Vegas introducing pops in MP4 audio

smhontz wrote on 7/12/2013, 11:17 AM

I was given an MP4 file from a client. When I drop it into a new Vegas 12 project, and let it set the project properties according to the media, I am hearing pops in the audio.

The audio levels are good; they're peaking at -12db or so. The pops are not throughout the clip, or in any rhythmic pattern, but they are at repeatable points, and are present if I render the clip out. I don't see any pop "peaks" in the waveform even when zoomed in which leads me to believe they are not actually in the recording but that Vegas is introducing them somehow.

MediaInfo says the file is 1440x1080 59.940 fps AVC, 128Kbps 44.1 Khz 2 channel AAC(LC).

If I play the MP4 file in VLC, there is no popping. In fact, I can use VLC to render the audio only to WAV and there is no popping. If I render the same segment to WAV in Vegas, you can hear the popping. This happens on two different computers.

If you have any advice, please listen to the two clips here. The first is rendered in Vegas and has the pops. The second is from VLC and doesn't have the pops.

https://dl.dropboxusercontent.com/u/100707917/pops.wav
https://dl.dropboxusercontent.com/u/100707917/nopops.wav

Listen in particular where he says "They're fun" (:16) ... "but overall" (:22) ... "one person" (:23)

Comments

john_dennis wrote on 7/12/2013, 2:16 PM

"I can use VLC to render the audio only to WAV and there is no popping."

I'd render the AAC to wav in another application, and replace the audio on the Vegas timeline with that wav.

If you want to fix the files before you add them to the Vegas timeline, you might try remuxing the video to the wav audio in tsMuxer or some such application.

Then, submit a bug report to SCS.

I feel so lucky that all my cameras record wav. But, there are the files we get from others...