FFmpeg.pde

import java.io.*;
import java.net.URLDecoder;
import java.nio.charset.StandardCharsets;
import java.text.NumberFormat;
import java.util.HashMap;
import java.util.List;
import java.util.ArrayList;
import java.util.Map;
import java.util.function.Consumer;
import java.util.regex.Matcher;
import java.util.regex.Pattern;


class FFmpegEngine {
  Pattern framePattern = Pattern.compile("^frame=(\\d+)$");
  String ffmpegPath;
  public int framecount = 0;

  Map<String, String> variantToFilename = new HashMap<>();

  // https://github.com/eugeneware/ffmpeg-static/releases/download/b5.0.1/darwin-arm64.gz
  static final String DOWNLOAD_URL = "";
  
  public String log = "";


  FFmpegEngine() {
    variantToFilename.put("macos-x86_64", "darwin-x64");
    variantToFilename.put("macos-aarch64", "darwin-arm64");
    variantToFilename.put("windows-amd64", "win32-x64");
    variantToFilename.put("linux-amd64", "linux-x64");
    variantToFilename.put("linux-arm", "linux-arm");
    variantToFilename.put("linux-aarch64", "linux-arm64");
    
    String ffmpegName = isWindows() ? "ffmpeg.exe" : "ffmpeg";
    File ffmpegFile = new File(sketchPath()+"/data/engine/ffmpeg/"+ffmpegName);
    ffmpegPath = ffmpegFile.getAbsolutePath();

    if (!ffmpegFile.exists()) {
      System.err.println("FFMPEG NOT FOUND");
      
      // download the binary from DOWNLOAD_URL, use a ProgressMonitor to track it
      // https://docs.oracle.com/javase/tutorial/uiswing/components/progress.html
    }
  }


  String[] getFormats() {
    return new String[] {
      "MPEG-4",
      "MPEG-4 (Lossless 4:2:0)",
      "MPEG-4 (Lossless 4:4:4)",
      "Apple ProRes 4444",
      "Animated GIF",
      "Animated GIF (Loop)"
    };
  }


  void write(File movieFile, File[] imgFiles, File soundFile,
             int width, int height, double fps, String formatName) throws IOException {
    
    log = "";
    
    // Write a temporary file with the names of all the images.
    // This removes the requirement for images using %04d format (and having
    // to detect the exact variant). Also, the number of images is likely to
    // be too long for command line arguments on some platforms.
    File listingFile = File.createTempFile("listing", ".txt");
    PrintWriter writer = new PrintWriter(new FileWriter(listingFile));
    for (File file : imgFiles) {
      writer.println("file '" + file.getAbsolutePath() + "'");
    }
    writer.flush();
    writer.close();

    // path specified by the user (may be changed later to append file type)
    String outputPath = movieFile.getAbsolutePath();

    List<String> cmd = new ArrayList<>();
    cmd.add(ffmpegPath);

    // delete the file if it already exists
    cmd.add("-y");

    // set frame rate
    cmd.add("-r");
    cmd.add(String.valueOf(fps));

    // input format is image files
    cmd.add("-f");
    cmd.add("image2");

    // allow absolute paths in the file list
    cmd.add("-safe");
    cmd.add("0");

    // use the concatenation filter to read our entries from a file
    // https://trac.ffmpeg.org/wiki/Concatenate
    // (not enough to simply specify -i with a .txt file)
    cmd.add("-f");
    cmd.add("concat");

    // temporary file with the list of all images
    cmd.add("-i");
    cmd.add(listingFile.getAbsolutePath());

    // pipe:1 sends progress to stdout, pipe:2 to stderr
    cmd.add("-progress");
    cmd.add("pipe:2");

    String formatArgs = "fps=" + fps;
    if (width != 0 && height != 0) {
      formatArgs += ",scale=" + width + ":" + height + ":flags=lanczos";
    }

    if (soundFile != null && !formatName.contains("GIF")) {
      cmd.add("-i");
      cmd.add(soundFile.getAbsolutePath());
    }

    if (formatName.startsWith("MPEG-4")) {
      // slideshow: http://trac.ffmpeg.org/wiki/Slideshow
      // options for compatibility: https://superuser.com/a/424024

      // use the h.264 video codec
      cmd.add("-vcodec");
      cmd.add("libx264");

      if (formatName.contains("4:2:0")) {
        // Best compatibility with QuickTime, macOS, and others
        cmd.add("-pix_fmt");
        cmd.add("yuv420p");

