Meg F/X can beep and click using a hardware timer so let us try it out. To match things up better, fix PCM beeping to give correct frequency (and get a pointer wrap bug too). Do some minor adjustments to compensate for corrections.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@19355 a1c6a512-1295-4272-9138-f99709370657

3 files changed, 15 insertions, 18 deletions

diff --git a/apps/action.c b/apps/action.c
index 5ceeeb8..5f845ab 100644
--- a/apps/action.c
+++ b/apps/action.c
@@ -130,7 +130,7 @@ static int get_action_worker(int context, int timeout,
     /* Produce keyclick */
     if (global_settings.keyclick && !(button & BUTTON_REL))
         if (!(button & BUTTON_REPEAT) || global_settings.keyclick_repeats)
-            pcmbuf_beep(5000, 2, 2500*global_settings.keyclick);
+            pcmbuf_beep(4000, 2, 2500*global_settings.keyclick);
 #endif
 
     if ((context != last_context) && ((last_button & BUTTON_REL) == 0))
diff --git a/apps/pcmbuf.c b/apps/pcmbuf.c
index 61c6c45..c7db4d3 100644
--- a/apps/pcmbuf.c
+++ b/apps/pcmbuf.c
@@ -954,14 +954,15 @@ bool pcmbuf_insert_buffer(char *buf, int count)
 }
 #endif
 
+#ifndef HAVE_HARDWARE_BEEP
 /* Generates a constant square wave sound with a given frequency
    in Hertz for a duration in milliseconds. */
 void pcmbuf_beep(unsigned int frequency, size_t duration, int amplitude)
 {
-    unsigned int count = 0;
-    unsigned int i;
-    unsigned int interval = NATIVE_FREQUENCY / frequency;
-    unsigned int samples = NATIVE_FREQUENCY / 1000 * duration;
+    int i;
+    unsigned int step = 0xffffffffu / NATIVE_FREQUENCY * frequency;
+    int32_t phase = 0;
+    int samples = NATIVE_FREQUENCY / 1000 * duration;
     int32_t sample;
     int16_t *bufstart;
     int16_t *bufptr;
@@ -986,21 +987,17 @@ void pcmbuf_beep(unsigned int frequency, size_t duration, int amplitude)
     bufptr = bufstart;
     for (i = 0; i < samples; ++i)
     {
+        int32_t amp = (phase >> 31) ^ (int32_t)amplitude;
         sample = mix ? *bufptr : 0;
-        *bufptr++ = clip_sample_16(sample + amplitude);
-        if (bufptr > pcmbuf_end)
+        *bufptr++ = clip_sample_16(sample + amp);
+        if (bufptr >= pcmbuf_end)
             bufptr = (int16_t *)audiobuffer;
         sample = mix ? *bufptr : 0;
-        *bufptr++ = clip_sample_16(sample + amplitude);
-        if (bufptr > pcmbuf_end)
+        *bufptr++ = clip_sample_16(sample + amp);
+        if (bufptr >= pcmbuf_end)
             bufptr = (int16_t *)audiobuffer;
 
-        /* Toggle square wave edge */
-        if (++count >= interval)
-        {
-            count = 0;
-            amplitude = -amplitude;
-        }
+        phase += step;
     }
 
     /* Kick off playback if required */
@@ -1009,7 +1006,7 @@ void pcmbuf_beep(unsigned int frequency, size_t duration, int amplitude)
         pcm_play_data(NULL, (unsigned char *)bufstart, samples * 4);
     }
 }
-
+#endif /* HAVE_HARDWARE_BEEP */
 
 /* Returns pcm buffer usage in percents (0 to 100). */
 int pcmbuf_usage(void)
diff --git a/apps/playback.c b/apps/playback.c
index b21a3c1..50c4017 100644
--- a/apps/playback.c
+++ b/apps/playback.c
@@ -694,7 +694,7 @@ static void audio_skip(int direction)
     if (playlist_check(ci.new_track + wps_offset + direction))
     {
         if (global_settings.beep)
-            pcmbuf_beep(5000, 100, 2500*global_settings.beep);
+            pcmbuf_beep(2000, 100, 2500*global_settings.beep);
 
         LOGFQUEUE("audio > audio Q_AUDIO_SKIP %d", direction);
         queue_post(&audio_queue, Q_AUDIO_SKIP, direction);
@@ -706,7 +706,7 @@ static void audio_skip(int direction)
     {
         /* No more tracks. */
         if (global_settings.beep)
-            pcmbuf_beep(1000, 100, 1000*global_settings.beep);
+            pcmbuf_beep(1000, 100, 1500*global_settings.beep);
     }
 }