FFmpegConvert/src/main/java/net/knarcraft/ffmpegconverter/converter/AnimeConverter.java

package net.knarcraft.ffmpegconverter.converter;

import net.knarcraft.ffmpegconverter.streams.AudioStream;
import net.knarcraft.ffmpegconverter.streams.StreamObject;
import net.knarcraft.ffmpegconverter.streams.SubtitleStream;
import net.knarcraft.ffmpegconverter.streams.VideoStream;

import java.io.File;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;

public class AnimeConverter extends Converter {
    private String[] audioLang;
    private String[] subtitleLang;
    private boolean toStereo;
    private boolean preventSignsAndSongs;
    private boolean debug = false;

    /**
     * @param ffprobePath           Path/command to ffprobe
     * @param ffmpegPath            Path/command to ffmpeg
     * @param audioLang             List of wanted audio languages in descending order
     * @param subtitleLang          List of wanted subtitle languages in descending order
     * @param toStereo              Convert video with several audio channels to stereo
     * @param preventSignsAndSongs  Prevent subtitles only converting signs and songs (not speech)
     */
    public AnimeConverter(String ffprobePath, String ffmpegPath, String[] audioLang, String[] subtitleLang, boolean toStereo, boolean preventSignsAndSongs) {
        this.ffprobePath = ffprobePath;
        this.ffmpegPath = ffmpegPath;
        this.audioLang = audioLang;
        this.subtitleLang = subtitleLang;
        this.toStereo = toStereo;
        this.preventSignsAndSongs = preventSignsAndSongs;
    }

    public void convert(File file) throws IOException {
        processFile(file.getParentFile(), file);
    }

    /**
     * Reads streams from a file, and converts it to an mp4.
     *
     * @param folder        The folder of the file to process
     * @param file          The file to process
     * @throws IOException  If the BufferedReader fails
     */
    private void processFile(File folder, File file) throws IOException {
        List<StreamObject> streams = probeFile(ffprobePath, file);
        if (streams.isEmpty()) {
            throw new IllegalArgumentException("The file has no valid streams. Please make sure the file exists and is not corrupt.");
        }
        String newPath = fileCollisionPrevention(folder.getAbsolutePath() + File.separator + stripExtension(file) + ".mp4", "mp4");
        printl("Preparing to start process...");
        String[] command = builderCommand(ffmpegPath, file.getName(), streams, newPath);
        ProcessBuilder processBuilder = new ProcessBuilder(command);
        convertProcess(processBuilder, folder);
    }

    /**
     * Generates a command for a ProcessBuilder.
     *
     * @param executable    The executable file for ffmpeg
     * @param fileName      The input file
     * @param streams       A list of ffprobe streams
     * @param outFile       The output file
     * @return              A list of commands
     */
    private String[] builderCommand(String executable, String fileName, List<StreamObject> streams, String outFile) {
        List<String> command = ffmpegWebVideo(executable, fileName);

        if (this.debug) {
            addDebug(command, 50, 120);
        }

        List<AudioStream> audioStreams = filterStreamsByType(streams, "audio");
        List<VideoStream> videoStreams = filterStreamsByType(streams, "video");
        List<SubtitleStream> subtitleStreams = filterStreamsByType(streams, "subtitle");

        audioStreams = filterAudioStreams(audioStreams, audioLang);
        subtitleStreams = filterSubtitleStreams(subtitleStreams, subtitleLang, preventSignsAndSongs);

        VideoStream videoStream = null;
        AudioStream audioStream = null;
        SubtitleStream subtitleStream = null;
        if (videoStreams.size() > 0) {
            videoStream = videoStreams.get(0);
        }
        if (audioStreams.size() > 0) {
            audioStream = audioStreams.get(0);
        }
        if (subtitleStreams.size() > 0) {
            subtitleStream = subtitleStreams.get(0);
        }

        if (videoStream == null) {
            throw new IllegalArgumentException("The file does not have any valid video streams.");
        }

        if (audioStream != null) {
            command.add("-map");
            command.add("0:" + audioStream.getAbsoluteIndex());
            if (toStereo && audioStream.getChannels() > 2) {
                command.add("-af");
                command.add("pan=stereo|FL=FC+0.30*FL+0.30*BL|FR=FC+0.30*FR+0.30*BR");
            }
        }

        if (subtitleStream != null && subtitleStream.getIsImageSubtitle()) {
            command.add("-filter_complex");
            command.add("[0:v:" + videoStream.getAbsoluteIndex() + "][0:" + subtitleStream.getAbsoluteIndex() + "]overlay");
        } else if (subtitleStream != null) {
            command.add("-map");
            command.add("0:" + videoStream.getAbsoluteIndex());
            command.add("-vf");
            String safeFileName = escapeSpecialCharactersInFileName(fileName);
            String subtitleCommand = String.format("subtitles=\"%s\"", safeFileName);
            command.add(subtitleCommand);
        } else {
            command.add("-map");
            command.add("0:" + videoStream.getAbsoluteIndex());
        }

        command.add(outFile);
        return command.toArray(new String[0]);
    }

    @Override
    public String[] getValidFormats() {
        return VIDEO_FORMATS;
    }
}