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/ IRIX Base Documentation 2002 November / SGI IRIX Base Documentation 2002 November.iso / usr / share / catman / p_man / cat3dm / audiofile / afSetConversionParams.z / afSetConversionParams
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Text File  |  2002-10-03  |  11.4 KB  |  199 lines
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  4. aaaaffffSSSSeeeettttCCCCoooonnnnvvvveeeerrrrssssiiiioooonnnnPPPPaaaarrrraaaammmmssss((((3333ddddmmmm))))                          aaaaffffSSSSeeeettttCCCCoooonnnnvvvveeeerrrrssssiiiioooonnnnPPPPaaaarrrraaaammmmssss((((3333ddddmmmm))))
  5.  
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  8. NNNNAAAAMMMMEEEE
  9.      afSetConversionParams, afGetConversionParams - set/get the parameters
  10.      associated with format conversion for a specified audio track via
  11.      ddddmmmmPPPPaaaarrrraaaammmmssss
  12.  
  13. SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS
  14.      ####iiiinnnncccclllluuuuddddeeee <<<<ddddmmmmeeeeddddiiiiaaaa////ddddmmmm____aaaauuuuddddiiiioooo....hhhh>>>>
  15.      ####iiiinnnncccclllluuuuddddeeee <<<<ddddmmmmeeeeddddiiiiaaaa////aaaauuuuddddiiiiooooffffiiiilllleeee....hhhh>>>>
  16.  
  17.      DDDDMMMMssssttttaaaattttuuuussss aaaaffffSSSSeeeettttCCCCoooonnnnvvvveeeerrrrssssiiiioooonnnnPPPPaaaarrrraaaammmmssss((((AAAAFFFFffffiiiilllleeeehhhhaaaannnnddddlllleeee ffffiiiilllleeee,,,, iiiinnnntttt ttttrrrraaaacccckkkk,,,,
  18.                                        DDDDMMMMppppaaaarrrraaaammmmssss ****ppppaaaarrrraaaammmmssss))))
  19.  
  20.      DDDDMMMMssssttttaaaattttuuuussss aaaaffffGGGGeeeettttCCCCoooonnnnvvvveeeerrrrssssiiiioooonnnnPPPPaaaarrrraaaammmmssss((((AAAAFFFFffffiiiilllleeeehhhhaaaannnnddddlllleeee ffffiiiilllleeee,,,, iiiinnnntttt ttttrrrraaaacccckkkk,,,,
  21.                                        DDDDMMMMppppaaaarrrraaaammmmssss ****ppppaaaarrrraaaammmmssss))))
  22.  
  23. PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRR
  24.      _f_i_l_e     is an AAAAFFFFffffiiiilllleeeehhhhaaaannnnddddlllleeee structure, previously created by a call to
  25.               aaaaffffOOOOppppeeeennnnFFFFiiiilllleeee(3dm) or its equivalent.
  26.  
  27.      _t_r_a_c_k    is an integer which identifies an audio track in _f_i_l_e.
  28.  
  29.               Since all currently supported file formats contain only one
  30.               audio track, the value AAAAFFFF____DDDDEEEEFFFFAAAAUUUULLLLTTTT____TTTTRRRRAAAACCCCKKKK should be used here for
  31.               now.
  32.  
  33.      _p_a_r_a_m_s   a DDDDMMMMppppaaaarrrraaaammmmssss list, previously created by a call to
  34.               ddddmmmmPPPPaaaarrrraaaammmmssssCCCCrrrreeeeaaaatttteeee(3dm).
  35.  
  36. RRRREEEETTTTUUUURRRRNNNN VVVVAAAALLLLUUUUEEEE
  37.      aaaaffffSSSSeeeettttCCCCoooonnnnvvvveeeerrrrssssiiiioooonnnnPPPPaaaarrrraaaammmmssss(((()))) and aaaaffffGGGGeeeettttCCCCoooonnnnvvvveeeerrrrssssiiiioooonnnnPPPPaaaarrrraaaammmmssss(((()))) return DM_SUCCESS on
  38.      success, otherwise they return DM_FAILURE.
  39.  
