Supported sound formats Supported sound formats

This is a list of supported sound formats.

Format Usual file extension
RIFF WAVE.wav
Native FLAC.flac

Please note that due to its 3D positional nature, openBVE will convert multi-channel audio to mono upon loading, so there is no point in providing multi-channel audio in the first place. For multi-channel audio, openBVE discards silent channels and tries to detect constructive or destructive interference in the mixed version of the remaining channels. If interference is detected, the first non-silent channel in the file is used, otherwise the mixed channel.

■ RIFF WAVE format
WAVE files are supported, which technically are RIFF (or RIFX) container files with the WAVE format type. WAVE itself allows different formats, of which only a subset are supported. These are:

Format Sample rate Bitrate Channels
PCManyanyany
Microsoft ADPCMany4 bitsany

Sample rate refers to the number of samples per second per channel. Bitrate refers to the number of bits per sample per channel.

■ Native FLAC format
All native FLAC files are supported with the following (in practice rarely occuring) exceptions:

  Changing the sample rate in the middle of the file is not supported.
  Negative predictor shifts are not supported.
  MD5 checks are skipped for bit rates other than 8, 16 or 24.



Further information about these formats from a programmer's point of view can be found on these external sites:

General information about RIFF, WAVE and PCM:
http://www-mmsp.ece.mcgill.ca/Documents/AudioFormats/WAVE/Docs/riffmci.pdf

Information about Microsoft ADPCM:
http://icculus.org/SDL_sound/downloads/external_documentation/wavecomp.htm

Official documentation on FLAC:
http://flac.sourceforge.net/documentation.html

Additional documentation on FLAC:
http://home.comcast.net/~b.langenb/audioformats_letter.pdf