Recherche avancée

Sur d’autres sites (7019)

• stop ffmpeg stream at specific time of the day

  28 juillet 2022, par drake7

  This stream will stop after 3600 seconds with the -t option.

  


  Is it possible to stop the stream at a certain time of the day, e.g. at 1:00 A.M. using ffmpeg only ?

  


  ffmpeg -f dshow -i video="Virtual-Camera" -preset ultrafast -vcodec libx264 -tune zerolatency -b 900k \
-f mpegts -t 3600 udp://10.1.0.102:1234


  


  The Docs are very clear about the syntax for Time duration.

  


  So something like -t (1+1) doesn't work. It is not evaluated to -t 2.

  


  I think Expression Evaluation doesn't help either because it seems to be only valid in filters.

  


  A simple bash solution to stop at 01:00 AM would be :

  


  # Set time to stop
# maximum value is 23:59:59
# use `offset_tomorrow` to set a time tomorrow
time_to_stop="23:59:59"

# remaining seconds until 1 AM
offset_tomorrow=3601

# calculate time difference between maximum time and now and add offset in seconds.
# add 1 hour and 1 minute to get the remaining seconds until 1 AM.
seconds_to_stop=$((`date -d$time_to_stop '+%s'`-`date '+%s'` + $offset_tomorrow))

ffmpeg -f dshow -i video="Virtual-Camera" -preset ultrafast -vcodec libx264 -tune zerolatency -b 900k \
-f mpegts -t $seconds_to_stop udp://10.1.0.102:1234


  


• FFMPEG filter_complex_script cropping by time

  29 mars 2018, par D_Corson

  I am trying to use FFMPEG’s filter_complex_script option to crop a video in different places depending on the time. I have a file that shows the bounding box of where an object should be and have written a text file called "myscript.txt" that has commands as follows :

  crop=x=125:y=190:w=105:h=98
  
  crop=x=124:y=193:w=106:h=99
  
  crop=x=124:y=194:w=106:h=99

  My command line call for ffmpeg is

  ffmpeg -y -i input.mp4 -filter_complex_script "myscript.txt" -c:v libx264 output.mp4

  This will run fine and produce an output, but the crop window only uses the first line of the file and does not change over time. Currently I have cropping details at the frame level but I can find a way to make this work by second if there is a solution out there.

  I am running FFMPEG version 3.4.1 on windows 10.

  Thank you !

• Getting accurate time from FFMPeg with Objective C (Audio Queue Services)

  2 avril 2012, par Winston

  My iPhone app plays an audio file using FFMPeg.

  I'm getting the elapsed time (to show to user) from the playing audio (in minutes and seconds after converting from microseconds, given by FFMPeg) like so :

  AudioTimeStamp currentTimeStamp;
  
  AudioQueueGetCurrentTime (audioQueue, NULL, &currentTimeStamp, NULL);
  
  
  
  getFFMPEGtime = currentTimeStamp.mSampleTime/self.basicAudioDescription.mSampleRate;
  
  
  
  self.currentAudioTime = [NSString stringWithFormat: @"%02d:%02d",
  
                              (int) getFFMPEGtime / (int)60000000,
  
                              (int) ((getFFMPEGtime % 60000000)/1000000)];

  Everything works fine, but when I scrub back or forward to play another portion of the song, the elapsed time will go back to zero, no matter the current position. The timer will always zero out.

  I know I'm suposed to do some math to keep track of the old time and the new time, maybe constructing another clock or so, perhaps implementing another callback function, etc... I'm not sure what way I should go.

  My questions are :

  1) What's the best approach to keep track of the elapsed time when going back/forward in a song, avoiding the clock to always going back to zero ?

  2) Should I look deeply into FFMPeg functions or should I stick with Objective-C and Cocoa Touch for solving this problem ?

  Please, I need some advices/ideas from experienced programmers. I'm stuck. Thanks beforehand !