diff --git a/README.md b/README.md
index fdbc65e..a888880 100644
--- a/README.md
+++ b/README.md
@@ -101,13 +101,14 @@ options:
   -ot N,    --offset-t N     time offset in milliseconds (default: 0)
   -on N,    --offset-n N     segment index offset (default: 0)
   -mc N,    --max-context N  maximum number of text context tokens to store (default: max)
+  -ml N,    --max-len N      maximum segment length in characters (default: 0)
   -wt N,    --word-thold N   word timestamp probability threshold (default: 0.010000)
   -v,       --verbose        verbose output
             --translate      translate from source language to english
   -otxt,    --output-txt     output result in a text file
   -ovtt,    --output-vtt     output result in a vtt file
   -osrt,    --output-srt     output result in a srt file
-  -owts,    --output-words   output word-level timestamps to a text file
+  -owts,    --output-words   output script for generating karaoke video
   -ps,      --print_special  print special tokens
   -pc,      --print_colors   print colors
   -nt,      --no_timestamps  do not print timestamps
diff --git a/examples/main/README.md b/examples/main/README.md
index 27f47ff..f2bf2a8 100644
--- a/examples/main/README.md
+++ b/examples/main/README.md
@@ -8,7 +8,6 @@ It can be used as a reference for using the `whisper.cpp` library in other proje
 
 usage: ./bin/main [options] file0.wav file1.wav ...
 
-options:
   -h,       --help           show this help message and exit
   -s SEED,  --seed SEED      RNG seed (default: -1)
   -t N,     --threads N      number of threads to use during computation (default: 4)
@@ -16,18 +15,20 @@ options:
   -ot N,    --offset-t N     time offset in milliseconds (default: 0)
   -on N,    --offset-n N     segment index offset (default: 0)
   -mc N,    --max-context N  maximum number of text context tokens to store (default: max)
+  -ml N,    --max-len N      maximum segment length in characters (default: 0)
   -wt N,    --word-thold N   word timestamp probability threshold (default: 0.010000)
   -v,       --verbose        verbose output
             --translate      translate from source language to english
   -otxt,    --output-txt     output result in a text file
   -ovtt,    --output-vtt     output result in a vtt file
   -osrt,    --output-srt     output result in a srt file
-  -owts,    --output-words   output word-level timestamps to a text file
+  -owts,    --output-words   output script for generating karaoke video
   -ps,      --print_special  print special tokens
   -pc,      --print_colors   print colors
   -nt,      --no_timestamps  do not print timestamps
   -l LANG,  --language LANG  spoken language (default: en)
   -m FNAME, --model FNAME    model path (default: models/ggml-base.en.bin)
   -f FNAME, --file FNAME     input WAV file path
+  -h,       --help           show this help message and exit
 
 ```
diff --git a/examples/main/main.cpp b/examples/main/main.cpp
index 8343892..b589459 100644
--- a/examples/main/main.cpp
+++ b/examples/main/main.cpp
@@ -36,6 +36,7 @@ std::string to_timestamp(int64_t t, bool comma = false) {
     return std::string(buf);
 }
 
+// helper function to replace substrings
 void replace_all(std::string & s, const std::string & search, const std::string & replace) {
     for (size_t pos = 0; ; pos += replace.length()) {
         pos = s.find(search, pos);
@@ -45,31 +46,6 @@ void replace_all(std::string & s, const std::string & search, const std::string
     }
 }
 
-// a cost-function that is high for text that takes longer to pronounce
-float voice_length(const std::string & text) {
-    float res = 0.0f;
-
-    for (size_t i = 0; i < text.size(); ++i) {
-        if (text[i] == ' ') {
-            res += 0.01f;
-        } else if (text[i] == ',') {
-            res += 2.00f;
-        } else if (text[i] == '.') {
-            res += 3.00f;
-        } else if (text[i] == '!') {
-            res += 3.00f;
-        } else if (text[i] == '?') {
-            res += 3.00f;
-        } else if (text[i] >= '0' && text[i] <= '9') {
-            res += 3.00f;
-        } else {
-            res += 1.00f;
-        }
-    }
-
-    return res;
-}
-
 // command-line parameters
 struct whisper_params {
     int32_t seed         = -1; // RNG seed, not used currently
@@ -78,6 +54,7 @@ struct whisper_params {
     int32_t offset_t_ms  = 0;
     int32_t offset_n     = 0;
     int32_t max_context  = -1;
+    int32_t max_len      = 0;
 
     float word_thold = 0.01f;
 
@@ -120,6 +97,8 @@ bool whisper_params_parse(int argc, char ** argv, whisper_params & params) {
             params.offset_n = std::stoi(argv[++i]);
         } else if (arg == "-mc" || arg == "--max-context") {
             params.max_context = std::stoi(argv[++i]);
+        } else if (arg == "-ml" || arg == "--max-len") {
+            params.max_len = std::stoi(argv[++i]);
         } else if (arg == "-wt" || arg == "--word-thold") {
             params.word_thold = std::stof(argv[++i]);
         } else if (arg == "-v" || arg == "--verbose") {
@@ -176,13 +155,14 @@ void whisper_print_usage(int argc, char ** argv, const whisper_params & params)
     fprintf(stderr, "  -ot N,    --offset-t N     time offset in milliseconds (default: %d)\n", params.offset_t_ms);
     fprintf(stderr, "  -on N,    --offset-n N     segment index offset (default: %d)\n", params.offset_n);
     fprintf(stderr, "  -mc N,    --max-context N  maximum number of text context tokens to store (default: max)\n");
+    fprintf(stderr, "  -ml N,    --max-len N      maximum segment length in characters (default: %d)\n", params.max_len);
     fprintf(stderr, "  -wt N,    --word-thold N   word timestamp probability threshold (default: %f)\n", params.word_thold);
     fprintf(stderr, "  -v,       --verbose        verbose output\n");
     fprintf(stderr, "            --translate      translate from source language to english\n");
