aaudio_loopback: general cleanup, use dlsym

Cleanup printing.
Use dlsym so this can run on O.

Test: aaudio_loopback -tl -pl -n2
Change-Id: I77b931e59cced32b0cc23076f9b156d082e6bf0b
diff --git a/media/libaaudio/examples/loopback/src/LoopbackAnalyzer.h b/media/libaaudio/examples/loopback/src/LoopbackAnalyzer.h
index b83851a..1e282d1 100644
--- a/media/libaaudio/examples/loopback/src/LoopbackAnalyzer.h
+++ b/media/libaaudio/examples/loopback/src/LoopbackAnalyzer.h
@@ -410,8 +410,7 @@
 
 
 static void printAudioScope(float sample) {
-    const int maxStars = 80
-    ; // arbitrary, fits on one line
+    const int maxStars = 80; // arbitrary, fits on one line
     char c = '*';
     if (sample < -1.0) {
         sample = -1.0;
@@ -555,7 +554,7 @@
                 break;
 
             case STATE_WAITING_FOR_SILENCE:
-                // Output silence.
+                // Output silence and wait for the echos to die down.
                 numSamples = numFrames * outputChannelCount;
                 for (int i = 0; i < numSamples; i++) {
                     outputData[i] = 0;
diff --git a/media/libaaudio/examples/loopback/src/loopback.cpp b/media/libaaudio/examples/loopback/src/loopback.cpp
index f2254ce..39d079e 100644
--- a/media/libaaudio/examples/loopback/src/loopback.cpp
+++ b/media/libaaudio/examples/loopback/src/loopback.cpp
@@ -128,7 +128,7 @@
 
             myData->audioRecording.write(myData->inputData,
                                         myData->actualInputChannelCount,
-                                        numFrames);
+                                         framesRead);
 
             int32_t numSamples = framesRead * myData->actualInputChannelCount;
             convertPcm16ToFloat(myData->inputData, myData->conversionBuffer, numSamples);
@@ -161,17 +161,17 @@
 static void usage() {
     printf("Usage: aaudio_loopback [OPTION]...\n\n");
     AAudioArgsParser::usage();
-    printf("          -C{channels}      number of input channels\n");
-    printf("          -g{gain}          recirculating loopback gain\n");
-    printf("          -P{inPerf}        set input AAUDIO_PERFORMANCE_MODE*\n");
-    printf("              n for _NONE\n");
-    printf("              l for _LATENCY\n");
-    printf("              p for _POWER_SAVING\n");
-    printf("          -t{test}          select test mode\n");
-    printf("              m for sine magnitude\n");
-    printf("              e for echo latency (default)\n");
-    printf("              f for file latency, analyzes %s\n\n", FILENAME_ECHOS);
-    printf("          -X  use EXCLUSIVE mode for input\n");
+    printf("      -C{channels}      number of input channels\n");
+    printf("      -g{gain}          recirculating loopback gain\n");
+    printf("      -P{inPerf}        set input AAUDIO_PERFORMANCE_MODE*\n");
+    printf("          n for _NONE\n");
+    printf("          l for _LATENCY\n");
+    printf("          p for _POWER_SAVING\n");
+    printf("      -t{test}          select test mode\n");
+    printf("          m for sine magnitude\n");
+    printf("          e for echo latency (default)\n");
+    printf("          f for file latency, analyzes %s\n\n", FILENAME_ECHOS);
+    printf("      -X  use EXCLUSIVE mode for input\n");
     printf("Example:  aaudio_loopback -n2 -pl -Pl -x\n");
 }
 
@@ -448,7 +448,7 @@
     }
 
     if (loopbackData.loopbackProcessor->getResult() < 0) {
-        printf("Test failed!\n");
+        printf("ERROR: Could not get a good loopback signal. Probably because the volume was too low.\n");
     } else {
         printf("input error = %d = %s\n",
                loopbackData.inputError, AAudio_convertResultToText(loopbackData.inputError));
@@ -467,11 +467,16 @@
         }
 
         int written = loopbackData.loopbackProcessor->save(FILENAME_ECHOS);
-        printf("main() wrote %d mono samples to %s on Android device\n", written,
-               FILENAME_ECHOS);
-        printf("main() loopbackData.audioRecording.getSampleRate() = %d\n", loopbackData.audioRecording.getSampleRate());
+        if (written > 0) {
+            printf("main() wrote %8d mono samples to \"%s\" on Android device\n",
+                   written, FILENAME_ECHOS);
+        }
+
         written = loopbackData.audioRecording.save(FILENAME_ALL);
-        printf("main() wrote %d mono samples to %s on Android device\n", written, FILENAME_ALL);
+        if (written > 0) {
+            printf("main() wrote %8d mono samples to \"%s\" on Android device\n",
+                   written, FILENAME_ALL);
+        }
     }
 
 finish:
@@ -481,9 +486,8 @@
     delete[] loopbackData.inputData;
     delete[] outputData;
 
-    printf(RESULT_TAG "error = %d = %s\n", result, AAudio_convertResultToText(result));
+    printf(RESULT_TAG "result = %s\n", AAudio_convertResultToText(result));
     if ((result != AAUDIO_OK)) {
-        printf("error %d = %s\n", result, AAudio_convertResultToText(result));
         return EXIT_FAILURE;
     } else {
         printf("SUCCESS\n");
diff --git a/media/libaaudio/examples/utils/AAudioArgsParser.h b/media/libaaudio/examples/utils/AAudioArgsParser.h
index 4fc5b9f..eb6925a 100644
--- a/media/libaaudio/examples/utils/AAudioArgsParser.h
+++ b/media/libaaudio/examples/utils/AAudioArgsParser.h
@@ -19,7 +19,8 @@
 
