dmMPEG1AudioHeaderGetParams(3dm)

NAME
     dmMPEG1AudioHeaderGetParams - get decoder parameter information from a
     header of any compressed MPEG1 audio data block.


SYNOPSIS
     #include <dmedia/dmedia.h>
     #include <dmedia/dm_audioutil.h>

     DMstatus dmMPEG1AudioHeaderGetParams(unsigned char *cmpData,
                                          DMparams *params)


PARAMETER
     cmpData
          points to a block of data bytes presumed to constitute the
          compressed data stream and start with a MPEG audio header.


     params
          List of parameters for specification.


RETURNED VALUE
     Returns DM_FAILURE or DM_SUCCESS.


DESCRIPTION
     dmMPEG1AudioHeaderGetParams(3dm) extracts MPEG1 audio compression
     parameter information from a header of a compressed data stream without
     going so far as to decompress the data.  These parameter values are then
     stored in DMparams *params structure and can be used to set decoder
     parameters by a call to dmMPEG1AudioDecoderSetParams(3dm).

     Extracted parameters from a compressed bit strem header are as follows:
          DM_AUDIO_BITRAT
          DM_AUDIO_RATE
          DM_AUDIO_CHANNELS
          DM_MPEG1_AUDIO_LAYER
          DM_MPEG1_AUDIO_BITRATE_POLICY

     The other three parameter values are set to decoder defaults:
          DM_AUDIO_FORMAT
          (set to DM_AUDIO_TWOS_COMPLEMENT)
          DM_AUDIO_WIDTH
          (set to DM_AUDIO_WIDTH_16)
          DM_AUDIO_CHANNEL_POLICY
          (set to DM_MPEG1_AUDIO_CONSTANT_QUALITY)
NOTE
SEE ALSO
     dmMPEG1AudioDecoderCreate(3dm), dmMPEG1AudioDecoderSetParams(3dm),
     dmMPEG1AudioDecoderGetParams(3dm), dmMPEG1AudioDecode(3dm).