render: properly defined "out of bounds time" behavior with footage

If a user extends a clip beyond the footage's length, they can
choose whether they want a black frame, the last frame continued,
or for the footage to loop infinitely (same for extending earlier
than the start of footage).

app/codec/decoder.cpp

@@ -107,7 +107,7 @@ FramePtr Decoder::RetrieveVideo(const rational &timecode, const int &divider)
   return RetrieveVideoInternal(timecode, divider);
 }
 
-SampleBufferPtr Decoder::RetrieveAudio(const TimeRange &range, const AudioParams &params, const QString& cache_path, const QAtomicInt *cancelled)
+SampleBufferPtr Decoder::RetrieveAudio(const TimeRange &range, const AudioParams &params, const QString& cache_path, Footage::LoopMode loop_mode, const QAtomicInt *cancelled)
 {
   QMutexLocker locker(&mutex_);
 
@@ -133,7 +133,7 @@ SampleBufferPtr Decoder::RetrieveAudio(const TimeRange &range, const AudioParams
   }
 
   // See if we got the conform
-  SampleBufferPtr buffer = RetrieveAudioFromConform(conform_filename, range);
+  SampleBufferPtr buffer = RetrieveAudioFromConform(conform_filename, range, loop_mode);
 
   if (!buffer) {
     // We'll need to conform this ourselves
@@ -151,7 +151,7 @@ SampleBufferPtr Decoder::RetrieveAudio(const TimeRange &range, const AudioParams
       QFile::rename(working_fn, conform_filename);
 
       // Return audio as planned
-      buffer = RetrieveAudioFromConform(conform_filename, range);
+      buffer = RetrieveAudioFromConform(conform_filename, range, loop_mode);
     } else {
       // Failed
       qCritical() << "Failed to conform audio";
@@ -302,16 +302,48 @@ bool Decoder::ConformAudioInternal(const QString& filename, const AudioParams &p
   return false;
 }
 
-SampleBufferPtr Decoder::RetrieveAudioFromConform(const QString &conform_filename, const TimeRange& range)
+SampleBufferPtr Decoder::RetrieveAudioFromConform(const QString &conform_filename, const TimeRange& range, Footage::LoopMode loop_mode)
 {
   WaveInput input(conform_filename);
 
   if (input.open()) {
     const AudioParams& input_params = input.params();
 
-    // Read bytes from wav
-    QByteArray packed_data = input.read(input_params.time_to_bytes(range.in()),
-                                        input_params.time_to_bytes(range.length()));
+    QByteArray packed_data(input_params.time_to_bytes(range.length()), Qt::Uninitialized);
+
+    qint64 read_index = input_params.time_to_bytes(range.in());
+    qint64 write_index = 0;
+
+    while (write_index < packed_data.size()) {
+      if (loop_mode == Footage::kLoopModeLoop) {
+        while (read_index >= input.data_length()) {
+          read_index -= input.data_length();
+        }
+
+        while (read_index < 0) {
+          read_index += input.data_length();
+        }
+      }
+
+      qint64 write_count = 0;
+
+      if (read_index < 0) {
+        // Reading before 0, write silence here until audio data would actually start
+        write_count = qMin(-read_index, qint64(packed_data.size()));
+        memset(packed_data.data() + write_index, 0, write_count);
+      } else if (read_index >= input.data_length()) {
+        // Reading after data length, write silence until the end of the buffer
+        write_count = packed_data.size() - write_index;
+        memset(packed_data.data() + write_index, 0, write_count);
+      } else {
+        write_count = qMin(input.data_length() - read_index, packed_data.size() - write_index);
+        input.read(read_index, packed_data.data() + write_index, write_count);
+      }
+
+      read_index += write_count;
+      write_index += write_count;
+    }
+
     input.close();
 
     // Create sample buffer

app/codec/decoder.h

@@ -163,7 +163,7 @@ public:
    *
    * This function is thread safe and can only run while the decoder is open. \see Open()
    */
-  SampleBufferPtr RetrieveAudio(const TimeRange& range, const AudioParams& params, const QString &cache_path, const QAtomicInt *cancelled);
+  SampleBufferPtr RetrieveAudio(const TimeRange& range, const AudioParams& params, const QString &cache_path, Footage::LoopMode loop_mode, const QAtomicInt *cancelled);
 
   /**
    * @brief Generate a Footage object from a file
@@ -276,7 +276,7 @@ signals:
   void IndexProgress(double);
 
 private:
-  SampleBufferPtr RetrieveAudioFromConform(const QString& conform_filename, const TimeRange &range);
+  SampleBufferPtr RetrieveAudioFromConform(const QString& conform_filename, const TimeRange &range, Footage::LoopMode loop_mode);
 
   CodecStream stream_;
 

app/codec/waveinput.cpp

@@ -158,38 +158,40 @@ bool WaveInput::is_open() const
   return file_.isOpen();
 }
 
-QByteArray WaveInput::read(int length)
+QByteArray WaveInput::read(qint64 length)
 {
   if (!is_open()) {
     return QByteArray();
   }
 
-  return file_.read(qMin(calculate_max_read(), static_cast<qint64>(length)));
+  return file_.read(qMin(calculate_max_read(), length));
 }
 
-QByteArray WaveInput::read(int offset, int length)
+QByteArray WaveInput::read(qint64 offset, qint64 length)
 {
   if (!is_open()) {
     return QByteArray();
   }
 
   seek(offset);
-  return file_.read(qMin(calculate_max_read(), static_cast<qint64>(length)));
+  return file_.read(qMin(calculate_max_read(), length));
 }
 
-qint64 WaveInput::read(int offset, char *buffer, int length)
+qint64 WaveInput::read(qint64 offset, char *buffer, qint64 length)
 {
   if (!is_open()) {
     return 0;
   }
 
+  Q_ASSERT(length > 0);
+
   seek(offset);
-  return file_.read(buffer, qMin(calculate_max_read(), static_cast<qint64>(length)));
+  return file_.read(buffer, qMin(calculate_max_read(), length));
 }
 
 bool WaveInput::seek(qint64 pos)
 {
-  return file_.seek(data_position_ + qMin(pos, static_cast<qint64>(data_size_)));
+  return file_.seek(data_position_ + qMin(pos, qint64(data_size_)));
 }
 
 bool WaveInput::at_end() const
@@ -216,7 +218,7 @@ const quint32 &WaveInput::data_length() const
 
 int WaveInput::sample_count() const
 {
-  return params_.bytes_to_samples(static_cast<int>(data_size_));
+  return params_.bytes_to_samples(data_size_);
 }
 
 bool WaveInput::find_str(QFile *f, const char *str)

app/codec/waveinput.h

@@ -40,9 +40,9 @@ public:
 
   bool is_open() const;
 
-  QByteArray read(int length);
-  QByteArray read(int offset, int length);
-  qint64 read(int offset, char *buffer, int length);
+  QByteArray read(qint64 length);
+  QByteArray read(qint64 offset, qint64 length);
+  qint64 read(qint64 offset, char *buffer, qint64 length);
 
   bool seek(qint64 pos);