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• How to use loop to play specific sequence of files

  24 juillet 2014, par Andy

  Files are played with the following tommand

  root/bin/ffmpeg -re -i $(ls /usr/btv/studio1/*.mp4 | shuf -n 1) -vcodec copy -preset superfast -acodec copy -ar 44100 -ab 32k -f flv rtmp://ip:1935/live/studio1

  This picks a random file usr/btv/studio1/ and streams it.

  Within the same directory, there is a commercial.mp4 file.

  How would I use a loop in this case to play commercial after each other file and have 5 second wait between the switches.

  As an example :

  root/bin/ffmpeg -re -i $(ls /usr/btv/studio1/*.mp4 | shuf -n 1) -vcodec copy -preset superfast -acodec copy -ar 44100 -ab 32k -f flv rtmp://ip:1935/live/studio1
  
  
  
  Play: JohnWedding.mp4
  
  File ends (+5 seconds)
  
  Play: commercial.mp4
  
  File ends (+5 seconds)
  
  Play: Flowers.mp4

• avcodec/tiff : Make decoder init-threadsafe

  27 novembre 2020, par Andreas Rheinhardt

  avcodec/tiff : Make decoder init-threadsafe
  The only thing that stands in the way of adding the
  
  FF_CODEC_CAP_INIT_THREADSAFE flag to the TIFF decoder is its usage
  
  of ff_codec_open2_recursive() : This function requires its caller to hold
  
  the lock for the mutex that guards initialization of AVCodecContexts
  
  whose codecs have a non-threadsafe init function and only callers whose
  
  codec does not have the FF_CODEC_CAP_INIT_THREADSAFE flag set hold said
  
  lock (the others don't need to care about said lock). But one can set
  
  the flag if one switches to avcodec_open2() at the same time.
  Reviewed-by : Anton Khirnov <anton@khirnov.net>
  
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
  

  • [DH] libavcodec/tiff.c

• How to switch between 2 stream inputs after a set duration using ffmpeg ?

  6 février 2021, par zlyfer

  I am tinkering with my two Raspberry Pis and would like to do the following :

  



  Both Pis record via a camera and stream it via cvlc to the network. Then one of them uses both streams to make a single stream wich alternates between both sources every 30 seconds.
My setup is as below :

  



  Pi 3 (192.168.0.158) and Pi 4 (192.168.0.87) both use the following command to stream the camera feed to my local network :

  



  raspivid -o - -t 0 -vf -hf -fps 30 -b 6000000 | cvlc -vvv stream:///dev/stdin --sout '#standard{access=http,mux=ts,dst=:8090}' :demux=h264


  



  The Pi 4 then uses

  



  ffmpeg -protocol_whitelist file,http,https,tcp,tls,crypto -f concat -safe 0 -i stream_list.txt -c copy output.mp4


  



  with content of stream_list.txt being :

  



  file http:\/\/192.168.0.87:8090
duration 00:00:02.00
file http:\/\/192.168.0.158:8090
duration 00:00:02.00


  



  I use output.mp4 as test, this will be a twitch server or somewhat. The current duration is 2 seconds just for testing as well. And I will add a loop -1 to keep switching. My problem is that the process doesnt stop after 4 seconds. It keeps "recording" forever until I CTRL+C and then output.mp4 only contains the camera feed of the first mentioned stream in the stream_list.txt. It doesn't stop after 2 seconds switches to the other stream and then stops after another 2 seconds as I expected.

  



  Is there something that I am essentially doing wrong or am I at least somewhat on the right way ?