  40. DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
  41.      When some type of format conversion takes place during aaaaffffRRRReeeeaaaaddddFFFFrrrraaaammmmeeeessss(((()))) or
  42.      aaaaffffWWWWrrrriiiitttteeeeFFFFrrrraaaammmmeeeessss(((()))) due to a difference between the ttttrrrraaaacccckkkk and the vvvviiiirrrrttttuuuuaaaallll
  43.      format, the precise mechanism for this conversion may be controlled via a
  44.      set of parameters.
  45.  
  46.      aaaaffffSSSSeeeettttCCCCoooonnnnvvvveeeerrrrssssiiiioooonnnnPPPPaaaarrrraaaammmmssss(((()))) sets all parameters associated with the
  47.      conversion of audio data to or from an audio track from or to an audio
  48.      buffer.
  49.  
  50.      aaaaffffGGGGeeeettttCCCCoooonnnnvvvveeeerrrrssssiiiioooonnnnPPPPaaaarrrraaaammmmssss(((()))) allows an application to retrieve the complete
  51.      set of conversion parameters currently contained within an AAAAFFFFffffiiiilllleeeehhhhaaaannnnddddlllleeee
  52.      structure for a given audio track.
  53.  
  54.      The following parameters are defined in _d_m_e_d_i_a/_d_m__a_u_d_i_o._h and may be set
  55.      or retrieved via _p_a_r_a_m_s:
  56.  
  57.      DDDDMMMM____AAAAUUUUDDDDIIIIOOOO____RRRRCCCC____AAAALLLLGGGGOOOORRRRIIIITTTTHHHHMMMM
  58.              The converson algorithm to be used if rate conversion is being
  59.              performed.  Its possible values are:
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  62.  
  63.                                                                         PPPPaaaaggggeeee 1111
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  70. aaaaffffSSSSeeeettttCCCCoooonnnnvvvveeeerrrrssssiiiioooonnnnPPPPaaaarrrraaaammmmssss((((3333ddddmmmm))))                          aaaaffffSSSSeeeettttCCCCoooonnnnvvvveeeerrrrssssiiiioooonnnnPPPPaaaarrrraaaammmmssss((((3333ddddmmmm))))
  71.  
  72.  
  73.  
  74.      DDDDMMMM____AAAAUUUUDDDDIIIIOOOO____RRRRCCCC____JJJJIIIITTTTTTTTEEEERRRR____FFFFRRRREEEEEEEE   Jitter-Free is the highest quality rate
  75.                                conversion available, and is the default for
  76.                                all sampling rate ratios which it can support.
  77.                                This includes all standard rate conversions
  78.                                (i.e., 44.1k to 8k, 48k to 22.05k, etc.).
  79.  
  80.      DDDDMMMM____AAAAUUUUDDDDIIIIOOOO____RRRRCCCC____PPPPOOOOLLLLYYYYNNNNOOOOMMMMIIIIAAAALLLL____OOOORRRRDDDDEEEERRRR____3333
  81.                                A third-order polynomial interpolating
  82.                                algorithm.  It is the default for all sampling
  83.                                rate ratios not covered by Jitter-Free.
  84.  
  85.      DDDDMMMM____AAAAUUUUDDDDIIIIOOOO____RRRRCCCC____PPPPOOOOLLLLYYYYNNNNOOOOMMMMIIIIAAAALLLL____OOOORRRRDDDDEEEERRRR____1111
  86.                                A simple linear-interpolating algorithm.  This
  87.                                is the least CPU-intensive, but also generated
  88.                                the most distortion.
  89.  
  90.      DDDDMMMM____AAAAUUUUDDDDIIIIOOOO____RRRRCCCC____JJJJIIIITTTTTTTTEEEERRRR____FFFFRRRREEEEEEEE____SSSSTTTTOOOOPPPPBBBBAAAANNNNDDDD____AAAATTTTTTTTEEEENNNNUUUUAAAATTTTIIIIOOOONNNN
  91.              The parameter is specific to the jitter free rate converter
  92.              algorithm.  The values correspond to the minimum attenuation
  93.              level of the out-of-band frequencies, those frequencies which do
  94.              not fit in the smaller of the output or input bandwidths.  Higher
  95.              values correspond to better noise suppression.  Supported values
  96.              are:
  97.  
