Saturday, February 18, 2006
Audio Settings and HZ: I'm a bit Baffled
Posted by Jason Dunn in "THOUGHT" @ 04:10 PM
I'm spending my Saturday working on a wedding video project, and am doing a bit of head scratching at the moment. I'm using muvee to create part of the project, and am pulling in video from my MiniDV camera and an MP3 ripped from a CD. The DV-AVI file's audio is 48,000hz, while the song from the CD is at 44,000hz. As far as I know, both of those settings are considered normal for the medium. I'm not an audio expert, so this is where I get a little confused: from what I know, maintaining quality while down-sampling is very easy, but up-sampling results in a significant drop in audio quality. As in, it's easy enough to get the audio in the DV-AVI file from 48,000hz down to 44,000hz to match the MP3 file. I reset muvee's DV-AVI export to be at 44,000hz, and the resulting file sounded great, because the audio track was entirely the MP3, none of the DV-AVI audio was included.
The problem arose when I imported that DV-AVI file into Adobe Premiere Elements 2.0, and tried to export it to a DVD-read MPEG2 file - the export setting is locked at 48,000hz and I can find no way to change it. The resulting MPEG2 file has bursts of static and crackling audio in it, seemingly from the up-sampled audio because the source material plays back without those audio problems. My scenario of combining MiniDV footage with an MP3 audio file is certainly not a unique one, yet I seem to have backed myself into a corner somehow. I'm going to install another DVD burning application and feed it the DV-AVI files that are still at 44,000hz in the hopes that it will either leave the audio untouched, or allow me to specify 44,000hz as the MPEG2 audio stream. Or is 48,000hz a requirement for DVD-compliant MPEG2?
I'm interested in hearing from the video experts among you about what on earth I'm doing wrong or additional settings I should be looking at.
UPDATE: I've imported a DV-AVI file into Videowave 8, a simple video editing program that comes with Roxio Easy Media Creator 8, and exported it as an MPEG2 file. The export settings we locked at 48,000hz, but the good news is that the resulting file sounded great. The upsampling from 44,000hz to 48,000hz resulted in no quality loss that I could detect. So is this a bug in Premiere Elements 2? There are no patches that I could find on Adobe's Web site. :?
The problem arose when I imported that DV-AVI file into Adobe Premiere Elements 2.0, and tried to export it to a DVD-read MPEG2 file - the export setting is locked at 48,000hz and I can find no way to change it. The resulting MPEG2 file has bursts of static and crackling audio in it, seemingly from the up-sampled audio because the source material plays back without those audio problems. My scenario of combining MiniDV footage with an MP3 audio file is certainly not a unique one, yet I seem to have backed myself into a corner somehow. I'm going to install another DVD burning application and feed it the DV-AVI files that are still at 44,000hz in the hopes that it will either leave the audio untouched, or allow me to specify 44,000hz as the MPEG2 audio stream. Or is 48,000hz a requirement for DVD-compliant MPEG2?
I'm interested in hearing from the video experts among you about what on earth I'm doing wrong or additional settings I should be looking at.
UPDATE: I've imported a DV-AVI file into Videowave 8, a simple video editing program that comes with Roxio Easy Media Creator 8, and exported it as an MPEG2 file. The export settings we locked at 48,000hz, but the good news is that the resulting file sounded great. The upsampling from 44,000hz to 48,000hz resulted in no quality loss that I could detect. So is this a bug in Premiere Elements 2? There are no patches that I could find on Adobe's Web site. :?
