Changes between Version 12 and Version 13 of AudioChannelManipulation


Ignore:
Timestamp:
Sep 19, 2014, 3:13:34 AM (5 years ago)
Author:
llogan
Comment:

add -ac 2 example, add statistics section

Legend:

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  • AudioChannelManipulation

    v12 v13  
    147147}}}
    148148
     149Or use `-ac 2` instead of the pan audio filter:
     150
     151{{{
     152ffmpeg -i input1.wav -i input2.wav -filter_complex "[0:a][1:a]amerge[aout]" -map "[aout]" -ac 2 output.mp3
     153}}}
     154
     155{{{
     156#!div style="border: 1pt dotted; margin: 1em; background-color: #fffff9;"
     157'''Note:''' The output produced with the pan audio filter may not be identical to the output produced with `-ac 2`, so you'll have to listen to your outputs or view [#Statistics audio statistics] to determine which output suits you.
     158}}}
     159
    149160== Mix both stereo channels to stereo ==
    150161
     
    181192{{{
    182193ffmpeg -i stereo.wav -map_channel -1 -map_channel 0.0.1 output.wav
     194}}}
     195
     196----
     197
     198== Statistics ==
     199
     200The [https://ffmpeg.org/ffmpeg-filters.html#astats astats audio filter] can display information including length, DC offset, min/max levels, peak/RMS level dB:
     201
     202{{{
     203$ ffmpeg -i input.wav -af astats -f null -
     204
     205[Parsed_astats_0 @ 0x168a260] Channel: 1
     206[Parsed_astats_0 @ 0x168a260] DC offset: -0.001829
     207[Parsed_astats_0 @ 0x168a260] Min level: -0.605072
     208[Parsed_astats_0 @ 0x168a260] Max level: 0.607056
     209[Parsed_astats_0 @ 0x168a260] Peak level dB: -4.335430
     210[Parsed_astats_0 @ 0x168a260] RMS level dB: -20.298984
     211[Parsed_astats_0 @ 0x168a260] RMS peak dB: -12.303891
     212[Parsed_astats_0 @ 0x168a260] RMS trough dB: -35.352893
     213[Parsed_astats_0 @ 0x168a260] Crest factor: 6.283154
     214[Parsed_astats_0 @ 0x168a260] Flat factor: 0.000000
     215[Parsed_astats_0 @ 0x168a260] Peak count: 2
     216[Parsed_astats_0 @ 0x168a260] Channel: 2
     217[Parsed_astats_0 @ 0x168a260] DC offset: -0.001826
     218[Parsed_astats_0 @ 0x168a260] Min level: -0.585999
     219[Parsed_astats_0 @ 0x168a260] Max level: 0.608490
     220[Parsed_astats_0 @ 0x168a260] Peak level dB: -4.314931
     221[Parsed_astats_0 @ 0x168a260] RMS level dB: -20.519969
     222[Parsed_astats_0 @ 0x168a260] RMS peak dB: -12.056472
     223[Parsed_astats_0 @ 0x168a260] RMS trough dB: -36.784681
     224[Parsed_astats_0 @ 0x168a260] Crest factor: 6.460288
     225[Parsed_astats_0 @ 0x168a260] Flat factor: 0.000000
     226[Parsed_astats_0 @ 0x168a260] Peak count: 2
     227[Parsed_astats_0 @ 0x168a260] Overall
     228[Parsed_astats_0 @ 0x168a260] DC offset: -0.001829
     229[Parsed_astats_0 @ 0x168a260] Min level: -0.605072
     230[Parsed_astats_0 @ 0x168a260] Max level: 0.608490
     231[Parsed_astats_0 @ 0x168a260] Peak level dB: -4.314931
     232[Parsed_astats_0 @ 0x168a260] RMS level dB: -20.408071
     233[Parsed_astats_0 @ 0x168a260] RMS peak dB: -12.056472
     234[Parsed_astats_0 @ 0x168a260] RMS trough dB: -36.784681
     235[Parsed_astats_0 @ 0x168a260] Flat factor: 0.000000
     236[Parsed_astats_0 @ 0x168a260] Peak count: 2.000000
     237[Parsed_astats_0 @ 0x168a260] Number of samples: 1440706
    183238}}}
    184239