Multi-channels support for windows/mac/linux (#426)

* Add QUAD and QUAD_LFE layouts.

* Remove dual mono layout.

It makes no sense to have a case for those as the data structure
used (a bitmask) do not allow to represent this channel layout (a
channel can only be present once). As such it was a non-functional
layout

* Fix up cubeb_pulse compilation using C++ keyword.

* Remove the concept of preferred layout.

Channel layout is derived by the content being played. The concept of
preferred layout is meaningless. Either we have a layout defined, or
we don't. There's no in-between.

So we remove it.

* Remove CHANNEL_MONO concept.

* Add cubeb_sample_size convenience method.

* Rework cubeb_mixer.

This completely replace the existing remixer which had serious limitations:
1- Had no memory bound checks
2- Could only downmix 5.1 and 7.1 to stereo.

This mixer allows to convert from any sane layout to any other and work directly on interleaved samples.

This cubeb_mixer doesn't have an API compatible with the previous one.

This commit is non-fonctional, and was split for ease of review.

* Fix remixing on mac, windows and pulse backend.

* Make cubeb_mixer creation infallible.

Rather than ignore nonsensical layouts, we attempt to play it according to the stream channels count instead. The audio data will be played as-is, dropping the extra channels or inserting silence where needed.

* User proper sample size when calculating offsets.

Should the user data be of a different type to what the AudioUnit output is set to, we would have written outside the end of our allocated buffer.

* Fix input mixing and clarify frames vs samples terminology

* If a layout is unknown or invalid, always treat it as plain stereo or mono.

1 files changed, 0 insertions, 6 deletions

diff --git a/test/test_sanity.cpp b/test/test_sanity.cpp
index d3546d6..d33666f 100644
--- a/test/test_sanity.cpp
+++ b/test/test_sanity.cpp
@@ -114,7 +114,6 @@ TEST(cubeb, context_variables)
   int r;
   cubeb * ctx;
   uint32_t value;
-  cubeb_channel_layout layout;
   cubeb_stream_params params;
 
   r = common_init(&ctx, "test_context_variables");
@@ -139,11 +138,6 @@ TEST(cubeb, context_variables)
     ASSERT_TRUE(value > 0);
   }
 
-  r = cubeb_get_preferred_channel_layout(ctx, &layout);
-  ASSERT_TRUE(r == CUBEB_ERROR_NOT_SUPPORTED ||
-              (r == CUBEB_OK && layout != CUBEB_LAYOUT_UNDEFINED) ||
-              (r == CUBEB_ERROR && layout == CUBEB_LAYOUT_UNDEFINED));
-
   cubeb_destroy(ctx);
 }