mpegsubb.a

Application (fix point) for playing MP3 data on embedded systems. mp3play is designed to be able to

               bmi      window_band4
window_band3   move.w   (a3)+,d1
               muls.w   (a2)+,d1
               add.l    d1,d5
               dbra     d0,window_band3
window_band4
               add.l    a5,a3                ; buf1 += off1

               move.w   d4,d0                ; d0 = cnt0
               bmi      window_band6
window_band5   move.w   (a4)+,d1
               muls.w   (a2)+,d1
               add.l    d1,d5
               dbra     d0,window_band5
window_band6
               add.l    a6,a4                ; buf0 += off0
               add.l    d2,a2                ; dewindow += offd

               asr.l    d7,d5                ; sum >>= (WINDOW_FACTOR+INT_FACTOR-15)

               IFD      WINDOW_CLIP
               cmp.l    #-32768,d5
               blt      window_band4l
               cmp.l    #32767,d5
               bgt      window_band4h
window_band4n
               ENDC

               move.w   d5,(a1)+
               dbra     d6,window_band2

               IFD      WINDOW_CLIP
               bra      window_band9
window_band4l  move.l   #-32768,d5
               bra.s    window_band4n
window_band4h  move.l   #32767,d5
               bra.s    window_band4n
               ENDC

window_band9
               move.w   (sp)+,d2 ; #2
               movem.l  (sp)+,d2-d7/a2-a6
               rts

               ; ##1 Begin

               ELSE

;              MULADDWIN {a3|a4}
MULADDWIN      MACRO
               move.w   (\1)+,d1
               muls.w   (a2)+,d1
               add.l    d1,d5
               ENDM

               ; WARING GENAM bug in rept & macros
               ; rept part is moved to END of MACRO !
               ;
;              MULADDN <rept num>,{a3|a4}
MULADDN        MACRO
               IFNE     \2
               REPT     \2
               MULADDWIN \1
               ENDR
               ENDC
               ENDM

;              MULADD0 <rept num>
MULADD0        MACRO
               clr.l    d5
               MULADDN  a3,\1
               ENDM

;              MULADD1 <rept num>
MULADD1        MACRO
               add.l    a5,a3
               MULADDN  a4,\1
               ENDM

               IFD      OLD_OVERFLOW ; ##3 Begin

               ; CHECKBOUNDS <loop label>
CHECKBOUNDS    MACRO
               add.l    a6,a4
               add.l    d2,a2
               asr.l    d7,d5
               IFD      WINDOW_CLIP
               cmp.l    #-32768,d5
               blt      .window_bandl
               cmp.l    #32767,d5
               bgt      .window_bandh
.window_bandn
               ENDC
               move.w   d5,(a1)+
               dbra     d6,\1
               bra      window_band9
               IFD      WINDOW_CLIP
               bra      window_band9
.window_bandl  move.w   #-32768,d5
               bra.s    .window_bandn
.window_bandh  move.w   #32767,d5
               bra.s    .window_bandn
               ENDC
               ENDM

               ELSE ; ##3

               ; CHECKBOUNDS <loop label>
CHECKBOUNDS    MACRO
               add.l    a6,a4
               add.l    d2,a2
               asr.l    d7,d5
               IFD      WINDOW_CLIP
               move.w   d5,a0
               cmp.l    a0,d5
               bne.b    .window_bandov
.window_bandn
               ENDC
               move.w   d5,(a1)+
               dbra     d6,\1
               bra      window_band9
               IFD      WINDOW_CLIP
               bra      window_band9
.window_bandov not.l    d5
               add.l    d5,d5
               move.w   #$8000,d5
               negx.w   d5
               bra.s    .window_bandn
;               move.w   d5,(a1)+
;               dbra     d6,\1
;               bra      window_band9
               ENDC
               ENDM

