can't be an issue with the version of windows media player as I have watched many of my wmv's at work before. Could the problem be that my hard disk is close to full capacity ? Could this explain why the bitrate in the file properties is so ridiculously high ?

June 27th, 2007, 02:30 AM	#5
Mark Howells Regular Crew Join Date: Jul 2006 Location: UK Posts: 99	Latest update I rendered my edited film in 2 minute segments to wmv using video VBR. This identified at what point the bitrate, when played, exceeded 10,000. I found that in most cases the playback bitrate was as expected, around 500 - 800 kbps. The problem area was right at the end of the film when the footage goes to a few seconds of tv static. This was achieved using the extreme noise and B&W filters. The bitrate shot up to 20,000. I then changed the video settings for this segment to 2-pass cbr 1Mb. Result !! The bitrate came to a more acceptable level. All this was at home, using wmp 10. I then re-rendered the whole film to 2-pass cbr 1Mb and was horrified when the playback bitrate again showed around 20,000. Demoralised, I copied the segments that worked using vbr onto a cdr together with this re-rendered whole film and took the disc to work. Work uses windows 2000 and is therefore limited to wmp9. Playback here is where the problems have arisen. When I played the whole film, rendered with 2-pass cbr 1Mb, all the posterisation had gone, even though the playback bitrate was showing 20,000 kbps. When I played the vbr segments the posterisation was back, even though the playback bitrate was an acceptable 500-800 kbps. I would really appreciate if anyone can rationalise these findings as I am stumped. 1. It appears that wmp9 does not like video vbr but I know all of my previous films have been rendered using video vbr and played back with no issues. 2. Why if the render is set at a constant rate of 1Mb does it result in a bitrate shown of 20,000 kbs.