add batch processing to sherpa-onnx (#166)

@@ -5,6 +5,8 @@
 #include <stdio.h>
 
 #include <chrono>  // NOLINT
+#include <iomanip>
+#include <iostream>
 #include <string>
 #include <vector>
 
@@ -14,6 +16,12 @@
 #include "sherpa-onnx/csrc/parse-options.h"
 #include "sherpa-onnx/csrc/wave-reader.h"
 
+typedef struct {
+  std::unique_ptr<sherpa_onnx::OnlineStream> online_stream;
+  float duration;
+  float elapsed_seconds;
+} Stream;
+
 int main(int32_t argc, char *argv[]) {
   const char *kUsageMessage = R"usage(
 Usage:
@@ -61,29 +69,26 @@ for a list of pre-trained models to download.
 
   sherpa_onnx::OnlineRecognizer recognizer(config);
 
-  float duration = 0;
+  std::vector<Stream> ss;
+
+  const auto begin = std::chrono::steady_clock::now();
+  std::vector<float> durations;
+
   for (int32_t i = 1; i <= po.NumArgs(); ++i) {
     const std::string wav_filename = po.GetArg(i);
     int32_t sampling_rate = -1;
 
     bool is_ok = false;
     const std::vector<float> samples =
-        sherpa_onnx::ReadWave(wav_filename, &sampling_rate, &is_ok);
+      sherpa_onnx::ReadWave(wav_filename, &sampling_rate, &is_ok);
 
     if (!is_ok) {
       fprintf(stderr, "Failed to read %s\n", wav_filename.c_str());
       return -1;
     }
-    fprintf(stderr, "sampling rate of input file: %d\n", sampling_rate);
 
     const float duration = samples.size() / static_cast<float>(sampling_rate);
 
-    fprintf(stderr, "wav filename: %s\n", wav_filename.c_str());
-    fprintf(stderr, "wav duration (s): %.3f\n", duration);
-
-    fprintf(stderr, "Started\n");
-    const auto begin = std::chrono::steady_clock::now();
-
     auto s = recognizer.CreateStream();
     s->AcceptWaveform(sampling_rate, samples.data(), samples.size());
 
@@ -94,33 +99,46 @@ for a list of pre-trained models to download.
 
     // Call InputFinished() to indicate that no audio samples are available
     s->InputFinished();
+    ss.push_back({ std::move(s), duration, 0 });
+  }
 
-    while (recognizer.IsReady(s.get())) {
-      recognizer.DecodeStream(s.get());
-    }
-
-    const std::string text = recognizer.GetResult(s.get()).AsJsonString();
-
-    const auto end = std::chrono::steady_clock::now();
-    const float elapsed_seconds =
-        std::chrono::duration_cast<std::chrono::milliseconds>(end - begin)
+  std::vector<sherpa_onnx::OnlineStream *> ready_streams;
+  for (;;) {
+    ready_streams.clear();
+    for (auto &s : ss) {
+      const auto p_ss = s.online_stream.get();
+      if (recognizer.IsReady(p_ss)) {
+        ready_streams.push_back(p_ss);
+      } else if (s.elapsed_seconds == 0) {
+        const auto end = std::chrono::steady_clock::now();
+        const float elapsed_seconds =
+          std::chrono::duration_cast<std::chrono::milliseconds>(end - begin)
             .count() / 1000.;
+        s.elapsed_seconds = elapsed_seconds;
+      }
+    }
 
-    fprintf(stderr, "Done!\n");
-    fprintf(stderr,
-            "Recognition result for %s:\n%s\n",
-            wav_filename.c_str(), text.c_str());
-    fprintf(stderr, "num threads: %d\n", config.model_config.num_threads);
-    fprintf(stderr, "decoding method: %s\n", config.decoding_method.c_str());
-    if (config.decoding_method == "modified_beam_search") {
-      fprintf(stderr, "max active paths: %d\n", config.max_active_paths);
+    if (ready_streams.empty()) {
+      break;
     }
 
-    fprintf(stderr, "Elapsed seconds: %.3f s\n", elapsed_seconds);
-    const float rtf = elapsed_seconds / duration;
-    fprintf(stderr, "Real time factor (RTF): %.3f / %.3f = %.3f\n",
-            elapsed_seconds, duration, rtf);
+    recognizer.DecodeStreams(ready_streams.data(), ready_streams.size());
   }
 
+  std::ostringstream os;
+  for (int32_t i = 1; i <= po.NumArgs(); ++i) {
+    const auto &s = ss[i - 1];
+    const float rtf = s.elapsed_seconds / s.duration;
+
+    os << po.GetArg(i) << "\n";
+    os << std::setprecision(2) << "Elapsed seconds: " << s.elapsed_seconds
+       << ", Real time factor (RTF): " << rtf << "\n";
+    const auto r = recognizer.GetResult(s.online_stream.get());
+    os << r.text << "\n";
+    os << r.AsJsonString() << "\n\n";
+  }
+
+  std::cerr << os.str();
+
   return 0;
 }