[pulseaudio-discuss] [PATCH] sink, source: Add a mode to avoid resampling if possible
Arun Raghavan
arun at arunraghavan.net
Sat Jan 28 07:56:28 UTC 2017
This adds an "avoid-resampling" option to daemon.conf that makes the
daemon try to use the stream sample rate if possible (the device needs
to support it, which currently only ALSA does), and there should not be
any other stream connected).
This should enable some of the "audiophile" use-cases where users wish
to play high sample rate audio files without resampling.
We still will do conversion, though which means that the 96/24 case will
require that the default format be set to be 24-bit as well, this will
force all streams to be upconverted, which other than the wasted
resources should be relatively harmless.
---
man/pulse-daemon.conf.5.xml.in | 9 +++++++++
src/daemon/daemon-conf.c | 3 +++
src/daemon/daemon-conf.h | 1 +
src/daemon/daemon.conf.in | 1 +
src/daemon/main.c | 1 +
src/pulsecore/core.h | 1 +
src/pulsecore/sink.c | 10 ++++++++--
src/pulsecore/source.c | 10 ++++++++--
8 files changed, 32 insertions(+), 4 deletions(-)
NOTE: I didn't want to editorialise the commit message itself, but if you're
excited about this feature, please do make sure you understand Monty's
excellent post on the subject of high sample rate audio at:
http://people.xiph.org/~xiphmont/demo/neil-young.html
diff --git a/man/pulse-daemon.conf.5.xml.in b/man/pulse-daemon.conf.5.xml.in
index b81a549..cb09b97 100644
--- a/man/pulse-daemon.conf.5.xml.in
+++ b/man/pulse-daemon.conf.5.xml.in
@@ -124,6 +124,15 @@ License along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
</option>
<option>
+ <p><opt>avoid-resampling=</opt> If set, try to configure the
+ device to avoid resampling. This only works if on devices that
+ support reconfiguring their rate, and when no other streams are
+ already playing or capturing audio. The device will also not be
+ configured to a rate less than the default and alternate sample
+ rates.</p>
+ </option>
+
+ <option>
<p><opt>enable-remixing=</opt> If disabled never upmix or
downmix channels to different channel maps. Instead, do a simple
name-based matching only. Defaults to <opt>yes.</opt></p>
diff --git a/src/daemon/daemon-conf.c b/src/daemon/daemon-conf.c
index 31e4b14..9883126 100644
--- a/src/daemon/daemon-conf.c
+++ b/src/daemon/daemon-conf.c
@@ -81,6 +81,7 @@ static const pa_daemon_conf default_conf = {
.log_meta = false,
.log_time = false,
.resample_method = PA_RESAMPLER_AUTO,
+ .avoid_resampling = false,
.disable_remixing = false,
.remixing_use_all_sink_channels = true,
.disable_lfe_remixing = true,
@@ -553,6 +554,7 @@ int pa_daemon_conf_load(pa_daemon_conf *c, const char *filename) {
{ "deferred-volume-extra-delay-usec",
pa_config_parse_int, &c->deferred_volume_extra_delay_usec, NULL },
{ "nice-level", parse_nice_level, c, NULL },
+ { "avoid-resampling", pa_config_parse_bool, &c->avoid_resampling, NULL },
{ "disable-remixing", pa_config_parse_bool, &c->disable_remixing, NULL },
{ "enable-remixing", pa_config_parse_not_bool, &c->disable_remixing, NULL },
{ "remixing-use-all-sink-channels",
@@ -750,6 +752,7 @@ char *pa_daemon_conf_dump(pa_daemon_conf *c) {
pa_strbuf_printf(s, "log-target = %s\n", pa_strempty(log_target));
pa_strbuf_printf(s, "log-level = %s\n", log_level_to_string[c->log_level]);
pa_strbuf_printf(s, "resample-method = %s\n", pa_resample_method_to_string(c->resample_method));
+ pa_strbuf_printf(s, "avoid-resampling = %s\n", pa_yes_no(!c->avoid_resampling));
pa_strbuf_printf(s, "enable-remixing = %s\n", pa_yes_no(!c->disable_remixing));
pa_strbuf_printf(s, "remixing-use-all-sink-channels = %s\n", pa_yes_no(c->remixing_use_all_sink_channels));
pa_strbuf_printf(s, "enable-lfe-remixing = %s\n", pa_yes_no(!c->disable_lfe_remixing));
diff --git a/src/daemon/daemon-conf.h b/src/daemon/daemon-conf.h
index e61f67f..953ea33 100644
--- a/src/daemon/daemon-conf.h
+++ b/src/daemon/daemon-conf.h
@@ -67,6 +67,7 @@ typedef struct pa_daemon_conf {
no_cpu_limit,
disable_shm,
disable_memfd,
+ avoid_resampling,
disable_remixing,
remixing_use_all_sink_channels,
disable_lfe_remixing,
diff --git a/src/daemon/daemon.conf.in b/src/daemon/daemon.conf.in
index 2d74afa..a955523 100644
--- a/src/daemon/daemon.conf.in
+++ b/src/daemon/daemon.conf.in
