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• C# Bitmap to AVI / WMV with Compression

  5 juillet 2019, par Digitalsa1nt

  Prelude :

  I’m going to preface this with, I have been learning C# in my spare time at work, and that I have been staring at code for a solid two days trying to wrap my head around this problem. I am developing some software to be used with a visualiser that connects by USB to a standard Desktop PC, the software detects the capture device and loads frames into bitmap using a New Frame Event, this is then displayed in a ’picture box’ as a live video stream. The problem as it sits is trying to encorporate the ability to record the stream and save to file, preferably a WMV or a compressed AVI.

  What’s been tried :

  I have considered and looked into the following :

  SharpAVI - cant seem to get this to compress or save the frames properly as it appears to mainly look at existing AVI files.

  AForge.Video.VFW - AVI files can be created but are far too large to be used, due to restrictions on the user areas of the individuals who will be using this software.

  AForge.Video.FFMPEG - Again due to considerations of those using this software I can’t have unmanaged DLL’s sat in the output folder with the Executable file, and unfortunately this particular DLL cant be compiled properly using Costura Fody.

  AVIFile Library Wrapper (From Code Project) - Again can’t seem to get this to compress a stream correctly from Bitmaps from the New Frame Events.

  DirectShow - Appears to use C++ and unfortunately is beyond my skill level at this time.

  The Relevant Code Snippets :

  Current References :

  using System.Data;
  
  using System.Drawing;
  
  using System.Linq;
  
  using System.Text;
  
  using System.Threading.Tasks;
  
  using System.Windows.Forms;
  
  using System.Resources;
  
  using System.Drawing.Imaging;
  
  using System.IO;
  
  //Aforge Video DLL's
  
  using AForge.Video;
  
  using AForge.Video.VFW;
  
  using AForge.Video.DirectShow;
  
  //Aforge Image DLL's
  
  using AForge.Imaging;
  
  using AForge.Imaging.Formats;
  
  using AForge.Imaging.Filters;
  
  //AviLibrary
  
  using AviFile;

  Global Variables :

      #region Global Variables
  
  
  
      private FilterInfoCollection CaptureDevice; // list of available devices
  
      private VideoCaptureDevice videoSource;
  
      public System.Drawing.Image CapturedImage;
  
  
  
      bool toggleMic = false;
  
  
  
      bool toggleRec = false;
  
      //aforge
  
      AVIWriter aviWriter;
  
      Bitmap image;
  
  
  
  
  
      #endregion

  Code for Displaying Stream

      #region Displays the Stream
  
  
  
      void videoSource_NewFrame(object sender, NewFrameEventArgs eventArgs)
  
      {
  
          picBoxStream.SizeMode = PictureBoxSizeMode.Zoom;
  
          picBoxStream.Image = (Bitmap)eventArgs.Frame.Clone();// clones the bitmap
  
  
  
  
  
          if (toggleRec == true)
  
          {
  
              image = (Bitmap)eventArgs.Frame.Clone();
  
              aviWriter.AddFrame(image);
  
          }
  
      }
  
  
  
      #endregion

  Current Code for Recording Stream

      #region Record Button
  
  
  
      private void btnRecord_Click(object sender, EventArgs e)
  
      {
  
          if (toggleRec == false)
  
          {
  
              saveAVI = new SaveFileDialog();
  
              saveAVI.Filter = "AVI Files (*.avi)|*.avi";
  
  
  
              if (saveAVI.ShowDialog() == DialogResult.OK)
  
              {
  
                  aviWriter = new AVIWriter();
  
                  aviWriter.Open(saveAVI.FileName, 1280, 720);
  
  
  
                  toggleRec = true;
  
                  Label lblRec = new Label();
  
              }
  
  
  
          }
  
          else if (toggleRec == true)
  
          {
  
              aviWriter.Close();
  
              toggleRec = false;
  
          }
  
      }
  
  
  
      #endregion

  I apoligise if the above code doesn’t look quite right, I have been swapping, changing and recoding those three sections a lot in order to find a working combination. This means that it’s rather untidy but I didn’t see the point in cleaning it all up until I had the code working. That being said really any help that you can provide is greatfully recieved, even if it’s a case of what I want to do just cannot be done.

  Thank you in advance.

