convert vector to use with C api

examples/stream/stream.cpp

@@ -345,7 +345,8 @@ int main(int argc, char ** argv) {
             wparams.audio_ctx            = params.audio_ctx;
             wparams.speed_up             = params.speed_up;
 
-            wparams.prompt_tokens        = &prompt_tokens;
+            wparams.prompt_tokens        = &prompt_tokens[0];
+            wparams.prompt_n_tokens      = prompt_tokens.size();
             
             if (whisper_full(ctx, wparams, pcmf32.data(), pcmf32.size()) != 0) {
                 fprintf(stderr, "%s: failed to process audio\n", argv[0]);

whisper.cpp

@@ -2413,6 +2413,8 @@ struct whisper_full_params whisper_full_default_params(enum whisper_sampling_str
                     /*.audio_ctx            =*/ 0,
 
                     /*.prompt_tokens        =*/ nullptr,
+                    /*.prompt_n_tokens      =*/ 0,
+
                     /*.language             =*/ "en",
 
                     /*.greedy               =*/ {
@@ -2457,6 +2459,8 @@ struct whisper_full_params whisper_full_default_params(enum whisper_sampling_str
                     /*.audio_ctx            =*/ 0,
 
                     /*.prompt_tokens        =*/ nullptr,
+                    /*.prompt_n_tokens      =*/ 0,
+
                     /*.language             =*/ "en",
 
                     /*.greedy               =*/ {
@@ -2588,10 +2592,11 @@ int whisper_full(
 
     // Prepend the prompt tokens to the prompt_past
     if (params.prompt_tokens) {
-        for (int i = 0; i < (int) params.prompt_tokens->size(); i++) {
-            prompt_past.push_back((*params.prompt_tokens)[i]);
+        // Parse tokens from the pointer (it points to an std::vector)
+        for (int i = 0; i < params.prompt_n_tokens; i++) {
+            prompt_past.push_back(params.prompt_tokens[i]);
         }
-        std::rotate(prompt_past.begin(), prompt_past.end() - params.prompt_tokens->size(), prompt_past.end());
+        std::rotate(prompt_past.begin(), prompt_past.end() - params.prompt_n_tokens, prompt_past.end());
     }
 
     // overwrite audio_ctx

whisper.h

@@ -209,7 +209,10 @@ extern "C" {
         bool speed_up;  // speed-up the audio by 2x using Phase Vocoder
         int  audio_ctx; // overwrite the audio context size (0 = use default)
 
-        const std::vector<whisper_token> * prompt_tokens;
+        // std::vector<whisper_token>: tokents to provide the whisper model as initial prompt
+        const whisper_token * prompt_tokens;
+        int prompt_n_tokens;
+
         const char * language;
 
         struct {