voice: Allow voice prompt volume to be configurable

It defaults to 100%, allow it to be dialed back

Change-Id: If997fb7d3057472a7fac0be4ae7d1e8fce654c49

apps/lang/english.lang

@@ -9499,6 +9499,20 @@
     *: "Announce Battery Level"
   </voice>
 </phrase>
+<phrase>
+  id: LANG_TALK_MIXER_LEVEL
+  desc: Relative volume of voice prompts
+  user: core
+  <source>
+    *: "Voice prompt volume"
+  </source>
+  <dest>
+    *: "Voice prompt volume"
+  </dest>
+  <voice>
+    *: "Voice prompt volume"
+  </voice>
+</phrase>
 <phrase>
   id: LANG_VOICE_FILETYPE
   desc: voice settings menu

apps/menus/settings_menu.c

@@ -709,10 +709,11 @@ static int talk_callback(int action,
 MENUITEM_SETTING(talk_filetype_item, &global_settings.talk_filetype, NULL);
 MENUITEM_SETTING(talk_battery_level_item,
                  &global_settings.talk_battery_level, NULL);
+MENUITEM_SETTING(talk_mixer_amp_item, &global_settings.talk_mixer_amp, NULL);
 MAKE_MENU(voice_settings_menu, ID2P(LANG_VOICE), 0, Icon_Voice,
           &talk_menu_item, &talk_dir_item, &talk_dir_clip_item,
           &talk_file_item, &talk_file_clip_item, &talk_filetype_item,
-          &talk_battery_level_item);
+          &talk_battery_level_item, &talk_mixer_amp_item);
 /*    VOICE MENU                   */
 /***********************************/
 

apps/settings.h

@@ -588,6 +588,7 @@ struct user_settings
     bool talk_file_clip; /* use file .talk clips */
     bool talk_filetype; /* say file type */
     bool talk_battery_level;
+    int  talk_mixer_amp; /* Relative volume of voices, MIX_AMP_MPUTE->MIX_AMP_UNITY */
 
     /* file browser sorting */
     bool sort_case; /* dir sort order: 0=case insensitive, 1=sensitive */

apps/settings_list.c

@@ -61,6 +61,8 @@
 #include "onplay.h"
 #endif
 
+#include "voice_thread.h"
+
 #if defined(DX50) || defined(DX90)
 #include "governor-ibasso.h"
 #include "usb-ibasso.h"
@@ -1327,6 +1329,8 @@ const struct settings_list settings[] = {
                   "talk filetype", NULL),
     OFFON_SETTING(F_TEMPVAR, talk_battery_level, LANG_TALK_BATTERY_LEVEL, false,
                   "Announce Battery Level", NULL),
+    INT_SETTING(0, talk_mixer_amp, LANG_TALK_MIXER_LEVEL, 100,
+        "talk mixer level", UNIT_PERCENT, 0, 100, 5, NULL, NULL, voice_set_mixer_level),
 
 #ifdef HAVE_RECORDING
      /* recording */

apps/voice_thread.c

@@ -31,6 +31,7 @@
 #include "pcm.h"
 #include "pcm_mixer.h"
 #include "codecs/libspeex/speex/speex.h"
+#include "settings.h"
 
 /* Default number of PCM frames to queue - adjust as necessary per-target */
 #define VOICE_FRAMES 4
@@ -327,6 +328,13 @@ void voice_wait(void)
         sleep(1);
 }
 
+void voice_set_mixer_level(int percent)
+{
+    percent *= MIX_AMP_UNITY;
+    percent /= 100;
+    mixer_channel_set_amplitude(PCM_MIXER_CHAN_VOICE, percent);
+}
+
 /* Initialize voice thread data that must be valid upon starting and the
  * setup the DSP parameters */
 static void voice_data_init(struct voice_thread_data *td)
@@ -337,7 +345,8 @@ static void voice_data_init(struct voice_thread_data *td)
     dsp_configure(td->dsp, DSP_SET_SAMPLE_DEPTH, VOICE_SAMPLE_DEPTH);
     dsp_configure(td->dsp, DSP_SET_STEREO_MODE, STEREO_MONO);
 
-    mixer_channel_set_amplitude(PCM_MIXER_CHAN_VOICE, MIX_AMP_UNITY);
+    voice_set_mixer_level(global_settings.talk_mixer_amp);
+
     voice_buf->td = td;
     td->dst = NULL;
 }

apps/voice_thread.h

@@ -38,6 +38,8 @@ void voice_stop(void);
 void voice_thread_init(void);
 void voice_thread_kill(void);
 
+void voice_set_mixer_level(int percent);
+
 #ifdef HAVE_PRIORITY_SCHEDULING
 void voice_thread_set_priority(int priority);
 #endif

manual/configure_rockbox/voice.tex

@@ -88,6 +88,10 @@
     When this option is enabled the battery level is announced when it falls
     under 50\%, 30\% and 15\%.
 
+  \item[Voice Volume Level.]
+    This allows you to specify the relative volume of the voice prompts as
+    a percentage of the main audio volume.  It defaults to 100\%.
+
   \end{description}
 
 See \wikilink{VoiceHowto} for more details on configuring speech support in Rockbox.