Move the aec_rdft* files to a more proper place beneath APM and make them thread-safe.

webrtc/modules/audio_processing/BUILD.gn

 # Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 import("//build/config/arm.gni")
 import("//third_party/protobuf/proto_library.gni")
 import("../../build/webrtc.gni")
 
 declare_args() {
   # Disables the usual mode where we trust the reported system delay
   # values the AEC receives. The corresponding define is set appropriately
   # in the code, but it can be force-enabled here for testing.
   aec_untrusted_delay_for_testing = false
 }
 
 rtc_static_library("audio_processing") {
   sources = [
     "aec/aec_core.cc",
     "aec/aec_core.h",
     "aec/aec_core_optimized_methods.h",
-    "aec/aec_rdft.cc",
-    "aec/aec_rdft.h",
     "aec/aec_resampler.cc",
     "aec/aec_resampler.h",
     "aec/echo_cancellation.cc",
     "aec/echo_cancellation.h",
     "aecm/aecm_core.cc",
     "aecm/aecm_core.h",
     "aecm/echo_control_mobile.cc",
     "aecm/echo_control_mobile.h",
     "agc/agc.cc",
     "agc/agc.h",
@@ skipping 85 matching lines @@
     "transient/wpd_tree.h",
     "typing_detection.cc",
     "typing_detection.h",
     "utility/block_mean_calculator.cc",
     "utility/block_mean_calculator.h",
     "utility/delay_estimator.cc",
     "utility/delay_estimator.h",
     "utility/delay_estimator_internal.h",
     "utility/delay_estimator_wrapper.cc",
     "utility/delay_estimator_wrapper.h",
+    "utility/ooura_fft.cc",
+    "utility/ooura_fft.h",
+    "utility/ooura_fft_tables_common.h",
     "vad/common.h",
     "vad/gmm.cc",
     "vad/gmm.h",
     "vad/noise_gmm_tables.h",
     "vad/pitch_based_vad.cc",
     "vad/pitch_based_vad.h",
     "vad/pitch_internal.cc",
     "vad/pitch_internal.h",
     "vad/pole_zero_filter.cc",
     "vad/pole_zero_filter.h",
@@ skipping 76 matching lines @@
 
   if (rtc_build_with_neon) {
     deps += [ ":audio_processing_neon" ]
   }
 
   if (current_cpu == "mipsel") {
     sources += [ "aecm/aecm_core_mips.cc" ]
     if (mips_float_abi == "hard") {
       sources += [
         "aec/aec_core_mips.cc",
-        "aec/aec_rdft_mips.cc",
+        "utility/ooura_fft_mips.cc",
       ]
     }
   } else {
     sources += [ "aecm/aecm_core_c.cc" ]
   }
 
   # TODO(jschuh): Bug 1348: fix this warning.
   configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
 
   deps += [
@@ skipping 10 matching lines @@
     ]
 
     proto_out_dir = "webrtc/modules/audio_processing"
   }
 }
 
 if (current_cpu == "x86" || current_cpu == "x64") {
   rtc_static_library("audio_processing_sse2") {
     sources = [
       "aec/aec_core_sse2.cc",
-      "aec/aec_rdft_sse2.cc",
+      "utility/ooura_fft_sse2.cc",
+      "utility/ooura_fft_tables_neon_sse2.h",
     ]
 
     if (is_posix) {
       cflags = [ "-msse2" ]
     }
 
     if (apm_debug_dump) {
       defines = [ "WEBRTC_APM_DEBUG_DUMP=1" ]
     } else {
       defines = [ "WEBRTC_APM_DEBUG_DUMP=0" ]
     }
   }
 }
 
 if (rtc_build_with_neon) {
   rtc_static_library("audio_processing_neon") {
     sources = [
       "aec/aec_core_neon.cc",
-      "aec/aec_rdft_neon.cc",
       "aecm/aecm_core_neon.cc",
       "ns/nsx_core_neon.c",
+      "utility/ooura_fft_neon.cc",
+      "utility/ooura_fft_tables_neon_sse2.h",
     ]
 
     if (current_cpu != "arm64") {
       # Enable compilation for the NEON instruction set. This is needed
       # since //build/config/arm.gni only enables NEON for iOS, not Android.
       # This provides the same functionality as webrtc/build/arm_neon.gypi.
       suppressed_configs += [ "//build/config/compiler:compiler_arm_fpu" ]
       cflags = [ "-mfpu=neon" ]
     }
 
@@ skipping 167 matching lines @@
         "test/protobuf_utils.cc",
         "test/protobuf_utils.h",
       ]
 
       deps = [
         ":audioproc_debug_proto",
       ]
     }
   }
 }