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• Playing 120fps in browser between original and re-made video, original is normal speed, new video is slo-mo

  1er mars 2023, par Patrick Vellia

  I used my GoPro Hero10 to record at 4k 120fps on a green screen. This original video plays slo-mo in QuickTime but "normal" speed in the browser. I want it playing normal speed, and if end user wants to slow it down they have the extra frames for that to maintain clarity, which is why I record at 120.

  


  I then used FFMPEG to create an image sequence of the video.

  


  Then I ran Image Magic to create the transparent frames.

  


  Then I put it back together with the following command for a HEVC mov file :

  


  ffmpeg -r 120 -f image2 -i transparent/image_transparent_%08d.png -vcodec hevc_videotoolbox -crf 28 -alpha_quality 1  -tag:v hvc1 output.mov


  


  I am still on an Intel MacBook Pro running FFMPEG 4.6 (as I've found 5+ was buggy with one of my commands a few months ago but can't remember which one, I think it was the videotoolbox).

  


  The GoPro video has the following stream data as input to the FFMPEG :

  


  Duration: 00:00:08.15, start: 0.000000, bitrate: 60160 kb/s
  Stream #0:0(eng): Video: hevc (Main) (hvc1 / 0x31637668), yuvj420p(pc, bt709), 3840x2160 [SAR 1:1 DAR 16:9], 59891 kb/s, 119.88 fps, 119.88 tbr, 120k tbn, 119.88 tbc (default)
    Metadata:
      creation_time   : 2023-02-28T19:06:41.000000Z
      handler_name    : GoPro H.265
      vendor_id       : [0][0][0][0]
      encoder         : GoPro H.265 encoder
      timecode        : 19:05:32:105
  Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 189 kb/s (default)
    Metadata:
      creation_time   : 2023-02-28T19:06:41.000000Z
      handler_name    : GoPro AAC  
      vendor_id       : [0][0][0][0]
      timecode        : 19:05:32:105
  Stream #0:2(eng): Data: none (tmcd / 0x64636D74), 0 kb/s (default)
    Metadata:
      creation_time   : 2023-02-28T19:06:41.000000Z
      handler_name    : GoPro TCD  
      timecode        : 19:05:32:105
  Stream #0:3(eng): Data: bin_data (gpmd / 0x646D7067), 76 kb/s (default)
    Metadata:
      creation_time   : 2023-02-28T19:06:41.000000Z
      handler_name    : GoPro MET  


  


  Whereas the re-constructed video has the following data :

  


  Duration: 00:00:08.13, start: 0.000000, bitrate: 763650 kb/s
  Stream #0:0: Video: hevc (Main) (hvc1 / 0x31637668), yuv420p(tv, progressive), 3840x2160 [SAR 1:1 DAR 16:9], 763696 kb/s, 120 fps, 120 tbr, 15360 tbn, 15360 tbc (default)
    Metadata:
      handler_name    : VideoHandler
      vendor_id       : FFMP
      encoder         : Lavc58.134.100 hevc_videotoolbo


  


  When this re-constructed video plays in the browser, it is in slow-mo and I need to set the playbackRate to 4.0 for it to play "normally".

  


  Is there something I need to add to the video for the browser to play it at "normal" speed ?

  


• Please tell us how to set up the option of HLS ffmpeg ?

  17 décembre 2014, par Mr.Park

  My ffmpeg Option :

  ffmpeg -i test.mp4 -max_delay 50000 -map 0:v -map 0:a -c copy -flags:v +global_header -bsf:v h264_mp4toannexb -f ssegment -segment_time 10 -segment_list playlist.m3u8 -segment_format mpegts -initial_offset 10  segment_%05d.ts

  if the WIFI, .m3u8 file plays not loading.

  if the 3G, the loading takes longer.

  my Works :

  .m3u8 URL : http://mytest/test/test.m3u8

  Simply call this URL into browser

  my Question is :

  Question 1.
  Can I split the HD video in .mp4 smaller capacity .ts files to .m3u8 file through the option of ffmpeg ?

  Question 2.
  .m3u8 when you play there a set way of WIFI and 3G options for ffmpeg ?

• mp4 generated using MediaMuxer doesn't play in ffmpeg

  7 février 2019, par APD

  I need to generate an mp4 video from the raw h264 bitstream only (hence don’t have any audio channel). To do the same, I used the MediaMuxer APIs from Android. The output mp4 videos that got generated, seems fine and are playing well on VLC media player. But the generated videos don’t play on chrome browser (on Ubuntu machine) and same is the case with ffmpeg.
  Other thing that I noticed is that, the mp4 generated with Android devices greater than Nougat (i.e., Oreo and later) are fine (i.e., they play on Chrome browser and ffmpeg also plays it well), however those generated from devices before Oreo, have this problem.
  Has anybody observed such a behavior and what can be done to handle this on Android-devices before Oreo ?