               ENDC  ; ##3 End


;               move.w   w_width,d3 ; #2
               move.w   (sp),d3 ; #2
               lea      window_q0muls,a0
               cmp.w    #4,d3
               ble      window_qmul
               lea      window_q1muls,a0
               cmp.w    #8,d3
               ble      window_qmul
               lea      window_q2muls,a0
window_qmul
               move.l   (a0,d4.w*4),a0
               jmp      (a0)

window_q2mul0
               MULADD0  16
               MULADD1  0
               CHECKBOUNDS window_q2mul0
window_q2mul1
               MULADD0  15
               MULADD1  1
               CHECKBOUNDS window_q2mul1
window_q2mul2
               MULADD0  14
               MULADD1  2
               CHECKBOUNDS window_q2mul2
window_q2mul3
               MULADD0  13
               MULADD1  3
               CHECKBOUNDS window_q2mul3
window_q2mul4
               MULADD0  12
               MULADD1  4
               CHECKBOUNDS window_q2mul4
window_q2mul5
               MULADD0  11
               MULADD1  5
               CHECKBOUNDS window_q2mul5
window_q2mul6
               MULADD0  10
               MULADD1  6
               CHECKBOUNDS window_q2mul6
window_q2mul7
               MULADD0  9
               MULADD1  7
               CHECKBOUNDS window_q2mul7
window_q2mul8
               MULADD0  8
               MULADD1  8
               CHECKBOUNDS window_q2mul8
window_q2mul9
               MULADD0  7
               MULADD1  9
               CHECKBOUNDS window_q2mul9
window_q2mul10
               MULADD0  6
               MULADD1  10
               CHECKBOUNDS window_q2mul10
window_q2mul11
               MULADD0  5
               MULADD1  11
               CHECKBOUNDS window_q2mul11
window_q2mul12
               MULADD0  4
               MULADD1  12
               CHECKBOUNDS window_q2mul12
window_q2mul13
               MULADD0  3
               MULADD1  13
               CHECKBOUNDS window_q2mul13
window_q2mul14
               MULADD0  2
               MULADD1  14
               CHECKBOUNDS window_q2mul14
window_q2mul15
               MULADD0  1
               MULADD1  15
               CHECKBOUNDS window_q2mul15

window_q1mul0
               MULADD0  8
               MULADD1  0
               CHECKBOUNDS window_q1mul0
window_q1mul1
               MULADD0  7
               MULADD1  1
               CHECKBOUNDS window_q1mul1
window_q1mul2
               MULADD0  6
               MULADD1  2
               CHECKBOUNDS window_q1mul2
window_q1mul3
               MULADD0  5
               MULADD1  3
               CHECKBOUNDS window_q1mul3
window_q1mul4
               MULADD0  4
               MULADD1  4
               CHECKBOUNDS window_q1mul4
window_q1mul5
               MULADD0  3
               MULADD1  5
               CHECKBOUNDS window_q1mul5
window_q1mul6
               MULADD0  2
               MULADD1  6
               CHECKBOUNDS window_q1mul6
window_q1mul7
               MULADD0  1
               MULADD1  7
               CHECKBOUNDS window_q1mul7


window_q0mul0
               MULADD0  4
               MULADD1  0
               CHECKBOUNDS window_q0mul0
window_q0mul1
               MULADD0  3
               MULADD1  1
               CHECKBOUNDS window_q0mul1
window_q0mul2
               MULADD0  2
               MULADD1  2
               CHECKBOUNDS window_q0mul2
window_q0mul3
               MULADD0  1
               MULADD1  3
               CHECKBOUNDS window_q0mul3

window_band9
               move.w   (sp)+,d2
               movem.l  (sp)+,d2-d7/a2-a6
               rts

window_q2muls  dc.l     window_q2mul0, window_q2mul1, window_q2mul2, window_q2mul3
               dc.l     window_q2mul4, window_q2mul5, window_q2mul6, window_q2mul7
               dc.l     window_q2mul8, window_q2mul9, window_q2mul10, window_q2mul11
               dc.l     window_q2mul12, window_q2mul13, window_q2mul14, window_q2mul15

window_q1muls  dc.l     window_q1mul0, window_q1mul1, window_q1mul2, window_q1mul3
               dc.l     window_q1mul4, window_q1mul5, window_q1mul6, window_q1mul7

window_q0muls  dc.l     window_q0mul0, window_q0mul1, window_q0mul2, window_q0mul3

