diff options
Diffstat (limited to 'firmware/target/arm/ipod/video/lcd-as-video.S')
| -rw-r--r-- | firmware/target/arm/ipod/video/lcd-as-video.S | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/firmware/target/arm/ipod/video/lcd-as-video.S b/firmware/target/arm/ipod/video/lcd-as-video.S new file mode 100644 index 0000000000..938df3e86a --- /dev/null +++ b/firmware/target/arm/ipod/video/lcd-as-video.S @@ -0,0 +1,226 @@ +/*************************************************************************** + * __________ __ ___. + * Open \______ \ ____ ____ | | _\_ |__ _______ ___ + * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / + * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < + * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ + * \/ \/ \/ \/ \/ + * $Id$ + * + * Copyright (C) 2007 by Andree Buschmann + * + * All files in this archive are subject to the GNU General Public License. + * See the file COPYING in the source tree root for full license agreement. + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY + * KIND, either express or implied. + * + ****************************************************************************/ + +/**************************************************************************** + * void lcd_write_yuv_420_lines(unsigned char const * const src[3], + * int width, + * int stride); + * + * |R| |1.000000 -0.000001 1.402000| |Y'| + * |G| = |1.000000 -0.334136 -0.714136| |Pb| + * |B| |1.000000 1.772000 0.000000| |Pr| + * Scaled, normalized, rounded and tweaked to yield RGB 565: + * |R| |74 0 101| |Y' - 16| >> 9 + * |G| = |74 -24 -51| |Cb - 128| >> 8 + * |B| |74 128 0| |Cr - 128| >> 9 + */ + .section .icode, "ax", %progbits + .align 2 + .global lcd_write_yuv420_lines + .type lcd_write_yuv420_lines, %function +lcd_write_yuv420_lines: + /* r0 = yuv_src */ + /* r1 = width */ + /* r2 = stride */ + stmfd sp!, { r4-r12 } /* save non-scratch */ + ldmia r0, { r10, r11, r12 } /* r10 = yuv_src[0] = Y'_p */ + /* r11 = yuv_src[1] = Cb_p */ + /* r12 = yuv_src[2] = Cr_p */ + add r2, r10, r2 /* r2 = &ysrc[stride] */ + add r3, r1, r1, asl #1 /* number of bytes for chroma buffer */ + add r3, r3, #15 /* plus room for 3 additional words, */ + bic r3, r3, #3 /* rounded up to multiples of 4 byte */ + sub sp, sp, r3 /* and allocate on stack */ + stmia sp, {r1, r2, r3} /* width, &ysrc[stride], stack_alloc */ + + mov r7, r1 /* r7 = loop count */ + add r8, sp, #12 /* chroma buffer */ + mov r9, #0x30000000 /* LCD data port */ + + /* 1st loop start */ +10: /* loop start */ + + ldrb r0, [r11], #1 /* r0 = *usrc++ = *Cb_p++ */ + ldrb r1, [r12], #1 /* r1 = *vsrc++ = *Cr_p++ */ + + sub r0, r0, #128 /* r0 = Cb-128 */ + sub r1, r1, #128 /* r1 = Cr-128 */ + + add r3, r1, r1, asl #1 /* r3 = Cr*51 + Cb*24 */ + add r3, r3, r3, asl #4 + add r3, r3, r0, asl #3 + add r3, r3, r0, asl #4 + + add r4, r1, r1, asl #2 /* r1 = Cr*101 */ + add r4, r4, r1, asl #5 + add r1, r4, r1, asl #6 + + add r1, r1, #256 /* r1 = rv = (r1 + 256) >> 9 */ + mov r1, r1, asr #9 + strb r1, [r8], #1 /* store r1 to chroma_buf */ + rsb r3, r3, #128 /* r3 = guv = (-r3 + 128) >> 8 */ + mov r3, r3, asr #8 + strb r3, [r8], #1 /* store r3 to chroma_buf */ + add r0, r0, #2 /* r0 = bu = (Cb*128 + 256) >> 9 */ + mov r0, r0, asr #2 + strb r0, [r8], #1 /* store r0 to chroma_buf */ + + /* 1st loop, first pixel */ + ldrb r5, [r10], #1 /* r5 = *ysrc++ = *Y'_p++ */ + sub r5, r5, #16 /* r5 = (Y'-16) * 74 */ + add r2, r5, r5, asl #2 + add r5, r2, r5, asl #5 + + add r6, r1, r5, asr #8 /* r6 = r = (Y >> 9) + rv */ + add r2, r3, r5, asr #7 /* r2 = g = (Y >> 8) + guv */ + add r4, r0, r5, asr #8 /* r4 = b = (Y >> 9) + bu */ + + orr