From bea29e9f2ea6061abc212809090548cba6d64081 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Volker=20R=C3=BCmelin?= Date: Sun, 10 Jan 2021 11:02:29 +0100 Subject: [PATCH] paaudio: avoid to clip samples multiple times MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Rümelin 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 --- audio/paaudio.c | 32 +++++++++++++++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-) 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,