Recherche avancée

Sur d’autres sites (2730)

• Error while transcoding video from one format to another

  24 octobre 2019, par MalTec

  I am using xuggler API to transcode Video from one format to another.

  Following the example, provided by

  http://wiki.xuggle.com/MediaTool_Introduction & http://www.javacodegeeks.com/2011/02/xuggler-tutorial-transcoding-media.html

   public void convertVideo() {
  
  
  
   String sourceUrl = getResourceDirectory() + "/in/AV36_1.AVI";
  
   String destUrl = getResourceDirectory() + "/out/output.mp4";
  
  
  
   IMediaReader reader = ToolFactory.makeReader(sourceUrl);
  
  
  
   // add a viewer to the reader, to see progress as the media is
  
   // transcoded
  
   reader.addListener(ToolFactory.makeViewer(true));
  
  
  
   // create a writer which receives the decoded media from
  
   // reader, encodes it and writes it out to the specified file
  
   IMediaWriter writer = ToolFactory.makeWriter(destUrl, reader);
  
  
  
   // add a debug listener to the writer to see media writer events
  
   writer.addListener(ToolFactory.makeDebugListener());
  
  
  
  
  
   ////
  
   ////       // create the media writer
  
   reader.addListener(ToolFactory.makeWriter(destUrl, reader));
  
  
  
   // read packets from the source file, which dispatch events to the
  
   // writer, this will continue until 
  
  
  
  
  
   while (reader.readPacket() == null)
  
    do {} while (false);
  
  }

  Provides Could Not Open Exception :

    Exception in thread "main" java.lang.RuntimeException: could not open: D:\Malhar\project_works\VideoConvertter/resources/in/AV36_1.AVI
  
      at com.xuggle.mediatool.MediaReader.open(MediaReader.java:637)
  
      at com.xuggle.mediatool.MediaReader.readPacket(MediaReader.java:434)
  
      at util.VideoEncoder.convertVideo(VideoEncoder.java:38)
  
      at ConvertVideo.main(ConvertVideo.java:12)

  Have tried with different file to.. But, the result is same.

• System.Diagnostics.Process pipe (vertical bar) not accepted as argument

  28 septembre 2019, par emp

  I’m trying to execute this code using System.Diagnostics.Process. It works fine in command line. But in C# it’s failing on the | character.

  var myProcess = new Process();
  
  var p = new ProcessStartInfo();
  
  
  
  var sArgs = " -i emp.mp3 -f wav - | neroAacEnc -ignorelength -q 0.5 -if - -of emp.mp4";
  
  p.FileName = "ffmpeg.exe";
  
  p.CreateNoWindow = false;
  
  p.RedirectStandardOutput = false;
  
  p.UseShellExecute = false;
  
  p.Arguments = sArgs;
  
  
  
  myProcess.StartInfo = p;
  
  
  
  myProcess.Start();
  
  myProcess.WaitForExit();

  It gives the following error :

  Unable to find a suitable output format for ’|’ : Invalid argument

  I’ve looked around on stackoverflow and found the following hint but it is also not working :

  var psi = new ProcessStartInfo("ffmpeg.exe");
  
  psi.Arguments = 
  
      "\"-i emp.mp3 -f wav -\" | \"neroAacEnc -ignorelength -q 0.5 -if - -of emp.mp4\"";
  
  psi.CreateNoWindow = false;
  
  psi.UseShellExecute = false;
  
  
  
  var process = new Process { StartInfo = psi };
  
  
  
  process.Start();
  
  process.WaitForExit();

  gives the following error :

  Unrecognized option ’i emp.mp3 -f wav -’
  Failed to set value ’|’ for option ’i emp.mp3 -f wav -’

• How to correctly calculate which segments are ready to be downloaded using MPEG-DASH

  24 avril 2019, par igal k

  What i’m trying to do ?

  Write a simple MPEG-DASH client using the SegmentTemplate pattern to calculate which segments are ready to be downloaded for a live source.

  A picture taken using chrome’s debugging tools at a moment X showing an mpd request(8af651fd747.....mpd) and the actual segments fetched respectfully to that request.

