VLC

About

Vlc is a video player/editor

Command line

vlc --sout '#transcode{vcodec=[video_codec], acodec=[audio_codec]}:standard{access=[type_of_output], dst=[name_of_output], mux=[output_type]}' [input_stream]

where:

  • –sout indicates the output stream (Generally a file).
    • transcode is a vlc module that define the codecs. See all parameters in the reference
      • vcodec the output video codec
      • acodec the output audio codec (the codecs supported by VLC, like mp4v, MPJG, WMV1, vorb, flac)
    • standard is a module that defines the output stream (Generally a file). See the reference
      • access” is the type of output (“file”, “udp”, “rtp”, or “http”)
      • dst stands for destination and defines the name of the output.
      • mux is the format, to select among ts, ps, ogg, avi, etc. (Encapsulation tab)

Converting in batch audio files (wma, …) to a MP3 file

@echo off
for /f "delims=|" %%f in ('dir /b *.wma') do (
	echo converting   %%f to %%~nf.mp3
	CALL "C:\Program Files (x86)\VideoLAN\VLC\vlc.exe" --sout="#transcode{acodec=mp3,ab=128,channels=2,samplerate=44100}:standard{access=file,mux=raw,dst=\"%%~nf.mp3\"}"  "%%f" vlc://quit 
)
echo conversion finished
  • vlc://quit to the end of the above command line.

Adapted from Example commandline: Converting an audio file to a MP3 file 

vlc --sout "#transcode{acodec=mp3,ab=128,channels=2,samplerate=44100}:std{access=file,mux=raw,dst=OUTPUT}" INPUT

Vlc Audio Parameter

mux is the encapsulation

Audio Properties

Bitrate

Bitrate is a measure of how much data is stored in a media stream.

  • default audio bitrate: 64k.
  • quality stereo sound, use 128k or 192k.
  • home DVD systems: up to 320k

Bit rate/file size mapping is simple.

The size of the audio stream is the audio bitrate multiplied by the duration and divided by 8:

size (bytes) = { bitrate (bps) * duration (sec) } / 8

Frequency

  • frequency is a measure of fidelity.

Volume

When either of Bitrate or Frequency are lowered, it can result in reduced volume.

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