Allow buffering some input when using a noop resampler, and rename it because it's not strictly no-op anymore (#223)

* Allow buffering some input when using a noop resampler, and rename it because it's not strictly no-op anymore.

* Fix build on windows

* fix build harder, and check that the buffers are correct

* Address achronop's comments.

* Silence a scan-build error.

This is caused by the fact that gtest assertions are not fatal, so scan-build
things the pointer is checked against null, and that we dereference it later.

1 files changed, 30 insertions, 13 deletions

diff --git a/src/cubeb_resampler.cpp b/src/cubeb_resampler.cpp
index 91fa35f..12de294 100644
--- a/src/cubeb_resampler.cpp
+++ b/src/cubeb_resampler.cpp
@@ -35,29 +35,46 @@ to_speex_quality(cubeb_resampler_quality q)
   }
 }
 
-long noop_resampler::fill(void * input_buffer, long * input_frames_count,
-                          void * output_buffer, long output_frames)
+template<typename T>
+passthrough_resampler<T>::passthrough_resampler(cubeb_stream * s,
+                                                cubeb_data_callback cb,
+                                                void * ptr,
+                                                uint32_t input_channels)
+  : processor(input_channels)
+  , stream(s)
+  , data_callback(cb)
+  , user_ptr(ptr)
+{
+}
+
+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 &&
-         *input_frames_count >= output_frames) ||
-         (!input_buffer && (!input_frames_count || *input_frames_count == 0)) ||
-         (!output_buffer && output_frames == 0));
+         *input_frames_count + static_cast<int>(samples_to_frames(internal_input_buffer.length())) >= output_frames) ||
+         (output_buffer && !input_buffer && (!input_frames_count || *input_frames_count == 0)) ||
+         (input_buffer && !output_buffer && output_frames == 0));
 
-  if (output_buffer == nullptr) {
-    assert(input_buffer);
-    output_frames = *input_frames_count;
+  if (input_buffer) {
+    if (!output_buffer) {
+      output_frames = *input_frames_count;
+    }
+    internal_input_buffer.push(static_cast<T*>(input_buffer),
+                               frames_to_samples(*input_frames_count));
   }
 
-  if (input_buffer && *input_frames_count != output_frames) {
-    assert(*input_frames_count > output_frames);
-    *input_frames_count = output_frames;
+  long rv = data_callback(stream, user_ptr, internal_input_buffer.data(),
+                          output_buffer, output_frames);
+
+  if (input_buffer) {
+    internal_input_buffer.pop(nullptr, frames_to_samples(output_frames));
   }
 
-  return data_callback(stream, user_ptr,
-                       input_buffer, output_buffer, output_frames);
+  return rv;
 }
 
 template<typename T, typename InputProcessor, typename OutputProcessor>