     fprintf(stderr, "  -otxt,    --output-txt     output result in a text file\n");
     fprintf(stderr, "  -ovtt,    --output-vtt     output result in a vtt file\n");
     fprintf(stderr, "  -osrt,    --output-srt     output result in a srt file\n");
-    fprintf(stderr, "  -owts,    --output-words   output word-level timestamps to a text file\n");
+    fprintf(stderr, "  -owts,    --output-words   output script for generating karaoke video\n");
     fprintf(stderr, "  -ps,      --print_special  print special tokens\n");
     fprintf(stderr, "  -pc,      --print_colors   print colors\n");
     fprintf(stderr, "  -nt,      --no_timestamps  do not print timestamps\n");
@@ -192,65 +172,67 @@ void whisper_print_usage(int argc, char ** argv, const whisper_params & params)
     fprintf(stderr, "\n");
 }
 
-void whisper_print_segment_callback(struct whisper_context * ctx, void * user_data) {
+void whisper_print_segment_callback(struct whisper_context * ctx, int n_new, void * user_data) {
     const whisper_params & params = *(whisper_params *) user_data;
 
     const int n_segments = whisper_full_n_segments(ctx);
 
-    // print the last segment
-    const int i = n_segments - 1;
-    if (i == 0) {
+    // print the last n_new segments
+    const int s0 = n_segments - n_new;
+    if (s0 == 0) {
         printf("\n");
     }
 
-    if (params.no_timestamps) {
-        if (params.print_colors) {
-            for (int j = 0; j < whisper_full_n_tokens(ctx, i); ++j) {
-                if (params.print_special_tokens == false) {
-                    const whisper_token id = whisper_full_get_token_id(ctx, i, j);
-                    if (id >= whisper_token_eot(ctx)) {
-                        continue;
+    for (int i = s0; i < n_segments; i++) {
+        if (params.no_timestamps) {
+            if (params.print_colors) {
+                for (int j = 0; j < whisper_full_n_tokens(ctx, i); ++j) {
+                    if (params.print_special_tokens == false) {
+                        const whisper_token id = whisper_full_get_token_id(ctx, i, j);
+                        if (id >= whisper_token_eot(ctx)) {
+                            continue;
+                        }
                     }
+
+                    const char * text = whisper_full_get_token_text(ctx, i, j);
+                    const float  p    = whisper_full_get_token_p   (ctx, i, j);
+
+                    const int col = std::max(0, std::min((int) k_colors.size(), (int) (std::pow(p, 3)*float(k_colors.size()))));
+
+                    printf("%s%s%s", k_colors[col].c_str(), text, "\033[0m");
                 }
-
-                const char * text = whisper_full_get_token_text(ctx, i, j);
-                const float  p    = whisper_full_get_token_p   (ctx, i, j);
-
-                const int col = std::max(0, std::min((int) k_colors.size(), (int) (std::pow(p, 3)*float(k_colors.size()))));
-
-                printf("%s%s%s", k_colors[col].c_str(), text, "\033[0m");
+            } else {
+                const char * text = whisper_full_get_segment_text(ctx, i);
+                printf("%s", text);
             }
+            fflush(stdout);
         } else {
-            const char * text = whisper_full_get_segment_text(ctx, i);
-            printf("%s", text);
-        }
-        fflush(stdout);
-    } else {
-        const int64_t t0 = whisper_full_get_segment_t0(ctx, i);
-        const int64_t t1 = whisper_full_get_segment_t1(ctx, i);
+            const int64_t t0 = whisper_full_get_segment_t0(ctx, i);
+            const int64_t t1 = whisper_full_get_segment_t1(ctx, i);
 
-        if (params.print_colors) {
-            printf("[%s --> %s]  ", to_timestamp(t0).c_str(), to_timestamp(t1).c_str());
-            for (int j = 0; j < whisper_full_n_tokens(ctx, i); ++j) {
-                if (params.print_special_tokens == false) {
-                    const whisper_token id = whisper_full_get_token_id(ctx, i, j);
-                    if (id >= whisper_token_eot(ctx)) {
-                        continue;
+            if (params.print_colors) {
+                printf("[%s --> %s]  ", to_timestamp(t0).c_str(), to_timestamp(t1).c_str());
+                for (int j = 0; j < whisper_full_n_tokens(ctx, i); ++j) {
+                    if (params.print_special_tokens == false) {
+                        const whisper_token id = whisper_full_get_token_id(ctx, i, j);
+                        if (id >= whisper_token_eot(ctx)) {
+                            continue;
+                        }
                     }
+
+                    const char * text = whisper_full_get_token_text(ctx, i, j);
+                    const float  p    = whisper_full_get_token_p   (ctx, i, j);
+
+                    const int col = std::max(0, std::min((int) k_colors.size(), (int) (std::pow(p, 3)*float(k_colors.size()))));
+
+                    printf("%s%s%s", k_colors[col].c_str(), text, "\033[0m");
                 }
+                printf("\n");
+            } else {
+                const char * text = whisper_full_get_segment_text(ctx, i);
 
-                const char * text = whisper_full_get_token_text(ctx, i, j);
-                const float  p    = whisper_full_get_token_p   (ctx, i, j);
-
-                const int col = std::max(0, std::min((int) k_colors.size(), (int) (std::pow(p, 3)*float(k_colors.size()))));
-
-                printf("%s%s%s", k_colors[col].c_str(), text, "\033[0m");
+                printf("[%s --> %s]  %s\n", to_timestamp(t0).c_str(), to_timestamp(t1).c_str(), text);
             }
-            printf("\n");
-        } else {
-            const char * text = whisper_full_get_segment_text(ctx, i);
-
-            printf("[%s --> %s]  %s\n", to_timestamp(t0).c_str(), to_timestamp(t1).c_str(), text);
         }
     }
 }