  

  Given the following MPD

  <mpd availabilitystarttime="2019-04-24T06:43:32Z" maxsegmentduration="PT4.096S" minbuffertime="PT4.096S" minimumupdateperiod="PT15.835S" profiles="urn:mpeg:dash:profile:isoff-live:2011" publishtime="2019-04-24T11:14:01Z" suggestedpresentationdelay="PT11.878S" timeshiftbufferdepth="PT65.536S" type="dynamic" xmlns="urn:mpeg:dash:schema:mpd:2011">
  
    <location>https://content-aaps1.uplynk.com/channel/8af651fd7473474f86a05ffb0a1c8972.mpd?rmt=wv&amp;amp;cid=8af651fd7473474f86a05ffb0a1c8972&amp;amp;oid=600e5c27541344a1bf3818617ad712ce&amp;amp;prettydash=1&amp;amp;exp=1556091088&amp;amp;rn=4138683939&amp;amp;tc=1&amp;amp;ct=c&amp;amp;sig=5fb7f0c18f3f1d2ad4fdee53c02c1e1ed904bc5e8474f4ebf886d209ff7f21c9&amp;amp;pbs=05b6594bcf4b4728ac1094976a80194d</location>
  
    <period start="PT2826.240S">
  
      <adaptationset maxframerate="30" maxheight="720" maxwidth="1280" mimetype="video/mp4" segmentalignment="true" startwithsap="1">
  
        <representation bandwidth="2604473" codecs="avc1.64001e" framerate="30" height="360" scantype="progressive" width="640">
  
          <baseurl>https://x-default-stgec.uplynk.com/aapm/slices/8c1/600e5c27541344a1bf3818617ad712ce/8c1027496a964b049f1bd5895f8f0412/</baseurl>
  
          <segmenttemplate duration="368640" initialization="https://x-default-stgec.uplynk.com/aapm/slices/8c1/600e5c27541344a1bf3818617ad712ce/8c1027496a964b049f1bd5895f8f0412/$RepresentationID$_init.mp4?pbs=05b6594bcf4b4728ac1094976a80194d&amp;amp;_jt=l&amp;amp;chid=8af651fd7473474f86a05ffb0a1c8972" media="$RepresentationID$$Number%08d$.m4f?pbs=05b6594bcf4b4728ac1094976a80194d&amp;amp;_jt=l&amp;amp;chid=8af651fd7473474f86a05ffb0a1c8972" presentationtimeoffset="254361599" startnumber="690" timescale="90000"></segmenttemplate>
  
        </representation>
  
      </adaptationset>
  
    </period>
  
    <utctiming schemeiduri="urn:mpeg:dash:utc:http-iso:2014" value="https://content-aaps1.uplynk.com/misc/utcservertime"></utctiming>
  
  </mpd>

  I see that the next segment request should be #3955

  What i have tried so far

      period.end = 1556104456;
  
      period.start = 2826;
  
      availability_start_time = 1556088212;
  
      max_segment_duration = 4;
  
      time_shift_buffer_depth = 65

  So, first of all, i read DASH-IF-IOP 4.3 section 4.3.4.2 page #82 and implemented the following code :

     int k1 = 1;
  
  int period_duration = period.end - (period.start + data_.availability_start_time);
  
  int k2 = ceil((float)period_duration / (float)data_.max_segment_duration);
  
  double duration = ((float)representation.duration / (float)representation.timeScale);
  
  size_t live_edge = std::min(
  
      (int)floor((float)((data_.publish_time - data_.availability_start_time - period.start) / duration)), k2);
  
  
  
  size_t oldest = std::max(k1, (int)floor((float)((data_.publish_time - data_.availability_start_time - period.start -
  
                                                      data_.time_shift_buffer_depth) /
  
                                                  duration)));

  after calculating everything : k1=1, k2=3355, live_edge=3272 and oldest=3256

  Also tried using ffmpeg’s dashdec.c

  for min_segment :

  if (c->is_live && pls->fragment_duration)
  
      {
  
          num = pls->first_seq_no + (((get_current_time_in_sec() - c->availability_start_time) - c->time_shift_buffer_depth) * pls->fragment_timescale) / pls->fragment_duration;
  
      }

  for max_segment :

  num = pls->first_seq_no + (((get_current_time_in_sec() - c->availability_start_time)) * pls->fragment_timescale) / pls->fragment_duration;

  after a small modification :

  size_t pmax = (((data_.publish_time - data_.availability_start_time))) / duration;
  
  size_t pmin = ((data_.publish_time - data_.availability_start_time) - data_.time_shift_buffer_depth) / duration;

  pmin=3946 pmax=3961

  in the ffmpeg example, i had to manually remove the first_seq_no variable because it looked like i doubled added the SegmentTemplate@StartNumber.

  even after succeeding in this task, how do i exactly build the request list of Segment(NOW) ----> Segment(LIVE_EDGE)