r5, r6, r4 /* check if clamping is needed... */ + orr r5, r5, r2, asr #1 /* ...at all */ + cmp r5, #31 + bls 15f /* -> no clamp */ + cmp r6, #31 /* clamp r */ + mvnhi r6, r6, asr #31 + andhi r6, r6, #31 + cmp r2, #63 /* clamp g */ + mvnhi r2, r2, asr #31 + andhi r2, r2, #63 + cmp r4, #31 /* clamp b */ + mvnhi r4, r4, asr #31 + andhi r4, r4, #31 +15: /* no clamp */ + + orr r4, r4, r2, lsl #5 /* pixel = r<<11 | g<<5 | b */ + orr r4, r4, r6, lsl #11 + strh r4, [r9] /* write pixel */ + + /* 1st loop, second pixel */ + ldrb r5, [r10], #1 /* r5 = *ysrc++ = *Y'_p++ */ + sub r5, r5, #16 /* r5 = (Y'-16) * 74 */ + add r2, r5, r5, asl #2 + add r5, r2, r5, asl #5 + + add r6, r1, r5, asr #8 /* r6 = r = (Y >> 9) + rv */ + add r2, r3, r5, asr #7 /* r2 = g = (Y >> 8) + guv */ + add r4, r0, r5, asr #8 /* r4 = b = (Y >> 9) + bu */ + + orr r5, r6, r4 /* check if clamping is needed... */ + orr r5, r5, r2, asr #1 /* ...at all */ + cmp r5, #31 + bls 15f /* -> no clamp */ + cmp r6, #31 /* clamp r */ + mvnhi r6, r6, asr #31 + andhi r6, r6, #31 + cmp r2, #63 /* clamp g */ + mvnhi r2, r2, asr #31 + andhi r2, r2, #63 + cmp r4, #31 /* clamp b */ + mvnhi r4, r4, asr #31 + andhi r4, r4, #31 +15: /* no clamp */ + + orr r4, r4, r2, lsl #5 /* pixel = r<<11 | g<<5 | b */ + orr r4, r4, r6, lsl #11 + strh r4, [r9] /* write pixel */ + + subs r7, r7, #2 /* check for loop end */ + bgt 10b /* back to beginning */ + /* 1st loop end */ + + add r8, sp, #12 /* chroma buffer */ + ldmia sp, { r7, r10 } /* r7 = loop count */ + /* r10 = &ysrc[stride] */ + + /* 2nd loop start */ +20: /* loop start */ + + /* restore r1, r3 and r0 from chroma buffer */ + ldrsb r1, [r8], #1 + ldrsb r3, [r8], #1 + ldrsb r0, [r8], #1 + + /* 2nd loop, first pixel */ + ldrb r5, [r10], #1 /* r5 = *ysrc++ = *Y'_p++ */ + sub r5, r5, #16 /* r5 = (Y'-16) * 74 */ + add r2, r5, r5, asl #2 + add r5, r2, r5, asl #5 + + add r6, r1, r5, asr #8 /* r6 = r = (Y >> 9) + rv */ + add r2, r3, r5, asr #7 /* r2 = g = (Y >> 8) + guv */ + add r4, r0, r5, asr #8 /* r4 = b = (Y >> 9) + bu */ + + orr r5, r6, r4 /* check if clamping is needed... */ + orr r5, r5, r2, asr #1 /* ...at all */ + cmp r5, #31 + bls 15f /* -> no clamp */ + cmp r6, #31 /* clamp r */ + mvnhi r6, r6, asr #31 + andhi r6, r6, #31 + cmp r2, #63 /* clamp g */ + mvnhi r2, r2, asr #31 + andhi r2, r2, #63 + cmp r4, #31 /* clamp b */ + mvnhi r4, r4, asr #31 + andhi r4, r4, #31 +15: /* no clamp */ + + orr r4, r4, r2, lsl #5 /* pixel = r<<11 | g<<5 | b */ + orr r4, r4, r6, lsl #11 + strh r4, [r9] /* write pixel */ + + /* 2nd loop, second pixel */ + ldrb r5, [r10], #1 /* r5 = *ysrc++ = *Y'_p++ */ + sub r5, r5, #16 /* r5 = (Y'-16) * 74 */ + add r2, r5, r5, asl #2 + add r5, r2, r5, asl #5 + + add r6, r1, r5, asr #8 /* r6 = r = (Y >> 9) + rv */ + add r2, r3, r5, asr #7 /* r2 = g = (Y >> 8) + guv */ + add r4, r0, r5, asr #8 /* r4 = b = (Y >> 9) + bu */ + + orr r5, r6, r4 /* check if clamping is needed... */ + orr r5, r5, r2, asr #1 /* ...at all */ + cmp r5, #31 + bls 15f /* -> no clamp */ + cmp r6, #31 /* clamp r */ + mvnhi r6, r6, asr #31 + andhi r6, r6, #31 + cmp r2, #63 /* clamp g */ + mvnhi r2, r2, asr #31 + andhi r2, r2, #63 + cmp r4, #31 /* clamp b */ + mvnhi r4, r4, asr #31 + andhi r4, r4, #31 +15: /* no clamp */ + + orr r4, r4, r2, lsl #5 /* pixel = r<<11 | g<<5 | b */ + orr r4, r4, r6, lsl #11 + strh r4, [r9] /* write pixel */ + + subs r7, r7, #2 /* check for loop end */ + bgt 20b /* back to beginning */ + /* 2nd loop end */ + + ldr r3, [sp, #8] + add sp, sp, r3 /* deallocate buffer */ + ldmfd sp!, { r4-r12 } /* restore registers */ + bx lr + + .ltorg + .size lcd_write_yuv420_lines, .-lcd_write_yuv420_lines |