ref #57, #62, #63 : remove unions in C-api + remove designated initializers

We are not ready for designated initializers - many compilers do not
support this C++ feature yet, so removing it's non-trivial usages.

main.cpp

@@ -216,7 +216,7 @@ int main(int argc, char ** argv) {
 
         // run the inference
         {
-            whisper_full_params wparams = whisper_full_default_params(WHISPER_DECODE_GREEDY);
+            whisper_full_params wparams = whisper_full_default_params(WHISPER_SAMPLING_GREEDY);
 
             wparams.print_realtime       = true;
             wparams.print_progress       = false;

stream.cpp

@@ -282,7 +282,7 @@ int main(int argc, char ** argv) {
 
         // run the inference
         {
-            whisper_full_params wparams = whisper_full_default_params(WHISPER_DECODE_GREEDY);
+            whisper_full_params wparams = whisper_full_default_params(WHISPER_SAMPLING_GREEDY);
 
             wparams.print_progress       = false;
             wparams.print_special_tokens = params.print_special_tokens;

whisper.cpp

@@ -2256,59 +2256,63 @@ void whisper_print_timings(struct whisper_context * ctx) {
 
 ////////////////////////////////////////////////////////////////////////////
 
-struct whisper_full_params whisper_full_default_params(enum whisper_decode_strategy strategy) {
+struct whisper_full_params whisper_full_default_params(enum whisper_sampling_strategy strategy) {
     struct whisper_full_params result;
 
     switch (strategy) {
-        case WHISPER_DECODE_GREEDY:
+        case WHISPER_SAMPLING_GREEDY:
             {
-#if defined(_MSC_VER)
                 result = {
-#else
-                result = (struct whisper_full_params) {
-#endif
-                    .strategy  = WHISPER_DECODE_GREEDY,
-                    .n_threads = std::min(4, (int32_t) std::thread::hardware_concurrency()),
-                    .offset_ms = 0,
+                    /*.strategy             =*/ WHISPER_SAMPLING_GREEDY,
 
-                    .translate            = false,
-                    .no_context           = false,
-                    .print_special_tokens = false,
-                    .print_progress       = true,
-                    .print_realtime       = false,
-                    .print_timestamps     = true,
+                    /*.n_threads            =*/ std::min(4, (int32_t) std::thread::hardware_concurrency()),
+                    /*.offset_ms            =*/ 0,
 
-                    .language = "en",
+                    /*.translate            =*/ false,
+                    /*.no_context           =*/ false,
+                    /*.print_special_tokens =*/ false,
+                    /*.print_progress       =*/ true,
+                    /*.print_realtime       =*/ false,
+                    /*.print_timestamps     =*/ true,
 
-                    .greedy = {
-                        .n_past = 0,
+                    /*.language             =*/ "en",
+
+                    /*.greedy               =*/ {
+                        /*.n_past =*/ 0,
+                    },
+
+                    /*.beam_search          =*/ {
+                        /*.n_past     =*/ -1,
+                        /*.beam_width =*/ -1,
+                        /*.n_best     =*/ -1,
                     },
                 };
             } break;
-        case WHISPER_DECODE_BEAM_SEARCH:
+        case WHISPER_SAMPLING_BEAM_SEARCH:
             {
-#if defined(_MSC_VER)
                 result = {
-#else
-                result = (struct whisper_full_params) {
-#endif
-                    .strategy  = WHISPER_DECODE_BEAM_SEARCH,
-                    .n_threads = std::min(4, (int32_t) std::thread::hardware_concurrency()),
-                    .offset_ms = 0,
-
-                    .translate            = false,
-                    .no_context           = false,
-                    .print_special_tokens = false,
-                    .print_progress       = true,
-                    .print_realtime       = false,
-                    .print_timestamps     = true,
-
-                    .language = "en",
-
-                    .beam_search = {
-                        .n_past = 0,
-                        .beam_width = 10,
-                        .n_best = 5,
+                    /*.strategy             =*/ WHISPER_SAMPLING_BEAM_SEARCH,
+
+                    /*.n_threads            =*/ std::min(4, (int32_t) std::thread::hardware_concurrency()),
+                    /*.offset_ms            =*/ 0,
+
+                    /*.translate            =*/ false,
+                    /*.no_context           =*/ false,
+                    /*.print_special_tokens =*/ false,
+                    /*.print_progress       =*/ true,
+                    /*.print_realtime       =*/ false,
+                    /*.print_timestamps     =*/ true,
+
+                    /*.language             =*/ "en",
+
+                    /*.greedy               =*/ {
+                        /*.n_past =*/ -1,
+                    },
+
+                    /*.beam_search          =*/ {
+                        /*.n_past     =*/ 0,
+                        /*.beam_width =*/ 10,
+                        /*.n_best     =*/ 5,
                     },
                 };
             } break;

whisper.h

@@ -153,14 +153,14 @@ extern "C" {
 
     ////////////////////////////////////////////////////////////////////////////
 
-    // Available decoding strategies
-    enum whisper_decode_strategy {
-        WHISPER_DECODE_GREEDY,      // Always select the most probable token
-        WHISPER_DECODE_BEAM_SEARCH, // TODO: not implemented yet!
+    // Available sampling strategies
+    enum whisper_sampling_strategy {
+        WHISPER_SAMPLING_GREEDY,      // Always select the most probable token
+        WHISPER_SAMPLING_BEAM_SEARCH, // TODO: not implemented yet!
     };
 
     struct whisper_full_params {
-        enum whisper_decode_strategy strategy;
+        enum whisper_sampling_strategy strategy;
 
         int n_threads;
         int offset_ms;
@@ -174,20 +174,18 @@ extern "C" {
 
         const char * language;
 
-        union {
-            struct {
-                int n_past;
-            } greedy;
-
-            struct {
-                int n_past;
-                int beam_width;
-                int n_best;
-            } beam_search;
-        };
+        struct {
+            int n_past;
+        } greedy;
+
+        struct {
+            int n_past;
+            int beam_width;
+            int n_best;
+        } beam_search;
     };
 
-    WHISPER_API struct whisper_full_params whisper_full_default_params(enum whisper_decode_strategy strategy);
+    WHISPER_API struct whisper_full_params whisper_full_default_params(enum whisper_sampling_strategy strategy);
 
     // Run the entire model: PCM -> log mel spectrogram -> encoder -> decoder -> text
     // Uses the specified decoding strategy to obtain the text.