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• What are supported ffmpeg rtp_mpegts Muxer options ? (mpegts Muxer options are ignored)

  7 mars 2020, par drake7

  I created a UDP stream with -f mpegts and some options like -mpegts_transport_stream_id.

  I received the stream with "StreamXpert - Real-time stream analyzer" that shows all options are in the output. See my ffmpeg parameters and the StreamXpert at the end.

  The same Muxer options seem to be ignored with -f rtp_mpegts.

  I have tried to use -f mpegts and pipe it to -f rtp_mpegts like so :

  ffmpeg -i ... -f mpegts pipe: | ffmpeg pipe: -c copy -f rtp_mpegts "rtp://239.1.1.9:1234?pkt_size=1316"

  The options are still ignored.

  This ticket "support options for MPEGTS muxer when using RTP_MPEGTS" also notices the ignored option. Furthermore in this comment, "thovo" gives an analysis and suggests a solution.

  Obviously the problem still exists. Anybody found a workaround for this ?

  My additional question : I have not questioned if my project really needs rtp in the first place. Maybe my coworker didn’t know better and requested rtp when udp would be sufficient as well.

  The aim was to receive the RTP stream with a TV using DVB via IP. This was successful an a Panasonic TV.

  The SAT>IP Specification on page 10 requires rtp for Media Transport :

  The SAT>IP protocol makes use of :

  • UPnP for Addressing, Discovery and Description,
  • RTSP or HTTP for Control,
  • RTP or HTTP for Media Transport.

  Is udp out of the equation ?

  ---

  ffmpeg : (all options are in the output with -f mpegts)

  (HEX to decimal : 0x005A = 90, 0x005B = 91 0x005C = 92, 0x005D = 93, 0x005E= 94)

  ffmpeg -f lavfi -i testsrc \
  
  -r 25 \
  
  -c:v libx264 \
  
  -pix_fmt yuv420p \
  
  -profile:v main -level 3.1 \
  
  -preset veryfast \
  
  -vf scale=1280:720,setdar=dar=16/9 \
  
  -an \
  
  -bsf:v h264_mp4toannexb \
  
  -flush_packets 0 \
  
  -b:v 4M \
  
  -muxrate 8M \
  
  -pcr_period 20 \
  
  -pat_period 0.10 \
  
  -sdt_period 0.25 \
  
  -metadata:s:a:0 language=nya \
  
  -mpegts_flags +pat_pmt_at_frames \
  
  -mpegts_transport_stream_id 0x005A \
  
  -mpegts_original_network_id 0x005B \
  
  -mpegts_service_id 0x005C \
  
  -mpegts_pmt_start_pid 0x005D \
  
  -mpegts_start_pid 0x005E \
  
  -mpegts_service_type advanced_codec_digital_hdtv \
  
  -metadata service_provider='WI' \ 
  
  -metadata service_name='W' \
  
  -mpegts_flags system_b -flush_packets 0 \
  
  -f mpegts "udp://239.1.1.10:1234?pkt_size=1316"

  StreamXpert Output :

  -mpegts_transport_stream_id = Transport Stream ID (yellow text highlight)

  -mpegts_original_network_id = Original Network ID, onw (green text highlight)

  -mpegts_service_id = Program, service (pink text highlight)

  -mpegts_pmt_start_pid = PMT PID, Table PID (turquoise text highlight)

  -mpegts_start_pid = PID, PCR PID (red text highlight)

  -mpegts_service_type = service type (blue text)

  service_name = Service name (orange text)

  service_provider = Service provider (pink text)

  

• Node.js, fluent-ffmpeg : Generate thumbnails with size dependent on if the video is wider or taller

  13 mars 2020, par Bone Jones

  I am trying to use fluent-ffmpeg to generate thumbnails in Node.js. These thumbnails need to be no wider/taller than 150px and maintain the original aspect ratio of the video. For example, if the width of the video is greater than the height the size should be 150xSmallerHeight and if the video is taller SmallerWidthx150.

  This is my current code :

  var ffmpeg = require('fluent-ffmpeg');
  
  ...
  
  ffmpeg(fileName)
  
      .thumbnail({
  
          timestamps: [0],
  
          folder: outFolder,
  
          filename: outName,
  
          size: '150x150' // Generates a 150px square thumbnail as expected, but is not the desired behavior
  
      })
  
      .on('end', function () {
  
           console.log('Screenshot taken');
  
      });

  From what I can see in the fluent-ffmpeg docs these are the only options to control the size of a thumbnail :

  - 640x480: set a fixed output frame size. Unless autopad() is called, this may result in the video being stretched or squeezed to fit the requested size.
  
  - 640x?: set a fixed width and compute height automatically. If aspect() is also called, it is used to compute video height; otherwise it is computed so that the input aspect ratio is preserved.
  
  - ?x480: set a fixed height and compute width automatically. If aspect() is also called, it is used to compute video width; otherwise it is computed so that the input aspect ratio is preserved.
  
  - 50%: rescale both width and height to the given percentage. Aspect ratio is always preserved.

  I don’t believe any of these options would allow me to generate the thumbnail described unless I had access to the video’s original width and height, for example :

  ...
  
  size: `${video.width >= video.height ? '150' : '?'}x${video.height >= video.width ? '150' : '?'}`
  
  ...

  How can I create a thumbnail as described using fluent-ffmpeg ?

• Different results between windows and Linux in opencv c++

  24 mars 2020, par Samer

  I have tried this opencv and ffmpeg C++ code to demux a video and edit it and mux it back again but it doesn’t seem to work properly on windows (using Visual Studio)

  the problem occurs by skipping some frames especially at the end of the video and increasing the video output size not on all windows PCs. We have tried it on a 35 MB video and when we did the editing the output video size was 2.8GB on some windows PCs and the last frames skipped (the problem) and some other PCs the output video size was 500MB and there were no skipped frames (all fine).

  so the question is, why would the same code with the same build and windows versions behave differently and produce problems on some Pcs ?

  (we also did it on linux ubuntu and macos and it was working fine on different PCs)

  https://github.com/WajdiMuh/parallelalgo for the files

  https://gjuedujo-my.sharepoint.com/personal/m_albizreh1_gju_edu_jo/_layouts/15/onedrive.aspx?id=%2Fpersonal%2Fm%5Falbizreh1%5Fgju%5Fedu%5Fjo%2FDocuments%2FParallel%20Project%2Fbinr&originalPath=aHR0cHM6Ly9nanVlZHVqby1teS5zaGFyZXBvaW50LmNvbS86ZjovZy9wZXJzb25hbC9tX2FsYml6cmVoMV9nanVfZWR1X2pvL0VzaHFWNDJCVThkQ25KOFV0dm82NHJNQmdoOWdCeEZOblkwQWtRMkQ0MU5UV3c_cnRpbWU9TTl4Zi1YblAxMGc for the release version (vidd.MP4 is the video)

  Thanks in Advance