@@ -320,297 +302,41 @@ bool output_srt(struct whisper_context * ctx, const char * fname, const whisper_
     return true;
 }
 
-// word-level timestamps (experimental)
-// TODO: make ffmpeg output optional
-// TODO: extra pass to detect unused speech and assign to tokens
+// karaoke video generation
+// outputs a bash script that uses ffmpeg to generate a video with the subtitles
 // TODO: font parameter adjustments
-// TODO: move to whisper.h/whisper.cpp and add parameter to select max line-length of subtitles
-bool output_wts(struct whisper_context * ctx, const char * fname, const char * fname_inp, const whisper_params & params, const std::vector<float> & pcmf32) {
-    std::vector<float> pcm_avg(pcmf32.size(), 0);
-
-    // average the fabs of the signal
-    {
-        const int hw = 32;
-
-        for (int i = 0; i < pcmf32.size(); i++) {
-            float sum = 0;
-            for (int j = -hw; j <= hw; j++) {
-                if (i + j >= 0 && i + j < pcmf32.size()) {
-                    sum += fabs(pcmf32[i + j]);
-                }
-            }
-            pcm_avg[i] = sum/(2*hw + 1);
-        }
-    }
-
-    struct token_info {
-        int64_t t0 = -1;
-        int64_t t1 = -1;
-
-        int64_t tt0 = -1;
-        int64_t tt1 = -1;
-
-        whisper_token id;
-        whisper_token tid;
-
-        float p     = 0.0f;
-        float pt    = 0.0f;
-        float ptsum = 0.0f;
-
-        std::string text;
-        float vlen = 0.0f; // voice length of this token
-    };
-
-    int64_t t_beg  = 0;
-    int64_t t_last = 0;
-
-    whisper_token tid_last = 0;
-
+bool output_wts(struct whisper_context * ctx, const char * fname, const char * fname_inp, const whisper_params & params, float t_sec) {
     std::ofstream fout(fname);
 
     fprintf(stderr, "%s: saving output to '%s'\n", __func__, fname);
 
+    // TODO: become parameter
+    static const char * font = "/System/Library/Fonts/Supplemental/Courier New Bold.ttf";
+
     fout << "!/bin/bash" << "\n";
     fout << "\n";
 
-    fout << "ffmpeg -i " << fname_inp << " -f lavfi -i color=size=1200x120:duration=" << float(pcmf32.size() + 1000)/WHISPER_SAMPLE_RATE << ":rate=25:color=black -vf \"";
-
-    bool is_first = true;
+    fout << "ffmpeg -i " << fname_inp << " -f lavfi -i color=size=1200x120:duration=" << t_sec << ":rate=25:color=black -vf \"";
 
     for (int i = 0; i < whisper_full_n_segments(ctx); i++) {
         const int64_t t0 = whisper_full_get_segment_t0(ctx, i);
         const int64_t t1 = whisper_full_get_segment_t1(ctx, i);
 
-        const char *text = whisper_full_get_segment_text(ctx, i);
-
-        const int s0 = std::max(0,                   (int) (t0*WHISPER_SAMPLE_RATE/100));
-        const int s1 = std::min((int) pcmf32.size(), (int) (t1*WHISPER_SAMPLE_RATE/100));
-
         const int n = whisper_full_n_tokens(ctx, i);
 
-        std::vector<token_info> tokens(n);
-
-        if (n <= 1) {
-            continue;
-        }
-
+        std::vector<whisper_token_data> tokens(n);
         for (int j = 0; j < n; ++j) {
-            struct whisper_token_data token = whisper_full_get_token_data(ctx, i, j);
-
-            if (j == 0) {
-                if (token.id == whisper_token_beg(ctx)) {
-                    tokens[j    ].t0 = t0;
-                    tokens[j    ].t1 = t0;
-                    tokens[j + 1].t0 = t0;
-
-                    t_beg  = t0;
-                    t_last = t0;
-                    tid_last = whisper_token_beg(ctx);
-                } else {
-                    tokens[j    ].t0 = t_last;
-                }
-            }
-
-            const int64_t tt = t_beg + 2*(token.tid - whisper_token_beg(ctx));
-
-            tokens[j].id    = token.id;
-            tokens[j].tid   = token.tid;
-            tokens[j].p     = token.p;
-            tokens[j].pt    = token.pt;
-            tokens[j].ptsum = token.ptsum;
-
-            tokens[j].text = whisper_token_to_str(ctx, token.id);
-            tokens[j].vlen = voice_length(tokens[j].text);
-
-            if (token.pt > params.word_thold && token.ptsum > 0.01 && token.tid > tid_last && tt <= t1) {
-                if (j > 0) {
-                    tokens[j - 1].t1 = tt;
-                }
-                tokens[j].t0 = tt;
-                tid_last = token.tid;
-            }
+            tokens[j] = whisper_full_get_token_data(ctx, i, j);
         }
 
-        tokens[n - 2].t1 = t1;
-        tokens[n - 1].t0 = t1;
-        tokens[n - 1].t1 = t1;
-
-        t_last = t1;
-
-        // find intervals of tokens with unknown timestamps
-        // fill the timestamps by proportionally splitting the interval based on the token voice lengths
-        {
-            int p0 = 0;
-            int p1 = 0;
-            while (true) {
-                while (p1 < n && tokens[p1].t1 < 0) {
-                    p1++;
-                }
-
-                if (p1 >= n) {
-                    p1--;
-                }
-
-                if (p1 > p0) {
-                    double psum = 0.0;
-                    for (int j = p0; j <= p1; j++) {
-                        psum += tokens[j].vlen;
-                    }
-
-                    //printf("analyzing %d - %d, psum = %f\n", p0, p1, psum);
-
-                    const double dt = tokens[p1].t1 - tokens[p0].t0;
-
-                    // split the time proportionally to the voice length
-                    for (int j = p0 + 1; j <= p1; j++) {
-                        const double ct = tokens[j - 1].t0 + dt*tokens[j - 1].vlen/psum;
-
-                        tokens[j - 1].t1 = ct;
-                        tokens[j    ].t0 = ct;
-                    }
-                }
-
-                p1++;
-                p0 = p1;
-                if (p1 >= n) {
-                    break;
-                }
-            }
-        }
-
-        // fix up (just in case)
-        for (int j = 0; j < n - 1; j++) {
