stream : add "max_tokens" parameter

Used to limit the number of tokens in a segment.
Useful to battle with word repetition when using partial encoder context

examples/stream/stream.cpp

@@ -322,6 +322,7 @@ int main(int argc, char ** argv) {
         {
             whisper_full_params wparams = whisper_full_default_params(WHISPER_SAMPLING_GREEDY);
 
+            wparams.max_tokens           = 32;
             wparams.print_progress       = false;
             wparams.print_special_tokens = params.print_special_tokens;
             wparams.print_realtime       = false;

whisper.cpp

@@ -2396,6 +2396,7 @@ struct whisper_full_params whisper_full_default_params(enum whisper_sampling_str
                     /*.thold_pt             =*/ 0.01f,
                     /*.thold_ptsum          =*/ 0.01f,
                     /*.max_len              =*/ 0,
+                    /*.max_tokens           =*/ 0,
 
                     /*.speed_up             =*/ false,
 
@@ -2437,6 +2438,7 @@ struct whisper_full_params whisper_full_default_params(enum whisper_sampling_str
                     /*.thold_pt             =*/ 0.01f,
                     /*.thold_ptsum          =*/ 0.01f,
                     /*.max_len              =*/ 0,
+                    /*.max_tokens           =*/ 0,
 
                     /*.speed_up             =*/ false,
 
@@ -2679,7 +2681,7 @@ int whisper_full(
                 //}
 
                 // end of text token
-                if (token.id == whisper_token_eot(ctx) || (i > WHISPER_EXPERIMENT_MAX_TOKENS_PER_SEGMENT)) {
+                if (token.id == whisper_token_eot(ctx) || (params.max_tokens > 0 && i > params.max_tokens)) {
                     if (result_len == 0) {
                         if (seek + seek_delta + 100 >= seek_end) {
                             result_len = i + 1;

whisper.h

@@ -25,7 +25,6 @@
 #define WHISPER_CHUNK_SIZE  30
 
 #define WHISPER_EXPERIMENT_AUDIO_CTX 512
-#define WHISPER_EXPERIMENT_MAX_TOKENS_PER_SEGMENT 32
 
 #ifdef __cplusplus
 extern "C" {
@@ -205,6 +204,7 @@ extern "C" {
         float thold_pt;         // timestamp token probability threshold (~0.01)
         float thold_ptsum;      // timestamp token sum probability threshold (~0.01)
         int   max_len;          // max segment length in characters
+        int   max_tokens;       // max tokens per segment (0 = no limit)
 
         // [EXPERIMENTAL] speed-up techniques
         bool speed_up; // speed-up the audio by 2x using Phase Vocoder