               ENDC

               ; ##1 End

               ; #2 Begin: MPEGSUBB_config suppressed
               IFNE     0

;              Configure subband routines
;
;              d0 = freq_div
;              d1 = quality
;              d2 = output_8bits
;
;@MPEGSUBB_config
;_MPEGSUBB_config
               movem.l  d2-d7/a2-a6,-(sp)
               move.w   d0,freq_div
               move.w   d1,quality
               move.w   d2,output_8bits

               move.w   #32,d3         ; pcm_count for full freq output
               cmp.w    #2,d0
               beq      init_decode_1
               cmp.w    #4,d0
               beq      init_decode_2
               bra      init_decode_5
init_decode_1  move.w   #16,d3         ; pcm_count for half freq output
               bra      init_decode_5
init_decode_2  moveq.l  #8,d3          ; pcm_count for quarter freq output
init_decode_5  move.w   d3,pcm_count
               moveq.l  #0,d3          ; start offset for windowing
               moveq.l  #16,d4         ; #coeff used for windowing
               move.w   quality,d2
               cmp.b    #2,d2          ; best quality
               beq.s    init_decode_6
               move.w   #4,d3
               moveq.l  #8,d4
               cmp.b    #1,d2
               beq.s    init_decode_6
               move.w   #6,d3
               moveq.l  #4,d4
init_decode_6  move.w   d3,w_begin
               move.w   d4,w_width
               movem.l  (sp)+,d2-d7/a2-a6
               rts