-            if (tokens[j].t1 < 0) {
-                tokens[j + 1].t0 = tokens[j].t1;
-            }
-
-            if (j > 0) {
-                if (tokens[j - 1].t1 > tokens[j].t0) {
-                    tokens[j].t0 = tokens[j - 1].t1;
-                    tokens[j].t1 = std::max(tokens[j].t0, tokens[j].t1);
-                }
-            }
-
-            tokens[j].tt0 = tokens[j].t0;
-            tokens[j].tt1 = tokens[j].t1;
-        }
-
-        // VAD
-        // expand or contract tokens based on voice activity
-        {
-            const int hw = WHISPER_SAMPLE_RATE/8;
-
-            for (int j = 0; j < n; j++) {
-                if (tokens[j].id >= whisper_token_eot(ctx)) {
-                    continue;
-                }
-
-                const int64_t t0 = tokens[j].t0;
-                const int64_t t1 = tokens[j].t1;
-
-                int s0 = std::max(0,                        (int) (t0*WHISPER_SAMPLE_RATE/100));
-                int s1 = std::min((int) pcmf32.size() - 1,  (int) (t1*WHISPER_SAMPLE_RATE/100));
-
-                const int ss0 = std::max(0,                       (int) (t0*WHISPER_SAMPLE_RATE/100) - hw);
-                const int ss1 = std::min((int) pcmf32.size() - 1, (int) (t1*WHISPER_SAMPLE_RATE/100) + hw);
-
-                const int n = ss1 - ss0;
-
-                float sum = 0.0f;
-
-                for (int k = ss0; k < ss1; k++) {
-                    sum += pcm_avg[k];
-                }
-
-                const float thold = 0.5*sum/n;
-
-                {
-                    int k = s0;
-                    if (pcm_avg[k] > thold && j > 0) {
-                        while (k > 0 && pcm_avg[k] > thold) {
-                            k--;
-                        }
-                        tokens[j].t0 = (int64_t) (100*k/WHISPER_SAMPLE_RATE);
-                        if (tokens[j].t0 < tokens[j - 1].t1) {
-                            tokens[j].t0 = tokens[j - 1].t1;
-                        } else {
-                            s0 = k;
-                        }
-                    } else {
-                        while (pcm_avg[k] < thold && k < s1) {
-                            k++;
-                        }
-                        s0 = k;
-                        tokens[j].t0 = 100*k/WHISPER_SAMPLE_RATE;
-                    }
-                }
-
-                {
-                    int k = s1;
-                    if (pcm_avg[k] > thold) {
-                        while (k < (int) pcmf32.size() - 1 && pcm_avg[k] > thold) {
-                            k++;
-                        }
-                        tokens[j].t1 = 100*k/WHISPER_SAMPLE_RATE;
-                        if (j < n - 1 && tokens[j].t1 > tokens[j + 1].t0) {
-                            tokens[j].t1 = tokens[j + 1].t0;
-                        } else {
-                            s1 = k;
-                        }
-                    } else {
-                        while (pcm_avg[k] < thold && k > s0) {
-                            k--;
-                        }
-                        s1 = k;
-                        tokens[j].t1 = 100*k/WHISPER_SAMPLE_RATE;
-                    }
-                }
-            }
-        }
-
-        // fixed token expand (optional)
-        {
-            const int t_expand = 0;
-
-            for (int j = 0; j < n; j++) {
-                if (j > 0) {
-                    tokens[j].t0 = std::max(0, (int) (tokens[j].t0 - t_expand));
-                }
-                if (j < n - 1) {
-                    tokens[j].t1 = tokens[j].t1 + t_expand;
-                }
-            }
-        }
-
-        // debug info
-        // TODO: toggle via parameter
-        for (int j = 0; j < n; ++j) {
-            const auto & token = tokens[j];
-            const auto tt = token.pt > params.word_thold && token.ptsum > 0.01 ? whisper_token_to_str(ctx, token.tid) : "[?]";
-            printf("%s: %10s %6.3f %6.3f %6.3f %6.3f %5d %5d '%s'\n", __func__,
-                    tt, token.p, token.pt, token.ptsum, token.vlen, (int) token.t0, (int) token.t1, token.text.c_str());
-
-            if (tokens[j].id >= whisper_token_eot(ctx)) {
-                continue;
-            }
-
-            //printf("[%s --> %s] %s\n", to_timestamp(token.t0).c_str(), to_timestamp(token.t1).c_str(), whisper_token_to_str(ctx, token.id));
-
-            //fout << "# " << to_timestamp(token.t0) << " --> " << to_timestamp(token.t1) << " " << whisper_token_to_str(ctx, token.id) << "\n";
-        }
-
-        // TODO: become parameters
-        static const int line_wrap = 60;
-        static const char * font = "/System/Library/Fonts/Supplemental/Courier New Bold.ttf";
-
-        if (!is_first) {
+        if (i > 0) {
             fout << ",";
         }
 
         // background text
         fout << "drawtext=fontfile='" << font << "':fontsize=24:fontcolor=gray:x=(w-text_w)/2:y=h/2:text='':enable='between(t," << t0/100.0 << "," << t0/100.0 << ")'";
 
-        is_first = false;
+        bool is_first = true;
 
         for (int j = 0; j < n; ++j) {
             const auto & token = tokens[j];
@@ -654,17 +380,6 @@ bool output_wts(struct whisper_context * ctx, const char * fname, const char * f
                     }
 
                     ncnt += txt.size();
-
-                    if (ncnt > line_wrap) {
-                        if (k < j) {
-                            txt_bg = "> ";
-                            txt_fg = "> ";
-                            txt_ul = "\\ \\ ";
-                            ncnt = 0;
-                        } else {
-                            break;
-                        }
-                    }
                 }
 
                 ::replace_all(txt_bg, "'", "’");
@@ -673,8 +388,11 @@ bool output_wts(struct whisper_context * ctx, const char * fname, const char * f
