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• Unable to find replacement for -vol [closed]

  21 février 2024, par Michael Benton

  I'm referring to this thread posted years ago.

  


  While I was testing Downmixing without discarding the LFE channel (Dave_750's answer) on ffmpeg, which included the formula

  


  ffmpeg -i "sourcetrack.dts" -c dca -vol 425 -af "pan=stereo|c0=0.5*c2+0.707*c0+0.707*c4+0.5*c3|c1=0.5*c2+0.707*c1+0.707*c5+0.5*c3" "outputstereo.dts"


  


  the cmd raised the following error :

  


  Unrecognized option 'vol'. Error splitting the argument list: Option not found


  


  The formula I put in cmd wasn't the same as the one in the thread at the beginning, because I replaced in it the attributes of my ac3 track.

  


  ffmpeg -i "inputsurround.ac3" -vol 425 -af "pan=stereo|c0=0.5*c2+0.707*c0+0.707*c4+0.5*c3|c1=0.5*c2+0.707*c1+0.707*c5+0.5*c3" -c:a ac3 -b:a 320k -ar 48000 "outputstereo.ac3"


  


  Through this thread, I discovered that the -vol function was deprecated years ago.

  


  I found another thread where the syntax used was

  


  -af volume=N


  


  (where N stands for a percentage or, if N is followed by "dB", a dB value).

  


  I'm not sure if -af volume behaves exactly like -vol while downmixing to stereo the ac3.

  


  I went back editing the formula :

  


  ffmpeg -i "inputsurround.ac3" -af "volume=425" -af "pan=stereo|c0=0.5*c2+0.707*c0+0.707*c4+0.5*c3|c1=0.5*c2+0.707*c1+0.707*c5+0.5*c3" -c:a ac3 -b:a 320k -ar 48000 "outputstereo.ac3"


  


  It raised the following warning (which didn't stop the file generation) :

  


  Multiple -filter/-af/-vf options specified for stream 0, only the last option '-filter:a pan=stereo|c0=0.5*c2+0.707*c0+0.707*c4+0.5*c3|c1=0.5*c2+0.707*c1+0.707*c5+0.5*c3' will be used


  


  As I already suspected, I couldn't use two "-af" in the same command. The generated file is useless, because ffmpeg only applied one of the two commands. I also tried with N defined in dB, with no success.

  


  I continued my search and, from another thread, I learned that I could use

  


  -filter_complex "[1] formula1;[0] formula2"


  


  to resolve my issue.

  


  My formula then became :

  


  ffmpeg -i "inputsurround.ac3" -filter_complex "[1]volume=425;[0]pan=stereo|c0=0.5*c2+0.707*c0+0.707*c4+0.5*c3|c1=0.5*c2+0.707*c1+0.707*c5+0.5*c3" -c:a ac3 -b:a 320k -ar 48000 "outputstereo.ac3"


  


  And it still raised an error :

  


  Invalid file index 1 in filtergraph description [1]volume=425;[0]pan=stereo|c0=0.5*c2+0.707*c0+0.707*c4+0.5*c3|c1=0.5*c2+0.707*c1+0.707*c5+0.5*c3.
Error initializing complex filters: Invalid argument


  


  To simplify the formula, I went back using -af with the properties of -filter_complex. And I got :

  


  ffmpeg -i "inputsurround.ac3" -af "[1]volume=425;[0]pan=stereo|c0=0.5*c2+0.707*c0+0.707*c4+0.5*c3|c1=0.5*c2+0.707*c1+0.707*c5+0.5*c3" -c:a ac3 -b:a 320k -ar 48000 "outputstereo.ac3"


  


  Again, another error :

  


  Simple filtergraph '[1]volume=425;[0]pan=stereo|c0=0.5*c2+0.707*c0+0.707*c4+0.5*c3|c1=0.5*c2+0.707*c1+0.707*c5+0.5*c3' was expected to have exactly 1 input and 1 output. However, it had 2 input(s) and 2 output(s). Please adjust, or use a complex filtergraph (-filter_complex) instead.
[aost#0:0/ac3 @ 000001d83b4c4200] Error initializing a simple filtergraph
Error opening output file outputstereo.ac3.
Error opening output files: Invalid argument


  


  whether I used a semicolon or comma as a separator.

  


  I'm completely lost at this point as I don't have deep knowledge of the topic.

  


  


  • has -vol been deprecated or I've searched badly/it's a syntax typo ?

    


  


  • if -vol has been deprecated, is there a way to rewrite the formula such that it outputs the result intended by the original user ?

    


  


  • if I replace c0, c1, c2, c3, c4, c5 to FL, FR, FC, LF, BL, BR in the formula, would I get a different channel layout ? (my file is : L, R, C, LFE, Ls, Rs)

    


  


  


  I'll try to clear every doubt. Any help is highly appreciated !

  


• NGINX RTMP Server - Continuity replacement of track

  6 janvier 2023, par sweetngx

  I broadcast my video archive as live streaming with FFMpeg or similar applications. But since there are multiple videos, ffmpeg reconnects with the rtmp server in each new track, and while watching the live stream, the connection naturally terminates in each video transition and I continue watching by reconnecting to rtmp. What I want to do is that when ffmpeg switches to each new track, the rtmp server does not terminate my connection and continues the new video stream without interruption, that is, in flow changes, the rtmp server can wait for the new flow for a while and continue where it left off. I actually tried to do this using wait_video but it is not efficient and stable enough. How do you think I can solve this problem ? Should I solve it on the FFMpeg side or should I solve it on the Rtmp Server side ? All my videos have the same resolution and codec properties

  


• avfilter/vf_drawtext : use replacement chars for invalid UTF8 sequences

  29 janvier 2020, par Marton Balint

  avfilter/vf_drawtext : use replacement chars for invalid UTF8 sequences
  continue is explicitly disallowed for GET_UTF8, so let's fix that as well.
  
  Fixes crash with invalid UTF8 sequences.
  Signed-off-by : Marton Balint <cus@passwd.hu>
  

  • [DH] libavfilter/vf_drawtext.c