Merge pull request #16054 from daschuer/valrind_firstsound

Fix false positive "First sound has been moved!" warnings

Author: acolombier

src/engine/cachingreader/cachingreaderworker.cpp

@@ -72,17 +72,19 @@ ReaderStatusUpdate CachingReaderWorker::processReadRequest(
         }
     }
 
-    // This call here assumes that the caching reader will read the first sound cue at
-    // one of the first chunks. The check serves as a sanity check to ensure that the
-    // sample data has not changed since it has ben analyzed. This could happen because
-    // of a change in actual audio data or because the file was decoded using a different
-    // decoder
-    // This is part of a first prove of concept and needs to be replaces with a different
-    // solution which is still under discussion. This might be also extended
-    // to further checks whether a automatic offset adjustment is possible or a the
-    // sample position metadata shall be treated as outdated.
-    // Failures of the sanity check only result in an entry into the log at the moment.
-    verifyFirstSound(pChunk);
+    if (status == CHUNK_READ_SUCCESS) {
+        // This call here assumes that the caching reader will read the first sound cue at
+        // one of the first chunks. The check serves as a sanity check to ensure that the
+        // sample data has not changed since it has ben analyzed. This could happen because
+        // of a change in actual audio data or because the file was decoded using a different
+        // decoder
+        // This is part of a first prove of concept and needs to be replaces with a different
+        // solution which is still under discussion. This might be also extended
+        // to further checks whether a automatic offset adjustment is possible or a the
+        // sample position metadata shall be treated as outdated.
+        // Failures of the sanity check only result in an entry into the log at the moment.
+        verifyFirstSound(pChunk);
+    }
 
     ReaderStatusUpdate result;
     result.init(status, pChunk, m_pAudioSource ? m_pAudioSource->frameIndexRange() : mixxx::IndexRange());
@@ -272,9 +274,18 @@ void CachingReaderWorker::verifyFirstSound(const CachingReaderChunk* pChunk) {
                             .value()));
     if (pChunk->getIndex() == firstSoundIndex) {
         CSAMPLE sampleBuffer[kNumSoundFrameToVerify * mixxx::kEngineChannelCount];
-        SINT end = static_cast<SINT>(m_firstSoundFrameToVerify.toLowerFrameBoundary().value());
-        pChunk->readBufferedSampleFrames(sampleBuffer,
-                mixxx::IndexRange::forward(end - 1, kNumSoundFrameToVerify));
+        // We read two frames, the last silence frame and the first non-silence frame from
+        // m_firstSoundFrameToVerify. end points to one position after them.
+        SINT end = static_cast<SINT>(m_firstSoundFrameToVerify.toLowerFrameBoundary().value()) + 1;
+        mixxx::IndexRange probeFrameIndexRange =
+                mixxx::IndexRange::between(end - kNumSoundFrameToVerify, end);
+        mixxx::IndexRange bufferedFrameIndexRange =
+                pChunk->readBufferedSampleFrames(
+                        sampleBuffer, probeFrameIndexRange);
+        VERIFY_OR_DEBUG_ASSERT(bufferedFrameIndexRange == probeFrameIndexRange) {
+            qWarning() << "skipping verifyFirstSound()";
+            return;
+        }
         if (AnalyzerSilence::verifyFirstSound(std::span<const CSAMPLE>(sampleBuffer),
                     mixxx::audio::FramePos(1))) {
             qDebug() << "First sound found at the previously stored position";