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• FFmpeg - Concatenate all videos with similar file name ?

  24 décembre 2017, par Pan Hart

  Is there any way to use ffmpeg to concatenate all video files that have the exact same file name for the specified first few characters ?

  For example, if I set it to match the first 5 characters, it will match and concatenate video_1.flv, video_2.flv, video_3.flv and so on.

  But, at the same time, it can also match and concatenate tests_1.flv, tests_2.flv, tests_3.flv and so on.

  Any help will be appreciated !

• avcodec : Implement mpeg4 nvdec hwaccel

  16 novembre 2017, par Philip Langdale

  avcodec : Implement mpeg4 nvdec hwaccel
  This was predictably nightmarish, given how ridiculous mpeg4 is.
  
  I had to stare at the cuvid parser output for a long time to work
  
  out what each field was supposed to be, and even then, I still don't
  
  fully understand some of them. Particularly :
  vop_coded : If I'm reading the decoder correctly, this flag will always
  
             be 1 as the decoder will not pass the hwaccel any frame
  
             where it is not 1.
  
  divx_flags : There's obviously no documentation on what the possible
  
              flags are. I simply observed that this is '0' for a
  
              normal bitstream and '5' for packed b-frames.
  
  gmc_enabled : I had a number of guesses as to what this mapped to.
  
               I picked the condition I did based on when the cuvid
  
               parser was setting flag.
  Also note that as with the vdpau hwaccel, the decoder needs to
  
  consume the entire frame and not the slice.
  

  • [DH] Changelog
  • [DH] configure
  • [DH] libavcodec/Makefile
  • [DH] libavcodec/allcodecs.c
  • [DH] libavcodec/h263dec.c
  • [DH] libavcodec/nvdec.c
  • [DH] libavcodec/nvdec_mpeg4.c
  • [DH] libavcodec/version.h

• Generating Video from Downloaded Images Using Fluent-FFmpeg : Issue with Multiple Image Inputs

  11 août 2023, par Pratham Bhagat

  I am having trouble creating Video from multiple images using fluent-ffmpeg in node.js.

  


  Here, I am getting the images from rquest body and downloading them in **temp **directory

  


     const imageUrls = req.body.imageUrls;
   const timeInBetween = parseFloat(req.query.time_in_between) || 1.0;

const tempDir = path.join(
      context.executionContext.functionDirectory,
      "temp"
    );

const downloadedImages = await Promise.all(
      imageUrls.map(async (imageUrl, index) => {
        try {
          const response = await axios.get(imageUrl, {
            responseType: "arraybuffer",
          });
          const imageName = `image_${index + 1}.png`;
          const imagePath = path.join(tempDir, imageName);
          await fs.writeFile(imagePath, response.data);
          return imagePath;
        } catch (error) {
          context.log(`Error downloading ${imageUrl}: ${error.message}`);
          return null;
        }
      })
    );


  


  I want to combine these images that are in downloadedImages array and create a video

  


  const outputVideoPath = path.join(tempDir, "output.mp4");

    let ffmpegCommand = ffmpeg();

    for (let i = 0; i < downloadedImages.length; i++) {
      context.log(downloadedImages.length);
      ffmpegCommand
        .input(downloadedImages[i])

        .inputOptions(["-framerate", `1/${timeInBetween}`])
        .inputFormat("image2")
        .videoCodec("libx264")
        .outputOptions(["-pix_fmt", "yuv420p"]);
    }

    ffmpegCommand
      .output(outputVideoPath)
      .on("end", () => {
        context.log("Video generation successful.");
        context.res = {
          status: 200,
          body: "Video generation and cleanup successful.",
        };
      })
      .on("error", (err) => {
        context.log.error("Error generating video:", err.message);
        context.res = {
          status: 500,
          body: "Error generating video: " + err.message,
        };
      })
      .run();


  


  By running it and giving value of "time_in_between" as 2 I get video of 2 seconds with a single image.

  


  

  • Utilized Fluent-FFmpeg library to generate a video from a list of downloaded images.

  


  • Expected the video to include all images, each displayed for a specified duration.

  


  • Tried mapping through the image paths and using chained inputs for each image.

  


  • Expected the video to have a sequence of images displayed.

  


  • Observed that the generated video only contained the first image and was of 0 seconds duration.