Add a simple, safe gain PostProcessor.

chromecast/media/cma/backend/alsa/BUILD.gn

 # Copyright 2015 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.
 
 import("//build/buildflag_header.gni")
 import("//build/config/chromecast_build.gni")
 import("//chromecast/chromecast.gni")
 import("//media/media_options.gni")
 import("//testing/test.gni")
 
 declare_args() {
   # Set true to use raw timestamps on non-desktop cast build.
   # ALSA version equal or later than 1.0.29 support this function.
   use_alsa_monotonic_raw_tstamps = !is_cast_desktop_build
 }
 
 # Alsa must be used for these targets to build.
 assert(use_alsa)
 
 shared_library("libcast_media_1.0_audio") {
   sources = [
     "cast_media_shlib.cc",
     "media_codec_support_cast_audio.cc",
     "post_processing_pipeline_impl.cc",
     "post_processing_pipeline_impl.h",
   ]
 
   deps = [
     ":alsa_cma_backend",
+    ":post_processor_factory",
     "//base",
     "//chromecast/base",
     "//chromecast/public",
     "//chromecast/public/media",
     "//media",
   ]
 }
 
 source_set("alsa_cma_backend") {
   sources = [
@@ skipping 17 matching lines @@
     "stream_mixer_alsa_input_impl.cc",
     "stream_mixer_alsa_input_impl.h",
     "volume_control.cc",
   ]
 
   libs = [ "asound" ]
 
   deps = [
     ":alsa_features",
     ":slew_volume",
+    ":volume_map",
     "//base",
     "//chromecast/base",
     "//chromecast/media/base",
     "//chromecast/media/cma/backend:null",
     "//chromecast/media/cma/base",
     "//chromecast/media/cma/decoder",
     "//chromecast/public/media",
     "//media",
     "//media:shared_memory_support",
   ]
 }
 
+source_set("volume_map") {
+  sources = [
+    "cast_audio_json.cc",
+    "cast_audio_json.h",
+    "volume_map.cc",
+    "volume_map.h",
+  ]
+  deps = [
+    "//base",
+    "//chromecast/base",
+  ]
+}
+
 source_set("slew_volume") {
   sources = [
     "slew_volume.cc",
     "slew_volume.h",
   ]
   deps = [
     "//base",
     "//media:shared_memory_support",
   ]
 }
 
 alsa_owns_volume = !enable_assistant
 
 buildflag_header("alsa_features") {
   header = "alsa_features.h"
 
   flags = [
     "ALSA_MONOTONIC_RAW_TSTAMPS=$use_alsa_monotonic_raw_tstamps",
     "ALSA_OWNS_VOLUME=$alsa_owns_volume",
   ]
 }
 
 test("cast_alsa_cma_backend_unittests") {
   sources = [
     "filter_group_unittest.cc",
+    "post_processors/governor_unittest.cc",
+    "post_processors/saturated_gain_unittest.cc",
+    "slew_volume_unittests.cc",
     "stream_mixer_alsa_unittest.cc",
   ]
 
   deps = [
+    ":governor",
+    ":libcast_governor_1.0",
+    ":libcast_saturated_gain_1.0",
+    ":post_processor_factory",
+    ":post_processor_test_support",
+    ":slew_volume",
     ":test_support",
     "//base",
     "//base/test:run_all_unittests",
     "//chromecast/media",
+    "//chromecast/public",
     "//media",
     "//media:shared_memory_support",
     "//testing/gmock",
     "//testing/gtest",
   ]
 }
 
 source_set("test_support") {
   testonly = true
 
   sources = [
     "mock_alsa_wrapper.cc",
     "mock_alsa_wrapper.h",
   ]
 
   public_deps = [
     ":alsa_cma_backend",
   ]
 
   deps = [
     "//base",
     "//media",
     "//testing/gmock",
   ]
 }
 
-test("slew_volume_unittests") {
+# This is separate from ":governor" because the associated unittest needs
+# to create a Governor directly (to use test functions).
+shared_library("libcast_governor_1.0") {
   sources = [
-    "slew_volume_unittests.cc",
-  ]
-  deps = [
-    ":slew_volume",
-    "//base",
-    "//base/test:run_all_unittests",
-    "//media",
-    "//testing/gtest",
-  ]
-}
-
-shared_library("libcast_governor_1.0") {
-  deps = [
-    ":governor",
-  ]
-}
-
-test("libcast_governor_unittests") {
-  sources = [
-    "post_processors/governor_unittest.cc",
+    "post_processors/governor_create.cc",
   ]
   deps = [
     ":governor",
-    ":post_processor_test_support",
-    "//base",
-    "//base/test:run_all_unittests",
-    "//media",
-    "//testing/gtest",
+    "//chromecast/public/media",
   ]
 }
 
 source_set("governor") {
   sources = [
     "post_processors/governor.cc",
     "post_processors/governor.h",
   ]
   deps = [
     ":slew_volume",
     "//base",
     "//chromecast/base",
     "//chromecast/public/media",
   ]
   public_configs = [ "//chromecast/public:public_config" ]
 }
 
+shared_library("libcast_saturated_gain_1.0") {
+  sources = [
+    "post_processors/saturated_gain.cc",
+    "post_processors/saturated_gain.h",
+  ]
+  deps = [
+    ":slew_volume",
+    ":volume_map",
+    "//base",
+    "//chromecast/base",
+    "//chromecast/public/media",
+  ]
+}
+
 source_set("post_processor_test_support") {
   testonly = true
   sources = [
     "post_processors/post_processor_unittest.cc",
     "post_processors/post_processor_unittest.h",
   ]
   deps = [
     "//base",
     "//chromecast/public/media",
     "//testing/gtest",
   ]
 }
+
+source_set("post_processor_factory") {
+  sources = [
+    "post_processor_factory.cc",
+    "post_processor_factory.h",
+  ]
+  deps = [
+    "//base",
+    "//chromecast/public/media",
+  ]
+}