[FFmpeg-user] select language ?

[Michele Salerno]

how-to select language.
example i preferred lang ita.
If lang ita non exist select only lang eng... not all lang.

in my script i testing lang with
https://github.com/mikysal78/scripting/blob/master/videoconverter#L47-L52

example in one conversions i see this:
    Last message repeated 1 times
[mpegts @ 0x555564c3ee40] PES packet size mismatch
    Last message repeated 3 times
Input #0, mpegts, from '18th Birthday Party.ts':
  Duration: 01:33:51.45, start: 61458.873633, bitrate: 4418 kb/s
  Program 50
  Program 51
  Program 52
  Program 1510
  Program 1731
  Program 16901
    Stream #0:0[0x191]: Video: h264 (High) ([27][0][0][0] / 0x001B),
yuv420p(tv, bt709, top first), 1920x1080 [SAR 1:1 DAR 16:9], 25 fps,
25 tbr, 90k tbn, 50 tbc
    Stream #0:1[0x192](fra): Audio: mp2 ([3][0][0][0] / 0x0003), 48000
Hz, stereo, fltp, 128 kb/s (clean effects)
    Stream #0:2[0x193](eng): Audio: mp2 ([3][0][0][0] / 0x0003), 48000
Hz, mono, fltp, 96 kb/s (clean effects)
    Stream #0:3[0x194](spa): Audio: mp2 ([3][0][0][0] / 0x0003), 48000
Hz, mono, fltp, 96 kb/s (clean effects)
    Stream #0:4[0x195](POL): Audio: mp2 ([3][0][0][0] / 0x0003), 48000
Hz, mono, fltp, 96 kb/s (clean effects)
  Program 16910
  Program 16911
  Program 16912
  Program 16913
  Program 16914
  Program 16915
  Program 16916
  Program 16917
  Program 16918
  Program 16919
  Program 16920
  Program 16921
  Program 16922
  Program 16923
  Program 16924
  Program 16925
  Program 16926
  Program 16927
  Program 16928
  Program 16929
  Program 16931
  Program 16932
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> h264 (h264_nvenc))
  Stream #0:1 -> #0:1 (mp2 (native) -> aac (native))
  Stream #0:2 -> #0:2 (mp2 (native) -> aac (native))
  Stream #0:3 -> #0:3 (mp2 (native) -> aac (native))
  Stream #0:4 -> #0:4 (mp2 (native) -> aac (native))
Press [q] to stop, [?] for help
[h264 @ 0x5555652409c0] co located POCs unavailable
[h264 @ 0x555565251940] reference picture missing during reorder
[h264 @ 0x555565251940] Missing reference picture, default is 66034
[h264 @ 0x555565299180] mmco: unref short failure
[h264 @ 0x555565251940] reference picture missing during reorder
[h264 @ 0x555565251940] Missing reference picture, default is 66050
[h264 @ 0x555565299180] mmco: unref short failure

i whant...if not present lang ita select only eng.

Thanks.