                 ::replace_all(txt_fg, "\"", "\\\"");
             }
 
-            // background text
-            fout << ",drawtext=fontfile='" << font << "':fontsize=24:fontcolor=gray:x=(w-text_w)/2:y=h/2:text='" << txt_bg << "':enable='between(t," << token.tt0/100.0 << "," << token.tt1/100.0 << ")'";
+            if (is_first) {
+                // background text
+                fout << ",drawtext=fontfile='" << font << "':fontsize=24:fontcolor=gray:x=(w-text_w)/2:y=h/2:text='" << txt_bg << "':enable='between(t," << t0/100.0 << "," << t1/100.0 << ")'";
+                is_first = false;
+            }
 
             // foreground text
             fout << ",drawtext=fontfile='" << font << "':fontsize=24:fontcolor=lightgreen:x=(w-text_w)/2+8:y=h/2:text='" << txt_fg << "':enable='between(t," << token.t0/100.0 << "," << token.t1/100.0 << ")'";
@@ -815,6 +533,10 @@ int main(int argc, char ** argv) {
             wparams.n_max_text_ctx       = params.max_context >= 0 ? params.max_context : wparams.n_max_text_ctx;
             wparams.offset_ms            = params.offset_t_ms;
 
+            wparams.token_timestamps     = params.output_wts || params.max_len > 0;
+            wparams.thold_pt             = params.word_thold;
+            wparams.max_len              = params.output_wts && params.max_len == 0 ? 60 : params.max_len;
+
             // this callback is called on each new segment
             if (!wparams.print_realtime) {
                 wparams.new_segment_callback           = whisper_print_segment_callback;
@@ -852,7 +574,7 @@ int main(int argc, char ** argv) {
             // output to WTS file
             if (params.output_wts) {
                 const auto fname_wts = fname_inp + ".wts";
-                output_wts(ctx, fname_wts.c_str(), fname_inp.c_str(), params, pcmf32);
+                output_wts(ctx, fname_wts.c_str(), fname_inp.c_str(), params, float(pcmf32.size() + 1000)/WHISPER_SAMPLE_RATE);
             }
         }
     }
diff --git a/whisper.cpp b/whisper.cpp
index b230d0c..02ab5cb 100644
--- a/whisper.cpp
+++ b/whisper.cpp
@@ -418,6 +418,12 @@ struct whisper_context {
     std::vector<whisper_segment> result_all;
 
     std::vector<whisper_token> prompt_past;
+
+    // [EXPERIMENTAL] token-level timestamps data
+    int64_t t_beg;
+    int64_t t_last;
+    whisper_token tid_last;
+    std::vector<float> energy; // PCM signal energy
 };
 
 // load the model from a ggml file
@@ -431,7 +437,7 @@ struct whisper_context {
 //
 // see the convert-pt-to-ggml.py script for details
 //
-bool whisper_model_load(const std::string & fname, whisper_context & wctx) {
+static bool whisper_model_load(const std::string & fname, whisper_context & wctx) {
     fprintf(stderr, "%s: loading model from '%s'\n", __func__, fname.c_str());
 
     auto & model = wctx.model;
@@ -1062,7 +1068,7 @@ bool whisper_model_load(const std::string & fname, whisper_context & wctx) {
 //   - n_threads:  number of threads to use
 //   - mel_offset: offset in the mel spectrogram (i.e. audio offset)
 //
-bool whisper_encode(
+static bool whisper_encode(
               whisper_context & wctx,
         const int n_threads,
         const int mel_offset) {
@@ -1448,7 +1454,7 @@ bool whisper_encode(
 //   - n_tokens:   number of tokens in the prompt
 //   - n_past:     number of past tokens to prefix the prompt with
 //
-bool whisper_decode(
+static bool whisper_decode(
               whisper_context & wctx,
         const int n_threads,
         const whisper_token * tokens,
@@ -1811,10 +1817,12 @@ bool whisper_decode(
 }
 
 // the most basic sampling scheme - select the top token
-whisper_token_data whisper_sample_best(
+static whisper_token_data whisper_sample_best(
         const whisper_vocab & vocab,
         const float * probs) {
-    whisper_token_data result;
+    whisper_token_data result = {
+        0, 0, 0.0f, 0.0f, 0.0f, -1, -1, 0.0f,
+    };
 
     int n_logits = vocab.id_to_token.size();
 
@@ -1887,7 +1895,7 @@ whisper_token_data whisper_sample_best(
 }
 
 // samples only from the timestamps tokens
-whisper_vocab::id whisper_sample_timestamp(
+static whisper_vocab::id whisper_sample_timestamp(
         const whisper_vocab & vocab,
         const float * probs) {
     int n_logits = vocab.id_to_token.size();
@@ -1939,7 +1947,7 @@ static std::string to_timestamp(int64_t t, bool comma = false) {
 // naive Discrete Fourier Transform
 // input is real-valued
 // output is complex-valued
-void dft(const std::vector<float> & in, std::vector<float> & out) {
+static void dft(const std::vector<float> & in, std::vector<float> & out) {
     int N = in.size();
 
     out.resize(N*2);
@@ -1963,7 +1971,7 @@ void dft(const std::vector<float> & in, std::vector<float> & out) {
 // poor man's implementation - use something better
 // input is real-valued
 // output is complex-valued
-void fft(const std::vector<float> & in, std::vector<float> & out) {
+static void fft(const std::vector<float> & in, std::vector<float> & out) {
     out.resize(in.size()*2);
 
     int N = in.size();
@@ -2014,7 +2022,7 @@ void fft(const std::vector<float> & in, std::vector<float> & out) {
 }
 
 // ref: https://github.com/openai/whisper/blob/main/whisper/audio.py#L92-L124
-bool log_mel_spectrogram(
+static bool log_mel_spectrogram(
     const float * samples,
     const int n_samples,
     const int sample_rate,
@@ -2339,6 +2347,11 @@ struct whisper_full_params whisper_full_default_params(enum whisper_sampling_str
                     /*.print_realtime       =*/ false,
                     /*.print_timestamps     =*/ true,
 
+                    /*.token_timestamps     =*/ false,
+                    /*.thold_pt             =*/ 0.01f,
+                    /*.thold_ptsum          =*/ 0.01f,
+                    /*.max_len              =*/ 0,
+
                     /*.language             =*/ "en",
 
