Sound issues depending on the format at DVinfo.net

Nils Hoover · September 3rd, 2006, 02:25 PM

Backing up and preparing my videos for upload to the internet i have found one video that is very stuburn. It seems when ever i encode it into mono i guess one of the audo tracks goes missing. It has a voice over and music and that is it. This is an old video that i made a long time ago and edited in imovie. I also have acouple other old videos from back when i used imovie and none of them have this problem.

It seems no matter what i do if i make it mono it loses the voice over track but the music remains. I wouldnt care that much but i am trying to put it on youtube and i guess the automaticaly convert stuff to mono, so even if i upload a stereo version of it, it loses the voice over any way. It does it no matter what program i use to compress it in, or no matter what audio codec i use. I have used sorenson squeeze, and i have compressed it straight from adobe premiere. If any one knows how to fix this please tell me.

p.s. It is currently in avi uncompressed format.

Steve House · September 3rd, 2006, 02:37 PM

Quote:

Originally Posted by Nils Hoover

Backing up and preparing my videos for upload to the internet i have found one video that is very stuburn. It seems when ever i encode it into mono i guess one of the audo tracks goes missing. It has a voice over and music and that is it. This is an old video that i made a long time ago and edited in imovie. I also have acouple other old videos from back when i used imovie and none of them have this problem.

It seems no matter what i do if i make it mono it loses the voice over track but the music remains. I wouldnt care that much but i am trying to put it on youtube and i guess the automaticaly convert stuff to mono, so even if i upload a stereo version of it, it loses the voice over any way. It does it no matter what program i use to compress it in, or no matter what audio codec i use. I have used sorenson squeeze, and i have compressed it straight from adobe premiere. If any one knows how to fix this please tell me.

p.s. It is currently in avi uncompressed format.

It sounds like the VO on the two stereo tracks is dual-mono with one track having inverted phase with respect to the other. When you mix them to a single mono track the two VO channels cancel each other out. Do you still have your orignal project files to fall back on and re-do the mix?

Nils Hoover · September 3rd, 2006, 02:40 PM

no, like i said these are old projects. I did them durring highschool in class acouple of years ago. All i have is the file on my computer and possibly on a mini dv tape some where. is there any thing that you know of that i can do?

Seth Bloombaum · September 3rd, 2006, 02:49 PM

If Steve is right, you have two choices:

Drop one of the channels before the conversion to mono. Depending on the nature of the stereo music mix, there may be no significant change to the music... or maybe there will be.

Invert the phase of one of the channels before the conversion to mono. It is likely that this will audibly mess with the music... or maybe not.

Try these things and see if they help. I'd start with some short tests in Premiere. You'll have to separate the channels for either approach, I'm no longer very familiar with Premiere...

Nils Hoover · September 3rd, 2006, 03:14 PM

i am not very experienced in editing audio so maybe what i say willy be silly or stupid. When importing the avi file into premiere or cool edit the only channels the audio has is the left and right channels. Both the channels are virtualy the same and both have the music as well as the voice over on it. I guess im asking how to seperate the tracks because i dont know what im doing.

September 3rd, 2006, 02:25 PM	#1
Nils Hoover Regular Crew Join Date: Feb 2006 Location: ithaca ny Posts: 57	Sound issues depending on the format Backing up and preparing my videos for upload to the internet i have found one video that is very stuburn. It seems when ever i encode it into mono i guess one of the audo tracks goes missing. It has a voice over and music and that is it. This is an old video that i made a long time ago and edited in imovie. I also have acouple other old videos from back when i used imovie and none of them have this problem. It seems no matter what i do if i make it mono it loses the voice over track but the music remains. I wouldnt care that much but i am trying to put it on youtube and i guess the automaticaly convert stuff to mono, so even if i upload a stereo version of it, it loses the voice over any way. It does it no matter what program i use to compress it in, or no matter what audio codec i use. I have used sorenson squeeze, and i have compressed it straight from adobe premiere. If any one knows how to fix this please tell me. p.s. It is currently in avi uncompressed format.

September 3rd, 2006, 02:40 PM	#3
Nils Hoover Regular Crew Join Date: Feb 2006 Location: ithaca ny Posts: 57	no, like i said these are old projects. I did them durring highschool in class acouple of years ago. All i have is the file on my computer and possibly on a mini dv tape some where. is there any thing that you know of that i can do? __________________ http://nils.tv www.vimeo.com/nilz

September 3rd, 2006, 03:14 PM	#5
Nils Hoover Regular Crew Join Date: Feb 2006 Location: ithaca ny Posts: 57	i am not very experienced in editing audio so maybe what i say willy be silly or stupid. When importing the avi file into premiere or cool edit the only channels the audio has is the left and right channels. Both the channels are virtualy the same and both have the music as well as the voice over on it. I guess im asking how to seperate the tracks because i dont know what im doing. __________________ http://nils.tv www.vimeo.com/nilz

September 3rd, 2006, 02:49 PM	#4
Seth Bloombaum Inner Circle Join Date: Sep 2003 Location: Portland, Oregon Posts: 3,420	If Steve is right, you have two choices: Drop one of the channels before the conversion to mono. Depending on the nature of the stereo music mix, there may be no significant change to the music... or maybe there will be. Invert the phase of one of the channels before the conversion to mono. It is likely that this will audibly mess with the music... or maybe not. Try these things and see if they help. I'd start with some short tests in Premiere. You'll have to separate the channels for either approach, I'm no longer very familiar with Premiere...