@@ -54,6 +54,7 @@ ifelse(@HAVE_DBUS@, 1, [dnl
; log-backtrace = 0
; resample-method = speex-float-1
+; avoid-resampling = false
; enable-remixing = yes
; remixing-use-all-sink-channels = yes
; enable-lfe-remixing = no
diff --git a/src/daemon/main.c b/src/daemon/main.c
index 280252a..f35252d 100644
--- a/src/daemon/main.c
+++ b/src/daemon/main.c
@@ -1036,6 +1036,7 @@ int main(int argc, char *argv[]) {
c->resample_method = conf->resample_method;
c->realtime_priority = conf->realtime_priority;
c->realtime_scheduling = conf->realtime_scheduling;
+ c->avoid_resampling = conf->avoid_resampling;
c->disable_remixing = conf->disable_remixing;
c->remixing_use_all_sink_channels = conf->remixing_use_all_sink_channels;
c->disable_lfe_remixing = conf->disable_lfe_remixing;
diff --git a/src/pulsecore/core.h b/src/pulsecore/core.h
index d2fe887..212f6f7 100644
--- a/src/pulsecore/core.h
+++ b/src/pulsecore/core.h
@@ -199,6 +199,7 @@ struct pa_core {
bool disallow_exit:1;
bool running_as_daemon:1;
bool realtime_scheduling:1;
+ bool avoid_resampling:1;
bool disable_remixing:1;
bool remixing_use_all_sink_channels:1;
bool disable_lfe_remixing:1;
diff --git a/src/pulsecore/sink.c b/src/pulsecore/sink.c
index aa21822..370ea9b 100644
--- a/src/pulsecore/sink.c
+++ b/src/pulsecore/sink.c
@@ -1414,6 +1414,7 @@ int pa_sink_update_rate(pa_sink *s, uint32_t rate, bool passthrough) {
pa_sink_input *i;
bool default_rate_is_usable = false;
bool alternate_rate_is_usable = false;
+ bool avoid_resampling = s->core->avoid_resampling;
if (rate == s->sample_spec.rate)
return 0;
@@ -1421,7 +1422,7 @@ int pa_sink_update_rate(pa_sink *s, uint32_t rate, bool passthrough) {
if (!s->update_rate)
return -1;
- if (PA_UNLIKELY(default_rate == alternate_rate && !passthrough)) {
+ if (PA_UNLIKELY(default_rate == alternate_rate && !passthrough && !avoid_resampling)) {
pa_log_debug("Default and alternate sample rates are the same, so there is no point in switching.");
return -1;
}
@@ -1442,7 +1443,12 @@ int pa_sink_update_rate(pa_sink *s, uint32_t rate, bool passthrough) {
if (PA_UNLIKELY(!pa_sample_rate_valid(desired_rate)))
return -1;
- if (!passthrough && default_rate != desired_rate && alternate_rate != desired_rate) {
+ if (avoid_resampling) {
+ /* We just try to set the sink input's sample rate if it's not too low */
+ if (rate > default_rate || rate > alternate_rate)
+ desired_rate = rate;
+
+ } else if (!passthrough && default_rate != desired_rate && alternate_rate != desired_rate) {
if (default_rate % 11025 == 0 && desired_rate % 11025 == 0)
default_rate_is_usable = true;
if (default_rate % 4000 == 0 && desired_rate % 4000 == 0)
diff --git a/src/pulsecore/source.c b/src/pulsecore/source.c
index 8ce7818..ba59929 100644
--- a/src/pulsecore/source.c
+++ b/src/pulsecore/source.c
@@ -982,6 +982,7 @@ int pa_source_update_rate(pa_source *s, uint32_t rate, bool passthrough) {
uint32_t alternate_rate = s->alternate_sample_rate;
bool default_rate_is_usable = false;
bool alternate_rate_is_usable = false;
+ bool avoid_resampling = s->core->avoid_resampling;
if (rate == s->sample_spec.rate)
return 0;
@@ -989,7 +990,7 @@ int pa_source_update_rate(pa_source *s, uint32_t rate, bool passthrough) {
if (!s->update_rate && !s->monitor_of)
return -1;
- if (PA_UNLIKELY(default_rate == alternate_rate && !passthrough)) {
+ if (PA_UNLIKELY(default_rate == alternate_rate && !passthrough && !avoid_resampling)) {
pa_log_debug("Default and alternate sample rates are the same, so there is no point in switching.");
return -1;
}
@@ -1010,7 +1011,12 @@ int pa_source_update_rate(pa_source *s, uint32_t rate, bool passthrough) {
if (PA_UNLIKELY(!pa_sample_rate_valid(desired_rate)))
return -1;
- if (!passthrough && default_rate != desired_rate && alternate_rate != desired_rate) {
+ if (avoid_resampling) {
+ /* We just try to set the source output's sample rate if it's not too low */
+ if (rate > default_rate || rate > alternate_rate)
+ desired_rate = rate;
+
+ } else if (!passthrough && default_rate != desired_rate && alternate_rate != desired_rate) {
if (default_rate % 11025 == 0 && desired_rate % 11025 == 0)
default_rate_is_usable = true;
if (default_rate % 4000 == 0 && desired_rate % 4000 == 0)
--
2.9.3
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