                     /*.greedy               =*/ {
@@ -2371,6 +2384,11 @@ struct whisper_full_params whisper_full_default_params(enum whisper_sampling_str
                     /*.print_realtime       =*/ false,
                     /*.print_timestamps     =*/ true,
 
+                    /*.token_timestamps     =*/ false,
+                    /*.thold_pt             =*/ 0.01f,
+                    /*.thold_ptsum          =*/ 0.01f,
+                    /*.max_len              =*/ 0,
+
                     /*.language             =*/ "en",
 
                     /*.greedy               =*/ {
@@ -2392,6 +2410,68 @@ struct whisper_full_params whisper_full_default_params(enum whisper_sampling_str
     return result;
 }
 
+// forward declarations
+static std::vector<float> get_signal_energy(const float * signal, int n_samples, int n_samples_per_half_window);
+static void whisper_exp_compute_token_level_timestamps(
+        struct whisper_context * ctx,
+        int   i_segment,
+        float thold_pt,
+        float thold_ptsum);
+
+// wrap the last segment to max_len characters
+// returns the number of new segments
+static int whisper_wrap_segment(struct whisper_context * ctx, int max_len) {
+    auto segment = ctx->result_all.back();
+
+    int res = 1;
+    int acc = 0;
+
+    std::string text;
+
+    for (int i = 0; i < (int) segment.tokens.size(); i++) {
+        const auto & token = segment.tokens[i];
+        if (token.id >= whisper_token_eot(ctx)) {
+            continue;
+        }
+
+        const auto txt = whisper_token_to_str(ctx, token.id);
+
+        const int cur = strlen(txt);
+
+        if (acc + cur > max_len && i > 0) {
+            // split here
+            ctx->result_all.back().text = std::move(text);
+            ctx->result_all.back().t1 = token.t0;
+            ctx->result_all.back().tokens.resize(i);
+
+            ctx->result_all.push_back({});
+            ctx->result_all.back().t0 = token.t0;
+            ctx->result_all.back().t1 = segment.t1;
+
+            // add tokens [i, end] to the new segment
+            ctx->result_all.back().tokens.insert(
+                    ctx->result_all.back().tokens.end(),
+                    segment.tokens.begin() + i,
+                    segment.tokens.end());
+
+            acc = 0;
+            text = "";
+
+            segment = ctx->result_all.back();
+            i = -1;
+
+            res++;
+        } else {
+            acc += cur;
+            text += txt;
+        }
+    }
+
+    ctx->result_all.back().text = std::move(text);
+
+    return res;
+}
+
 int whisper_full(
         struct whisper_context * ctx,
         struct whisper_full_params params,
@@ -2408,6 +2488,13 @@ int whisper_full(
         return -1;
     }
 
+    if (params.token_timestamps) {
+        ctx->t_beg = 0;
+        ctx->t_last = 0;
+        ctx->tid_last = 0;
+        ctx->energy = get_signal_energy(samples, n_samples, 32);
+    }
+
     const int seek_start = params.offset_ms/10;
 
     // if length of spectrogram is less than 1s (100 samples), then return
@@ -2557,6 +2644,7 @@ int whisper_full(
             }
         }
 
+        // shrink down to result_len
         tokens_cur.resize(result_len);
 
         for (const auto & r : tokens_cur) {
@@ -2595,8 +2683,19 @@ int whisper_full(
                         for (int j = i0; j <= i; j++) {
                             result_all.back().tokens.push_back(tokens_cur[j]);
                         }
+
+                        int n_new = 1;
+
+                        if (params.token_timestamps) {
+                            whisper_exp_compute_token_level_timestamps(
+                                    ctx, result_all.size() - 1, params.thold_pt, params.thold_ptsum);
+
+                            if (params.max_len > 0) {
+                                n_new = whisper_wrap_segment(ctx, params.max_len);
+                            }
+                        }
                         if (params.new_segment_callback) {
-                            params.new_segment_callback(ctx, params.new_segment_callback_user_data);
+                            params.new_segment_callback(ctx, n_new, params.new_segment_callback_user_data);
                         }
                     }
                     text = "";
@@ -2625,8 +2724,19 @@ int whisper_full(
                 for (int j = i0; j < (int) tokens_cur.size(); j++) {
                     result_all.back().tokens.push_back(tokens_cur[j]);
                 }
+
+                int n_new = 1;
+
+                if (params.token_timestamps) {
+                    whisper_exp_compute_token_level_timestamps(
+                            ctx, result_all.size() - 1, params.thold_pt, params.thold_ptsum);
+
+                    if (params.max_len > 0) {
+                        n_new = whisper_wrap_segment(ctx, params.max_len);
+                    }
+                }
                 if (params.new_segment_callback) {
-                    params.new_segment_callback(ctx, params.new_segment_callback_user_data);
+                    params.new_segment_callback(ctx, n_new, params.new_segment_callback_user_data);
                 }
             }
         }
@@ -2760,7 +2870,7 @@ int whisper_full_parallel(
 
             // call the new_segment_callback for each segment
             if (params.new_segment_callback) {
-                params.new_segment_callback(ctx, params.new_segment_callback_user_data);
+                params.new_segment_callback(ctx, 1, params.new_segment_callback_user_data);
             }
         }
 
@@ -2836,3 +2946,304 @@ const char * whisper_print_system_info() {
 
     return s.c_str();
 }
+
+// =================================================================================================
+
+//
+// Experimental stuff below
+//
