On Fri, 13.06.08 17:55, Takashi Iwai (tiwai@suse.de) wrote:
What about just providing three pointers: curr_ptr, hw_ptr and appl_ptr? curr_ptr corresponds to the point being played, and hw_ptr is the point where the data was already sent to h/w, and appl_ptr is the point where the data is filled by user. The above definitions are all combinations of these pointers.
I could agree to that. However, to be useful it must be possible to query those three pointers atomically. i.e. in a single call:
typedef struct snd_ptr_info { snd_uframes_t curr_ptr; snd_uframes_t hw_ptr; snd_uframes_t appl_ptr; } snd_ptr_info_t;
int snd_pcm_get_ptr_info(snd_pcm_t *pcm, snd_ptr_info_t *i);
I really don't understand why we need to hide hw_ptr and appl_ptr in the current API. To me, exposing these points is much more straightforward.
I think I could subscribe to that.
Lennart