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• Dynamic HLS segment filename using FFMPEG

  19 janvier 2021, par ewack

  Is is possible to change the segment filename while ffmpeg is running ?

  


  If I put this into my terminal

  


  custom="event-type1"
ffmpeg -nostdin -i "rtsp://192.168.7.88/axis-media/media.amp?resolution=640x480" -f hls -hls_time 4 -hls_segment_filename camera%03d-${custom}-.ts camera.m3u8 &


  


  This will run in the background, creating a camera.m3u8 file and camera000-event-type1-.ts, camera001-event-type1-.ts etc... files.

  


  But if I then run this

  


  custom="event-type2"


  


  The segment files still contain "event-type1" in the name. I would like it to change to "event-type2" after I update the custom variable.

  


  I have a separate program running that monitors the stream. I want to update the filename based on certain conditions. Is there any way to have ffmpeg to re-read the segment_filename input ?

  


• FFMPEG Chapter Metadata added to a song file is sometimes off by 1 second

  6 février 2021, par Elthfa

  I attempted to add chapter metadata to a .opus file, but afterward, the file metadata showed timestamps different than the ones I attempted to add.
It seems to be adding an extra second to the timestamps under certain conditions.
I'm not sure if this is a bug, or if maybe I am just using the command wrong.

  


  Here are the commands I performed :

  


  First I removed all existing metadata from the file. I did this using a command I found on stack overflow :

  


  ffmpeg -i test_song.opus -c copy -map_metadata -1 -fflags +bitexact -flags:a +bitexact no_metadata.opus


  


  Then I added the new metadata from an external file I had written :

  


  ffmpeg -i no_metadata.opus -f ffmetadata -i metadata.txt -c copy -map_metadata 1 out.opus


  


  The file 'metadata.txt' looks like :

  


  ;FFMETADATA1
[CHAPTER]
TIMEBASE=1/1000
START=0
END=400
title=400 ms
[CHAPTER]
TIMEBASE=1/1000
START=400
END=500
title=100 ms
[CHAPTER]
TIMEBASE=1/1000
START=500
END=2000s
title=1500 ms
[CHAPTER]
TIMEBASE=1/1000
START=2000
END=97000
title=The Rest


  


  When I print out the basic data from the file, not all the timestamps shown match the ones I had in the metadata file.

  


  > ffmpeg -i out.opus
...
Input #0, ogg, from 'out.opus':
  Duration: 00:01:37.00, start: 0.000000, bitrate: 147 kb/s

    Chapter #0:0: start 0.000000, end 0.400000
    Metadata:
      title           : 400 ms

    Chapter #0:1: start 0.400000, end 1.500000
    Metadata:
      title           : 100 ms
    
    Chapter #0:2: start 1.500000, end 2.000000
    Metadata:
      title           : 1500 ms
    
    Chapter #0:3: start 2.000000, end 97.000000
    Metadata:
      title           : The Rest
...


  


  You can see the issues for chapters 0:1 and 0:2, which show a start and end time of 1.5 seconds respectively, when it should be 0.5 seconds for each.
I tried several combinations for this, and it seems that if the digit in the hundreds of milliseconds place is between 5 and 9 inclusive, it adds and extra second to the timestamp it saves in the metadata.

  


  Is this due to me using the command wrong ? Or formatting the metadata file wrong ? Or is there an issue in the code with rounding timestamps ?

  


  Thanks !

  


• avcodec/frame_thread_encoder : Fix segfault on allocation error

  7 février 2021, par Andreas Rheinhardt

  avcodec/frame_thread_encoder : Fix segfault on allocation error
  Fixes a segfault from av_fifo_size(NULL) that happens in
  
  ff_frame_thread_encoder_free if the fifo couldn't be allocted ;
  
  furthermore the mutexes and conditions that are destroyed in
  
  ff_frame_thread_encoder_free are not even initialized at this point,
  
  so don't call said function.
  Reviewed-by : Paul B Mahol <onemda@gmail.com>
  
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
  

  • [DH] libavcodec/frame_thread_encoder.c