Fix QAudioBuffer sampleCount vs. channelCount.

There were some inconsistencies in when the sample count was per channel
or in total.  The docs mention that it is in total, so fix a few cases
where it went wrong and test it.

Change-Id: I55c855911fcde66a218d6cdd327e09ad5406d5a4
Reviewed-by: Jonas Rabbe <jonas.rabbe@nokia.com>
Reviewed-by: Lev Zelenskiy <lev.zelenskiy@nokia.com>
Reviewed-by: Michael Goddard <michael.goddard@nokia.com>

2 files changed, 48 insertions, 13 deletions

diff --git a/src/multimedia/audio/qaudiobuffer.cpp b/src/multimedia/audio/qaudiobuffer.cpp
index 7fa37f81b..fffa66c4a 100644
--- a/src/multimedia/audio/qaudiobuffer.cpp
+++ b/src/multimedia/audio/qaudiobuffer.cpp
@@ -111,7 +111,7 @@ public:
         , mSampleCount(sampleCount)
         , mFormat(format)
     {
-        int numBytes = (sampleCount * format.channelCount() * format.sampleSize()) / 8;
+        int numBytes = (sampleCount * format.sampleSize()) / 8;
         if (numBytes > 0) {
             mBuffer = malloc(numBytes);
             if (!mBuffer) {
@@ -245,9 +245,11 @@ QAudioBuffer::QAudioBuffer(const QAudioBuffer &other)
  */
 QAudioBuffer::QAudioBuffer(const QByteArray &data, const QAudioFormat &format)
 {
-    int sampleSize = (format.sampleSize() * format.channelCount()) / 8;
-    int sampleCount = data.size() / sampleSize; // truncate
-    d = new QAudioBufferPrivate(new QMemoryAudioBufferProvider(data.constData(), sampleCount, format, -1));
+    if (format.isValid()) {
+        int sampleCount = (data.size() * 8) / format.sampleSize(); // truncate
+        d = new QAudioBufferPrivate(new QMemoryAudioBufferProvider(data.constData(), sampleCount, format, -1));
+    } else
+        d = 0;
 }
 
 /*!
@@ -327,7 +329,7 @@ int QAudioBuffer::sampleCount() const
 int QAudioBuffer::byteCount() const
 {
     const QAudioFormat f(format());
-    return (f.channelCount() * f.sampleSize() * sampleCount()) / 8; // sampleSize is in bits
+    return (f.sampleSize() * sampleCount()) / 8; // sampleSize is in bits
 }
 
 /*!
diff --git a/tests/auto/unit/qaudiobuffer/tst_qaudiobuffer.cpp b/tests/auto/unit/qaudiobuffer/tst_qaudiobuffer.cpp
index 7339cc772..ff403b33b 100644
--- a/tests/auto/unit/qaudiobuffer/tst_qaudiobuffer.cpp
+++ b/tests/auto/unit/qaudiobuffer/tst_qaudiobuffer.cpp
@@ -80,7 +80,7 @@ tst_QAudioBuffer::tst_QAudioBuffer()
 
     QByteArray b(4000, 0x80);
     mNull = new QAudioBuffer;
-    mEmpty = new QAudioBuffer(1000, mFormat);
+    mEmpty = new QAudioBuffer(1000, mFormat); // 1000 samples of 16 bits -> 2KB
     mFromArray = new QAudioBuffer(b, mFormat);
 }
 
@@ -109,9 +109,9 @@ void tst_QAudioBuffer::ctors()
     QVERIFY(mEmpty->constData() != 0);
     QVERIFY(mEmpty->data() != 0);
     QVERIFY(((const QAudioBuffer*)mEmpty)->data() != 0);
-    QCOMPARE(mEmpty->duration(), 50000LL);
-    QCOMPARE(mEmpty->byteCount(), 4000);
     QCOMPARE(mEmpty->sampleCount(), 1000);
+    QCOMPARE(mEmpty->duration(), 50000LL);
+    QCOMPARE(mEmpty->byteCount(), 2000);
     QCOMPARE(mEmpty->startTime(), -1LL);
 
