<html> <head> <style> .hmmessage P { margin:0px; padding:0px } body.hmmessage { FONT-SIZE: 10pt; FONT-FAMILY:Tahoma } </style> </head> <body class='hmmessage'> Ok, I'm seeing some really odd qtdemux behavior in my development here. I have a .MP4 file that contains MP3 audio only.  It plays fine in VLC, which figures out it's MP3 audio. HOWEVER, when I run gst-launch using decodebin, it picks up qtdemux to to the parsing (which is the Right Thing), but the caps it sets for it's sourcepad say "mpegversion=(int)4" - which causes decodebin to load up an AAC decoder!  Things then go to heck in a handbasket, because the AAC decoder has no clue what it's being fed and errors out. This seems strange me.. I'd sure like to know why VLC understands that it's an MP3 audio payload but qtdemux seems to guess wrong. Anyone have any ideas what's going on here?  Could our MP3 decoder not be setting its typefind properly? All help appreciated! ..ed.. </body> </html>