Voice prompts bugfixes:

- added missing initialization of codec2 in voice prompts code
- discarding the voice prompt header as we only support 3200 bit rate
- fixed wrong offset in pick vpQueueStringTableEntry
- fixed bug in vpInit causing voiceprompts to hang

meson.build

@@ -697,6 +697,10 @@ sine_test = executable('sine_test',
                       sources : unit_test_src + ['tests/unit/play_sine.c'],
                       kwargs  : unit_test_opts)
 
+vp_test = executable('vp_test',
+                      sources : unit_test_src + ['tests/unit/voice_prompts.c'],
+                      kwargs  : unit_test_opts)
+
 test('M17 Golay Unit Test',   m17_golay_test)
 test('M17 Viterbi Unit Test', m17_viterbi_test)
 test('M17 Demodulator Test',  m17_demodulator_test)
@@ -704,3 +708,4 @@ test('M17 RRC Test',          m17_rrc_test)
 test('Codeplug Test',         cps_test)
 test('Linux InputStream Test', linux_inputStream_test)
 test('Sine Test',             sine_test)
+test('Voice Prompts Test',    vp_test)

openrtx/include/core/voicePrompts.h

@@ -22,6 +22,9 @@
 #include <datatypes.h>
 #include <stdbool.h>
 
+// Voice prompts are encoded using the codec2 file format used by ffmpeg
+#define CODEC2_HEADER_SIZE 7
+
 /*
 Please note, these prompts represent spoken words or phrases which are not in
 the UI string table, for example letters of the alphabet, digits, and

openrtx/src/core/voicePrompts.c

@@ -137,6 +137,8 @@ void vpCacheInit(void)
        // loaded.
         if (state.settings.vpLevel > vpBeep) state.settings.vpLevel = vpBeep;
     }
+    // TODO: Move this somewhere else for compatibility with M17
+    codec_init();
 }
 
 bool vpCheckHeader(uint32_t* bufferAddress)
@@ -155,7 +157,8 @@ static void GetCodec2Data(int offset, int length)
     if ((offset < 0) || (length > Codec2DataBufferSize))
         return;
 
-    fseek(voice_prompt_file, vpDataOffset+offset, SEEK_SET);
+    // Skip codec2 header
+    fseek(voice_prompt_file, vpDataOffset+offset+CODEC2_HEADER_SIZE, SEEK_SET);
     fread((void*)&Codec2Data, length, 1, voice_prompt_file);
     // zero buffer from length to the next multiple of 8 to avoid garbage 
     // being played back, since codec2 frames are pushed in lots of 8 bytes.
@@ -181,11 +184,6 @@ void vpTerminate(void)
 
 void vpInit(void)
 {
-    if (voicePromptIsActive)
-    {
-        vpTerminate();
-    }
-
     vpCurrentSequence.length = 0;
     vpCurrentSequence.pos    = 0;
     vpCurrentSequence.codec2DataIndex = 0;
@@ -343,8 +341,9 @@ void vpQueueStringTableEntry(const char* const* stringTableStringPtr)
     {
         return;
     }
-    vpQueuePrompt(NUM_VOICE_PROMPTS +
+    vpQueuePrompt(NUM_VOICE_PROMPTS + 1 +
-                  (stringTableStringPtr - &currentLanguage->languageName));
+                  (stringTableStringPtr - &currentLanguage->languageName)
+                  / sizeof(const char *));
 }
 
 void vpPlay(void)

tests/unit/voice_prompts.c

@@ -0,0 +1,45 @@
+/***************************************************************************
+ *   Copyright (C) 2021 by Federico Amedeo Izzo IU2NUO,                    *
+ *                         Niccolò Izzo IU2KIN                             *
+ *                         Frederik Saraci IU2NRO                          *
+ *                         Silvano Seva IU2KWO                             *
+ *                                                                         *
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 3 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ *   This program is distributed in the hope that it will be useful,       *
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
+ *   GNU General Public License for more details.                          *
+ *                                                                         *
+ *   You should have received a copy of the GNU General Public License     *
+ *   along with this program; if not, see <http://www.gnu.org/licenses/>   *
+ ***************************************************************************/
+
+// Test private methods
+#define private public
+
+#include <state.h>
+#include <voicePromptUtils.h>
+
+/**
+ * Test voice prompts playback
+ */
+
+int main()
+{
+    state.settings.vpLevel = 3;
+	VoicePromptQueueFlags_T flags = GetQueueFlagsForVoiceLevel();
+
+    vpCacheInit();
+    vpInit();
+    vpQueueStringTableEntry(&currentLanguage->allChannels);
+    vpPlay();
+    while(true)
+    {
+        vpTick();
+    }
+}