volume: add direct support for S32N, FL64 and U8

modules/audio_mixer/Modules.am

-SOURCES_float32_mixer = float32.c
-SOURCES_integer_mixer = integer.c
+libfloat_mixer_plugin_la_SOURCES = float.c
+libfloat_mixer_plugin_la_CFLAGS = $(AM_CFLAGS)
+libfloat_mixer_plugin_la_LIBADD = $(AM_LIBADD) $(LIBM)
+
+libinteger_mixer_plugin_la_SOURCES = integer.c
+libinteger_mixer_plugin_la_CFLAGS = $(AM_CFLAGS)
+libinteger_mixer_plugin_la_LIBADD = $(AM_LIBADD)
 
 libvlc_LTLIBRARIES += \
-	libfloat32_mixer_plugin.la \
+	libfloat_mixer_plugin.la \
 	libinteger_mixer_plugin.la

modules/audio_mixer/float32.c → modules/audio_mixer/float.c

@@ -39,7 +39,6 @@
  * Local prototypes
  *****************************************************************************/
 static int Create( vlc_object_t * );
-static void DoWork( audio_volume_t *, block_t *, float );
 
 /*****************************************************************************
  * Module descriptor
@@ -53,31 +52,52 @@ vlc_module_begin ()
 vlc_module_end ()
 
 /**
- * Initializes the mixer
+ * Mixes a new output buffer
  */
-static int Create( vlc_object_t *p_this )
+static void FilterFL32( audio_volume_t *p_volume, block_t *p_buffer,
+                        float f_multiplier )
 {
-    audio_volume_t *p_volume = (audio_volume_t *)p_this;
+    if( f_multiplier == 1.f )
+        return; /* nothing to do */
 
-    if (p_volume->format != VLC_CODEC_FL32)
-        return -1;
+    float *p = (float *)p_buffer->p_buffer;
+    for( size_t i = p_buffer->i_buffer / sizeof(float); i > 0; i-- )
+        *(p++) *= f_multiplier;
 
-    p_volume->amplify = DoWork;
-    return 0;
+    (void) p_volume;
 }
 
-/**
- * Mixes a new output buffer
- */
-static void DoWork( audio_volume_t *p_volume, block_t *p_buffer,
-                    float f_multiplier )
+static void FilterFL64( audio_volume_t *p_volume, block_t *p_buffer,
+                        float f_multiplier )
 {
-    if( f_multiplier == 1.0 )
+    double *p = (double *)p_buffer->p_buffer;
+    double mult = f_multiplier;
+    if( mult == 1. )
         return; /* nothing to do */
 
-    float *p = (float *)p_buffer->p_buffer;
     for( size_t i = p_buffer->i_buffer / sizeof(float); i > 0; i-- )
-        *(p++) *= f_multiplier;
+        *(p++) *= mult;
 
     (void) p_volume;
 }
+
+/**
+ * Initializes the mixer
+ */
+static int Create( vlc_object_t *p_this )
+{
+    audio_volume_t *p_volume = (audio_volume_t *)p_this;
+
+    switch (p_volume->format)
+    {
+        case VLC_CODEC_FL32:
+            p_volume->amplify = FilterFL32;
+            break;
+        case VLC_CODEC_FL64:
+            p_volume->amplify = FilterFL64;
+            break;
+        default:
+            return -1;
+    }
+    return 0;
+}

modules/audio_mixer/integer.c

@@ -22,6 +22,9 @@
 # include "config.h"
 #endif
 
+#include <math.h>
+#include <limits.h>
+
 #include <vlc_common.h>
 #include <vlc_plugin.h>
 #include <vlc_aout.h>
@@ -37,51 +40,92 @@ vlc_module_begin ()
     set_callbacks (Activate, NULL)
 vlc_module_end ()
 
-static void FilterS16N (audio_volume_t *, block_t *, float);
-
-static int Activate (vlc_object_t *obj)
+static void FilterS32N (audio_volume_t *vol, block_t *block, float volume)
 {
-    audio_volume_t *vol = (audio_volume_t *)obj;
+    int32_t *p = (int32_t *)block->p_buffer;
 
