Read the header information from a WAV format audio file. If called without an output argument, the results are displayed.

info=wavinfo(filename);

name of input WAV file (with optional .WAV extension).

[optional] structure containing header information with the some or all of the following fields (note: the italicized fields do NOT correspond to fields contained in the WAV file header -- they are included to provide supplementary descriptive information based on that found in the header):

• FormatTag code corresponding to WAV file format (e.g. 1 for WAVE_FORMAT_PCM, 65534 for WAVE_FORMAT_EXTENSIBLE etc)
• FormatDescription verbal description of format
• NumberOfChannels number of (interleaved) channels
• SampleRate sample rate (in Hz)
• AvBytesPerSec should equal: SampleRate*BlockAlign; gives indication of data throughput (e.g. for design of I/O buffers, etc)
• BlockAlign should equal: ContainerBits*NumberOfChannels/8
• BitsPerSample ambiguously defined for WAVE_FORMAT_PCM. Originally intended to be the actual valid number of bits, but often used as container size (in bits). For WAVE_FORMAT_EXTENSIBLE, unambiguously defined as container size (in bits)
• cbSize length (in bytes) of extra information at end of fmt chunk (must be greater than or equal to 22 for WAVE_FORMAT_EXTENSIBLE)
• ValidBitsPerSample actual number of bits per sample (only explicitly included in header for WAVE_FORMAT_EXTENSIBLE).
• ChannelMask (in decimal format) which prescribes the multichannel speaker allocation for WAVE_FORMAT_EXTENSIBLE. Type 'help chnmsk2spkrlist' to read more about the ChannelMask property.
• SpeakerList cell array containing ordered list of speakers (only valid for WAVE_FORMAT_EXTENSIBLE
• ChannelMaskFormats sub-structure containing ChannelMask in decimal, binary, and hexadecimal formats (only valid for WAVE_FORMAT_EXTENSIBLE)
• ContainerBytes size of sample container (expressed in bytes)
• ContainerBits size of sample container (expressed in bits)
• SamplesPerChannel number of samples per channel
• Notes useful information about the file e.g. if ValidBits ambiguity detected for WAVE_FORMAT_PCM
• Error description of fatal error encountered when attempting to open and/or read the file

See the M-Pack 1 overview (plus references) for a discussion of the WAV format.

Makes use of the chnmsk2spkrlist function to determine the speaker list from the ChannelMask.

An error is reported if the file has the WAVE_FORMAT_EXTENSIBLE FormatTag but does not have the SubFormat field corresponding to the PCM storage format (Microsoft GUID KSDATAFORMAT_SUBTYPE_PCM).