Firelight Technologies FMOD Studio API

FMOD_CODEC_READ_CALLBACK

Read callback for the codec for when FMOD tries to read some data from the file to the destination format (format specified in the open callback).

C/C++ Syntax

FMOD_RESULT F_CALLBACK FMOD_CODEC_READ_CALLBACK(
  FMOD_CODEC_STATE *codec_state,
  void *buffer,
  unsigned int samples_in,
  unsigned int *samples_out
);

Parameters

codec_state

Pointer to the codec state. The user can use this variable to access runtime plugin specific variables and plugin writer user data.

buffer

Buffer to read PCM data to. Note that the format of this data is the format described in FMOD_CODEC_WAVEFORMAT.

samples_in

Number of PCM samples to decode

samples_out

Number of PCM samples decoded

Return Values

If the function succeeds then the return value is FMOD_OK.
If the function fails then the return value will be one of the values defined in the FMOD_RESULT enumeration.

Remarks

If you cannot read number of samples requested, simply return FMOD_OK and give samples_out the number of samples you decoded.

Read and seek within the file using the 'fileread' and 'fileseek' members of the FMOD_CODEC codec that is passed in.
Note: DO NOT USE YOUR OWN FILESYSTEM.
The reasons for this are:

• The user may have set their own file system via user filesystem callbacks.
• FMOD allows file reading via disk, memory and TCP/IP. If you use your own file routines you will lose this ability.

Remember to return FMOD_OK at the bottom of the function, or an appropriate error code from FMOD_RESULT.

See Also

• FMOD_CODEC_STATE
• FMOD_CODEC_DESCRIPTION
• FMOD_CODEC_OPEN_CALLBACK
• FMOD_CODEC_CLOSE_CALLBACK
• FMOD_CODEC_GETLENGTH_CALLBACK
• FMOD_CODEC_SETPOSITION_CALLBACK
• FMOD_CODEC_GETPOSITION_CALLBACK
• FMOD_CODEC_SOUNDCREATE_CALLBACK

Version 1.10.03 Built on Feb 1, 2018