1 files changed, 373 insertions, 0 deletions
diff --git a/media/libcubeb/src/cubeb_resampler.cpp b/media/libcubeb/src/cubeb_resampler.cpp
new file mode 100644
index 0000000000..c31944b826
--- /dev/null
+++ b/media/libcubeb/src/cubeb_resampler.cpp
@@ -0,0 +1,373 @@
+/*
+ * Copyright © 2014 Mozilla Foundation
+ *
+ * This program is made available under an ISC-style license.  See the
+ * accompanying file LICENSE for details.
+ */
+#ifndef NOMINMAX
+#define NOMINMAX
+#endif // NOMINMAX
+
+#include "cubeb_resampler.h"
+#include "cubeb-speex-resampler.h"
+#include "cubeb_resampler_internal.h"
+#include "cubeb_utils.h"
+#include <algorithm>
+#include <cassert>
+#include <cmath>
+#include <cstddef>
+#include <cstdio>
+#include <cstring>
+
+int
+to_speex_quality(cubeb_resampler_quality q)
+{
+  switch (q) {
+  case CUBEB_RESAMPLER_QUALITY_VOIP:
+    return SPEEX_RESAMPLER_QUALITY_VOIP;
+  case CUBEB_RESAMPLER_QUALITY_DEFAULT:
+    return SPEEX_RESAMPLER_QUALITY_DEFAULT;
+  case CUBEB_RESAMPLER_QUALITY_DESKTOP:
+    return SPEEX_RESAMPLER_QUALITY_DESKTOP;
+  default:
+    assert(false);
+    return 0XFFFFFFFF;
+  }
+}
+
+uint32_t
+min_buffered_audio_frame(uint32_t sample_rate)
+{
+  return sample_rate / 20;
+}
+
+template <typename T>
+passthrough_resampler<T>::passthrough_resampler(cubeb_stream * s,
+                                                cubeb_data_callback cb,
+                                                void * ptr,
+                                                uint32_t input_channels,
+                                                uint32_t sample_rate)
+    : processor(input_channels), stream(s), data_callback(cb), user_ptr(ptr),
+      sample_rate(sample_rate)
+{
+}
+
+template <typename T>
+long
+passthrough_resampler<T>::fill(void * input_buffer, long * input_frames_count,
+                               void * output_buffer, long output_frames)
+{
+  if (input_buffer) {
+    assert(input_frames_count);
+  }
+  assert((input_buffer && output_buffer) ||
+         (output_buffer && !input_buffer &&
+          (!input_frames_count || *input_frames_count == 0)) ||
+         (input_buffer && !output_buffer && output_frames == 0));
+
+  // When we have no pending input data and exactly as much input
+  // as output data, we don't need to copy it into the internal buffer
+  // and can directly forward it to the callback.
+  void * in_buf = input_buffer;
+  unsigned long pop_input_count = 0u;
+  if (input_buffer && !output_buffer) {
+    output_frames = *input_frames_count;
+  } else if (input_buffer) {
+    if (internal_input_buffer.length() != 0 ||
+        *input_frames_count < output_frames) {
+      // If we have pending input data left and have to first append the input
+      // so we can pass it as one pointer to the callback. Or this is a glitch.
+      // It can happen when system's performance is poor. Audible silence is
+      // being pushed at the end of the short input buffer. An improvement for
+      // the future is to resample to the output number of frames, when that
+      // happens.
+      internal_input_buffer.push(static_cast<T *>(input_buffer),
+                                 frames_to_samples(*input_frames_count));
+      if (internal_input_buffer.length() < frames_to_samples(output_frames)) {
+        // This is unxpected but it can happen when a glitch occurs. Fill the
+        // buffer with silence. First keep the actual number of input samples
+        // used without the silence.
+        pop_input_count = internal_input_buffer.length();
+        internal_input_buffer.push_silence(frames_to_samples(output_frames) -
+                                           internal_input_buffer.length());
+      } else {
+        pop_input_count = frames_to_samples(output_frames);
+      }
+      in_buf = internal_input_buffer.data();
+    } else if (*input_frames_count > output_frames) {
+      // In this case we have more input that we need output and
+      // fill the overflowing input into internal_input_buffer
+      // Since we have no other pending data, we can nonetheless
+      // pass the current input data directly to the callback
+      assert(pop_input_count == 0);
+      unsigned long samples_off = frames_to_samples(output_frames);
+      internal_input_buffer.push(
+          static_cast<T *>(input_buffer) + samples_off,
+          frames_to_samples(*input_frames_count - output_frames));
+    }
+  }
+
+  long rv =
+      data_callback(stream, user_ptr, in_buf, output_buffer, output_frames);
+
+  if (input_buffer) {
+    if (pop_input_count) {
+      internal_input_buffer.pop(nullptr, pop_input_count);
+      *input_frames_count = samples_to_frames(pop_input_count);
+    } else {
+      *input_frames_count = output_frames;
+    }
+    drop_audio_if_needed();
+  }
+
+  return rv;
+}
+
+// Explicit instantiation of template class.
