LibAudio: Resample FLAC audio data

FlacLoader initialized, but never used its resampler; this is now fixed
and all subframes are resampled before decorrelation occurs. FLAC files
with non-44100-Hz sample rates now play properly.

Userland/Libraries/LibAudio/FlacLoader.cpp

@@ -41,7 +41,7 @@ FlacLoaderPlugin::FlacLoaderPlugin(const StringView& path)
     if (!m_valid)
         return;
 
-    m_resampler = make<ResampleHelper<double>>(m_sample_rate, 44100);
+    m_resampler = make<ResampleHelper<i32>>(m_sample_rate, 44100);
 }
 
 FlacLoaderPlugin::FlacLoaderPlugin(const ByteBuffer& buffer)
@@ -59,7 +59,7 @@ FlacLoaderPlugin::FlacLoaderPlugin(const ByteBuffer& buffer)
     if (!m_valid)
         return;
 
-    m_resampler = make<ResampleHelper<double>>(m_sample_rate, 44100);
+    m_resampler = make<ResampleHelper<i32>>(m_sample_rate, 44100);
 }
 
 bool FlacLoaderPlugin::sniff()
@@ -244,10 +244,6 @@ RefPtr<Buffer> FlacLoaderPlugin::get_more_samples(size_t max_bytes_to_read_from_
                 m_error_string = String::formatted("Frame parsing error: {}", m_error_string);
                 return nullptr;
             }
-            // HACK: Test the start of the next subframe
-            // auto input = m_stream->bit_stream();
-            // u64 next = input.read_bits_big_endian(64);
-            // dbgln("After frame end: {}", next);
         }
         samples.append(m_current_frame_data.take_first());
         if (m_current_frame_data.size() == 0) {
@@ -352,7 +348,8 @@ void FlacLoaderPlugin::next_frame()
         FlacSubframeHeader new_subframe = next_subframe_header(bit_stream, i);
         CHECK_ERROR_STRING;
         Vector<i32> subframe_samples = parse_subframe(new_subframe, bit_stream);
-        // HACK: Test the start of the next subframe
+        m_resampler->reset();
+        subframe_samples = m_resampler->resample(subframe_samples);
         CHECK_ERROR_STRING;
         current_subframes.append(move(subframe_samples));
     }

Userland/Libraries/LibAudio/FlacLoader.h

@@ -124,7 +124,7 @@ private:
     bool m_valid { false };
     RefPtr<Core::File> m_file;
     String m_error_string;
-    OwnPtr<ResampleHelper<double>> m_resampler;
+    OwnPtr<ResampleHelper<i32>> m_resampler;
 
     // Data obtained directly from the FLAC metadata: many values have specific bit counts
     u32 m_sample_rate { 0 };         // 20 bit