--- /dev/null
+@ vim:filetype=armasm
+
+@ Generic routines for mixing audio samples
+@ (c) Copyright 2007, Grazvydas "notaz" Ignotas
+
+
+.text
+.align 4
+
+@ this assumes src is word aligned
+.global mix_16h_to_32 @ int *dest, short *src, int count
+
+mix_16h_to_32:
+ stmfd sp!, {r4-r6,lr}
+/*
+ tst r1, #2
+ beq m16_32_mo_unalw
+ ldrsh r4, [r1], #2
+ ldr r3, [r0]
+ sub r2, r2, #1
+ add r3, r3, r4, asr #1
+ str r3, [r0], #4
+*/
+m16_32_mo_unalw:
+ subs r2, r2, #4
+ bmi m16_32_end
+
+m16_32_loop:
+ ldmia r0, {r3-r6}
+ ldmia r1!,{r12,lr}
+ subs r2, r2, #4
+ add r4, r4, r12,asr #17 @ we use half volume
+ mov r12,r12,lsl #16
+ add r3, r3, r12,asr #17
+ add r6, r6, lr, asr #17
+ mov lr, lr, lsl #16
+ add r5, r5, lr, asr #17
+ stmia r0!,{r3-r6}
+ bpl m16_32_loop
+
+m16_32_end:
+ tst r2, #2
+ beq m16_32_no_unal2
+ ldr r5, [r1], #4
+ ldmia r0, {r3,r4}
+ mov r12,r5, lsl #16
+ add r3, r3, r12,asr #17
+ add r4, r4, r5, asr #17
+ stmia r0!,{r3,r4}
+
+m16_32_no_unal2:
+ tst r2, #1
+ ldmeqfd sp!, {r4-r6,pc}
+ ldrsh r4, [r1], #2
+ ldr r3, [r0]
+ add r3, r3, r4, asr #1
+ str r3, [r0], #4
+
+ ldmfd sp!, {r4-r6,lr}
+ bx lr
+
+
+
+.global mix_16h_to_32_s1 @ int *dest, short *src, int count
+
+mix_16h_to_32_s1:
+ stmfd sp!, {r4-r6,lr}
+
+ subs r2, r2, #4
+ bmi m16_32_s1_end
+
+m16_32_s1_loop:
+ ldmia r0, {r3-r6}
+ ldr r12,[r1], #8
+ ldr lr, [r1], #8
+ subs r2, r2, #4
+ add r4, r4, r12,asr #17
+ mov r12,r12,lsl #16
+ add r3, r3, r12,asr #17 @ we use half volume
+ add r6, r6, lr, asr #17
+ mov lr, lr, lsl #16
+ add r5, r5, lr, asr #17
+ stmia r0!,{r3-r6}
+ bpl m16_32_s1_loop
+
+m16_32_s1_end:
+ tst r2, #2
+ beq m16_32_s1_no_unal2
+ ldr r5, [r1], #8
+ ldmia r0, {r3,r4}
+ mov r12,r5, lsl #16
+ add r3, r3, r12,asr #17
+ add r4, r4, r5, asr #17
+ stmia r0!,{r3,r4}
+
+m16_32_s1_no_unal2:
+ tst r2, #1
+ ldmeqfd sp!, {r4-r6,pc}
+ ldrsh r4, [r1], #2
+ ldr r3, [r0]
+ add r3, r3, r4, asr #1
+ str r3, [r0], #4
+
+ ldmfd sp!, {r4-r6,lr}
+ bx lr
+
+
+
+.global mix_16h_to_32_s2 @ int *dest, short *src, int count
+
+mix_16h_to_32_s2:
+ stmfd sp!, {r4-r6,lr}
+
+ subs r2, r2, #4
+ bmi m16_32_s2_end
+
+m16_32_s2_loop:
+ ldmia r0, {r3-r6}
+ ldr r12,[r1], #16
+ ldr lr, [r1], #16
+ subs r2, r2, #4
+ add r4, r4, r12,asr #17
+ mov r12,r12,lsl #16
+ add r3, r3, r12,asr #17 @ we use half volume
+ add r6, r6, lr, asr #17
+ mov lr, lr, lsl #16
