chmap_sel: add multichannel fallback heuristic

Instead of just failing during channel map selection, try to select a close
layout that makes most sense and upmix/downmix to that instead of failing AO
initialization. The heuristic is rather simple, and uses the following steps:

1) If mono is required always prefer stereo to a multichannel upmix.
2) Search for an upmix that is an exact superset of the required channel map.
3) Search for a downmix that is the exact subset of the required channel map.
4) Search for either an upmix or downmix that is the closest (minimum difference
   of channels) to the required channel map.

1 files changed, 25 insertions, 4 deletions

diff --git a/wscript_build.py b/wscript_build.py
index 58925444cf..6c6b6bd3ae 100644
--- a/wscript_build.py
+++ b/wscript_build.py
@@ -33,6 +33,10 @@ def _build_pdf(ctx):
 
     _add_rst_manual_dependencies(ctx)
 
+def _all_includes(ctx):
+    return [ctx.bldnode.abspath(), ctx.srcnode.abspath()] + \
+            ctx.dependencies_includes()
+
 def build(ctx):
     ctx.load('waf_customizations')
     ctx.load('generators.sources')
@@ -415,13 +419,21 @@ def build(ctx):
                 ctx.path.find_node('osdep/mpv.rc'),
                 ctx.path.find_node(node))
 
+    if ctx.dependency_satisfied('cplayer') or ctx.dependency_satisfied('test'):
+        ctx(
+            target       = "objects",
+            source       = ctx.filtered_sources(sources),
+            use          = ctx.dependencies_use(),
+            includes     = _all_includes(ctx),
+            features     = "c",
+        )
+
     if ctx.dependency_satisfied('cplayer'):
         ctx(
             target       = "mpv",
-            source       = ctx.filtered_sources(sources) + ["player/main_fn.c"],
-            use          = ctx.dependencies_use(),
-            includes     = [ctx.bldnode.abspath(), ctx.srcnode.abspath()] + \
-                           ctx.dependencies_includes(),
+            source       = "player/main_fn.c",
+            use          = 'objects',
+            includes     = _all_includes(ctx),
             features     = "c cprogram",
             install_path = ctx.env.BINDIR
         )
@@ -443,6 +455,15 @@ def build(ctx):
             wrapctx.env.CFLAGS = wrapflags
             wrapctx.env.LAST_LINKFLAGS = wrapflags
 
+    if ctx.dependency_satisfied('test'):
+        for test in ctx.path.ant_glob("test/*.c"):
+            ctx(
+                target   = os.path.splitext(test.srcpath())[0],
+                source   = test.srcpath(),
+                use      = "objects",
+                includes = _all_includes(ctx),
+                features = "c cprogram",
+            )
 
     build_shared = ctx.dependency_satisfied('libmpv-shared')
     build_static = ctx.dependency_satisfied('libmpv-static')