     // bytearray buffer
@@ -119,10 +119,43 @@ void tst_QAudioBuffer::ctors()
     QVERIFY(mFromArray->constData() != 0);
     QVERIFY(mFromArray->data() != 0);
     QVERIFY(((const QAudioBuffer*)mFromArray)->data() != 0);
-    QCOMPARE(mFromArray->duration(), 50000LL); // 4000 bytes
+    /// 4000 bytes at 10KHz, 2ch, 16bit = 40kBps -> 0.1s
+    QCOMPARE(mFromArray->duration(), 100000LL);
     QCOMPARE(mFromArray->byteCount(), 4000);
-    QCOMPARE(mFromArray->sampleCount(), 1000);
+    QCOMPARE(mFromArray->sampleCount(), 2000);
     QCOMPARE(mFromArray->startTime(), -1LL);
+
+
+    // Now some invalid buffers
+    QAudioBuffer badFormat(1000, QAudioFormat());
+    QVERIFY(!badFormat.isValid());
+    QVERIFY(badFormat.constData() == 0);
+    QVERIFY(badFormat.data() == 0);
+    QVERIFY(((const QAudioBuffer*)&badFormat)->data() == 0);
+    QCOMPARE(badFormat.duration(), 0LL);
+    QCOMPARE(badFormat.byteCount(), 0);
+    QCOMPARE(badFormat.sampleCount(), 0);
+    QCOMPARE(badFormat.startTime(), -1LL);
+
+    QAudioBuffer badArray(QByteArray(), mFormat);
+    QVERIFY(!badArray.isValid());
+    QVERIFY(badArray.constData() == 0);
+    QVERIFY(badArray.data() == 0);
+    QVERIFY(((const QAudioBuffer*)&badArray)->data() == 0);
+    QCOMPARE(badArray.duration(), 0LL);
+    QCOMPARE(badArray.byteCount(), 0);
+    QCOMPARE(badArray.sampleCount(), 0);
+    QCOMPARE(badArray.startTime(), -1LL);
+
+    QAudioBuffer badBoth = QAudioBuffer(QByteArray(), QAudioFormat());
+    QVERIFY(!badBoth.isValid());
+    QVERIFY(badBoth.constData() == 0);
+    QVERIFY(badBoth.data() == 0);
+    QVERIFY(((const QAudioBuffer*)&badBoth)->data() == 0);
+    QCOMPARE(badBoth.duration(), 0LL);
+    QCOMPARE(badBoth.byteCount(), 0);
+    QCOMPARE(badBoth.sampleCount(), 0);
+    QCOMPARE(badBoth.startTime(), -1LL);
 }
 
 void tst_QAudioBuffer::assign()
@@ -245,11 +278,11 @@ void tst_QAudioBuffer::durations_data()
     QTest::newRow("M8_2000_8K") << 1 << 8 << 2000 << QAudioFormat::UnSignedInt << 8000 << 250000LL << 2000;
     QTest::newRow("M8_1000_4K") << 1 << 8 << 1000 << QAudioFormat::UnSignedInt << 4000 << 250000LL << 1000;
 
-    QTest::newRow("S8_1000_8K") << 2 << 8 << 1000 << QAudioFormat::UnSignedInt << 8000 << 62500LL << 2000;
+    QTest::newRow("S8_1000_8K") << 2 << 8 << 1000 << QAudioFormat::UnSignedInt << 8000 << 62500LL << 1000;
 
-    QTest::newRow("SF_1000_8K") << 2 << 32 << 1000 << QAudioFormat::Float << 8000 << 62500LL << 8000;
+    QTest::newRow("SF_1000_8K") << 2 << 32 << 1000 << QAudioFormat::Float << 8000 << 62500LL << 4000;
 
-    QTest::newRow("4x128_1000_16K") << 4 << 128 << 1000 << QAudioFormat::SignedInt << 16000 << 15625LL << 64000;
+    QTest::newRow("4x128_1000_16K") << 4 << 128 << 1000 << QAudioFormat::SignedInt << 16000 << 15625LL << 16000;
 }
 
 void tst_QAudioBuffer::stereoSample()