Real Lossless Codec

• FOURCCs: ralf
• Company: RealNetworks
• Samples: http://samples.mplayerhq.hu/A-codecs/lossless/ (luckynight.rmvb)

This is RealNetworks lossless audio codec.

Audio header in rm files is different from other Real audio codecs; the interface of the binary decoder is also different.

Extradata format

Numbers are stored big-endian.

bytes  0- 3 - codec FOURCC, always "LSD:"
bytes  4- 5 - version
bytes  8- 9 - number of channels
bytes 10-11 - bits per sample
bytes 12-15 - sampling rate
bytes 16-19 - block size in samples?
bytes 20-23 - ignored?

Known decoder support only 1/2 channel 16-bit audio with sampling rate up to 96 kHz.