Hi, I just checked ubuntu was applied patch which you mentioned. > alsa-plugins (1.0.17-0ubuntu5) intrepid-proposed; urgency=low > >   * debian/patches/pulse_recording_fix.patch:  pa_stream_trigger() > returns >     NULL for capture, so test for it first.  Spotted by Takashi Iwai > and >     acked by Lennart Poettering. >   * LP: #282316 - erratic elapsed time count in "sound recorder" >     <a href="https://bugs.launchpad.net/ubuntu/+bug/282316">https://bugs.launchpad.net/ubuntu/+bug/282316</a> > >  -- Daniel T Chen <<a href="mailto:crimsun@ubuntu.com">crimsun@ubuntu.com</a>>  Mon, 27 Oct 2008 00:14:00 > -0400 and I upgraded to 1.0.17-0ubuntu5, then -5 I/O error has gone. :-) but, still there is a problem, and it looks related with pulseaudio Before using pulseaudio my recording program works well... I know my source is not good code, but I want to know, what I have to pay attention when backend of sound system is pulseaudio? I use alsa lib to recording from input device, so I made linux_audio_capture() function. When I use snd_pcm_readi() function, the program is aborted or terminated cause of segmentation fault. > audio_linux_capture() >   -> snd_pcm_readi() >     -> ...(?)... >       -> pulse_poll_activate() >         -> write() <- crash! gdb tells... > (gdb) thread 6 > [Switching to thread 6 (Thread 0xb57e9b90 (LWP 11361))]#0  0xb7ff4430 in __kernel_vsyscall () > (gdb) bt > #0  0xb7ff4430 in __kernel_vsyscall () > #1  0xb77d53bb in write () from /lib/tls/i686/cmov/libc.so.6 > #2  0xb4f8d796 in pulse_poll_activate () from /usr/lib/alsa-lib/libasound_module_pcm_pulse.so > #3  0xb4f8be8f in ?? () from /usr/lib/alsa-lib/libasound_module_pcm_pulse.so > #4  0xb4f8c01d in ?? () from /usr/lib/alsa-lib/libasound_module_pcm_pulse.so > #5  0xb78f2201 in ?? () from /usr/lib/libasound.so.2 > #6  0xb78ae0d0 in ?? () from /usr/lib/libasound.so.2 > #7  0xb78f2465 in ?? () from /usr/lib/libasound.so.2 > #8  0xb78a8544 in snd_pcm_readi () from /usr/lib/libasound.so.2 > #9  0x0805e641 in audio_linux_capture (handle=0x979ee00) at audio_linux.c:720 > #10 0x0805c07c in audio_do_thread_work (data=0x97cd648, user_data=0xb57e933c) at audio.c:474 > #11 0x0805c1d0 in audio_thread_func (data=0x0) at audio.c:514 > #12 0xb799b02f in ?? () from /usr/lib/libglib-2.0.so.0 > #13 0xb75f350f in start_thread () from /lib/tls/i686/cmov/libpthread.so.0 > #14 0xb77e57ee in clone () from /lib/tls/i686/cmov/libc.so.6 > (gdb) my audio_linux_capture() function looks like: > static int > audio_linux_capture (void *handle) > { >   AudioLinux *al = handle; >   snd_pcm_uframes_t frames; >   int err, worked; > >   worked = 0; > >   if (!al->first) >     { >       /* is it time for reading? */ >       err = audio_linux_wait_poll (al); >       if (err < 0) >         { >           if (snd_pcm_state (al->handle) == SND_PCM_STATE_XRUN || >               snd_pcm_state (al->handle) == SND_PCM_STATE_SUSPENDED) >             { >               err = snd_pcm_state (al->handle) == SND_PCM_STATE_XRUN ? -EPIPE : -ESTRPIPE; >               if (audio_linux_xrun_recovery (al, err) < 0) >                 { >                   log_warning (NULL, "write error: %s", snd_strerror (err)); >                   return worked; >                 } >               al->first = 1; >             } >           else if (snd_pcm_state (al->handle) == SND_PCM_STATE_RUNNING) >             { >               /* nothing to do */ >             } >           else >             { >               log_debug (NULL, "failed to wait poll"); >               return worked; >             } >         } > >       /* nothing to do yet */ >       if (!err) >         return worked; >     } > >   al->frame->len = 0; >   al->frame_offset = 0; > > capture_loop: > >   /* read it now */ >   if (0) log_debug (NULL, "bytes: %d", err * al->bytes_per_frame); >   err = snd_pcm_readi (al->handle, al->frame->data, frames); >   if (err < 0) >     { >       if (1) log_debug (NULL, "err: %d", err); >       if (audio_linux_xrun_recovery (al, err) < 0) >         { >           if (err != -EAGAIN) >             log_warning (NULL, "failed to read: %s", snd_strerror (err)); >         } >       al->first = 1; >       return worked; >     } > >   if (snd_pcm_state (al->handle) == SND_PCM_STATE_RUNNING) >     al->first = 0; > >   if (!err) >     return worked; > >   al->frame->len = err * al->bytes_per_frame; > >   if (al->capture_callback) >     al->capture_callback (al->frame, al->capture_callback_data); > >   ++worked; > >   goto capture_loop; > } Thanks, -- Best Regards, Keedi Kim <div class="gmail_quote">2008/10/17 Colin Guthrie <<a href="mailto:gmane@colin.guthr.ie">gmane@colin.guthr.ie</a>> <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div class="Ih2E3d">Keedi Kim wrote: > Hi. > > I followed PerfectSetup of pulseaudio wiki, >  then aplay works well, but arecord doesn't. > ALSA's arecord terminates with > "pcm_read:1473: read error: Input/output error" message. > > Does anybody has idea? </div>I know you've said that the package is using 1.0.17 but there is a chacne that the Ubuntu package updated the pulse plugin to the latest version in git (from the 1.0.18rc3 tree). If this is the case, then Takashi found a problem with recording via alsa with these recently on the alsa Mailing list. Lennart has yet to ACK this and an earlier message on the Alsa mailing list from a couple weeks back (unless he's done so privately to Takashi) so I'm guessing he's a little behind on things right now. In lieu of an ACK from Lennart, it may be worth trying out the patch from Takashi. <a href="http://thread.gmane.org/gmane.linux.alsa.devel/56875" target="_blank">http://thread.gmane.org/gmane.linux.alsa.devel/56875</a> I'd also like to know if it works (not had a moment to try yet) so I can issue an update package for this. Col -- Colin Guthrie gmane(at)<a href="http://colin.guthr.ie" target="_blank">colin.guthr.ie</a> <a href="http://colin.guthr.ie/" target="_blank">http://colin.guthr.ie/</a> Day Job:   Tribalogic Limited [<a href="http://www.tribalogic.net/" target="_blank">http://www.tribalogic.net/</a>] Open Source:   Mandriva Linux Contributor [<a href="http://www.mandriva.com/" target="_blank">http://www.mandriva.com/</a>]   PulseAudio Hacker [<a href="http://www.pulseaudio.org/" target="_blank">http://www.pulseaudio.org/</a>]   Trac Hacker [<a href="http://trac.edgewall.org/" target="_blank">http://trac.edgewall.org/</a>] <div><div></div><div class="Wj3C7c"> _______________________________________________ pulseaudio-discuss mailing list <a href="mailto:pulseaudio-discuss@mail.0pointer.de">pulseaudio-discuss@mail.0pointer.de</a> <a href="https://tango.0pointer.de/mailman/listinfo/pulseaudio-discuss" target="_blank">https://tango.0pointer.de/mailman/listinfo/pulseaudio-discuss</a> </div></div></blockquote></div>