Libraries: Move to Userland/Libraries/

1 files changed, 148 insertions, 0 deletions

diff --git a/Userland/Libraries/LibAudio/Buffer.h b/Userland/Libraries/LibAudio/Buffer.h
new file mode 100644
index 0000000000..5be0c2443a
--- /dev/null
+++ b/Userland/Libraries/LibAudio/Buffer.h
@@ -0,0 +1,148 @@
+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <AK/ByteBuffer.h>
+#include <AK/MemoryStream.h>
+#include <AK/SharedBuffer.h>
+#include <AK/Types.h>
+#include <AK/Vector.h>
+#include <string.h>
+
+namespace Audio {
+
+// A single sample in an audio buffer.
+// Values are floating point, and should range from -1.0 to +1.0
+struct Sample {
+    Sample()
+        : left(0)
+        , right(0)
+    {
+    }
+
+    // For mono
+    Sample(double left)
+        : left(left)
+        , right(left)
+    {
+    }
+
+    // For stereo
+    Sample(double left, double right)
+        : left(left)
+        , right(right)
+    {
+    }
+
+    void clip()
+    {
+        if (left > 1)
+            left = 1;
+        else if (left < -1)
+            left = -1;
+
+        if (right > 1)
+            right = 1;
+        else if (right < -1)
+            right = -1;
+    }
+
+    void scale(int percent)
+    {
+        double pct = (double)percent / 100.0;
+        left *= pct;
+        right *= pct;
+    }
+
+    Sample& operator+=(const Sample& other)
+    {
+        left += other.left;
+        right += other.right;
+        return *this;
+    }
+
+    double left;
+    double right;
+};
+
+// Small helper to resample from one playback rate to another
+// This isn't really "smart", in that we just insert (or drop) samples.
+// Should do better...
+class ResampleHelper {
+public:
+    ResampleHelper(double source, double target);
+
+    void process_sample(double sample_l, double sample_r);
+    bool read_sample(double& next_l, double& next_r);
+
+private:
+    const double m_ratio;
+    double m_current_ratio { 0 };
+    double m_last_sample_l { 0 };
+    double m_last_sample_r { 0 };
+};
+
+// A buffer of audio samples, normalized to 44100hz.
+class Buffer : public RefCounted<Buffer> {
+public:
+    static RefPtr<Buffer> from_pcm_data(ReadonlyBytes data, ResampleHelper& resampler, int num_channels, int bits_per_sample);
+    static RefPtr<Buffer> from_pcm_stream(InputMemoryStream& stream, ResampleHelper& resampler, int num_channels, int bits_per_sample, int num_samples);
+    static NonnullRefPtr<Buffer> create_with_samples(Vector<Sample>&& samples)
+    {
+        return adopt(*new Buffer(move(samples)));
+    }
+    static NonnullRefPtr<Buffer> create_with_shared_buffer(NonnullRefPtr<SharedBuffer>&& buffer, int sample_count)
+    {
+        return adopt(*new Buffer(move(buffer), sample_count));
+    }
+
+    const Sample* samples() const { return (const Sample*)data(); }
+    int sample_count() const { return m_sample_count; }
+    const void* data() const { return m_buffer->data<void>(); }
+    int size_in_bytes() const { return m_sample_count * (int)sizeof(Sample); }
+    int shbuf_id() const { return m_buffer->shbuf_id(); }
+    SharedBuffer& shared_buffer() { return *m_buffer; }
+
+private:
+    explicit Buffer(Vector<Sample>&& samples)
+        : m_buffer(*SharedBuffer::create_with_size(samples.size() * sizeof(Sample)))
+        , m_sample_count(samples.size())
+    {
+        memcpy(m_buffer->data<void>(), samples.data(), samples.size() * sizeof(Sample));
+    }
+
+    explicit Buffer(NonnullRefPtr<SharedBuffer>&& buffer, int sample_count)
+        : m_buffer(move(buffer))
+        , m_sample_count(sample_count)
+    {
+    }
+
+    NonnullRefPtr<SharedBuffer> m_buffer;
+    const int m_sample_count;
+};
+
+}