+template class passthrough_resampler<float>;
+template class passthrough_resampler<short>;
+
+template <typename T, typename InputProcessor, typename OutputProcessor>
+cubeb_resampler_speex<T, InputProcessor, OutputProcessor>::
+    cubeb_resampler_speex(InputProcessor * input_processor,
+                          OutputProcessor * output_processor, cubeb_stream * s,
+                          cubeb_data_callback cb, void * ptr)
+    : input_processor(input_processor), output_processor(output_processor),
+      stream(s), data_callback(cb), user_ptr(ptr)
+{
+  if (input_processor && output_processor) {
+    fill_internal = &cubeb_resampler_speex::fill_internal_duplex;
+  } else if (input_processor) {
+    fill_internal = &cubeb_resampler_speex::fill_internal_input;
+  } else if (output_processor) {
+    fill_internal = &cubeb_resampler_speex::fill_internal_output;
+  }
+}
+
+template <typename T, typename InputProcessor, typename OutputProcessor>
+cubeb_resampler_speex<T, InputProcessor,
+                      OutputProcessor>::~cubeb_resampler_speex()
+{
+}
+
+template <typename T, typename InputProcessor, typename OutputProcessor>
+long
+cubeb_resampler_speex<T, InputProcessor, OutputProcessor>::fill(
+    void * input_buffer, long * input_frames_count, void * output_buffer,
+    long output_frames_needed)
+{
+  /* Input and output buffers, typed */
+  T * in_buffer = reinterpret_cast<T *>(input_buffer);
+  T * out_buffer = reinterpret_cast<T *>(output_buffer);
+  return (this->*fill_internal)(in_buffer, input_frames_count, out_buffer,
+                                output_frames_needed);
+}
+
+template <typename T, typename InputProcessor, typename OutputProcessor>
+long
+cubeb_resampler_speex<T, InputProcessor, OutputProcessor>::fill_internal_output(
+    T * input_buffer, long * input_frames_count, T * output_buffer,
+    long output_frames_needed)
+{
+  assert(!input_buffer && (!input_frames_count || *input_frames_count == 0) &&
+         output_buffer && output_frames_needed);
+
+  if (!draining) {
+    long got = 0;
+    T * out_unprocessed = nullptr;
+    long output_frames_before_processing = 0;
+
+    /* fill directly the input buffer of the output processor to save a copy */
+    output_frames_before_processing =
+        output_processor->input_needed_for_output(output_frames_needed);
+
+    out_unprocessed =
+        output_processor->input_buffer(output_frames_before_processing);
+
+    got = data_callback(stream, user_ptr, nullptr, out_unprocessed,
+                        output_frames_before_processing);
+
+    if (got < output_frames_before_processing) {
+      draining = true;
+
+      if (got < 0) {
+        return got;
+      }
+    }
+
+    output_processor->written(got);
+  }
+
+  /* Process the output. If not enough frames have been returned from the
+   * callback, drain the processors. */
+  return output_processor->output(output_buffer, output_frames_needed);
+}
+
+template <typename T, typename InputProcessor, typename OutputProcessor>
+long
+cubeb_resampler_speex<T, InputProcessor, OutputProcessor>::fill_internal_input(
+    T * input_buffer, long * input_frames_count, T * output_buffer,
+    long /*output_frames_needed*/)
+{
+  assert(input_buffer && input_frames_count && *input_frames_count &&
+         !output_buffer);
+
+  /* The input data, after eventual resampling. This is passed to the callback.
+   */
+  T * resampled_input = nullptr;
+  uint32_t resampled_frame_count =
+      input_processor->output_for_input(*input_frames_count);
+
+  /* process the input, and present exactly `output_frames_needed` in the
+   * callback. */
+  input_processor->input(input_buffer, *input_frames_count);
+
+  /* resampled_frame_count == 0 happens if the resampler
+   * doesn't have enough input frames buffered to produce 1 resampled frame. */
+  if (resampled_frame_count == 0) {
+    return *input_frames_count;
+  }
+
+  size_t frames_resampled = 0;
+  resampled_input =
+      input_processor->output(resampled_frame_count, &frames_resampled);
+  *input_frames_count = frames_resampled;
+
+  long got = data_callback(stream, user_ptr, resampled_input, nullptr,
+                           resampled_frame_count);
+
+  /* Return the number of initial input frames or part of it.
