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• FFMPEG scaling watermark

  27 mai 2020, par razz

  I'm currently using a command to add a watermark + scrolling text and some extra encoding options to a video.

  



  The watermark + scrolling text are made to fit correctly when the video is 1280px (width) but when the original video is any other size (for example 1920px) the watermark + scrolling text gets tiny so i need to scale this.

  



  watermark size= 400x48

  



  Current code i'm using

  



  -i logo.png -filter_complex "[0:v][1:v] overlay=x=(main_w-overlay_w):y=(main_h-overlay_h-4)[out];[out]drawtext=fontsize=20:font=tahoma:alpha=0.5:fontcolor=white:borderw=0.8:bordercolor=black:text=THIS IS MY SCROLLING TEXT :y=line_h-4:x=w-(t-300)*w/40" -keyint_min 20 -vcodec libx264 -c:a copy -b:v 1700k -movflags +faststart

  



  I think that this piece of code scale2ref=400*iw/1280:48*iw/1280 might do the work but i have no clue where exactly to paste this in. I keep on getting errors.

  


• fluent-ffmpeg throw er when concatenate videos

  2 mai 2020, par Romualdo Arrechea Hernández

  I'm using fluent-ffmpeg version 2.1.2.
When I execute the current code the output show off a error message :

  



  var ffmpeg = require('fluent-ffmpeg');
var glob= require('glob');
ffmpeg.setFfmpegPath("/usr/bin/ffmpeg");
ffmpeg.setFfprobePath("/usr/bin/ffprobe");
var command = ffmpeg();

const path='/home/username/somefolder/*/output.mp4';

var videos=glob.sync(path);
var output="./output.mp4";
videos.map(video=>command.addInput(video));
command.mergeToFile(output);


  



  the console output>

  



  **events.js:287&#xA;      throw er; // Unhandled &#x27;error&#x27; event&#xA;      ^&#xA;&#xA;Error: ffmpeg exited with code 1: Conversion failed!&#xA;&#xA;    at ChildProcess.<anonymous> (/home/r/Projects/prueba/node_modules/fluent-ffmpeg/lib/processor.js:182:22)&#xA;    at ChildProcess.emit (events.js:310:20)&#xA;    at Process.ChildProcess._handle.onexit (internal/child_process.js:275:12)&#xA;Emitted &#x27;error&#x27; event on FfmpegCommand instance at:&#xA;    at emitEnd (/home/r/Projects/prueba/node_modules/fluent-ffmpeg/lib/processor.js:424:16)&#xA;    at endCB (/home/r/Projects/prueba/node_modules/fluent-ffmpeg/lib/processor.js:544:13)&#xA;    at handleExit (/home/r/Projects/prueba/node_modules/fluent-ffmpeg/lib/processor.js:170:11)&#xA;    at ChildProcess.<anonymous> (/home/r/Projects/prueba/node_modules/fluent-ffmpeg/lib/processor.js:182:11)&#xA;    at ChildProcess.emit (events.js:310:20)&#xA;    at Process.ChildProcess._handle.onexit (internal/child_process.js:275:12)**&#xA;</anonymous></anonymous>

  



  The video should be created, but it's unable to concat. Some clue ?

  


• Interesting behavior in Media Source Extensions

  28 mai 2020, par newtonian_fig

  I'm trying to build a fairly standard video player using Media Source Extensions ; however, I want the user to be able to control when the player moves on to a new video segment. For example, we might see the following behavior :

  



  

  1. Video player plays 1st segment

  


  2. Source Buffer runs out of data causing the video to appear paused

  


  3. When the user is ready, they click a button that adds the 2nd segment to the Source Buffer

  


  4. The video continues by playing the 2nd segment

  


  



  This works well, except that when the video appears paused during step 2 it doesn't stop at the last frame of the 1st segment. Instead, it stops two frames before the end of the 1st segment. Those last two frames aren't being dropped, they just get played after the user clicks the button to advance the video. This is an issue for my application, and I'm trying to figure out a way to make sure all of the frames from the 1st segment get played before the end of step 2.

  



  I suspect that these last two frames are getting held up in the video decoder buffer. Especially since calling endOfStream() on my Media Source after adding the 1st segment to the Source Buffer causes the 1st segment to play all the way through with no frames left behind.

  



  Additional Info

  



  

  • I created each video segment file from a series of PNGs using the following ffmpeg command

  


  



  ffmpeg -i %04d.png -movflags frag_keyframe+empty_moov+default_base_moof video_segment.mp4

  



  

  • Maybe this is a clue ? End of stream situations not handled correctly (last frames are dropped)

  


  • Another interesting thing to note is that if the video only has 2 frames or less, MSE doesn't play it at all.

  


  • The browser I'm using is Chrome. The code for my MSE player is just taken from the Google Developers example, but I'll post it here for completeness. This code only covers up to step 2 since that's where the issue is.

  


  



  <code class="echappe-js">&lt;script&gt;&amp;#xA;const mediaSource = new MediaSource();&amp;#xA;video.src = URL.createObjectURL(mediaSource);&amp;#xA;mediaSource.addEventListener(&amp;#x27;sourceopen&amp;#x27;, sourceOpen, { once: true });&amp;#xA;&amp;#xA;function sourceOpen() {&amp;#xA;  URL.revokeObjectURL(video.src);&amp;#xA;  const sourceBuffer = mediaSource.addSourceBuffer(&amp;#x27;video/mp4; codecs=&quot;avc1.64001f&quot;&amp;#x27;);&amp;#xA;  sourceBuffer.mode = &amp;#x27;sequence&amp;#x27;;&amp;#xA;&amp;#xA;  // Fetch the video and add it to the Source Buffer&amp;#xA;  fetch(&amp;#x27;https://s3.amazonaws.com/bucket_name/video_file.mp4&amp;#x27;)&amp;#xA;  .then(response =&gt; response.arrayBuffer())&amp;#xA;  .then(data =&gt; sourceBuffer.appendBuffer(data));&amp;#xA;}&amp;#xA;&amp;#xA;&lt;/code&gt;&lt;/pre&gt;&amp;#xA;