Added APIs for audio preprocessing

Added APIs to control pre processes applied on captured audio.
Those APIs are still hidden until reviewed by API council.

Three types of standard pre processes are supported:
- Automatic Gain Control (AGC) by AutomaticGainControl class
- Acoustic Echo Cancellation (AEC) by AcousticEchoCanceler class
- Noise Suppression (NS) by NoiseSuppressor class

A method is added to AudioEffect class to query audio pre processings
applied by default by the platform on a given AudioRecord session ID.

Change-Id: I0b9fceeb8c704dd06319c3b52b85c96fe871d51d

6 files changed, 132 insertions, 0 deletions

diff --git a/include/media/AudioEffect.h b/include/media/AudioEffect.h
index 496b23e..1417416 100644
--- a/include/media/AudioEffect.h
+++ b/include/media/AudioEffect.h
@@ -21,6 +21,7 @@
 #include <sys/types.h>
 
 #include <media/IAudioFlinger.h>
+#include <media/IAudioPolicyService.h>
 #include <media/IEffect.h>
 #include <media/IEffectClient.h>
 #include <hardware/audio_effect.h>
@@ -111,6 +112,36 @@ public:
 
 
     /*
+     * Returns a list of descriptors corresponding to the pre processings enabled by default
+     * on an AudioRecord with the supplied audio session ID.
+     *
+     * Parameters:
+     *      audioSession:  audio session ID.
+     *      descriptors: address where the effect descriptors should be returned.
+     *      count: as input, the maximum number of descriptor than should be returned
+     *             as output, the number of descriptor returned if status is NO_ERROR or the actual
+     *             number of enabled pre processings if status is NO_MEMORY
+     *
+     * Returned status (from utils/Errors.h) can be:
+     *      NO_ERROR        successful operation.
+     *      NO_MEMORY       the number of descriptor to return is more than the maximum number
+     *                      indicated by count.
+     *      PERMISSION_DENIED could not get AudioFlinger interface
+     *      NO_INIT         effect library failed to initialize
+     *      BAD_VALUE       invalid audio session or descriptor pointers
+     *
+     * Returned value
+     *   *descriptor updated with descriptors of pre processings enabled by default
+     *   *count      number of descriptors returned if returned status is N_ERROR.
+     *               total number of pre processing enabled by default if returned status is
+     *               NO_MEMORY. This happens if the count passed as input is less than the number
+     *               of descriptors to return
+     */
+    static status_t queryDefaultPreProcessing(int audioSession,
+                                              effect_descriptor_t *descriptors,
+                                              uint32_t *count);
+
+    /*
      * Events used by callback function (effect_callback_t).
      */
     enum event_type {
diff --git a/include/media/IAudioPolicyService.h b/include/media/IAudioPolicyService.h
index 86b9f85..ed265e1 100644
--- a/include/media/IAudioPolicyService.h
+++ b/include/media/IAudioPolicyService.h
@@ -85,6 +85,9 @@ public:
                                     int id) = 0;
     virtual status_t unregisterEffect(int id) = 0;
     virtual bool     isStreamActive(int stream, uint32_t inPastMs = 0) const = 0;
+    virtual status_t queryDefaultPreProcessing(int audioSession,
+                                              effect_descriptor_t *descriptors,
+                                              uint32_t *count) = 0;
 };
 
 
diff --git a/media/libmedia/AudioEffect.cpp b/media/libmedia/AudioEffect.cpp
index 3919551..0633744 100644
--- a/media/libmedia/AudioEffect.cpp
+++ b/media/libmedia/AudioEffect.cpp
@@ -419,6 +419,15 @@ status_t AudioEffect::getEffectDescriptor(effect_uuid_t *uuid, effect_descriptor
     return af->getEffectDescriptor(uuid, descriptor);
 }
 
+
+status_t AudioEffect::queryDefaultPreProcessing(int audioSession,
+                                          effect_descriptor_t *descriptors,
+                                          uint32_t *count)
+{
+    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
+    if (aps == 0) return PERMISSION_DENIED;
+    return aps->queryDefaultPreProcessing(audioSession, descriptors, count);
+}
 // -------------------------------------------------------------------------
 
 status_t AudioEffect::stringToGuid(const char *str, effect_uuid_t *guid)
diff --git a/media/libmedia/IAudioPolicyService.cpp b/media/libmedia/IAudioPolicyService.cpp
index 49d410f..15f4be0 100644
--- a/media/libmedia/IAudioPolicyService.cpp
+++ b/media/libmedia/IAudioPolicyService.cpp
@@ -53,6 +53,7 @@ enum {
     UNREGISTER_EFFECT,
     IS_STREAM_ACTIVE,
     GET_DEVICES_FOR_STREAM,
+    QUERY_DEFAULT_PRE_PROCESSING
 };
 
