Echo Cancellation

1 files changed, 176 insertions, 0 deletions

diff --git a/plugins/rtp/src/voice_processor.vala b/plugins/rtp/src/voice_processor.vala
new file mode 100644
index 00000000..e6dc7e8f
--- /dev/null
+++ b/plugins/rtp/src/voice_processor.vala
@@ -0,0 +1,176 @@
+using Gst;
+
+namespace Dino.Plugins.Rtp {
+public static extern Buffer adjust_to_running_time(Base.Transform transform, Buffer buf);
+}
+
+public class Dino.Plugins.Rtp.EchoProbe : Audio.Filter {
+    private static StaticPadTemplate sink_template = {"sink", PadDirection.SINK, PadPresence.ALWAYS, {null, "audio/x-raw,rate=48000,channels=1,layout=interleaved,format=S16LE"}};
+    private static StaticPadTemplate src_template = {"src", PadDirection.SRC, PadPresence.ALWAYS, {null, "audio/x-raw,rate=48000,channels=1,layout=interleaved,format=S16LE"}};
+    public Audio.Info audio_info { get; private set; }
+    public signal void on_new_buffer(Buffer buffer);
+    private uint period_samples;
+    private uint period_size;
+    private Base.Adapter adapter = new Base.Adapter();
+
+    static construct {
+        add_static_pad_template(sink_template);
+        add_static_pad_template(src_template);
+        set_static_metadata("Acoustic Echo Canceller probe", "Generic/Audio", "Gathers playback buffers for echo cancellation", "Dino Team <contact@dino.im>");
+    }
+
+    construct {
+        set_passthrough(true);
+    }
+
+    public override bool setup(Audio.Info info) {
+        audio_info = info;
+        period_samples = info.rate / 100; // 10ms buffers
+        period_size = period_samples * info.bpf;
+        return true;
+    }
+
+
+    public override FlowReturn transform_ip(Buffer buf) {
+        lock (adapter) {
+            adapter.push(adjust_to_running_time(this, buf));
+            while (adapter.available() > period_size) {
+                on_new_buffer(adapter.take_buffer(period_size));
+            }
+        }
+        return FlowReturn.OK;
+    }
+
+    public override bool stop() {
+        adapter.clear();
+        return true;
+    }
+}
+
+public class Dino.Plugins.Rtp.VoiceProcessor : Audio.Filter {
+    private static StaticPadTemplate sink_template = {"sink", PadDirection.SINK, PadPresence.ALWAYS, {null, "audio/x-raw,rate=48000,channels=1,layout=interleaved,format=S16LE"}};
+    private static StaticPadTemplate src_template = {"src", PadDirection.SRC, PadPresence.ALWAYS, {null, "audio/x-raw,rate=48000,channels=1,layout=interleaved,format=S16LE"}};
+    public Audio.Info audio_info { get; private set; }
+    private ulong process_outgoing_buffer_handler_id;
+    private uint adjust_delay_timeout_id;
+    private uint period_samples;
+    private uint period_size;
+    private Base.Adapter adapter = new Base.Adapter();
+    private EchoProbe? echo_probe;
+    private Audio.StreamVolume? stream_volume;
+    private ClockTime last_reverse;
+    private void* native;
+
+    static construct {
+        add_static_pad_template(sink_template);
+        add_static_pad_template(src_template);
+        set_static_metadata("Voice Processor (AGC, AEC, filters, etc.)", "Generic/Audio", "Pre-processes voice with WebRTC Audio Processing Library", "Dino Team <contact@dino.im>");
+    }
+
+    construct {
+        set_passthrough(false);
+    }
+
+    public VoiceProcessor(EchoProbe? echo_probe = null, Audio.StreamVolume? stream_volume = null) {
+        this.echo_probe = echo_probe;
+        this.stream_volume = stream_volume;
+    }
+
+    private static extern void* init_native(int stream_delay);
+    private static extern void setup_native(void* native);
+    private static extern void destroy_native(void* native);
+    private static extern void analyze_reverse_stream(void* native, Audio.Info info, Buffer buffer);