+   * Since output_frames_needed == 0 in input scenario, the only
+   * available number outside resampler is the initial number of frames. */
+  return (*input_frames_count) * (got / resampled_frame_count);
+}
+
+template <typename T, typename InputProcessor, typename OutputProcessor>
+long
+cubeb_resampler_speex<T, InputProcessor, OutputProcessor>::fill_internal_duplex(
+    T * in_buffer, long * input_frames_count, T * out_buffer,
+    long output_frames_needed)
+{
+  if (draining) {
+    // discard input and drain any signal remaining in the resampler.
+    return output_processor->output(out_buffer, output_frames_needed);
+  }
+
+  /* The input data, after eventual resampling. This is passed to the callback.
+   */
+  T * resampled_input = nullptr;
+  /* The output buffer passed down in the callback, that might be resampled. */
+  T * out_unprocessed = nullptr;
+  long output_frames_before_processing = 0;
+  /* The number of frames returned from the callback. */
+  long got = 0;
+
+  /* We need to determine how much frames to present to the consumer.
+   * - If we have a two way stream, but we're only resampling input, we resample
+   * the input to the number of output frames.
+   * - If we have a two way stream, but we're only resampling the output, we
+   * resize the input buffer of the output resampler to the number of input
+   * frames, and we resample it afterwards.
+   * - If we resample both ways, we resample the input to the number of frames
+   * we would need to pass down to the consumer (before resampling the output),
+   * get the output data, and resample it to the number of frames needed by the
+   * caller. */
+
+  output_frames_before_processing =
+      output_processor->input_needed_for_output(output_frames_needed);
+  /* fill directly the input buffer of the output processor to save a copy */
+  out_unprocessed =
+      output_processor->input_buffer(output_frames_before_processing);
+
+  if (in_buffer) {
+    /* process the input, and present exactly `output_frames_needed` in the
+     * callback. */
+    input_processor->input(in_buffer, *input_frames_count);
+
+    size_t frames_resampled = 0;
+    resampled_input = input_processor->output(output_frames_before_processing,
+                                              &frames_resampled);
+    *input_frames_count = frames_resampled;
+  } else {
+    resampled_input = nullptr;
+  }
+
+  got = data_callback(stream, user_ptr, resampled_input, out_unprocessed,
+                      output_frames_before_processing);
+
+  if (got < output_frames_before_processing) {
+    draining = true;
+
+    if (got < 0) {
+      return got;
+    }
+  }
+
+  output_processor->written(got);
+
+  input_processor->drop_audio_if_needed();
+
+  /* Process the output. If not enough frames have been returned from the
+   * callback, drain the processors. */
+  got = output_processor->output(out_buffer, output_frames_needed);
+
+  output_processor->drop_audio_if_needed();
+
+  return got;
+}
+
+/* Resampler C API */
+
+cubeb_resampler *
+cubeb_resampler_create(cubeb_stream * stream,
+                       cubeb_stream_params * input_params,
+                       cubeb_stream_params * output_params,
+                       unsigned int target_rate, cubeb_data_callback callback,
+                       void * user_ptr, cubeb_resampler_quality quality,
+                       cubeb_resampler_reclock reclock)
+{
+  cubeb_sample_format format;
+
+  assert(input_params || output_params);
+
+  if (input_params) {
+    format = input_params->format;
+  } else {
+    format = output_params->format;
+  }
+
+  switch (format) {
+  case CUBEB_SAMPLE_S16NE:
+    return cubeb_resampler_create_internal<short>(
+        stream, input_params, output_params, target_rate, callback, user_ptr,
+        quality, reclock);
+  case CUBEB_SAMPLE_FLOAT32NE:
+    return cubeb_resampler_create_internal<float>(
+        stream, input_params, output_params, target_rate, callback, user_ptr,
+        quality, reclock);
+  default:
+    assert(false);
+    return nullptr;
+  }
+}
+
+long
+cubeb_resampler_fill(cubeb_resampler * resampler, void * input_buffer,
+                     long * input_frames_count, void * output_buffer,
+                     long output_frames_needed)
+{
+  return resampler->fill(input_buffer, input_frames_count, output_buffer,
+                         output_frames_needed);
+}
+
+void
+cubeb_resampler_destroy(cubeb_resampler * resampler)
+{
+  delete resampler;
+}
+
+long
+cubeb_resampler_latency(cubeb_resampler * resampler)
+{
+  return resampler->latency();
+}