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authorVolker RĂ¼melin <vr_qemu@t-online.de>2021-01-10 11:02:29 +0100
committerGerd Hoffmann <kraxel@redhat.com>2021-01-15 11:25:22 +0100
commitbea29e9f2ea6061abc212809090548cba6d64081 (patch)
treede588e2da2bbaa8e573a8b5377aa954f183f0fe7 /audio
parent6fb0cd50541465114d8dd868bef8463e4edf7522 (diff)
paaudio: avoid to clip samples multiple times
The pulseaudio backend currently converts, clips and copies audio playback samples in the mixing-engine sample buffer multiple times. In qpa_get_buffer_out() the function pa_stream_begin_write() returns a rather large buffer and this allows audio_pcm_hw_run_out() in audio/audio.c to copy all samples in the mixing-engine buffer to the pulse audio buffer. Immediately after copying, qpa_write() notices with a call to pa_stream_writable_size() that pulse audio only needs a smaller part of the copied samples and ignores the rest. This copy and ignore process happens several times for each audio sample. To fix this behaviour, call pa_stream_writable_size() in qpa_get_buffer_out() to limit the number of samples audio_pcm_hw_run_out() will convert. With this change the pulseaudio pcm_ops functions put_buffer_out and write are no longer identical and a separate qpa_put_buffer_out is needed. Signed-off-by: Volker RĂ¼melin <vr_qemu@t-online.de> Message-id: 9315afe5-5958-c0b4-ea1e-14769511a9d5@t-online.de Message-Id: <20210110100239.27588-13-vr_qemu@t-online.de> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Diffstat (limited to 'audio')
-rw-r--r--audio/paaudio.c32
1 files changed, 31 insertions, 1 deletions
diff --git a/audio/paaudio.c b/audio/paaudio.c
index b052084698..229bcfcae8 100644
--- a/audio/paaudio.c
+++ b/audio/paaudio.c
@@ -207,6 +207,7 @@ static void *qpa_get_buffer_out(HWVoiceOut *hw, size_t *size)
PAVoiceOut *p = (PAVoiceOut *) hw;
PAConnection *c = p->g->conn;
void *ret;
+ size_t l;
int r;
pa_threaded_mainloop_lock(c->mainloop);
@@ -214,12 +215,19 @@ static void *qpa_get_buffer_out(HWVoiceOut *hw, size_t *size)
CHECK_DEAD_GOTO(c, p->stream, unlock_and_fail,
"pa_threaded_mainloop_lock failed\n");
+ l = pa_stream_writable_size(p->stream);
+ CHECK_SUCCESS_GOTO(c, l != (size_t) -1, unlock_and_fail,
+ "pa_stream_writable_size failed\n");
+
*size = -1;
r = pa_stream_begin_write(p->stream, &ret, size);
CHECK_SUCCESS_GOTO(c, r >= 0, unlock_and_fail,
"pa_stream_begin_write failed\n");
pa_threaded_mainloop_unlock(c->mainloop);
+ if (*size > l) {
+ *size = l;
+ }
return ret;
unlock_and_fail:
@@ -228,6 +236,28 @@ unlock_and_fail:
return NULL;
}
+static size_t qpa_put_buffer_out(HWVoiceOut *hw, void *data, size_t length)
+{
+ PAVoiceOut *p = (PAVoiceOut *)hw;
+ PAConnection *c = p->g->conn;
+ int r;
+
+ pa_threaded_mainloop_lock(c->mainloop);
+
+ CHECK_DEAD_GOTO(c, p->stream, unlock_and_fail,
+ "pa_threaded_mainloop_lock failed\n");
+
+ r = pa_stream_write(p->stream, data, length, NULL, 0LL, PA_SEEK_RELATIVE);
+ CHECK_SUCCESS_GOTO(c, r >= 0, unlock_and_fail, "pa_stream_write failed\n");
+
+ pa_threaded_mainloop_unlock(c->mainloop);
+ return length;
+
+unlock_and_fail:
+ pa_threaded_mainloop_unlock(c->mainloop);
+ return 0;
+}
+
static size_t qpa_write(HWVoiceOut *hw, void *data, size_t length)
{
PAVoiceOut *p = (PAVoiceOut *) hw;
@@ -861,7 +891,7 @@ static struct audio_pcm_ops qpa_pcm_ops = {
.fini_out = qpa_fini_out,
.write = qpa_write,
.get_buffer_out = qpa_get_buffer_out,
- .put_buffer_out = qpa_write, /* pa handles it */
+ .put_buffer_out = qpa_put_buffer_out,
.volume_out = qpa_volume_out,
.init_in = qpa_init_in,