Quicktime and GDB

Debugging Components Using Quicktime Player and GDB

To get a debugger attached and put breakpoints into functions in your component files:

• launch qt player
• find its pid using ps
• launch gdb
• attach to the pid (attach pid). This will cause qt player to freeze
• use future-break to set breakpoints (or source them from a file)
• type "continue" (or just "c") to resume qt player
• load an ogg vorbis file in qt player
• press play
• work in gdb as your breakpoints are hit.

On other way, if you work with XCode:

• Select create New Custom Executable
• Choose an application that use component (QuickTime, iTunes, AudioUnit Lab...)
• Set break points in your projects.
• Use the Debug command to launch the application, and GDB will break normally.

A few useful gdb commands

future-break

sets a breakpoint at a function from a dynamic library that hasn't been loaded yet

rbreak regexp

break in any function matching regexp

source fname

execute gdb commands found in fname

Also, stdout from any printf's ends up in console.log, which can be viewed in Console.app