Fix detection of encode complete in test

The -d argument was thought to delete the existing Android
logs. However, this was not the case. As a result, the
python tests were concluding that the file being encoded
finished near immediately, and concluded that the incomplete
file existed so the test passed.

This change uses the -t argument of logcat to gather all logs
since a given time, and will pass in the time the test started.
This way, the python test will properly wait until the encoding
has completed before pulling the file. Further, it will not
conclude that encoding was successful if it never even started.

Author: brarcher

app/src/test/shell/test.py

@@ -5,6 +5,7 @@
 import json
 import collections
 import time
+from datetime import datetime
 
 ASSETS = os.path.dirname(os.path.realpath(__file__)) + os.sep + "assets"
 
@@ -18,11 +19,8 @@ def adb(args):
     if result != 0:
         raise Exception("adb failed with " + str(result) + ": " + str(cmd))
 
-def clearLogcat():
-    adb(["shell", "logcat", "-c"])
-
-def logcat():
-    p = subprocess.Popen(["adb", "logcat", "-d"], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+def logcat(sinceTime):
+    p = subprocess.Popen(["adb", "logcat", "-t", sinceTime], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
     stdout, stderr = p.communicate()
     rc = p.wait()
     if rc != 0:
@@ -40,12 +38,12 @@ def pushAsset(filename):
 
 def encodeVideoTest(test, output):
     pushAsset(test.filename)
-    clearLogcat()
+    startTime = datetime.now().strftime('%m-%d %H:%M:%S.000')
     encodeVideo(test.filename, output, test.mediaContainer, test.videoCodec, test.videoBitrateK, test.resolution, test.fps, test.audioCodec, test.audioSampleRate, test.audioBitrateK, test.audioChannel)
 
     logs = None
     for count in range(1, 300):
-        logs = logcat()
+        logs = logcat(startTime)
         if "Encode result" in logs:
             break
         time.sleep(1)
@@ -122,12 +120,12 @@ def encodeVideo(filename, output, mediaContainer, videoCodec, videoBitrateK, res
 
 def encodeAudioTest(test, output):
     pushAsset(test.filename)
-    clearLogcat()
+    startTime = datetime.now().strftime('%m-%d %H:%M:%S.000')
     encodeAudio(test.filename, output, test.mediaContainer, test.audioCodec, test.audioSampleRate, test.audioBitrateK, test.audioChannel)
 
     logs = None
     for count in range(1, 300):
-        logs = logcat()
+        logs = logcat(startTime)
         if "Encode result" in logs:
             break
         time.sleep(1)