 #define MAX_CHANNELS                     8
 
-#include <cctype>
+//#include <cctype>
+#include <dlfcn.h>
 #include <unistd.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -29,6 +30,63 @@
 
 #include "AAudioExampleUtils.h"
 
+
+static void (*s_setUsage)(AAudioStreamBuilder* builder, aaudio_usage_t usage) = nullptr;
+static void (*s_setContentType)(AAudioStreamBuilder* builder,
+                                aaudio_content_type_t contentType) = nullptr;
+static void (*s_setInputPreset)(AAudioStreamBuilder* builder,
+                                aaudio_input_preset_t inputPreset) = nullptr;
+
+static bool s_loadAttempted = false;
+static aaudio_usage_t (*s_getUsage)(AAudioStream *stream) = nullptr;
+static aaudio_content_type_t (*s_getContentType)(AAudioStream *stream) = nullptr;
+static aaudio_input_preset_t (*s_getInputPreset)(AAudioStream *stream) = nullptr;
+
+// Link to test functions in shared library.
+static void loadFutureFunctions() {
+    if (s_loadAttempted)  return; // only try once
+    s_loadAttempted = true;
+
+    void *handle = dlopen("libaaudio.so", RTLD_NOW);
+    if (handle != nullptr) {
+        s_setUsage = (void (*)(AAudioStreamBuilder *, aaudio_usage_t))
+                dlsym(handle, "AAudioStreamBuilder_setUsage");
+        if (s_setUsage == nullptr) goto error;
+
+        s_setContentType = (void (*)(AAudioStreamBuilder *, aaudio_content_type_t))
+                dlsym(handle, "AAudioStreamBuilder_setContentType");
+        if (s_setContentType == nullptr) goto error;
+
+        s_setInputPreset = (void (*)(AAudioStreamBuilder *, aaudio_input_preset_t))
+                dlsym(handle, "AAudioStreamBuilder_setInputPreset");
+        if (s_setInputPreset == nullptr) goto error;
+
+        s_getUsage = (aaudio_usage_t (*)(AAudioStream *))
+                dlsym(handle, "AAudioStream_getUsage");
+        if (s_getUsage == nullptr) goto error;
+
+        s_getContentType = (aaudio_content_type_t (*)(AAudioStream *))
+                dlsym(handle, "AAudioStream_getContentType");
+        if (s_getContentType == nullptr) goto error;
+
+        s_getInputPreset = (aaudio_input_preset_t (*)(AAudioStream *))
+                dlsym(handle, "AAudioStream_getInputPreset");
+        if (s_getInputPreset == nullptr) goto error;
+    }
+    return;
+
+error:
+    // prevent any calls to these functions
+    s_setUsage = nullptr;
+    s_setContentType = nullptr;
+    s_setInputPreset = nullptr;
+    s_getUsage = nullptr;
+    s_getContentType = nullptr;
+    s_getInputPreset = nullptr;
+    dlclose(handle);
+    return;
+}
+
 // TODO use this as a base class within AAudio
 class AAudioParameters {
 public:
@@ -140,9 +198,24 @@
         AAudioStreamBuilder_setDeviceId(builder, mDeviceId);
         AAudioStreamBuilder_setSharingMode(builder, mSharingMode);
         AAudioStreamBuilder_setPerformanceMode(builder, mPerformanceMode);
-        AAudioStreamBuilder_setUsage(builder, mUsage);
-        AAudioStreamBuilder_setContentType(builder, mContentType);
-        AAudioStreamBuilder_setInputPreset(builder, mInputPreset);
+
+        // Call P functions if supported.
+        loadFutureFunctions();
+        if (s_setUsage != nullptr) {
+            s_setUsage(builder, mUsage);
+        } else if (mUsage != AAUDIO_UNSPECIFIED){
+            printf("WARNING: setUsage not supported");
+        }
+        if (s_setContentType != nullptr) {
+            s_setContentType(builder, mContentType);
+        } else if (mUsage != AAUDIO_UNSPECIFIED){
+            printf("WARNING: setContentType not supported");
+        }
+        if (s_setInputPreset != nullptr) {
+            s_setInputPreset(builder, mInputPreset);
+        } else if (mUsage != AAUDIO_UNSPECIFIED){
+            printf("WARNING: setInputPreset not supported");
+        }
     }
 
 private:
@@ -332,14 +405,21 @@
         printf("  PerformanceMode: requested = %d, actual = %d\n",
                getPerformanceMode(), AAudioStream_getPerformanceMode(stream));
 
-        printf("  Usage:        requested = %d, actual = %d\n",
-               getUsage(), AAudioStream_getUsage(stream));
-        printf("  ContentType:  requested = %d, actual = %d\n",
-               getContentType(), AAudioStream_getContentType(stream));
+        loadFutureFunctions();
 
-        if (AAudioStream_getDirection(stream) == AAUDIO_DIRECTION_INPUT) {
-            printf("  InputPreset:  requested = %d, actual = %d\n",
-                   getInputPreset(), AAudioStream_getInputPreset(stream));
+        if (s_setUsage != nullptr) {
+            printf("  Usage:        requested = %d, actual = %d\n",
+                   getUsage(), s_getUsage(stream));
+        }
+        if (s_getContentType != nullptr) {
+            printf("  ContentType:  requested = %d, actual = %d\n",
+                   getContentType(), s_getContentType(stream));
+        }
+
+        if (AAudioStream_getDirection(stream) == AAUDIO_DIRECTION_INPUT
+            && s_getInputPreset != nullptr) {
+                printf("  InputPreset:  requested = %d, actual = %d\n",
+                       getInputPreset(), s_getInputPreset(stream));
         }
 
         printf("  Is MMAP used? %s\n", AAudioStream_isMMapUsed(stream)