Recherche avancée

Sur d’autres sites (13208)

• ffmpeg - how can I capture the timestamp of a screenshot using a seek and finding the nearest iframe ?

  17 novembre 2015, par Charles Kirk

  I’ve tried various different methods. ffprobe has always shown sensical results, with the pts_time increasing as the frames go on, using this command :

  ffprobe -show_frames video.mp4 > probestats.txt

  I thought about using that data to find the video frame nearest to the seconds I’m seeking to in ffmpeg, but I am trying to keep this performant, as I’m generating thumbnails on uploads that could exceed 5GB, which means I would end up with 50MB+ probe files to parse.

  So, currently, I’m looping over this ffmpeg command, so as to end up with 10 thumbnails total per file, regardless of length :

  ffmpeg -i video.mp4 -ss 00:00:05 -vf select="eq(pict_type\\,I)[s1];[s1]showinfo[out]" -vframes 1 -q:v 1 thumbs/thumb-1.jpg 2>&1

  The aim is to get the nearest iframe of the seconds I’m seeking to, e.g. find the nearest iframe near the 5 second mark and take a thumbnail — which gives some increased performance.

  The issue is, ffmpeg is outputting seemingly random pts_time’s, definitely not correct compared to the pkt_pts_time shown in ffprobe.

  So as the title states, I’m looking for an ffmpeg command to generate a thumbnail at the nearest iframe to a specified seek, and get the timestamp.

• AS3 NetStream AppendBytes Seek issue

  18 novembre 2015, par AntBirch

  I’m having trouble with NetStream in AS3. The project I am working on allows users to browse a video (locally) and play it back. The issue I am having is that netStream.seek(0); from what I can tell it doesn’t do anything, although I get inside a NetStatusEvent function and NetStream.Seek.Notify is triggered. I’m using NativeProcess and the following function is this makes any difference.

  public function ProgressEventOutputHandler(e:ProgressEvent):void {
  
      videoByteArray = new ByteArray();
  
      nativeProcess.standardOutput.readBytes(videoByteArray, 0, nativeProcess.standardOutput.bytesAvailable);
  
      netStream.appendBytes(videoByteArray);
  
  }

  Am I missing something here ? I am pausing netStream before using netStream.seek(0);.

  EDIT :

  In an attempt to fix this issue I followed the instructions by VC.One I’ve done the following :

  • Moved videoByteArray = new ByteArray(); to my init function and also created tempVideoByteArray = new ByteArray(); in this function.

  • Update my ProgressEventOutputHandler function so that it no longer created a new ByteArray for videoByteArray and changed this line - nativeProcess.standardOutput.readBytes(videoByteArray, videoByteArray.length, nativeProcess.standardOutput.bytesAvailable);

  I have changed nothing else and now the video will not load. If I allow a new ByteArray to be created inside the ProgressEventOutputHandler function the video does load again.

• configure : update copyright year

  1er janvier, par Lynne

  configure : update copyright year
  On 01/01/2025 19:05, Peter Ross wrote :
  
  > FFmpeg turns 25 this year.
  

  • [DH] configure