-    switch (vol->format)
+    int32_t mult = lroundf (volume * 0x1.p24f);
+    if (mult == (1 << 24))
+        return;
+
+    for (size_t n = block->i_buffer / sizeof (*p); n > 0; n--)
     {
-        case VLC_CODEC_S16N:
-            vol->amplify = FilterS16N;
-            break;
-        default:
-            return -1;
+        int64_t s = *p * (int64_t)mult;
+        if (s >= (INT32_MAX << INT64_C(24)))
+            *p = INT32_MAX;
+        else
+        if (s < (INT32_MIN << INT64_C(24)))
+            *p = INT32_MIN;
+        else
+            *p = s >> INT64_C(24);
+        p++;
     }
-    return 0;
+    (void) vol;
 }
 
 static void FilterS16N (audio_volume_t *vol, block_t *block, float volume)
 {
-    int32_t mult = volume * 0x1.p16;
+    int16_t *p = (int16_t *)block->p_buffer;
 
-    if (mult == 0x10000)
+    int16_t mult = lroundf (volume * 0x1.p8f);
+    if (mult == (1 << 8))
         return;
 
-    int16_t *p = (int16_t *)block->p_buffer;
-
-    if (mult < 0x10000)
+    for (size_t n = block->i_buffer / sizeof (*p); n > 0; n--)
     {
-        for (size_t n = block->i_buffer / sizeof (*p); n > 0; n--)
-        {
-            *p = (*p * mult) >> 16;
-            p++;
-        }
+        int32_t s = *p * (int32_t)mult;
+        if (s >= (INT16_MAX << 8))
+            *p = INT16_MAX;
+        else
+        if (s < (INT_MIN << 8))
+            *p = INT16_MIN;
+        else
+            *p = s >> 8;
+        p++;
     }
-    else
+    (void) vol;
+}
+
+static void FilterU8 (audio_volume_t *vol, block_t *block, float volume)
+{
+    uint8_t *p = (uint8_t *)block->p_buffer;
+
+    int16_t mult = lroundf (volume * 0x1.p8f);
+    if (mult == (1 << 8))
+        return;
+
+    for (size_t n = block->i_buffer / sizeof (*p); n > 0; n--)
     {
-        mult >>= 4;
-        for (size_t n = block->i_buffer / sizeof (*p); n > 0; n--)
-        {
-            int32_t v = (*p * mult) >> 12;
-            if (abs (v) > 0x7fff)
-                v = 0x8000;
-            *(p++) = v;
-        }
+        int32_t s = (*p - 128) * mult;
+        if (s >= (INT8_MAX << 8))
+            *p = 255;
+        else
+        if (s < (INT8_MIN << 8))
+            *p = 0;
+        else
+            *p = (s >> 8) + 128;
+        p++;
     }
-
     (void) vol;
 }
+
+static int Activate (vlc_object_t *obj)
+{
+    audio_volume_t *vol = (audio_volume_t *)obj;
+
+    switch (vol->format)
+    {
+        case VLC_CODEC_S32N:
+            vol->amplify = FilterS32N;
+            break;
+        case VLC_CODEC_S16N:
+            vol->amplify = FilterS16N;
+            break;
+        case VLC_CODEC_U8:
+            vol->amplify = FilterU8;
+            break;
+        default:
+            return -1;
+    }
+    return 0;
+}

po/POTFILES.in

@@ -318,7 +318,7 @@ modules/audio_filter/spatializer/revmodel.hpp
 modules/audio_filter/spatializer/spatializer.cpp
 modules/audio_filter/spatializer/tuning.h
 modules/audio_filter/stereo_widen.c
-modules/audio_mixer/float32.c
+modules/audio_mixer/float.c
 modules/audio_mixer/integer.c
 modules/audio_output/adummy.c
 modules/audio_output/alsa.c