+// Not sure if these should be part of the library at all, because the quality of the results is not
+// guaranteed. Might get removed at some point unless a robust algorithm implementation is found
+//
+
+// =================================================================================================
+
+//
+// token-level timestamps
+//
+
+static int timestamp_to_sample(int64_t t, int n_samples) {
+    return std::max(0, std::min((int) n_samples - 1, (int) ((t*WHISPER_SAMPLE_RATE)/100)));
+}
+
+static int64_t sample_to_timestamp(int i_sample) {
+    return (100*i_sample)/WHISPER_SAMPLE_RATE;
+}
+
+// a cost-function / heuristic that is high for text that takes longer to pronounce
+// obviously, can be improved
+static float voice_length(const std::string & text) {
+    float res = 0.0f;
+
+    for (size_t i = 0; i < text.size(); ++i) {
+        if (text[i] == ' ') {
+            res += 0.01f;
+        } else if (text[i] == ',') {
+            res += 2.00f;
+        } else if (text[i] == '.') {
+            res += 3.00f;
+        } else if (text[i] == '!') {
+            res += 3.00f;
+        } else if (text[i] == '?') {
+            res += 3.00f;
+        } else if (text[i] >= '0' && text[i] <= '9') {
+            res += 3.00f;
+        } else {
+            res += 1.00f;
+        }
+    }
+
+    return res;
+}
+
+// average the fabs of the signal
+static std::vector<float> get_signal_energy(const float * signal, int n_samples, int n_samples_per_half_window) {
+    const int hw = n_samples_per_half_window;
+
+    std::vector<float> result(n_samples);
+
+    for (int i = 0; i < n_samples; i++) {
+        float sum = 0;
+        for (int j = -hw; j <= hw; j++) {
+            if (i + j >= 0 && i + j < n_samples) {
+                sum += fabs(signal[i + j]);
+            }
+        }
+        result[i] = sum/(2*hw + 1);
+    }
+
+    return result;
+}
+
+static void whisper_exp_compute_token_level_timestamps(
+        struct whisper_context * ctx,
+        int   i_segment,
+        float thold_pt,
+        float thold_ptsum) {
+    auto & segment = ctx->result_all[i_segment];
+    auto & tokens  = segment.tokens;
+
+    const int n_samples = ctx->energy.size();
+
+    if (n_samples == 0) {
+        fprintf(stderr, "%s: no signal data available\n", __func__);
+        return;
+    }
+
+    const int64_t t0 = segment.t0;
+    const int64_t t1 = segment.t1;
+
+    const int s0 = timestamp_to_sample(t0, n_samples);
+    const int s1 = timestamp_to_sample(t1, n_samples);
+
+    const int n = tokens.size();
+
+    if (n == 0) {
+        return;
+    }
+
+    if (n == 1) {
+        tokens[0].t0 = t0;
+        tokens[0].t1 = t1;
+
+        return;
+    }
+
+    auto & t_beg    = ctx->t_beg;
+    auto & t_last   = ctx->t_last;
+    auto & tid_last = ctx->tid_last;
+
+    for (int j = 0; j < n; ++j) {
+        auto & token = tokens[j];
+
+        if (j == 0) {
+            if (token.id == whisper_token_beg(ctx)) {
+                tokens[j    ].t0 = t0;
+                tokens[j    ].t1 = t0;
+                tokens[j + 1].t0 = t0;
+
+                t_beg    = t0;
+                t_last   = t0;
+                tid_last = whisper_token_beg(ctx);
+            } else {
+                tokens[j    ].t0 = t_last;
+            }
+        }
+
+        const int64_t tt = t_beg + 2*(token.tid - whisper_token_beg(ctx));
+
+        tokens[j].id    = token.id;
+        tokens[j].tid   = token.tid;
+        tokens[j].p     = token.p;
+        tokens[j].pt    = token.pt;
+        tokens[j].ptsum = token.ptsum;
+
+        tokens[j].vlen = voice_length(whisper_token_to_str(ctx, token.id));
+
+        if (token.pt > thold_pt && token.ptsum > thold_ptsum && token.tid > tid_last && tt <= t1) {
+            if (j > 0) {
+                tokens[j - 1].t1 = tt;
+            }
+            tokens[j].t0 = tt;
+            tid_last = token.tid;
+        }
+    }
+
+    tokens[n - 2].t1 = t1;
+    tokens[n - 1].t0 = t1;
+    tokens[n - 1].t1 = t1;
+
+    t_last = t1;
+
+    // find intervals of tokens with unknown timestamps
+    // fill the timestamps by proportionally splitting the interval based on the token voice lengths
+    {
+        int p0 = 0;
+        int p1 = 0;
+
+        while (true) {
+            while (p1 < n && tokens[p1].t1 < 0) {
+                p1++;
+            }
+
+            if (p1 >= n) {
+                p1--;
+            }
+
+            if (p1 > p0) {
+                double psum = 0.0;
+                for (int j = p0; j <= p1; j++) {
+                    psum += tokens[j].vlen;
+                }
+
+                //printf("analyzing %d - %d, psum = %f\n", p0, p1, psum);
+
+                const double dt = tokens[p1].t1 - tokens[p0].t0;
+
+                // split the time proportionally to the voice length
+                for (int j = p0 + 1; j <= p1; j++) {
+                    const double ct = tokens[j - 1].t0 + dt*tokens[j - 1].vlen/psum;
+
+                    tokens[j - 1].t1 = ct;
+                    tokens[j    ].t0 = ct;
+                }
+            }
+
+            p1++;
+            p0 = p1;
+            if (p1 >= n) {
+                break;
+            }
+        }
+    }
+
+    // fix up (just in case)
+    for (int j = 0; j < n - 1; j++) {
+        if (tokens[j].t1 < 0) {
+            tokens[j + 1].t0 = tokens[j].t1;
+        }
+
+        if (j > 0) {
+            if (tokens[j - 1].t1 > tokens[j].t0) {
+                tokens[j].t0 = tokens[j - 1].t1;
+                tokens[j].t1 = std::max(tokens[j].t0, tokens[j].t1);
+            }
+        }
+    }
+
+    // VAD
+    // expand or contract tokens based on voice activity
+    {
+        const int hw = WHISPER_SAMPLE_RATE/8;
+
+        for (int j = 0; j < n; j++) {
+            if (tokens[j].id >= whisper_token_eot(ctx)) {
+                continue;
+            }
+
+            int s0 = timestamp_to_sample(tokens[j].t0, n_samples);
