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• How to improve the animation quality with ffmpeg ?

  17 janvier 2017, par Loïc Poncin

  With ffmpeg I was able to get animation as an MP4 file and then I converted it into a GIF file.

  # Animation
  
  ani = animation.ArtistAnimation(fig, film, interval=100, blit=True, repeat_delay=100)
  
  ani.save('animation.mp4', writer="ffmpeg", fps=30)
  
  
  
  os.system("ffmpeg -i C:\my_path\\animation.mp4 C:\my_path\\animation.gif")

  My problem is that the quality is not really good.

  In my google drive (https://drive.google.com/open?id=0B7P95aWmH4DUbzJCaVZQM3Y0Y1U) you can find 3 files showing the animation : 1 PNG image (good quality), 1 MP4 file (normal quality), 1 GIF file (bad quality).

  How can I keep a good quality during the process ?

• Why does fluent-ffmpeg only work when it throws the error Output stream closed

  29 mars 2024, par volume one

  I am using fluent-ffmpeg to process a video file (and then upload that to Amazon S3). The code is very straightforward but it only works if :

  


  

  • pipe option {end: true} is set in .output()

  


  • which has a side-effect that causes the following console log output

  


  


  


  Processing : 19.261847354642416% done Processing :
32.365144874807335% done Processing : 48.80978326261429% done Processing : 78.35771917058617%
Processing : 91.49377493455148% done Processing :
99.91264359125745% done An error occurred : Output stream closed

  


  


  Despite that error, it seems the file is generated correctly and it gets uploaded to Amazon S3 fine.

  


  This is the fluent-ffmpeg code :

  


  import {PassThrough} from 'node:stream';
import FFMpeg from 'fluent-ffmpeg';

let PassThroughStream = new PassThrough();

             FFMpeg('/testvideo.mp4')
                    .videoCodec('libx264')
                    .audioCodec('libmp3lame')
                    .size(`640x480`)
                    // Stream output requires manually specifying output formats
                    .format('mp4')
                    .outputOptions('-movflags dash')
                    .on('progress', function (progress) {
                        console.log('Processing: ' + progress.percent + '% done');
                    })
                    .on('error', function (err) {
                        console.log('An error occurred: ' + err.message);
                    })
                    .on('end', function () {
                        console.log('FFMpeg Processing finished!');
                    })
                    .output(PassThroughStream, {end: true})
                    .run();

   // Now upload to S3
    try {
          await s3Upload({
              AWSS3Client: 'mys3client',
              Bucket: 'publicbucket,
              ACL: "public-read",
              ContentType: 'video/mp4',
              Key: 'whoever/whatever.mp4',
              Body: PassThroughStream
           });
    } catch (error) {
                    console.log(`s3Upload error`, error)
                }


  


  If I set the pipe output() option to {end: false} then there is no error from fluent-ffmpeg and I get "Processing: 100% done FFMpeg Processing finished!" as the final console log.

  


  BUT the problem is that the s3Upload() does not do anything. There are no errors. Just no activity.

  


  I feel very uncomfortable letting fluent-ffmpeg end in an error even if the code itself does the job intended. It will also cause testing to fail. What could be the issue ?

  


  The command line code is : ffmpeg -i https:/xxxbucket.s3.amazonaws.com/14555/file-example.mp4 -acodec libmp3lame -vcodec libx264 -filter:v scale=w=trunc(oh*a/2)*2:h=480 -f mp4 -movflags dash pipe:1

  


• Continously running a PHP script waiting for videos to trancode

  12 mai 2017, par Ian

  I’m making a transcoding server which uses FFMPEG to convert videos to flv. After user uploads a video it’s queued for processing in amazon Simple Queue Service. System is linux ubuntu.

  Instead of running CRON each 1min I wonder if it would be possible to continously run several PHP scripts (dowload queued files, process downloaded etc). Each of them would have its own queue which would be read every 10s or so looking for new tasks.

  My question is :

  How to detect if the script is already running ? I’d run CRON each 1min and if one of the programs would not be running I’d load it again. How stuff like that is done on linux ? PID files ?

  thanks for help,
  ian