 class BpAudioPolicyService : public BpInterface<IAudioPolicyService>
@@ -321,6 +322,31 @@ public:
         remote()->transact(IS_STREAM_ACTIVE, data, &reply);
         return reply.readInt32();
     }
+
+    virtual status_t queryDefaultPreProcessing(int audioSession,
+                                               effect_descriptor_t *descriptors,
+                                               uint32_t *count)
+    {
+        if (descriptors == NULL || count == NULL) {
+            return BAD_VALUE;
+        }
+        Parcel data, reply;
+        data.writeInterfaceToken(IAudioPolicyService::getInterfaceDescriptor());
+        data.writeInt32(audioSession);
+        data.writeInt32(*count);
+        status_t status = remote()->transact(QUERY_DEFAULT_PRE_PROCESSING, data, &reply);
+        if (status != NO_ERROR) {
+            return status;
+        }
+        status = static_cast <status_t> (reply.readInt32());
+        uint32_t retCount = reply.readInt32();
+        if (retCount != 0) {
+            uint32_t numDesc = (retCount < *count) ? retCount : *count;
+            reply.read(descriptors, sizeof(effect_descriptor_t) * numDesc);
+        }
+        *count = retCount;
+        return status;
+    }
 };
 
 IMPLEMENT_META_INTERFACE(AudioPolicyService, "android.media.IAudioPolicyService");
@@ -559,6 +585,29 @@ status_t BnAudioPolicyService::onTransact(
             return NO_ERROR;
         } break;
 
+        case QUERY_DEFAULT_PRE_PROCESSING: {
+            CHECK_INTERFACE(IAudioPolicyService, data, reply);
+            int audioSession = data.readInt32();
+            uint32_t count = data.readInt32();
+            uint32_t retCount = count;
+            effect_descriptor_t *descriptors =
+                    (effect_descriptor_t *)new char[count * sizeof(effect_descriptor_t)];
+            status_t status = queryDefaultPreProcessing(audioSession, descriptors, &retCount);
+            reply->writeInt32(status);
+            if (status != NO_ERROR && status != NO_MEMORY) {
+                retCount = 0;
+            }
+            reply->writeInt32(retCount);
+            if (retCount) {
+                if (retCount < count) {
+                    count = retCount;
+                }
+                reply->write(descriptors, sizeof(effect_descriptor_t) * count);
+            }
+            delete[] descriptors;
+            return status;
+        }
+
         default:
             return BBinder::onTransact(code, data, reply, flags);
     }
diff --git a/services/audioflinger/AudioPolicyService.cpp b/services/audioflinger/AudioPolicyService.cpp
index dd1e153..6d06d83 100644
--- a/services/audioflinger/AudioPolicyService.cpp
+++ b/services/audioflinger/AudioPolicyService.cpp
@@ -497,6 +497,43 @@ bool AudioPolicyService::isStreamActive(int stream, uint32_t inPastMs) const
     return mpAudioPolicy->is_stream_active(mpAudioPolicy, stream, inPastMs);
 }
 
+status_t AudioPolicyService::queryDefaultPreProcessing(int audioSession,
+                                                       effect_descriptor_t *descriptors,
+                                                       uint32_t *count)
+{
+
+    if (mpAudioPolicy == NULL) {
+        *count = 0;
+        return NO_INIT;
+    }
+    Mutex::Autolock _l(mLock);
+    status_t status = NO_ERROR;
+
+    size_t index;
+    for (index = 0; index < mInputs.size(); index++) {
+        if (mInputs.valueAt(index)->mSessionId == audioSession) {
+            break;
+        }
+    }
+    if (index == mInputs.size()) {
+        *count = 0;
+        return BAD_VALUE;
+    }
+    Vector< sp<AudioEffect> > effects = mInputs.valueAt(index)->mEffects;
+
+    for (size_t i = 0; i < effects.size(); i++) {
+        effect_descriptor_t desc = effects[i]->descriptor();
+        if (i < *count) {
+            memcpy(descriptors + i, &desc, sizeof(effect_descriptor_t));
+        }
+    }
+    if (effects.size() > *count) {
+        status = NO_MEMORY;
+    }
+    *count = effects.size();
+    return status;
+}
+
 void AudioPolicyService::binderDied(const wp<IBinder>& who) {
     LOGW("binderDied() %p, tid %d, calling tid %d", who.unsafe_get(), gettid(),
             IPCThreadState::self()->getCallingPid());
diff --git a/services/audioflinger/AudioPolicyService.h b/services/audioflinger/AudioPolicyService.h
index 62ad29e..834b794 100644
--- a/services/audioflinger/AudioPolicyService.h
+++ b/services/audioflinger/AudioPolicyService.h
@@ -104,6 +104,9 @@ public:
     virtual status_t unregisterEffect(int id);
     virtual bool isStreamActive(int stream, uint32_t inPastMs = 0) const;
 
+    virtual status_t queryDefaultPreProcessing(int audioSession,
+                                              effect_descriptor_t *descriptors,
+                                              uint32_t *count);
     virtual     status_t    onTransact(
                                 uint32_t code,
                                 const Parcel& data,