+ add r5, r5, lr, asr #17
+ stmia r0!,{r3-r6}
+ bpl m16_32_s2_loop
+
+m16_32_s2_end:
+ tst r2, #2
+ beq m16_32_s2_no_unal2
+ ldr r5, [r1], #16
+ ldmia r0, {r3,r4}
+ mov r12,r5, lsl #16
+ add r3, r3, r12,asr #17
+ add r4, r4, r5, asr #17
+ stmia r0!,{r3,r4}
+
+m16_32_s2_no_unal2:
+ tst r2, #1
+ ldmeqfd sp!, {r4-r6,pc}
+ ldrsh r4, [r1], #2
+ ldr r3, [r0]
+ add r3, r3, r4, asr #1
+ str r3, [r0], #4
+
+ ldmfd sp!, {r4-r6,lr}
+ bx lr
+
+
+
+@ limit
+@ reg=int_sample, lr=1, r3=tmp, kills flags
+.macro Limit reg
+ add r3, lr, \reg, asr #15
+ bics r3, r3, #1 @ in non-overflow conditions r3 is 0 or 1
+ movne \reg, #0x8000
+ subpl \reg, \reg, #1
+.endm
+
+
+@ limit and shift up by 16
+@ reg=int_sample, lr=1, r3=tmp, kills flags
+.macro Limitsh reg
+@ movs r4, r3, asr #16
+@ cmnne r4, #1
+@ beq c32_16_no_overflow
+@ tst r4, r4
+@ mov r3, #0x8000
+@ subpl r3, r3, #1
+
+ add r3, lr, \reg, asr #15
+ bics r3, r3, #1 @ in non-overflow conditions r3 is 0 or 1
+ moveq \reg, \reg, lsl #16
+ movne \reg, #0x80000000
+ subpl \reg, \reg, #0x00010000
+.endm
+
+
+@ mix 32bit audio (with 16bits really used, upper bits indicate overflow) with normal 16 bit audio with left channel only
+@ warning: this function assumes dest is word aligned
+.global mix_32_to_16l_stereo @ short *dest, int *src, int count
+
+mix_32_to_16l_stereo:
+ stmfd sp!, {r4-r8,lr}
+
+ mov lr, #1
+
+ mov r2, r2, lsl #1
+ subs r2, r2, #4
+ bmi m32_16l_st_end
+
+m32_16l_st_loop:
+ ldmia r0, {r8,r12}
+ ldmia r1!, {r4-r7}
+ mov r8, r8, lsl #16
+ mov r12,r12,lsl #16
+ add r4, r4, r8, asr #16
+ add r5, r5, r8, asr #16
+ add r6, r6, r12,asr #16
+ add r7, r7, r12,asr #16
+ Limitsh r4
+ Limitsh r5
+ Limitsh r6
+ Limitsh r7
+ subs r2, r2, #4
+ orr r4, r5, r4, lsr #16
+ orr r5, r7, r6, lsr #16
+ stmia r0!, {r4,r5}
+ bpl m32_16l_st_loop
+
+m32_16l_st_end:
+ @ check for remaining bytes to convert
+ tst r2, #2
+ beq m32_16l_st_no_unal2
+ ldrsh r6, [r0]
+ ldmia r1!,{r4,r5}
+ add r4, r4, r6
+ add r5, r5, r6
+ Limitsh r4
+ Limitsh r5
+ orr r4, r5, r4, lsr #16
+ str r4, [r0], #4
+
+m32_16l_st_no_unal2:
+ ldmfd sp!, {r4-r8,lr}
+ bx lr
+
+
+@ mix 32bit audio (with 16bits really used, upper bits indicate overflow) with normal 16 bit audio (for mono sound)
+.global mix_32_to_16_mono @ short *dest, int *src, int count
+
+mix_32_to_16_mono:
+ stmfd sp!, {r4-r8,lr}
+
+ mov lr, #1
