Adding pulseaudio input support to chrome

media/audio/pulse/pulse_util.cc

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "media/audio/pulse/pulse_util.h"
+
+#include "base/logging.h"
+#include "base/time.h"
+#include "media/audio/audio_manager_base.h"
+
+namespace media {
+
+namespace pulse {
+
+namespace {
+
+pa_channel_position ChromiumToPAChannelPosition(Channels channel) {
+  switch (channel) {
+    // PulseAudio does not differentiate between left/right and
+    // stereo-left/stereo-right, both translate to front-left/front-right.
+    case LEFT:
+      return PA_CHANNEL_POSITION_FRONT_LEFT;
+    case RIGHT:
+      return PA_CHANNEL_POSITION_FRONT_RIGHT;
+    case CENTER:
+      return PA_CHANNEL_POSITION_FRONT_CENTER;
+    case LFE:
+      return PA_CHANNEL_POSITION_LFE;
+    case BACK_LEFT:
+      return PA_CHANNEL_POSITION_REAR_LEFT;
+    case BACK_RIGHT:
+      return PA_CHANNEL_POSITION_REAR_RIGHT;
+    case LEFT_OF_CENTER:
+      return PA_CHANNEL_POSITION_FRONT_LEFT_OF_CENTER;
+    case RIGHT_OF_CENTER:
+      return PA_CHANNEL_POSITION_FRONT_RIGHT_OF_CENTER;
+    case BACK_CENTER:
+      return PA_CHANNEL_POSITION_REAR_CENTER;
+    case SIDE_LEFT:
+      return PA_CHANNEL_POSITION_SIDE_LEFT;
+    case SIDE_RIGHT:
+      return PA_CHANNEL_POSITION_SIDE_RIGHT;
+    case CHANNELS_MAX:
+      return PA_CHANNEL_POSITION_INVALID;
+    default:
+      NOTREACHED() << "Invalid channel: " << channel;
+      return PA_CHANNEL_POSITION_INVALID;
+  }
+}
+
+}  // namespace
+
+// static, pa_stream_success_cb_t
+void StreamSuccessCallback(pa_stream* s, int error, void* mainloop) {
+  pa_threaded_mainloop* pa_mainloop =
+      static_cast<pa_threaded_mainloop*>(mainloop);
+  pa_threaded_mainloop_signal(pa_mainloop, 0);
+}
+
+// |pa_context| and |pa_stream| state changed cb.
+void ContextStateCallback(pa_context* context, void* mainloop) {
+  pa_threaded_mainloop* pa_mainloop =
+      static_cast<pa_threaded_mainloop*>(mainloop);
+  pa_threaded_mainloop_signal(pa_mainloop, 0);
+}
+
+pa_sample_format_t BitsToPASampleFormat(int bits_per_sample) {
+  switch (bits_per_sample) {
+    case 8:
+      return PA_SAMPLE_U8;
+    case 16:
+      return PA_SAMPLE_S16LE;
+    case 24:
+      return PA_SAMPLE_S24LE;
+    case 32:
+      return PA_SAMPLE_S32LE;
+    default:
+      NOTREACHED() << "Invalid bits per sample: " << bits_per_sample;
+      return PA_SAMPLE_INVALID;
+  }
+}
+
+pa_channel_map ChannelLayoutToPAChannelMap(ChannelLayout channel_layout) {
+  pa_channel_map channel_map;
+  pa_channel_map_init(&channel_map);
+
+  channel_map.channels = ChannelLayoutToChannelCount(channel_layout);
+  for (Channels ch = LEFT; ch < CHANNELS_MAX;
+       ch = static_cast<Channels>(ch + 1)) {
+    int channel_index = ChannelOrder(channel_layout, ch);
+    if (channel_index < 0)
+      continue;
+
+    channel_map.map[channel_index] = ChromiumToPAChannelPosition(ch);
+  }
+
+  return channel_map;
+}
+
+void WaitForOperationCompletion(pa_threaded_mainloop* pa_mainloop,
+                                pa_operation* operation) {
+  if (!operation) {
+    DLOG(WARNING) << "Operation is NULL";
+    return;
+  }
+
+  while (pa_operation_get_state(operation) == PA_OPERATION_RUNNING)
+    pa_threaded_mainloop_wait(pa_mainloop);
+
+  pa_operation_unref(operation);
+}
+
+int GetHardwareLatencyInBytes(pa_stream* stream,
+                              int sample_rate,
+                              int bytes_per_frame) {
+  DCHECK(stream);
+  int negative = 0;
+  pa_usec_t latency_micros = 0;
+  if (pa_stream_get_latency(stream, &latency_micros, &negative) != 0)
+    return 0;
+
+  if (negative)
+    return 0;
+
+  return latency_micros * sample_rate * bytes_per_frame /
+      base::Time::kMicrosecondsPerSecond;
+}
+
+}  // namespace pulse
+
+}  // namespace media