        // https://trac.ffmpeg.org/wiki/Encode/H.264
        cmd.add("-preset");
        // can also use "veryslow" for better compression
        cmd.add("ultrafast");

        cmd.add("-crf");
        cmd.add("0");

      } else if (formatName.contains("4:4:4")) {
        // Based on https://stackoverflow.com/a/18506577
        // Not compatible with QuickTime and macOS, but works in VLC
        cmd.add("-pix_fmt");
        cmd.add("yuv444p");

        cmd.add("-profile:v");
        cmd.add("high444");

        cmd.add("-preset:v");
        cmd.add("slow");

        cmd.add("-crf");
        cmd.add("0");

      } else {
        cmd.add("-pix_fmt");
        cmd.add("yuv420p");

        // decent quality images
        cmd.add("-crf");
        cmd.add("21");  // 18 to 25, with 18 the lowest
      }

      // if there's a resize, specify it and the type of scaling
      if (width != 0 && height != 0) {
        cmd.add("-vf");
        cmd.add(formatArgs);
      }

      if (soundFile != null) {
        cmd.add("-acodec");
        cmd.add("aac");
      }

      // move container metadata to the beginning of the file
      cmd.add("-movflags");
      cmd.add("faststart");

      if (!outputPath.toLowerCase().endsWith(".mp4")) {
        outputPath += ".mp4";
      }

    } else if (formatName.contains("ProRes 4444")) {
      // https://ottverse.com/ffmpeg-convert-to-apple-prores-422-4444-hq/
      // https://avpres.net/FFmpeg/im_ProRes.html

      cmd.add("-c:v");
      cmd.add("prores_ks");

      cmd.add("-profile:v");
      cmd.add("4");

      cmd.add("-vendor");
      cmd.add("apl0");

      cmd.add("-bits_per_mb");
      cmd.add("8000");

      cmd.add("-pix_fmt");
      cmd.add("yuva444p10le");

      if (soundFile != null) {
        cmd.add("-c:a");
        cmd.add("copy");
      }

      if (!outputPath.toLowerCase().endsWith(".mov")) {
        outputPath += ".mov";
      }

    } else if (formatName.startsWith("Animated GIF")) {
      // ffmpeg -r 30 -f image2 -safe 0 -f concat -i listing.txt -vf "fps=30,scale=320:-1:flags=lanczos,split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse" -loop 0 ~/Desktop/output.gif
      // sets the gif palette nicely, based on https://superuser.com/a/556031
      formatArgs += ",split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse";
      cmd.add("-vf");
      cmd.add(formatArgs);

      // https://www.ffmpeg.org/ffmpeg-formats.html#gif-2
      cmd.add("-loop");
      // -1 means no loop, 0 means infinite loop (1+ means number of loops?)
      cmd.add(formatName.contains("Loop") ? "0" : "-1");

      if (!outputPath.toLowerCase().endsWith(".gif")) {
        outputPath += ".gif";
      }
    }

    cmd.add(outputPath);

    // pass cmd to Runtime exec
    // read the output and set the progress bar
    // show a message (success/failure) when complete
    

    // https://stackoverflow.com/a/33386692
    Process p = new ProcessBuilder(cmd).start();
    StreamGobbler outputGobbler = new StreamGobbler(p.getInputStream(), System.out::println);
    StreamGobbler errorGobbler = new StreamGobbler(p.getErrorStream(), line -> {
      log += line+"\n";
      
      // TODO handle process.isCanceled()
      Matcher m = framePattern.matcher(line);
      if (m.find()) {
        framecount = Integer.parseInt(m.group(1));
      }
      //System.out.println(line);
    });

    new Thread(outputGobbler).start();
    new Thread(errorGobbler).start();
    try {
      int result = p.waitFor();
      //System.out.println("encoding result was " + result);
      if (result != 0) {
        throw new IOException("Unknown error while creating movie. " +
                              "(FFmpeg result was " + result + ")");
      }

    } catch (InterruptedException ignored) {  }
  }


  class StreamGobbler implements Runnable {
    final private InputStream inputStream;
    final private Consumer<String> consumeInputLine;

    public StreamGobbler(InputStream inputStream, Consumer<String> consumeInputLine) {
      this.inputStream = inputStream;
      this.consumeInputLine = consumeInputLine;
    }

    public void run() {
      new BufferedReader(new InputStreamReader(inputStream)).lines().forEach(consumeInputLine);
    }
  }


  NumberFormat formatter = NumberFormat.getInstance();
}