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• ffmpeg : Create a fake shadow below alpha channel webm/png sequence

  6 mai 2021, par Beneos Battlemaps

  Purpose : I'd like to render out animated 3D meshes as png sequence to use them as animated tokens for virtual tabletop games. To make the mesh looks more natural I'd like to create a fake show beneath the actual token.

  


  Problem : I have a png sequence 1 (as well as a webm file created with ffmpet out of this png sequence if it makes it easier) with alpha channel. To create the webm I use :
ffmpeg -framerate 24 -f image2 -i Idle_Top.%04d.png -c:v libvpx-vp9 -crf 25 -pix_fmt yuva420p Idle_Top.webm (If its relevant). I'd like to render out the png sequence to a webm file that have the current images as well as the transparent shadow beneath the token combined.

  


  Possible workflow : I think a good way to achieve the wanted shadow effect is to use the alpha channel image as a mask on a black picture with the same resolution as the source image 2. Then you have a complete black version of the image. Then you need to place this image beneath the colored image and make a offset of 10px left and 10px down to create the ilusion of perspective 3. At the end the black image below the colored image must have a transparency as well ( 30% visibility should be enough) 4.

  


  Workflow overview

  


  Assets : I've put the webm file and the png files on my gDrive https://drive.google.com/drive/folders/1wznGaPwhKc2UyPpSZBSISa1gs3oixsHR?usp=sharing

  


  Though I work with ffmpeg on a regular basis I have no clue where to start. Can you please help me out with this interesting problem ?

  


  Best regards
Ben

  


• Download,modify and upload video with S3

  9 février 2017, par Gold Fish

  I’m trying to write a Lambda function in nodejs that will download a file from S3 bucket, modify it, and then upload it back to another S3 bucket. For some reason, the algorithm prints the ’Modify Video’ log and then finishes and exit without error. What am I doing wrong ?

  var AWS = require('aws-sdk');
  
  var util = require('util');
  
  var ffmpeg = require('fluent-ffmpeg');
  
  var s3 = require('s3');
  
  
  
  // get reference to S3 client
  
  
  
  var awsS3Client = new AWS.S3();
  
  var options = {
  
    s3Client: awsS3Client,
  
  };
  
  var client = s3.createClient(options);
  
  
  
  exports.handler = function(event, context, callback) {
  
      // Read options from the event.
  
      console.log("Reading options from event:\n", util.inspect(event, {depth: 5}));
  
      var srcBucket = event.Records[0].s3.bucket.name;
  
      // Object key may have spaces or unicode non-ASCII characters.
  
      var srcKey    =
  
      decodeURIComponent(event.Records[0].s3.object.key.replace(/\+/g, " "));
  
      var dstBucket = srcBucket + "-dst";
  
      var dstKey    = "mod_" + srcKey;
  
  
  
      var dwnld_file_name = '/tmp/vid.mp4';
  
      var mdfy_file_name = '/tmp/mod_vid.mp4';
  
  
  
      // Sanity check: validate that source and destination are different buckets.
  
      if (srcBucket == dstBucket) {
  
          callback("Source and destination buckets are the same.");
  
          return;
  
      }
  
  
  
      // Infer the video type.
  
      var typeMatch = srcKey.match(/\.([^.]*)$/);
  
      if (!typeMatch) {
  
          callback("Could not determine the video type.");
  
          return;
  
      }
  
      var videoType = typeMatch[1];
  
      if (videoType != "mp4") {
  
          callback('Unsupported video type: ${videoType}');
  
          return;
  
      }
  
      console.log("Source bucket: ", srcBucket);
  
      console.log("srcKey: ", srcKey);
  
      console.log("Dest bucket: ", dstBucket);
  
      console.log("dstKey: ", dstKey);
  
  
  
      var params = {
  
        localFile: dwnld_file_name,
  
  
  
        s3Params: {
  
          Bucket: srcBucket,
  
          Key: srcKey,
  
        },
  
      };
  
      console.log("params for download: ", params);
  
      var downloader = client.downloadFile(params);
  
      downloader.on('error', function(err) {
  
        console.error("unable to download:", err.stack);
  
        callback("unable to download");
  
      });
  
      downloader.on('end', function() {
  
        console.log("done downloading");
  
        console.log("modify video");
  
        ffmpeg(dwnld_file_name)
  
            .setStartTime('00:00:01')
  
            .setDuration('1').output(mdfy_file_name).on('end', function() {
  
              console.log('Finished processing');
  
              params = {
  
                localFile: mdfy_file_name,
  
                //localFile: dwnld_file_name,
  
                s3Params: {
  
                  Bucket: dstBucket,
  
                  Key: dstKey,
  
                },
  
              };
  
              console.log("params for upload: ", params);
  
              var uploader = client.uploadFile(params);
  
              uploader.on('error', function(err) {
  
                console.error("unable to upload:", err.stack);
  
                callback("unable to upload");
  
              });
  
              uploader.on('end', function() {
  
                console.log("done uploading");
  
                callback('done');
  
                return;
  
              });
  
          });  //
  
      });
  
  };

• Anomalie #4717 : Erreurs nombre d’argument des filtres

  17 avril 2021, par jluc -

  Voici la PR : https://git.spip.net/spip/spip/pulls/160 qui du coup teste aussi $reflection->isInternal()
  et qui utilise la chaine de langue erreur existante.
  Ça permet donc un message d’erreur i18n et qui fait référence au source SPIP au lieu du source PHP compilé que personne n’est sensé connaître.