Popping sound in ac3 render

YesMaestro wrote on 11/4/2008, 6:31 AM

I am rendering my timeline (in V7) to ac3. There is a 2 sec gap at the beginning where there are no clips at all. On the ac3 render, there is a popping sound at the very first frame. I rendered out to avi and there is no pop. Is this a bug with the ac3 codec or what?

Paul

Comments

blink3times wrote on 11/4/2008, 9:00 AM

I doubt it's a bug. I do a fair bit of AC3 work and have never seen this. What you need to do though is give a bit more info. What track is the popping on (front right... front left... all channels)? Can the popping be SEEN in the output file? Which encoder are you using (studio, or pro)? What are your pro settings? Is this originally a stereo track or 5.1 track? Where did these tracks originate? Do your tracks start at the zero crossing or do they start with a peak way off the zero line? Are you SURE the pop is there and it is not your soundcard or other hardware? Do you have a 5 or 10 milli second fade in at the start?

YesMaestro wrote on 11/4/2008, 10:17 AM

Blink, it was a straight single camera interview with a single stereo track. The client wanted 2 sec of black before the video starts so the clip starts at the 2 sec mark with nothing on the timeline in front of it. I am using the Dolby Digital AC3 in V7. When I bring it into DVDA, I can hear & see the pop at the first frame. The thing is, there is a pop where there is no clip what so ever.

Paul

blink3times wrote on 11/5/2008, 5:42 AM

I don't know what to tell you.

IF it is a bug then it would have to live in DVDa. I know for a fact that it does not exist in Vegas because I create ac3 files in vages all the time and have never seen this. I DO NOT however use DVDa very much and the few times that I have used it, it has done some funny things with my ac3 file.

Just last night for example I was playing with DVDa and burned a blu ray disk. Only 2 of the six tracks showed up. I know this because I analyzed the ac3 file that vegas created with Adobe Audition and all was good, but after burning the disk with dvda, and reimporting the ac3 file on the disk for analysis in Adobe Audition, 4 out of the 6 tracks were flat lined.

At any rate, what I suggest you do is down load Ulead Movie Factory which has (I think) a full trial. It's a real cheapy consumer program but it does do ac3 burns and I've never had a problem with it. Do a test strip with it and see if the pop is still there.