  98.                  DM_AUDIO_RC_JITTER_FREE_STOPBAND_ATTENUATION_78_DB (default)
  99.                  DM_AUDIO_RC_JITTER_FREE_STOPBAND_ATTENUATION_96_DB
  100.                  DM_AUDIO_RC_JITTER_FREE_STOPBAND_ATTENUATION_120_DB
  101.  
  102.      DDDDMMMM____AAAAUUUUDDDDIIIIOOOO____RRRRCCCC____JJJJIIIITTTTTTTTEEEERRRR____FFFFRRRREEEEEEEE____TTTTRRRRAAAANNNNSSSSIIIITTTTIIIIOOOONNNN____BBBBAAAANNNNDDDDWWWWIIIIDDDDTTTTHHHH
  103.              This parameter is specific to the jitter free rate converter
  104.              algorithm.  The values correspond to the percent of the high
  105.              frequency response of the output signal lost in the conversion
  106.              process.  Lower percentages correspond to better high frequency
  107.              response.  Supported values are:
  108.  
  109.                  DM_AUDIO_RC_JITTER_FREE_TRANSITION_BANDWIDTH_1_PERCENT
  110.                  DM_AUDIO_RC_JITTER_FREE_TRANSITION_BANDWIDTH_10_PERCENT
  111.                  DM_AUDIO_RC_JITTER_FREE_TRANSITION_BANDWIDTH_20_PERCENT (default)
  112.  
  113.      DDDDMMMM____AAAAUUUUDDDDIIIIOOOO____DDDDIIIITTTTHHHHEEEERRRR____AAAALLLLGGGGOOOORRRRIIIITTTTHHHHMMMM
  114.              When performing conversions from larger into smaller data types
  115.              (i.e., floating point to 16-bit integer or 16-bit integer to 8-
  116.              bit integer), a dithering algorithm may be applied to reduce the
  117.              quantization error distortion inherant in such conversions.  This
  118.              parameter is ignored if such a conversion is not happening.
  119.              Supported values are:
  120.  
  121.                  DM_AUDIO_DITHER_NONE (default)
  122.                  DM_AUDIO_DITHER_LSB_TPDF (LSB TPDF dither)
  123.  
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  129.                                                                         PPPPaaaaggggeeee 2222
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  136. aaaaffffSSSSeeeettttCCCCoooonnnnvvvveeeerrrrssssiiiioooonnnnPPPPaaaarrrraaaammmmssss((((3333ddddmmmm))))                          aaaaffffSSSSeeeettttCCCCoooonnnnvvvveeeerrrrssssiiiioooonnnnPPPPaaaarrrraaaammmmssss((((3333ddddmmmm))))
  137.  
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  139.  
  140.      DDDDMMMM____AAAAUUUUDDDDIIIIOOOO____CCCCHHHHAAAANNNNNNNNEEEELLLL____MMMMAAAATTTTRRRRIIIIXXXX
  141.              Allows specification of input to output channel routing via a
  142.              matrix of values.
  143.  
  144.              This is a type DMfloatarray which must be set and retrieved via
  145.              ddddmmmmPPPPaaaarrrraaaammmmssssSSSSeeeettttFFFFllllooooaaaattttAAAArrrrrrrraaaayyyy(3dm) and ddddmmmmPPPPaaaarrrraaaammmmssssGGGGeeeettttFFFFllllooooaaaattttAAAArrrrrrrraaaayyyy(3dm),
  146.              respectively.  The data itself is a one-dimensional array of
  147.              double-precision floating point numbers arranged as if it were an
  148.              n x m matrix of values, where rows == output_channels and columns
  149.              == input_channels. See the aaaaffffSSSSeeeettttCCCChhhhaaaannnnnnnneeeellllMMMMaaaattttrrrriiiixxxx(3dm) manual page
  150.              for a detailed explanation of this.
  151.  
  152. SSSSEEEEEEEE AAAALLLLSSSSOOOO
  153.      afWriteFrames(3dm), afInitFormatParams(3dm),
  154.      afSetVirtualFormatParams(3dm), dmACSetParams(3dm)
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  195.                                                                         PPPPaaaaggggeeee 3333
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