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• lavc/videotoolboxenc : make transfer_fnc initialized for unsupport function

  18 juillet 2019, par Limin Wang

  lavc/videotoolboxenc : make transfer_fnc initialized for unsupport function
  The current function will report one error message, but the caller func
  
  haven't check it, so change the default to process as AVCOL_TRC_UNSPECIFIED.
  Signed-off-by : Limin Wang <lance.lmwang@gmail.com>
  
  Signed-off-by : Rick Kern <kernrj@gmail.com>
  

  • [DH] libavcodec/videotoolboxenc.c

• How to set comma delimited values from stdout ?

  28 octobre 2017, par gregm

  I have a batch file that processes the output of an ffprobe query. It retrieves several bits of data that I use to determine some ffmpeg directives. In particular I’m converting h264 videos into h265 if the video frame height is 720 or greater. I also convert the audio stream to aac if it isn’t already and if that stream is higher than 128 kbps I convert it down to 128.

  I can do all of that by calling ffprobe a number of times and use if statements to decide what my ffmpeg command will be.

  I’d like my batch file to be more efficient so I was thinking that if I could take the output of one (maybe two) ffprobe queries and then stick that output into a for /f token=.... loop then I could set each ffprobe data point to a variable and then just check the variables to decide what the resulting ffmpeg command will be.

  Here’s what I have right now to simply check if the video stream is hevc. If it isn’t then ffmpeg converts the video to hevc and copies the audio to aac.

  for %%a in ("*.*") do (
  
  ffprobe -v quiet -show_entries stream=index,codec_name,height -of csv "%%a" 2>&1 | findstr "hevc"
  
  if errorlevel 1 (
  
      ffmpeg.exe -hwaccel cuvid -i "%%a" -pix_fmt p010le -c:v hevc_nvenc -preset slow -rc vbr_hq -b:v 4M -maxrate:v 10M -c:a aac "%%~na.h265-convert.mp4"
  
  ))

  That ffprobe query output looks like this :

  stream,0,h264,480

  I was thinking if I could tokenize that output with something like :

  for /f "tokens=1,2,3,4 delims= " %%a in ("______") do set codec=%%b&set fheight=%%d

  I don’t know what to put in the spot where I have the _______. I really don’t want to create a temp file unless that’s the only option though.

  1) Is this an efficient way to achieve what I’m trying to do ?

  2) What do I use where I have a blank line above ________ to call the output of the ffprobe query to use in my for loop ?

• Pushing on-fly transcoded video to embeded http results with no seekbar

  11 juillet 2017, par BigRetroMike

  I’m trying to achieve a simple home-based solution for streaming/transcoding video to low-end machine that is unable to play file properly.

  I’m trying to do it with ffmpeg (as ffserver will be discontinued)
  I found out that ffmpeg have build in http server that can be used for this.

  The application Im’ testing with (for seekbar) is vlc

  I’m probably doing something wrong here (or trying to do something that other does with other applications)

  My ffmpeg code I use is :

  d :\ffmpeg\bin\ffmpeg.exe -r 24 -i "D :\test.mkv" -threads 2 -vf
  scale=1280:720 -c:v libx264 -preset medium -crf 20 -maxrate 1000k
  -bufsize 2000k -c:a ac3 -seekable 1 -movflags faststart -listen 1 -f mpegts http://127.0.0.1:8080/test.mpegts

  This code also give me ability to start watching it when I want (as opposite to using rtmp via udp that would start video as soon as it transcode it)

  I readed about moving atoom thing at file begging which should be handled by movflags faststart

  I also checked the -re option without any luck, -r 25 is just to suppress the Past duration 0.xx too large warning which I read is normal thing.
  test file is one from many ones with different encoder setting etc.

  The setting above give me a seekbar but it doesn’t work and no overall duration (and no progress bar), when I switch from mpegts to matroska/mkv I see duration of video (and progress) but no seekbar.

  If its possible with only ffmpeg I would prefer to stick to it as standalone solution without extra rtmp/others servers.