Recherche avancée

Sur d’autres sites (12069)

• ffmpeg transcoding reset the start time of file

  12 août 2013, par diousk

  I use a segmenter to segment my MPEG 2 Ts file into a series of media segment for HTTP live streaming

  and each segment's start time following the previous one
  (ex:start time of segments : 00:00,00:10,00:20,00:30,...)

  (In Ubuntu)

  The Question is :

  When I use ffmpeg to transcode one of the media segment (ex 800k bps to 200k bps)

  the start time of transcoded media segment will be reset to 0

  ex:As I transcode the third segement,

  start time of segments changing to : 00:00,00:10,00:00,00:30,...

  It cause my player freezing once play the transcoded media segment

  Is there any solution to transcode media file with the same start time ?

  I guess it's the ffmpeg reset the PTS(presentation timestamp) of segment

  But I don't know how to fix it...

  here is my ffmpeg command (transcode to 250k bps)

  ============================

  ffmpeg -y -i sample-03.ts -f mpegts -acodec libfaac -ar 48000 -ab 64k -vcodec libx264 -b 250k -flags +loop -cmp +chroma \
  
   -partitions +parti4x4+partp8x8+partb8x8 -subq 7 -trellis 0 -refs 0 -coder 0 -me_range 16 -keyint_min 25 \
  
   -sc_threshold 40 -i_qfactor 0.71 -maxrate 250k -bufsize 250k -rc_eq 'blurCplx^(1-qComp)' -qcomp 0.6 \
  
   -qmin 10 -qmax 51 -qdiff 4 -level 30 -aspect 320:240 -g 30 -async 2 sample.ts

  ============================

  Help !

  thanks

• 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 !