Play generated audio using alsa for TTS (#482)

2023-12-13 22:28:03 +08:00
parent 9829d7c4d3
commit b18812ceff
7 changed files with 465 additions and 10 deletions
--- a/sherpa-onnx/csrc/alsa-play.cc
+++ b/sherpa-onnx/csrc/alsa-play.cc
@@ -0,0 +1,150 @@
+// sherpa-onnx/csrc/alsa-play.cc
+//
+// Copyright (c)  2022-2023  Xiaomi Corporation
+
+#ifdef SHERPA_ONNX_ENABLE_ALSA
+
+#include "sherpa-onnx/csrc/alsa-play.h"
+
+#include <algorithm>
+
+namespace sherpa_onnx {
+
+AlsaPlay::AlsaPlay(const char *device_name, int32_t sample_rate) {
+  int32_t err = snd_pcm_open(&handle_, device_name, SND_PCM_STREAM_PLAYBACK, 0);
+
+  if (err) {
+    fprintf(stderr, "Unable to open: %s. %s\n", device_name, snd_strerror(err));
+    exit(-1);
+  }
+
+  SetParameters(sample_rate);
+}
+
+AlsaPlay::~AlsaPlay() {
+  if (handle_) {
+    int32_t err = snd_pcm_close(handle_);
+    if (err < 0) {
+      printf("Failed to close pcm: %s\n", snd_strerror(err));
+    }
+  }
+}
+
+void AlsaPlay::SetParameters(int32_t sample_rate) {
+  // set the following parameters
+  // 1. sample_rate
+  // 2. sample format: int16_t
+  // 3. num_channels: 1
+  snd_pcm_hw_params_t *params;
+  snd_pcm_hw_params_alloca(&params);
+  snd_pcm_hw_params_any(handle_, params);
+
+  int32_t err = snd_pcm_hw_params_set_access(handle_, params,
+                                             SND_PCM_ACCESS_RW_INTERLEAVED);
+  if (err < 0) {
+    printf("SND_PCM_ACCESS_RW_INTERLEAVED is not supported: %s\n",
+           snd_strerror(err));
+    exit(-1);
+  }
+
+  err = snd_pcm_hw_params_set_format(handle_, params, SND_PCM_FORMAT_S16_LE);
+
+  if (err < 0) {
+    printf("Can't set format to 16-bit: %s\n", snd_strerror(err));
+    exit(-1);
+  }
+
+  err = snd_pcm_hw_params_set_channels(handle_, params, 1);
+
+  if (err < 0) {
+    printf("Can't set channel number to 1: %s\n", snd_strerror(err));
+  }
+
+  uint32_t rate = sample_rate;
+  err = snd_pcm_hw_params_set_rate_near(handle_, params, &rate, 0);
+  if (err < 0) {
+    printf("Can't set rate to %d. %s\n", rate, snd_strerror(err));
+  }
+
+  err = snd_pcm_hw_params(handle_, params);
+  if (err < 0) {
+    printf("Can't set hardware parameters. %s\n", snd_strerror(err));
+    exit(-1);
+  }
+
+  uint32_t tmp;
+  snd_pcm_hw_params_get_rate(params, &tmp, 0);
+  int32_t actual_sample_rate = tmp;
+  if (actual_sample_rate != sample_rate) {
+    fprintf(stderr,
+            "Creating a resampler:\n"
+            "   in_sample_rate: %d\n"
+            "   output_sample_rate: %d\n",
+            sample_rate, actual_sample_rate);
+
+    float min_freq = std::min(actual_sample_rate, sample_rate);
+    float lowpass_cutoff = 0.99 * 0.5 * min_freq;
+
+    int32_t lowpass_filter_width = 6;
+    resampler_ = std::make_unique<LinearResample>(
+        sample_rate, actual_sample_rate, lowpass_cutoff, lowpass_filter_width);
+  }
+
+  snd_pcm_uframes_t frames;
+  snd_pcm_hw_params_get_period_size(params, &frames, 0);
+  buf_.resize(frames);
+}
+
+void AlsaPlay::Play(const std::vector<float> &samples) {
+  std::vector<float> tmp;
+  const float *p = samples.data();
+  int32_t num_samples = samples.size();
+  if (resampler_) {
+    resampler_->Resample(samples.data(), samples.size(), false, &tmp);
+    p = tmp.data();
+    num_samples = tmp.size();
+  }
+
+  int32_t frames = buf_.size();
+  int32_t i = 0;
+  for (; i + frames < num_samples; i += frames) {
+    for (int32_t k = 0; k != frames; ++k) {
+      buf_[k] = p[i + k] * 32767;
+    }
+
+    int32_t err = snd_pcm_writei(handle_, buf_.data(), frames);
+    if (err == -EPIPE) {
+      printf("XRUN.\n");
+      snd_pcm_prepare(handle_);
+    } else if (err < 0) {
+      printf("Can't write to PCM device: %s\n", snd_strerror(err));
+      exit(-1);
+    }
+  }
+
+  if (i < num_samples) {
+    for (int32_t k = 0; k + i < num_samples; ++k) {
+      buf_[k] = p[i + k] * 32767;
+    }
+
+    int32_t err = snd_pcm_writei(handle_, buf_.data(), num_samples - i);
+    if (err == -EPIPE) {
+      printf("XRUN.\n");
+      snd_pcm_prepare(handle_);
+    } else if (err < 0) {
+      printf("Can't write to PCM device: %s\n", snd_strerror(err));
+      exit(-1);
+    }
+  }
+}
+
+void AlsaPlay::Drain() {
+  int32_t err = snd_pcm_drain(handle_);
+  if (err < 0) {
+    printf("Failed to drain pcm. %s\n", snd_strerror(err));
+  }
+}
+
+}  // namespace sherpa_onnx
+
+#endif  // SHERPA_ONNX_ENABLE_ALSA