stagefright: Support audio in slow motion

We need to query AVUtil for slow motion recording to
support audio in slow motion recording instead of using
mCaptureFps and mCaptureFpsEnable, since qcom camera1 HAL
don't call setCaptureRate for slow motion recording.

CYNGNOS-2196

Change-Id: I7b75ab44499ed13cb1e4e6f527103ec0f09ffcc8

media/libmediaplayerservice/StagefrightRecorder.cpp

@@ -963,6 +963,30 @@ sp<MediaSource> StagefrightRecorder::createAudioSource() {
         }
     }
 
+    // If using QCOM extension (Camera 1 HAL) for slow motion recording
+    // mCaptureFpsEnable and mCaptureFps will not be set via setCaptureRate
+    // We need to query from AVUtil, in order to support slow motion audio recording
+    if (mVideoSourceNode != NULL) {
+        int hfrRatio =  AVUtils::get()->HFRUtils().getHFRRatio(mVideoSourceNode->getFormat());
+        if (hfrRatio != 1) {
+            // Upscale the sample rate for slow motion recording.
+            // Fail audio source creation if source sample rate is too high, as it could
+            // cause out-of-memory due to large input buffer size. And audio recording
+            // probably doesn't make sense in the scenario, since the slow-down factor
+            // is probably huge (eg. mSampleRate=48K, hfrRatio=240, mFrameRate=1).
+            const static int32_t SAMPLE_RATE_HZ_MAX = 192000;
+            sourceSampleRate =
+                    (mSampleRate * hfrRatio + mFrameRate / 2) / mFrameRate;
+            if (sourceSampleRate < mSampleRate || sourceSampleRate > SAMPLE_RATE_HZ_MAX) {
+                ALOGE("source sample rate out of range! "
+                        "(mSampleRate %d, hfrRatio %d, mFrameRate %d",
+                        mSampleRate, hfrRatio, mFrameRate);
+                return NULL;
+            }
+        }
+    }
+
+
     sp<AudioSource> audioSource = AVFactory::get()->createAudioSource(
         mAudioSource,
         mOpPackageName,