  EDIT : 2019 :

  It’s been awhile since I posted this and it still gets the odd bit of interest here and there. Back when I posted this I was teaching myself to code and I had this weird quirk that I didn’t like using 3rd party libraries if I could avoid it, I wanted to do my own work, since then I’ve learnt a lot and one of those things is that the open source world is immense, impressive and kind. So if there is a 3rd party library that does what you want just use it, it’ll save you time.

• FFMPEG unexpected behavior inside nodejs Lambda function

  29 juin 2021, par Rafael Castelo

  I'm trying to burn subtitles into a video using FFMPEG. I'm working within a serverless lambda architecture, and we've used FFMPEG with lambda by using layers before and everything worked okay.
Now I'm trying to burn subtitles inside a video using the following command :

  


  ffmpeg -i https://some-bucket.s3.region.amazonaws.com/my-video.mp4 -f mp4 -vf subtitles=sub.srt subtitled-video.mp4


  


  The issue is, that command works perfectly inside my local machine or any other instance I try. However inside my lambda function, I just get the original video without the subtitles.
At first I thought it could be the ffmpeg build I was using, but after trying wiht it, it worked in every other environment I tried.

  


  Also I don't get any error in the output from the ffmpeg job inside lambda, everything seeems to work okay. Just that it doesn't burn the subtitles

  


  I hope you can help me with this issue. Or at least point me in the right direction.

  


  Thanks in advance

  


• how to download portion of video which was uploaded into AWS s3 bucket, though Nodejs SDKs

  22 février 2024, par rama rangeswara reddy

  I have uploaded a 1GB .mp4 file to an AWS S3 bucket. Using the AWS-SDK provided by the npm package, I am able to download the entire video. However, I have a specific requirement to generate a thumbnail at the 6-second mark of the video. Currently, I download the entire 1GB video to my local machine and then generate the thumbnail at the desired duration.

  


  To optimize server resources and reduce disk load, I plan to download only the first 10 seconds of the video, which should be approximately 10MB or less in size. By doing so, I can significantly reduce download time and server load while still fulfilling my requirement of generating the thumbnail at the 6-second mark. Therefore, instead of downloading the entire 1GB video, I aim to download only the 10MB segment corresponding to the first 10 seconds of the video.

  


  I am using nodejs, expressJS, as backed Technologies.

  


  `

  


  `async function downloadS3FileToLocalDirAndReturnPath(videoKey) {
    return new Promise(async (resolve, reject) => {
        try {
            AWS.config.update({
                accessKeyId: config.AWS.KEYS.accessKeyId,
                secretAccessKey: config.AWS.KEYS.secretAccessKey,
                region: config.AWS.KEYS.region,
                httpOptions: config.AWS.KEYS.httpOptions
            });
            const s3 = new AWS.S3();

            // Specify the local file path where you want to save the downloaded video
            const localFilePath = `${os.tmpdir()}/${Date.now()}_sre.mp4`;

            // Configure the parameters for the S3 getObject operation
            const params = {
                Bucket: config.AWS.S3_BUCKET,
                Key: videoKey
            };

            const result = await s3.getObject(params).promise();
            const fileContent = result.Body;
            fs.writeFileSync(localFilePath, fileContent);
            resolve(localFilePath);
        } catch (error) {
            reject(error);
        }
    });
}`


  


  this code was working fine to download the whole video , but i need to download only first 10 seconds duration

  


  S3 : How to do a partial read / seek without downloading the complete file ?

  


  I tried this ,before posting this question with above post, video was downloading , it was not playing , by throwing this error , the file contains no playable streams

  


  async function generateThumbnails(videoKey) {

const s3 = new AWS.S3();

const params = {
    Bucket: KEYS.bucket,
    Key: videoKey, // Specify the key of the video file in S3
    Range: `bytes=0-${1024 * 800}`, // Specify the range of bytes you want to retrieve
};

const file = fs.createWriteStream(`/tmp/${Date.now()}_rama.mp4`);

const s3Stream = s3.getObject(params).createReadStream();

s3Stream.pipe(file);

s3Stream.on("error", (error) => {
    console.log("Error Occured while File downloading!! ");
});

s3Stream.on("finish", () => {
    console.log("File downloaded Successfully ");
});


  


  }