Problems with H.264 and B-frames

[mingteck]

I'm not very good at this and I use Avidemux mostly by simply clicking on the various options. Often, though, I'd get this error message: H.264 detected If the file is using B-frames as reference it can lead to a crash or stuttering. Avidemux can use another mode which ls safe but YOU WILL LOSE FRAME ACCURACY. Do you want to use that mode?

If I click Yes, the resulting video has mismatched video and audio. If I click no, it asks if I want to rebuild Frames. What should I do?

Also, some of my mp4 files cannot load onto my iPhone - loads into iTunes OK. Any suggestions?

[Jan Gruuthuse]

yes, use exprimental avidemux 2.6 (beta):
Howto build Avidemux using Homebrew on Snow Leopard or Lion (possible support in this forum)
or if you want it done by Macports: Bash script to compile & install Avidemux 2.6 (SVN revision 7891) on Mac OS X 10.6.8 that may work on Mac OS 10.7 Lion (no idea on this support status)

[styrol]

Or just use some QuickTime based applications like MPEG Streamclip for cutting and converting or Handbrake for converting only (Handbrake supplies presets for mobile an other devices).

Also, some of my mp4 files cannot load onto my iPhone - loads into iTunes OK. Any suggestions?

Mobile devices (e.g iPhones) do only support a subset of h.264 profiles and levels.