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• Saving highest quality video from video-capture card

  23 décembre 2013, par DusteD

  I have a machine with 2x3 3ghz dual-core xeon and 4x10krpm scsi 320 disks in raid0.
  The capture card is an osprey 560 64 bit pci card.
  Operating system is currently Windows Server 2003.

  The video-stream that I can open with VLC using direct show is rather nice quality.
  However, trying to save this video-stream without loss of quality has proven quite difficult,
  using the h264 codec I am able to achieve a satisfying quality, however, all 4 cores jump to 100% load after a few second and then it start dropping frames, the machine is not powerful enough for realtime encoding. I've not been able to achieve satisfying mpeg1 or 4 quality, no matter which bitrate I set..

  Thing is, the disks in this machine are pretty fast even by todays standard, and they are bored.. I don't care about disk-usage, I want quality.
  I have searched in vain for a way to pump that beautiful videostream that I see in VLC onto the disk for later encoding, I reckon the disks would be fast enough, or maybe something which would apply a light compression, enough that the disks can keep up, but not so much as to loose visible quality.

  I have tried FFMPEG as it seems capable of streaming a yuv4 stream down to the disk, but ofcause FFMPEG is unable to open the dshow device ( same error as this guy Ffmpeg streaming from capturing device Osprey 450e fails )

  Please recommend a capable and (preferably) software which can do this.

• Overlay video with alpha using FFmpeg on macOS Catalina... problems

  16 octobre 2019, par jogga

  In previous versions of macOS (10.14 Mojave and older) I used FFmpeg to overlay a video with alpha on top of another video with much success. Now when updated to macOS Catalina the same FFmpeg commands suddenly doesn’t work. It just produces black where the transparency should have been according to the alpha channel. The video I overlay on top is a ProRes 4444 file (which includes an alpha channel) and it no longer works as expected.

  I have tried several versions of FFmpeg from the nightly builds to the latest stable one (version 4.2.1) to no avail. Nothing works :-(

  The simplest form of the command I have been using looks like this :

  ffmpeg -y -i skiing.mp4 -i subtitles.ap4h -filter_complex overlay subtitled.m4v 

  Doesn’t work. But if I replace the subtitles.ap4h file with a simple .png image with alpha, it works ?

  I have also been experimenting with the blend filter, but I really don’t understand the gist of it yet.

  Can someone please shed some light on this. Have anyone else out there seen this problem.

  Do you have any suggestions on how to use the blend filter instead of the overlay filter to accomplish the same task ?

  You can find the sample files I used in my dropbox...

  https://www.dropbox.com/s/8z3grpsbejb1na0/skiing.mp4?dl=0
  https://www.dropbox.com/s/8c79lg07rbuqyhn/subtitles.ap4h?dl=0

  Really looking forward to someone help me solve this mystery.

  Best regards / Jörgen

• Rtsp streaming, no live

  14 août 2018, par Alejandro

  i follow this topic for streaming rtsp here
  now this is my conf in the server : ffmpeg -v info -i rtsp://XXXXX.ddns.net/onvif1 -c:v copy -c:a copy -bufsize 1835k -pix_fmt yuv420p -flags -global_header -hls_time 10 -hls_list_size 6 -hls_wrap 10 -start_number 1 /var/www/html/p433/assets/video/test.m3u8 -loglevel debug

  The client :

  <code class="echappe-js">&lt;script src=&quot;https://cdnjs.cloudflare.com/ajax/libs/hls.js/0.10.1/hls.light.min.js&quot;&gt;&lt;/script&gt;
  &lt;script src=&quot;https://releases.flowplayer.org/7.2.6/flowplayer.min.js&quot;&gt;&lt;/script&gt;
  
  &lt;script&gt;<br />
  
          flowplayer('#player', {<br />
  
              live: true,  // set if it's a live stream          <br />
  
              ratio: 9/16, // set the aspect ratio of the stream<br />
  
              clip: {<br />
  
                  sources: [<br />
  
                      // path to the HLS m3u8<br />
  
                      { type: &quot;application/x-mpegurl&quot;, src: &quot;&amp;lt;?php echo asset_url();?&gt;video/test.m3u8&quot;},<br />
  
                      // path to an optional MP4 fallback<br />
  
                      { type: &quot;video/mp4&quot;, src: &quot;//yourserver/path/index.mp4&quot;}<br />
  
                  ]<br />
  
              }<br />
  
          });<br />
  
  &lt;/script&gt;
  
  

  The problem ? dont show video in "Live", only show 20seconds aprox and the video is loop icon loading

  what am I doing wrong ? I try it all night but I think that it reaches the point of not finding the right path

  thanks for your time !