Recherche avancée

Sur d’autres sites (3954)

• avcodec/pngenc : set default prediction method to PAETH

  6 février, par Michael Niedermayer

  avcodec/pngenc : set default prediction method to PAETH
  this is a good compromise between speed and compression
   rw-r----- 1 michael michael 180987 Feb  6 14:29 lena-def.png
  
   rw-r----- 1 michael michael 128430 Feb  6 14:36 lena-pavg.png
  
   rw-r----- 1 michael michael 126269 Feb  6 14:36 lena-pmixed.png
  
   rw-r----- 1 michael michael 180987 Feb  6 14:35 lena-pnone.png
  
   rw-r----- 1 michael michael 127758 Feb  6 14:35 lena-ppaeth.png
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavcodec/pngenc.c
  • [DH] tests/ref/fate/copy-apng
  • [DH] tests/ref/fate/cover-art-aiff-id3v2-remux
  • [DH] tests/ref/fate/cover-art-flac-remux
  • [DH] tests/ref/fate/cover-art-mp3-id3v2-remux
  • [DH] tests/ref/fate/mov-cover-image
  • [DH] tests/ref/fate/png-icc
  • [DH] tests/ref/fate/png-mdcv
  • [DH] tests/ref/lavf/apng
  • [DH] tests/ref/lavf/apng.png
  • [DH] tests/ref/lavf/gray16be.png
  • [DH] tests/ref/lavf/png
  • [DH] tests/ref/lavf/rgb48be.png
  • [DH] tests/ref/vsynth/vsynth1-mpng
  • [DH] tests/ref/vsynth/vsynth2-mpng
  • [DH] tests/ref/vsynth/vsynth3-mpng
  • [DH] tests/ref/vsynth/vsynth_lena-mpng

• FFmpeg error with ffmpeg.FS("readfile", "output.mp4"). trying to get ffmpeg to work in the react app

  21 juin 2024, par Paul Tham

   const stackVideos = useCallback(
    async (video1) => {
      try {
        console.log("Fetching video2 from storage...");
        const video2Ref = ref(storage, "video2.mp4");
        const video2Url = await getDownloadURL(video2Ref);
        const video2Blob = await (await fetch(video2Url)).blob();

        console.log("Writing video1 to FFmpeg FS...");
        await ffmpeg.FS("writeFile", "video1.mp4", await fetchFile(video1));

        console.log("Writing video2 to FFmpeg FS...");
        await ffmpeg.FS("writeFile", "video2.mp4", await fetchFile(video2Blob));

        console.log("Files in FFmpeg FS after write:");
        const files = await ffmpeg.FS("readdir", "/");
        console.log(files);

        const { start, end } = inputs[0];
        const startSeconds = new Date(`1970-01-01T${start}Z`).getTime() / 1000;
        const endSeconds = new Date(`1970-01-01T${end}Z`).getTime() / 1000;
        const duration = endSeconds - startSeconds;

        console.log("Running FFmpeg command...");
        await ffmpeg.run(
          "-i",
          "video1.mp4",
          "-ss",
          startSeconds.toString(),
          "-t",
          duration.toString(),
          "-i",
          "video2.mp4",
          "-filter_complex",
          "[0:v]scale=1080:-1[v1];[1:v]scale=-1:1920/2[v2scaled];[v2scaled]crop=1080:1920/2[v2cropped];[v1][v2cropped]vstack=inputs=2,scale=1080:1920[vid]",
          "-map",
          "[vid]",
          "-map",
          "0:a",
          "-c:v",
          "libx264",
          "-crf",
          "23",
          "-preset",
          "veryfast",
          "-shortest",
          "output1.mp4"
        );

        console.log("Files in FFmpeg FS after run:");
        const filesAfterRun = await ffmpeg.FS("readdir", "/");
        console.log(filesAfterRun);

        console.log("Reading output1.mp4 from FFmpeg FS...");
        const data = await ffmpeg.FS("readfile", "output1.mp4");
        console.log("after the FS readfile");
        const url = URL.createObjectURL(
          new Blob([data.buffer], { type: "video/mp4" })
        );
        setStackedVideo(url);
        setOutputFileReady(true); // Mark output file as ready
      } catch (err) {
        console.error("FFmpeg error output:", err);
        setError(`FFmpeg run error: ${err.message}`);
        setIsProcessing(false);
      }
    },
    [inputs]
  );


  


  My error seems to be stemming from this line :

  


   const data = await ffmpeg.FS("readfile", "output1.mp4");


  


  Seeing the ffmpeg.wasm documentation i thought the functions for some of the functions had changed, but when I changed it, it seemed like they did not recognise the new functions. Sometimes this will also give me some other errors like worker.js which I dont understand enough to debug this myself.

  


  words word words words words words word words words wordswords word words words wordswords word words words wordswords word words words wordswords word words words wordswords word words words words

  


• ffmpeg fix video orientation

  22 juillet 2020, par PiTheNumber

  A video can contain a meta info about the camera orientation. For example iPhone and other phones set this flag if you turn the device. Problem is while some player read this info and rotate the video accordingly, other players do not.

  



  To fix this the video has to be rotated and the meta info needs to be set correctly.

  



  Does ffmpeg provide a fix for this or do I have to go the hard way (Read rotation, rotate, set meta data)