Enable to stop TTS generation (#1041)

sherpa-onnx/csrc/offline-tts-vits-impl.h

@@ -216,9 +216,11 @@ class OfflineTtsVitsImpl : public OfflineTtsImpl {
 
     GeneratedAudio ans;
 
+    int32_t should_continue = 1;
+
     int32_t k = 0;
 
-    for (int32_t b = 0; b != num_batches; ++b) {
+    for (int32_t b = 0; b != num_batches && should_continue; ++b) {
       batch.clear();
       for (int32_t i = 0; i != batch_size; ++i, ++k) {
         batch.push_back(std::move(x[k]));
@@ -229,8 +231,8 @@ class OfflineTtsVitsImpl : public OfflineTtsImpl {
       ans.samples.insert(ans.samples.end(), audio.samples.begin(),
                          audio.samples.end());
       if (callback) {
-        callback(audio.samples.data(), audio.samples.size(),
-                 b * 1.0 / num_batches);
+        should_continue = callback(audio.samples.data(), audio.samples.size(),
+                                   b * 1.0 / num_batches);
         // Caution(fangjun): audio is freed when the callback returns, so users
         // should copy the data if they want to access the data after
         // the callback returns to avoid segmentation fault.
@@ -238,7 +240,7 @@ class OfflineTtsVitsImpl : public OfflineTtsImpl {
     }
 
     batch.clear();
-    while (k < static_cast<int32_t>(x.size())) {
+    while (k < static_cast<int32_t>(x.size()) && should_continue) {
       batch.push_back(std::move(x[k]));
       ++k;
     }

sherpa-onnx/csrc/offline-tts.h

@@ -59,7 +59,9 @@ struct GeneratedAudio {
 
 class OfflineTtsImpl;
 
-using GeneratedAudioCallback = std::function<void(
+// If the callback returns 0, then it stop generating
+// if the callback returns 1, then it keeps generating
+using GeneratedAudioCallback = std::function<int32_t(
     const float * /*samples*/, int32_t /*n*/, float /*progress*/)>;
 
 class OfflineTts {

sherpa-onnx/csrc/sherpa-onnx-offline-tts-play-alsa.cc

@@ -44,13 +44,20 @@ static void Handler(int32_t /*sig*/) {
   fprintf(stderr, "\nCaught Ctrl + C. Exiting\n");
 }
 
-static void AudioGeneratedCallback(const float *s, int32_t n,
-                                   float /*progress*/) {
+static int32_t AudioGeneratedCallback(const float *s, int32_t n,
+                                      float /*progress*/) {
   if (n > 0) {
     std::lock_guard<std::mutex> lock(g_buffer.mutex);
     g_buffer.samples.push({s, s + n});
     g_cv.notify_all();
   }
+
+  if (g_killed) {
+    return 0;  // stop generating
+  }
+
+  // continue generating
+  return 1;
 }
 
 static void StartPlayback(const std::string &device_name, int32_t sample_rate) {

sherpa-onnx/csrc/sherpa-onnx-offline-tts-play.cc

@@ -47,8 +47,8 @@ static void Handler(int32_t /*sig*/) {
   fprintf(stderr, "\nCaught Ctrl + C. Exiting\n");
 }
 
-static void AudioGeneratedCallback(const float *s, int32_t n,
-                                   float /*progress*/) {
+static int32_t AudioGeneratedCallback(const float *s, int32_t n,
+                                      float /*progress*/) {
   if (n > 0) {
     Samples samples;
     samples.data = std::vector<float>{s, s + n};
@@ -57,6 +57,12 @@ static void AudioGeneratedCallback(const float *s, int32_t n,
     g_buffer.samples.push(std::move(samples));
     g_started = true;
   }
+  if (g_killed) {
+    return 0;  // stop generating
+  }
+
+  // continue generating
+  return 1;
 }
 
 static int PlayCallback(const void * /*in*/, void *out,

sherpa-onnx/csrc/sherpa-onnx-offline-tts.cc

@@ -9,8 +9,9 @@
 #include "sherpa-onnx/csrc/parse-options.h"
 #include "sherpa-onnx/csrc/wave-writer.h"
 
-void audioCallback(const float * /*samples*/, int32_t n, float progress) {
+int32_t audioCallback(const float * /*samples*/, int32_t n, float progress) {
   printf("sample=%d, progress=%f\n", n, progress);
+  return 1;
 }
 
 int main(int32_t argc, char *argv[]) {