+    private static extern void process_stream(void* native, Audio.Info info, Buffer buffer);
+    private static extern void adjust_stream_delay(void* native);
+    private static extern void notify_gain_level(void* native, int gain_level);
+    private static extern int get_suggested_gain_level(void* native);
+    private static extern bool get_stream_has_voice(void* native);
+
+    public override bool setup(Audio.Info info) {
+        debug("VoiceProcessor.setup(%s)", info.to_caps().to_string());
+        audio_info = info;
+        period_samples = info.rate / 100; // 10ms buffers
+        period_size = period_samples * info.bpf;
+        adapter.clear();
+        setup_native(native);
+        return true;
+    }
+
+    public override bool start() {
+        native = init_native(150);
+        if (process_outgoing_buffer_handler_id == 0 && echo_probe != null) {
+            process_outgoing_buffer_handler_id = echo_probe.on_new_buffer.connect(process_outgoing_buffer);
+        }
+        if (stream_volume == null && sinkpad.get_peer() != null && sinkpad.get_peer().get_parent_element() is Audio.StreamVolume) {
+            stream_volume = sinkpad.get_peer().get_parent_element() as Audio.StreamVolume;
+        }
+        return true;
+    }
+
+    private bool adjust_delay() {
+        if (native != null) {
+            adjust_stream_delay(native);
+            return Source.CONTINUE;
+        } else {
+            adjust_delay_timeout_id = 0;
+            return Source.REMOVE;
+        }
+    }
+
+    private void process_outgoing_buffer(Buffer buffer) {
+        if (buffer.pts != uint64.MAX) {
+            last_reverse = buffer.pts;
+        }
+        analyze_reverse_stream(native, echo_probe.audio_info, buffer);
+        if (adjust_delay_timeout_id == 0 && echo_probe != null) {
+            adjust_delay_timeout_id = Timeout.add(5000, adjust_delay);
+        }
+    }
+
+    public override FlowReturn submit_input_buffer(bool is_discont, Buffer input) {
+        lock (adapter) {
+            if (is_discont) {
+                adapter.clear();
+            }
+            adapter.push(adjust_to_running_time(this, input));
+        }
+        return FlowReturn.OK;
+    }
+
+    public override FlowReturn generate_output(out Buffer output_buffer) {
+        lock (adapter) {
+            if (adapter.available() >= period_size) {
+                output_buffer = (Gst.Buffer) adapter.take_buffer(period_size).make_writable();
+                int old_gain_level = 0;
+                if (stream_volume != null) {
+                    old_gain_level = (int) (stream_volume.get_volume(Audio.StreamVolumeFormat.LINEAR) * 255.0);
+                    notify_gain_level(native, old_gain_level);
+                }
+                process_stream(native, audio_info, output_buffer);
+                if (stream_volume != null) {
+                    int new_gain_level = get_suggested_gain_level(native);
+                    if (old_gain_level != new_gain_level) {
+                        debug("Gain: %i -> %i", old_gain_level, new_gain_level);
+                        stream_volume.set_volume(Audio.StreamVolumeFormat.LINEAR, ((double)new_gain_level) / 255.0);
+                    }
+                }
+            }
+        }
+        return FlowReturn.OK;
+    }
+
+    public override bool stop() {
+        if (process_outgoing_buffer_handler_id != 0) {
+            echo_probe.disconnect(process_outgoing_buffer_handler_id);
+            process_outgoing_buffer_handler_id = 0;
+        }
+        if (adjust_delay_timeout_id != 0) {
+            Source.remove(adjust_delay_timeout_id);
+            adjust_delay_timeout_id = 0;
+        }
+        adapter.clear();
+        destroy_native(native);
+        native = null;
+        return true;
+    }
+}
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