               ENDC
               ; #2 End

; ##4 Begin  (Table suppressed)
               IFD OLD_DEW_TABLE

               section  ASM_TABLES,data

WINDOW_FACTOR  equ      14

               even
window_table
               dc.w  +0,    -7,   +53,  -114,  +509, -1288, +1643, -9372,+18759, +9372, +1643, +1288,  +509,  +114,   +53,    +7
               dc.w  +0,    -7,   +54,  -129,  +499, -1379, +1489, -9833,+18747, +8909, +1783, +1196,  +515,  +100,   +51,    +6
               dc.w  +0,    -8,   +55,  -145,  +487, -1469, +1321,-10293,+18713, +8447, +1909, +1106,  +519,   +86,   +50,    +6
               dc.w  +0,    -9,   +56,  -161,  +473, -1559, +1140,-10751,+18657, +7986, +2022, +1015,  +521,   +73,   +49,    +5
               dc.w  +0,   -10,   +56,  -177,  +455, -1647,  +943,-11205,+18578, +7527, +2122,  +926,  +521,   +61,   +47,    +4
               dc.w  +0,   -11,   +57,  -194,  +434, -1733,  +733,-11654,+18476, +7072, +2209,  +837,  +518,   +49,   +45,    +4
               dc.w  +0,   -12,   +57,  -211,  +410, -1817,  +509,-12097,+18353, +6620, +2284,  +750,  +514,   +38,   +44,    +4
               dc.w  +0,   -13,   +56,  -229,  +383, -1899,  +270,-12534,+18208, +6173, +2347,  +665,  +507,   +27,   +42,    +3
               dc.w  +0,   -14,   +56,  -247,  +353, -1977,   +17,-12963,+18042, +5732, +2397,  +582,  +500,   +18,   +40,    +3
               dc.w  +0,   -15,   +55,  -266,  +320, -2052,  -249,-13383,+17854, +5297, +2437,  +501,  +490,    +8,   +38,    +2
               dc.w  +0,   -17,   +53,  -284,  +282, -2122,  -530,-13794,+17647, +4869, +2465,  +422,  +479,    +0,   +36,    +2
               dc.w  +0,   -18,   +51,  -302,  +242, -2188,  -824,-14194,+17419, +4449, +2483,  +346,  +467,    -7,   +34,    +2
               dc.w  +0,   -19,   +50,  -320,  +198, -2249, -1133,-14583,+17172, +4038, +2491,  +273,  +454,   -14,   +32,    +1
               dc.w  +0,   -21,   +47,  -338,  +151, -2304, -1454,-14959,+16907, +3636, +2489,  +203,  +439,   -20,   +31,    +1
               dc.w  +0,   -22,   +44,  -356,  +100, -2353, -1788,-15322,+16623, +3244, +2478,  +136,  +424,   -26,   +29,    +1
               dc.w  -1,   -24,   +40,  -374,   +46, -2396, -2134,-15670,+16322, +2863, +2459,   +71,  +408,   -31,   +27,    +1
               dc.w  -1,   -25,   +36,  -391,   -11, -2431, -2493,-16004,+16004, +2493, +2431,   +11,  +391,   -36,   +25,    +1
               dc.w  -1,   -27,   +31,  -408,   -71, -2459, -2863,-16322,+15670, +2134, +2396,   -46,  +374,   -40,   +24,    +1
               dc.w  -1,   -29,   +26,  -424,  -136, -2478, -3244,-16623,+15322, +1788, +2353,  -100,  +356,   -44,   +22,    +0
               dc.w  -1,   -31,   +20,  -439,  -203, -2489, -3636,-16907,+14959, +1454, +2304,  -151,  +339,   -47,   +21,    +0
               dc.w  -1,   -32,   +14,  -454,  -273, -2491, -4038,-17172,+14583, +1133, +2249,  -198,  +320,   -50,   +19,    +0
               dc.w  -2,   -34,    +7,  -467,  -346, -2483, -4449,-17419,+14194,  +825, +2188,  -242,  +302,   -51,   +18,    +0
               dc.w  -2,   -36,    +0,  -479,  -422, -2465, -4869,-17647,+13794,  +530, +2122,  -282,  +284,   -53,   +17,    +0
               dc.w  -2,   -38,    -8,  -490,  -501, -2437, -5297,-17854,+13383,  +249, +2052,  -319,  +266,   -55,   +15,    +0
               dc.w  -3,   -40,   -18,  -500,  -582, -2397, -5732,-18042,+12963,   -17, +1977,  -353,  +247,   -55,   +14,    +0
               dc.w  -3,   -42,   -27,  -507,  -665, -2347, -6173,-18208,+12534,  -270, +1899,  -383,  +229,   -56,   +13,    +0
               dc.w  -4,   -44,   -38,  -514,  -750, -2284, -6620,-18353,+12097,  -509, +1817,  -410,  +211,   -57,   +12,    +0
               dc.w  -4,   -45,   -49,  -518,  -837, -2209, -7072,-18476,+11654,  -733, +1733,  -434,  +194,   -57,   +11,    +0
               dc.w  -4,   -47,   -61,  -521,  -926, -2122, -7527,-18578,+11205,  -943, +1647,  -455,  +177,   -56,   +10,    +0
               dc.w  -5,   -49,   -73,  -521, -1015, -2022, -7986,-18657,+10751, -1140, +1559,  -473,  +161,   -56,    +9,    +0
               dc.w  -6,   -50,   -86,  -519, -1106, -1909, -8447,-18713,+10293, -1321, +1469,  -487,  +145,   -55,    +8,    +0
               dc.w  -6,   -51,  -100,  -515, -1196, -1783, -8909,-18747, +9833, -1489, +1379,  -499,  +129,   -54,    +7,    +0

               ENDC
; ##4 End

               ; #2: vars suppressed
;               section  ASMVARS,bss

;freq_div       ds.w     1  ; 1,2 or 4
;output_8bits   ds.w     1  ; 0 if 16 bits output
;quality        ds.w     1  ; 0..2 (best)

;w_begin        ds.w     1  ; start offset for windowing
;w_width        ds.w     1  ; #coeff used for windowing
;pcm_count      ds.w     1  ; # of samples per subband