From: Andreas Pape apape@de.adit-jv.com
Plugin file provides no private hw_ptr and appl_ptr but instead links them to the slave pcm. If the slave pcm itself changes its hw_ptr or app_prt this needs to be done in file plugin, too. Plugin 'plug' is such a candidate changing the hw_ptr and app_ptr in hw_params call dependent on the automatically inserted plugins. ALSA unfortunately has no support for automatically updating chained pointers. A notification on pointer change seems to be prepared inside the snd_pcm_set_ptr() routine via rbptr->changed(), but it is not (yet) implemented so that we need to care for it manually.
Signed-off-by: Andreas Pape apape@de.adit-jv.com --- src/pcm/pcm_file.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/src/pcm/pcm_file.c b/src/pcm/pcm_file.c index fec76eb..1e3d35b 100644 --- a/src/pcm/pcm_file.c +++ b/src/pcm/pcm_file.c @@ -634,6 +634,14 @@ static int snd_pcm_file_hw_params(snd_pcm_t *pcm, snd_pcm_hw_params_t * params) return err; } } + + /* pointer may have changed - e.g if plug is used. */ + snd_pcm_unlink_hw_ptr(pcm, file->gen.slave); + snd_pcm_unlink_appl_ptr(pcm, file->gen.slave); + + snd_pcm_link_hw_ptr(pcm, file->gen.slave); + snd_pcm_link_appl_ptr(pcm, file->gen.slave); + return 0; }