[pulseaudio-discuss] [PATCH 2/4] Enabled libsoxr resampler backend.

[Andrey Semashev]

Added ID and names for the resampler presets and also updated the working sample rate deduction to take the new resampler into account.
---
 src/pulsecore/resampler.c | 30 ++++++++++++++++++++++++++----
 src/pulsecore/resampler.h |  4 ++++
 2 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/src/pulsecore/resampler.c b/src/pulsecore/resampler.c
index 183d05f..8a80b7d 100644
--- a/src/pulsecore/resampler.c
+++ b/src/pulsecore/resampler.c
@@ -111,6 +111,15 @@ static int (* const init_table[])(pa_resampler *r) = {
     [PA_RESAMPLER_AUTO]                    = NULL,
     [PA_RESAMPLER_COPY]                    = copy_init,
     [PA_RESAMPLER_PEAKS]                   = pa_resampler_peaks_init,
+#ifdef HAVE_SOXR
+    [PA_RESAMPLER_SOXR_MQ]                 = pa_resampler_soxr_init,
+    [PA_RESAMPLER_SOXR_HQ]                 = pa_resampler_soxr_init,
+    [PA_RESAMPLER_SOXR_VHQ]                = pa_resampler_soxr_init,
+#else
+    [PA_RESAMPLER_SOXR_MQ]                 = NULL,
+    [PA_RESAMPLER_SOXR_HQ]                 = NULL,
+    [PA_RESAMPLER_SOXR_VHQ]                = NULL,
+#endif
 };
 
 static pa_resample_method_t choose_auto_resampler(pa_resample_flags_t flags) {
@@ -278,10 +287,20 @@ static pa_sample_format_t choose_work_format(
             }
                                                 /* Else fall trough */
         case PA_RESAMPLER_PEAKS:
-            if (a == PA_SAMPLE_S16NE || b == PA_SAMPLE_S16NE)
+            /* PEAKS, COPY and TRIVIAL do not benefit from increased
+             * working precision, so for better performance use s16ne
+             * if either input or output fits in it. */
+            if (a == PA_SAMPLE_S16NE || b == PA_SAMPLE_S16NE) {
                 work_format = PA_SAMPLE_S16NE;
-            else if (sample_format_more_precise(a, PA_SAMPLE_S16NE) ||
-                     sample_format_more_precise(b, PA_SAMPLE_S16NE))
+                break;
+            }
+                                                /* Else fall trough */
+        case PA_RESAMPLER_SOXR_MQ:
+        case PA_RESAMPLER_SOXR_HQ:
+        case PA_RESAMPLER_SOXR_VHQ:
+            /* Do processing with max precision of input and output. */
+            if (sample_format_more_precise(a, PA_SAMPLE_S16NE) ||
+                sample_format_more_precise(b, PA_SAMPLE_S16NE))
                 work_format = PA_SAMPLE_FLOAT32NE;
             else
                 work_format = PA_SAMPLE_S16NE;
@@ -601,7 +620,10 @@ static const char * const resample_methods[] = {
     "ffmpeg",
     "auto",
     "copy",
-    "peaks"
+    "peaks",
+    "soxr-mq",
+    "soxr-hq",
+    "soxr-vhq"
 };
 
 const char *pa_resample_method_to_string(pa_resample_method_t m) {
diff --git a/src/pulsecore/resampler.h b/src/pulsecore/resampler.h
index 5a84cf0..a0306e7 100644
--- a/src/pulsecore/resampler.h
+++ b/src/pulsecore/resampler.h
@@ -59,6 +59,9 @@ typedef enum pa_resample_method {
     PA_RESAMPLER_AUTO, /* automatic select based on sample format */
     PA_RESAMPLER_COPY,
     PA_RESAMPLER_PEAKS,
+    PA_RESAMPLER_SOXR_MQ,
+    PA_RESAMPLER_SOXR_HQ,
+    PA_RESAMPLER_SOXR_VHQ,
     PA_RESAMPLER_MAX
 } pa_resample_method_t;
 
@@ -163,6 +166,7 @@ int pa_resampler_libsamplerate_init(pa_resampler *r);
 int pa_resampler_peaks_init(pa_resampler *r);
 int pa_resampler_speex_init(pa_resampler *r);
 int pa_resampler_trivial_init(pa_resampler*r);
+int pa_resampler_soxr_init(pa_resampler *r);
 
 /* Resampler-specific quirks */
 bool pa_speex_is_fixed_point(void);
-- 
2.1.0