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• ffmpeg does not produce smooth videos from mkv h265

  13 décembre 2018, par user3776738

  It’s kind of subjective, but I’m not able to produce 100% smooth videos with ffmpeg.
  As input I use https://www.libde265.org/hevc-bitstreams/tos-1720x720-cfg01.mkv as a example.This is a h264 mkv video which is running really badly with my vlc player on my win7 laptop.Converting it to a h264 video let it play much better, but it still appears not to be 100% smooth. Especialy in Vegas 9 it even hangs like once a second.

  Other h264 videos even with 1080p or bigger run perfect with vlc and much better with Vegas, so it is not my laptop.

  its seems that there can be a lot of differences between h264 and h264 ??
  what could i try to make them more smooth ?

  I’m using following command to convert the video :

  ffmpeg.exe -i INPUT_FILE -ac 2 -vf scale=trunc\\(oh*a/2\\)*2:480 -c:v libx264 -sn -dn -map_metadata -1 -map_chapters -1 -profile:v high -level:v 4.0 -pix_fmt yuv420p OUTPUT_FILE  

• Using ffmpeg to pipe Logitech C920 video to two outputs : re-encoded to RTMP stream and hardware-encoded to file

  18 décembre 2018, par Maros Hluska

  I’m trying to use ffmpeg to accept video from a Logitech C920 and broadcast it to an RTMP stream (e.g. Twitch). But there’s a twist : I would like to also save to file the original 1080p hardware-encoded video.

  So I would like to do both of these :

  1. Re-encode the input to 852x480 resolution and upload to an RTMP url with 1500 bitrate
  2. Save the original input to a file without re-encoding (C920 does hardware encoding with the h.264 codec)

  I’ve tried saving the video to file without re-encoding using the following :

  ffmpeg -s 1920x1080 -framerate 30 -pixel_format uyvy422 -vcodec h264 -f avfoundation -i 'HD Pro' -copyinkf -vcodec copy out.mp4

  This seems to almost work. The webcam light turns on and a few seconds of running this produces a massive file (1GB or so). However, I can’t seem to open the file with VLC. I do see a warning from ffmpeg :

  [AVBSFContext @ 0x7fbd4fc3e9c0] No start code is found.
  
  HD Pro: could not find codec parameters

  I’m on a Mac using ffmpeg 4.1.

  Edit :

  It seems the file that ffmpeg produces is not h264 encoded but rather raw pixel data. I’m starting to think that it’s not possible to set the webcam into the h264 mode with Mac (most other cases do it in Linux with v4l2).

  To anyone answering the question, I’d be happy with a solution that involves Linux as well. Especially if I can use a bootable live USB.

• Creating a Master Playlist after creating multiple renditions with FFMPEG for multi bitrate VOD

  15 septembre 2020, par Bill

  I am trying to upload a video to a server, convert the video file to 3 different videos with different resolutions (i.e. 1080p,720p, 480p), and then use FFMPEG to create a master playlist out of each of the resolutions all within the same command ? Is this possible ? So far I am able to upload a video and create 3 different resolutions but I haven't been able to use ffmpeg to create the master manifest. So far my FFMPEG command looks like this :

  



   ffmpeg -hide_banner -y -i beach.mkv \
  -vf scale=w=640:h=360:force_original_aspect_ratio=decrease -c:a aac -ar 48000 -c:v h264 -profile:v main -crf 20 -sc_threshold 0 -g 48 -keyint_min 48 -hls_time 4 -hls_playlist_type vod  -b:v 800k -maxrate 856k -bufsize 1200k -b:a 96k -hls_segment_filename beach/360p_%03d.ts beach/360p.m3u8 \
  -vf scale=w=842:h=480:force_original_aspect_ratio=decrease -c:a aac -ar 48000 -c:v h264 -profile:v main -crf 20 -sc_threshold 0 -g 48 -keyint_min 48 -hls_time 4 -hls_playlist_type vod -b:v 1400k -maxrate 1498k -bufsize 2100k -b:a 128k -hls_segment_filename beach/480p_%03d.ts beach/480p.m3u8 \
  -vf scale=w=1280:h=720:force_original_aspect_ratio=decrease -c:a aac -ar 48000 -c:v h264 -profile:v main -crf 20 -sc_threshold 0 -g 48 -keyint_min 48 -hls_time 4 -hls_playlist_type vod -b:v 2800k -maxrate 2996k -bufsize 4200k -b:a 128k -hls_segment_filename beach/720p_%03d.ts beach/720p.m3u8 


  



  This command is based of research from this page https://docs.peer5.com/guides/production-ready-hls-vod/

  



  What do I need to add to the FFMPEG command to generate a master playlist ?