+
+ @ check if dest is word aligned
+ tst r0, #2
+ beq m32_16_mo_no_unalw
+ ldrsh r5, [r0]
+ ldr r4, [r1], #4
+ sub r2, r2, #1
+ add r4, r4, r5
+ Limit r4
+ strh r4, [r0], #2
+
+m32_16_mo_no_unalw:
+ subs r2, r2, #4
+ bmi m32_16_mo_end
+
+m32_16_mo_loop:
+ ldmia r0, {r8,r12}
+ ldmia r1!, {r4-r7}
+ add r5, r5, r8, asr #16
+ mov r8, r8, lsl #16
+ add r4, r4, r8, asr #16
+ add r7, r7, r12,asr #16
+ mov r12,r12,lsl #16
+ add r6, r6, r12,asr #16
+ Limitsh r4
+ Limitsh r5
+ Limitsh r6
+ Limitsh r7
+ subs r2, r2, #4
+ orr r4, r5, r4, lsr #16
+ orr r5, r7, r6, lsr #16
+ stmia r0!, {r4,r5}
+ bpl m32_16_mo_loop
+
+m32_16_mo_end:
+ @ check for remaining bytes to convert
+ tst r2, #2
+ beq m32_16_mo_no_unal2
+ ldr r6, [r0]
+ ldmia r1!,{r4,r5}
+ add r5, r5, r6, asr #16
+ mov r6, r6, lsl #16
+ add r4, r4, r6, asr #16
+ Limitsh r4
+ Limitsh r5
+ orr r4, r5, r4, lsr #16
+ str r4, [r0], #4
+
+m32_16_mo_no_unal2:
+ tst r2, #1
+ ldmeqfd sp!, {r4-r8,pc}
+ ldrsh r5, [r0]
+ ldr r4, [r1], #4
+ add r4, r4, r5
+ Limit r4
+ strh r4, [r0], #2
+
+ ldmfd sp!, {r4-r8,lr}
+ bx lr
+
+
+
+.data
+.align 4
+
+.global mix_32_to_16l_level
+mix_32_to_16l_level:
+ .word 0
+
+.text
+.align 4
+
+@ same as mix_32_to_16l_stereo, but with additional shift
+.global mix_32_to_16l_stereo_lvl @ short *dest, int *src, int count
+
+mix_32_to_16l_stereo_lvl:
+ stmfd sp!, {r4-r9,lr}
+
+ ldr r9, =mix_32_to_16l_level
+ mov lr, #1
+ ldr r9, [r9]
+
+ mov r2, r2, lsl #1
+ subs r2, r2, #4
+ bmi m32_16l_st_l_end
+
+m32_16l_st_l_loop:
+ ldmia r0, {r8,r12}
+ ldmia r1!, {r4-r7}
+ mov r8, r8, lsl #16
+ mov r12,r12,lsl #16
+ add r4, r4, r8, asr #16
+ add r5, r5, r8, asr #16
+ add r6, r6, r12,asr #16
+ add r7, r7, r12,asr #16
+ mov r4, r4, asr r9
+ mov r5, r5, asr r9
+ mov r6, r6, asr r9
+ mov r7, r7, asr r9
+ Limitsh r4
+ Limitsh r5
+ Limitsh r6
+ Limitsh r7
+ subs r2, r2, #4
+ orr r4, r5, r4, lsr #16
+ orr r5, r7, r6, lsr #16
+ stmia r0!, {r4,r5}
+ bpl m32_16l_st_l_loop
+
+m32_16l_st_l_end:
+ @ check for remaining bytes to convert
+ tst r2, #2
+ beq m32_16l_st_l_no_unal2
+ ldrsh r6, [r0]
+ ldmia r1!,{r4,r5}
+ add r4, r4, r6
+ add r5, r5, r6
+ mov r4, r4, asr r9
+ mov r5, r5, asr r9
+ Limitsh r4
+ Limitsh r5
+ orr r4, r5, r4, lsr #16
+ str r4, [r0], #4
+
+m32_16l_st_l_no_unal2:
+ ldmfd sp!, {r4-r9,lr}
+ bx lr
+
+
notaz.gp2x.de / picodrive.git / blobdiff