Hi, > -----Original Message----- > From: stan [mailto:ghjeold_i_mwee@xxxxxxx] > Sent: Wednesday, July 23, 2008 11:26 AM > To: Mitul Sen (misen) > Cc: alsa-devel@xxxxxxxxxxxxxxxx > Subject: Re: Setting format to > SND_PCM_FORMAT_MU_LAW does not let me apply hardware parameters > > Mitul Sen (misen) wrote: > > Hi, > > > > I have tried using gdb both from the command line as you > suggested and > > also from within eclipse. Even though I can step through > the code and > > break properly, I think there is some mismatch between the > source code > > and object code used by gdb. I say that because it sometimes steps > > through code in a way that makes no sense. For example, I > see that a > > particular 'if' condition is satified and it goes into the > 'if' clause > > and then again goes into the 'else' clause that is not expected. Is > > there any module that needs to be reloaded after building and > > installing the shared library? I have done a clean make at > all times, > > checked timestamps, even rebooted the machine in case some driver > > related data needs to be reloaded at startup but none of > this has helped. > I suspect you are debugging optimized code. The optimizer > rearranges and deletes instructions. Did you specify -O0 so > that no optimization occurs? The other gotcha in the > alsa-lib code is that some of the functions are actually > macros. They cannot be stepped through. When you hit them > in the debugger it is disconcerting. > > I did specify -O0 to disable optimizations. > > Another thing that I notice is that when I use aplay to > play the rtp > > data that I save to file (before writing to the sound device), and > > check the output of /proc/asound/card0/pcm0p/sub0/hw_params > file, it > > is exactly the same as when I run my application. Using > aplay does the > > playback properly even though hw_params still shows as > > > > access: MMAP_INTERLEAVED > > format: S16_LE > > subformat: STD > > channels: 2 > > rate: 48000 (48000/1) > It is decoding it before it is playing it, it must be calling > a routine somewhere to do that, or else it is built in. > > > > Please note that I can play back the file using aplay, I > only have the > > problem of bad audio when I try to write to the sound device in > > real-time. With this observation though I am not sure if > the fact that > > the library seems to not use the card's decoder is really > the problem. > > I am trying to look into the source code of aplay to see if > I can spot > > any difference in the way the data is written to the buffer. > > > Good not to limit the possibilities you are examining. > > Meanwhile, any comments and help will be greatly > appreciated as usual. > > > > Thanks for your help. > > > > Regards, > > Mitul > > > > _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
