Revert breaking change on soundsource and improve docstrings

src/sources/soundsource.cpp

@@ -32,7 +32,7 @@ QString SoundSource::getTypeFromUrl(const QUrl& url) {
 
 //static
 QString SoundSource::getTypeFromFile(const QFileInfo& fileInfo) {
-    const QString fileSuffix = fileInfo.completeSuffix().toLower().trimmed();
+    const QString fileSuffix = fileInfo.suffix().toLower().trimmed();
 
     if (fileSuffix == QLatin1String("opus")) {
         // Bypass the insufficient mime type lookup from content for opus files
@@ -52,13 +52,13 @@ QString SoundSource::getTypeFromFile(const QFileInfo& fileInfo) {
         // https://mixxx.zulipchat.com/#narrow/stream/109171-development/topic/mimetype.20sometimes.20wrong
         return fileSuffix;
     }
-    if (fileSuffix == QLatin1String("stem.mp4")) {
+    if (fileInfo.fileName().toLower().trimmed().endsWith(QLatin1String(".stem.mp4"))) {
         // STEM suffix extends the ".mp4" suffix. This is because stem files are
         // meant to fall back to MP4 decoder, in case a player doesn't have the
         // capability to extract the different stem track. However, we need to
         // detect that early as the file natively looks like a traditional MP4
         // with multiple tracks (audio and video)
-        return fileSuffix;
+        return QLatin1String("stem.mp4");
     }
 
     QMimeType mimeType = QMimeDatabase().mimeTypeForFile(

src/sources/soundsourcestem.h

@@ -10,7 +10,7 @@ namespace mixxx {
 class SoundSourceSingleSTEM : public SoundSourceFFmpeg {
   public:
     // streamIdx is the FFmpeg stream id, which may different than stemIdx + 1
-    // because STEm may contain other non audio stream
+    // because STEM may contain other non audio stream
     explicit SoundSourceSingleSTEM(const QUrl& url, unsigned int streamIdx);
 
   protected:

src/track/steminfoimporter.cpp

@@ -32,23 +32,23 @@ const uint32_t kStemManifestAtomPath[] = {
 /// @param reader The IODevice to search MP4 atom in
 /// @param path The list of atom to traverse in the tree, from top to bottom.
 /// Must be null terminated
-/// @param box_size The size of the box currently under the cursor to focus the
+/// @param boxSize The size of the box currently under the cursor to focus the
 /// search in
 /// @param pathIdx The level of the tree currently search (index of path)
 /// @return the size of the box data if found, -1 otherwise
 uint32_t seekTillAtom(QIODevice& reader,
         const uint32_t path[],
-        uint32_t box_size = 0,
+        uint32_t boxSize = 0,
         uint32_t pathIdx = 0) {
     if (!path[pathIdx]) {
-        return box_size;
+        return boxSize;
     }
 
     uint32_t byteRead = 0;
     char buffer[kAtomHeaderSize];
-    while (!reader.atEnd() || (box_size && byteRead >= box_size)) {
+    while (!reader.atEnd() || (boxSize && byteRead >= boxSize)) {
         reader.read(buffer, kAtomHeaderSize);
-        byteRead += box_size;
+        byteRead += boxSize;
         if (ATOM_TYPE(buffer + 4) == path[pathIdx]) {
             return seekTillAtom(reader, path, ATOM_TYPE(buffer) - kAtomHeaderSize, pathIdx + 1);
         }
@@ -61,8 +61,8 @@ uint32_t seekTillAtom(QIODevice& reader,
 
 // static
 bool StemInfoImporter::isStemFile(
-        const QString& aFileName) {
-    return aFileName.endsWith(kStemFileExtension);
+        const QString& fileName) {
+    return fileName.endsWith(kStemFileExtension);
 }
 
 QList<StemInfo> StemInfoImporter::importStemInfos(
@@ -128,8 +128,8 @@ QList<StemInfo> StemInfoImporter::importStemInfos(
     }
 
     // Extract DSP information
-    // TODO(XXX) DSP only contains limit and a compressor, which aren't
-    // supported by Mixxx yet. parse and implement when supported
+    // TODO(XXX) DSP only contains a limiter and a compressor effect, which
+    // Mixxx doesn't have yet. Parse and implement when supported
 
     file.close();
 

src/track/steminfoimporter.h

@@ -4,8 +4,7 @@
 
 namespace mixxx {
 
-/// Importer class for StemInfo objects that can correct timing offsets when the
-/// signal info (channel number, sample rate, bitrate) is known.
+/// Importer class for StemInfo objects that contains metadata about the stems of a track.
 class StemInfoImporter {
   public:
     static QList<StemInfo> importStemInfos(