+            int s1 = timestamp_to_sample(tokens[j].t1, n_samples);
+
+            const int ss0 = std::max(s0 - hw, 0);
+            const int ss1 = std::min(s1 + hw, n_samples);
+
+            const int ns = ss1 - ss0;
+
+            float sum = 0.0f;
+
+            for (int k = ss0; k < ss1; k++) {
+                sum += ctx->energy[k];
+            }
+
+            const float thold = 0.5*sum/ns;
+
+            {
+                int k = s0;
+                if (ctx->energy[k] > thold && j > 0) {
+                    while (k > 0 && ctx->energy[k] > thold) {
+                        k--;
+                    }
+                    tokens[j].t0 = sample_to_timestamp(k);
+                    if (tokens[j].t0 < tokens[j - 1].t1) {
+                        tokens[j].t0 = tokens[j - 1].t1;
+                    } else {
+                        s0 = k;
+                    }
+                } else {
+                    while (ctx->energy[k] < thold && k < s1) {
+                        k++;
+                    }
+                    s0 = k;
+                    tokens[j].t0 = sample_to_timestamp(k);
+                }
+            }
+
+            {
+                int k = s1;
+                if (ctx->energy[k] > thold) {
+                    while (k < n_samples - 1 && ctx->energy[k] > thold) {
+                        k++;
+                    }
+                    tokens[j].t1 = sample_to_timestamp(k);
+                    if (j < ns - 1 && tokens[j].t1 > tokens[j + 1].t0) {
+                        tokens[j].t1 = tokens[j + 1].t0;
+                    } else {
+                        s1 = k;
+                    }
+                } else {
+                    while (ctx->energy[k] < thold && k > s0) {
+                        k--;
+                    }
+                    s1 = k;
+                    tokens[j].t1 = sample_to_timestamp(k);
+                }
+            }
+        }
+    }
+
+    // fixed token expand (optional)
+    //{
+    //    const int t_expand = 0;
+
+    //    for (int j = 0; j < n; j++) {
+    //        if (j > 0) {
+    //            tokens[j].t0 = std::max(0, (int) (tokens[j].t0 - t_expand));
+    //        }
+    //        if (j < n - 1) {
+    //            tokens[j].t1 = tokens[j].t1 + t_expand;
+    //        }
+    //    }
+    //}
+
+    // debug info
+    //for (int j = 0; j < n; ++j) {
+    //    const auto & token = tokens[j];
+    //    const auto tt = token.pt > thold_pt && token.ptsum > 0.01 ? whisper_token_to_str(ctx, token.tid) : "[?]";
+    //    printf("%s: %10s %6.3f %6.3f %6.3f %6.3f %5d %5d '%s'\n", __func__,
+    //            tt, token.p, token.pt, token.ptsum, token.vlen, (int) token.t0, (int) token.t1, whisper_token_to_str(ctx, token.id));
+
+    //    if (tokens[j].id >= whisper_token_eot(ctx)) {
+    //        continue;
+    //    }
+    //}
+}
diff --git a/whisper.h b/whisper.h
index 5d7c40d..57ea5db 100644
--- a/whisper.h
+++ b/whisper.h
@@ -68,14 +68,21 @@ extern "C" {
 
     typedef int whisper_token;
 
-    struct whisper_token_data {
+    typedef struct whisper_token_data {
         whisper_token id;  // token id
         whisper_token tid; // forced timestamp token id
 
         float p;     // probability of the token
         float pt;    // probability of the timestamp token
         float ptsum; // sum of probabilities of all timestamp tokens
-    };
+
+        // token-level timestamp data
+        // do not use if you haven't computed token-level timestamps
+        int64_t t0; // start time of the token
+        int64_t t1; //   end time of the token
+
+        float vlen; // voice length of the token
+    } whisper_token_data;
 
     // Allocates all memory needed for the model and loads the model from the given file.
     // Returns NULL on failure.
@@ -129,7 +136,7 @@ extern "C" {
     // You can also implement your own sampling method using the whisper_get_probs() function.
     // whisper_sample_best() returns the token with the highest probability
     // whisper_sample_timestamp() returns the most probable timestamp token
-    WHISPER_API struct whisper_token_data whisper_sample_best(struct whisper_context * ctx);
+    WHISPER_API whisper_token_data whisper_sample_best(struct whisper_context * ctx);
     WHISPER_API whisper_token whisper_sample_timestamp(struct whisper_context * ctx);
 
     // Return the id of the specified language, returns -1 if not found
@@ -172,7 +179,7 @@ extern "C" {
     // Text segment callback
     // Called on every newly generated text segment
     // Use the whisper_full_...() functions to obtain the text segments
-    typedef void (*whisper_new_segment_callback)(struct whisper_context * ctx, void * user_data);
+    typedef void (*whisper_new_segment_callback)(struct whisper_context * ctx, int n_new, void * user_data);
 
     struct whisper_full_params {
         enum whisper_sampling_strategy strategy;
@@ -188,6 +195,12 @@ extern "C" {
         bool print_realtime;
         bool print_timestamps;
 
+        // [EXPERIMENTAL] token-level timestamps
+        bool  token_timestamps; // enable token-level timestamps
+        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
+
         const char * language;
 
         struct {
@@ -244,7 +257,7 @@ extern "C" {
 
     // Get token data for the specified token in the specified segment.
     // This contains probabilities, timestamps, etc.
-    WHISPER_API struct whisper_token_data whisper_full_get_token_data(struct whisper_context * ctx, int i_segment, int i_token);
+    WHISPER_API whisper_token_data whisper_full_get_token_data(struct whisper_context * ctx, int i_segment, int i_token);
 
     // Get the probability of the specified token in the specified segment.
     WHISPER_API float whisper_full_get_token_p(struct whisper_context * ctx, int i_segment, int i_token);