Publicate/src/Video/VideoProcessor.vala

using Gtk;
using Adw;

namespace Publicate.Video {


    public class VideoProcessor : Adw.Window {

        private ProgressBar progress_bar;
        private Label label;
        private Button cancel_button;    

        public VideoProcessor() {

            this.resizable = false;

            var hbox = new Box(Orientation.HORIZONTAL, 8);
            hbox.margin_bottom = 18;
            hbox.margin_top = 18;
            hbox.margin_start = 18;
            hbox.margin_end = 18;

            var vbox = new Box(Orientation.VERTICAL, 8);

            hbox.append (vbox);
            content = hbox;

            label = new Label("Reading Video…");
            progress_bar = new ProgressBar ();
            cancel_button = new Button.from_icon_name ("process-stop-symbolic");

            //  hbox.append(cancel_button);
            vbox.append (label);
            vbox.append(progress_bar);

        }

        public async VideoProcessResult? process_video(string path, ViewerWindow window) {

            this.modal = true;
            this.transient_for = window;
            present();

            var video_file = File.new_for_path(path);
            var video_info = new VideoInfo(video_file);
            yield video_info.read_info();

            var profiles = construct_vp9_profiles().concat(construct_theora_profiles());
            var use_profiles = profiles.where(p => p.suitable_for(video_info));

            use_profiles.iterate(p => p.setup_for(video_info));
            var encoders = use_profiles.select<Encoder>(p => new Encoder(video_file, "/tmp/", p)).to_sequence();
            foreach (var encoder in encoders) {
                encoder.progress_changed.connect((frac, done) => {
                    var amount = frac;
                    amount = amount / (double)encoders.count();
                    Idle.add(() => { progress_bar.fraction += amount; return false; });

                });
            }

            progress_bar.fraction = 0.0;
            label.label = "Encoding Video…";
            yield encode_video(encoders);

            progress_bar.fraction = 1;
            label.label = "Writing PPUB…";

            var manifest = new Ppub.VideoManifest();
            manifest.streams = encoders.select<Ppub.VideoDescription>(e => e.get_video_description()).to_sequence();
            manifest.duration = video_info.duration;
            var ratio_parts = video_info.aspect_ratio.split(":");
            manifest.ratio = new double[] { double.parse(ratio_parts[0]), double.parse(ratio_parts[1]) };

            return new VideoProcessResult(manifest, encoders.select<File>(e => e.get_output_file()).to_sequence());
        }

        private async void encode_video(Invercargill.Enumerable<Encoder> encoders) {
            SourceFunc callback = encode_video.callback;
        
            ThreadFunc<bool> run = () => {
                encoders.parallel_iterate(e => e.encode());
                Idle.add((owned) callback);
                return true;
            };
            new Thread<bool>("encoder thread", run);
            yield;
        }

        public void complete() {
            close();
        }

    }

    public class VideoProcessResult {

        public Ppub.VideoManifest manifest { get; private set; }
        public Invercargill.Enumerable<File> video_files { get; private set; }

        public VideoProcessResult(Ppub.VideoManifest manifest, Invercargill.Enumerable<File> videos) {
            this.manifest = manifest;
            video_files = videos;
        }
    }

}