[pulseaudio-discuss] [PATCH RFCv3 48/51] alsa-sink: Assume left_to_play can be computed, save one call to snd_pcm_avail()
Peter Meerwald
pmeerw at pmeerw.net
Tue Nov 4 15:26:43 PST 2014
From: Peter Meerwald <p.meerwald at bct-electronic.com>
after a completed write in mmap_write(), compute the new left_to_play instead
of asking ALSA what the new value would be
Signed-off-by: Peter Meerwald <pmeerw at pmeerw.net>
---
src/modules/alsa/alsa-sink.c | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)
diff --git a/src/modules/alsa/alsa-sink.c b/src/modules/alsa/alsa-sink.c
index 3690d8d..0d13716 100644
--- a/src/modules/alsa/alsa-sink.c
+++ b/src/modules/alsa/alsa-sink.c
@@ -512,13 +512,16 @@ static int mmap_write(struct userdata *u, pa_usec_t *sleep_usec, bool polled, bo
bool work_done = false;
pa_usec_t max_sleep_usec = 0, process_usec = 0;
size_t left_to_play, input_underrun;
+ size_t sleep_bytes = 0;
unsigned j = 0;
pa_assert(u);
pa_sink_assert_ref(u->sink);
- if (u->use_tsched)
+ if (u->use_tsched) {
hw_sleep_time(u, &max_sleep_usec, &process_usec);
+ sleep_bytes = PA_USEC_TO_BYTES(process_usec + max_sleep_usec/2, &u->sink->sample_spec);
+ }
for (;;) {
snd_pcm_sframes_t n;
@@ -554,8 +557,7 @@ static int mmap_write(struct userdata *u, pa_usec_t *sleep_usec, bool polled, bo
* need to guarantee that clients only have to keep around
* a single hw buffer length. */
- if (!polled &&
- PA_BYTES_TO_USEC(left_to_play, &u->sink->sample_spec) > process_usec+max_sleep_usec/2) {
+ if (!polled && left_to_play > sleep_bytes) {
#ifdef DEBUG_TIMING
pa_log_debug("Not filling up, because too early.");
#endif
@@ -666,13 +668,21 @@ static int mmap_write(struct userdata *u, pa_usec_t *sleep_usec, bool polled, bo
pa_log_debug("Wrote %lu bytes (of possible %lu bytes)", (unsigned long) written, (unsigned long) n_bytes);
#endif
- if (written >= n_bytes)
- break;
+ if (written >= n_bytes) {
+ if (u->use_tsched &&
+ sframes * u->frame_size == n_bytes &&
+ left_to_play + n_bytes > sleep_bytes) {
+ left_to_play += n_bytes;
+ goto done;
+ } else
+ break;
+ }
n_bytes -= written;
}
}
+done:
input_underrun = pa_sink_process_input_underruns(u->sink, left_to_play);
if (u->use_tsched) {
--
1.9.1
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