clipping/popping artifacts with aac+ffmpeg

[Mordordotnet]

Hi there,

I'm trying to convert some uncompressed video (with pcm audio) to streamable h.264 files with ffmpeg. It mostly works, except I get stuttering/clicking audio artifacts with aac encoding. I am running RedHat Enterprise Linux on a quad-cpu machine and am using the following command line:

ffmpeg -i inputfile -vcodec h264 -b 350 -acodec aac -ac 2 -ab 96 inputfile.mp4

The input file is an uncompressed avi clip.

I am able to encode with QT 7 Pro on a windows box, but ffmpeg is so much faster on the quad-core Linux machine. I've been through the FAQs and am getting a bit frustrated. Any help would be very much appreciated.

Best,

[Kurtnoise]

Try with bitrate higher than 96 kbps...

Maybe it's a decoder issue.

[Mordordotnet]

Try with bitrate higher than 96 kbps...

Maybe it's a decoder issue.

Now I'm really confused. I've found some files that exhibit the problem and other files do not. All of the input files are the same:

uncompressed video
audio 48hkz, stereo, 16-bit PCM

and they are all edited originally by Virtualdub on a windows machine. According to virtualdub, the input audio/video properties are exactly the same on every input file, but some of the files will cause the clipping/noise artifacts and others do not. The behavior seems unaffected by the audio bitrate (I have tried 96/128/160/256kbit).

Any other suggestions?

Best,