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authorMarc Hoffman <mmh@pleasantst.com>2007-04-01 22:28:45 +0000
committerDiego Biurrun <diego@biurrun.de>2007-04-01 22:28:45 +0000
commit67fd620c01ee3b18a0aacb0fc83ff5f86f481850 (patch)
tree1cd1be18867c9e564705ef212c4edaaeab4a4fbd /libavcodec/bfin/fdct_bfin.S
parentf8fb86e9bb2c6c15103c5d3b6704cf5ae0fdd914 (diff)
downloadffmpeg-67fd620c01ee3b18a0aacb0fc83ff5f86f481850.tar.gz
bfin dsputils, basic pixel operations sads, diffs, motion compensation
and standard IEEE 8x8 block transforms patch by Marc Hoffman, mmh pleasantst com Originally committed as revision 8594 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec/bfin/fdct_bfin.S')
-rw-r--r--libavcodec/bfin/fdct_bfin.S324
1 files changed, 324 insertions, 0 deletions
diff --git a/libavcodec/bfin/fdct_bfin.S b/libavcodec/bfin/fdct_bfin.S
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+/*
+ * fdct BlackFin
+ *
+ * Copyright (C) 2007 Marc Hoffman <marc.hoffman@analog.com>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+/*
+ void ff_bfin_fdct (DCTELEM *buf);
+
+ This implementation works only for 8x8 input. The range of input
+ must be -256 to 255 i.e. 8bit input represented in a 16bit data
+ word. The original data must be sign extended into the 16bit data
+ words.
+
+
+ Chen factorization of
+
+ 8
+ X(m) = sum (x(n) * cos ((2n+1)*m*pi/16))
+ n=0
+
+ C4
+ 0 --*-------------*0+7---*-----*0+3-------*-*-------------------> 0
+ \ / \ / X S4,S4
+ 1 --*-\---------/-*1+6---*-\-/-*1+2-------*-*-------------------> 4
+ \ / \ -C4 C3
+ 2 --*---\-----/---*2+5---*-/-\-*1-2---------------*-*-----------> 2
+ \ / / \ X S3,-S3
+ 3 --*-----\-/-----*3+4---*-----*0-3---------------*-*-----------> 6
+ / C7 C3
+ 4 --*-----/-\-----*3-4------------*-*4+5--*-----*---------------> 1
+ / \ -C4 X \ /S7 C3
+ 5 --*---/-----\---*2-5---*-*------*=*4-5----\-/------*-*--------> 5
+ / \ X S4,S4 / X S3,-S3
+ 6 --*-/---------\-*1-6---*-*------*=*7-6----/-\------*-*--------> 3
+ / \ C4 X / \-S7 C3
+ --*-------------*0-7------------*-*7+6--*-----*---------------> 7
+ C7
+
+Notation
+ Cn = cos(n*pi/8) used throughout the code.
+
+
+ Registers used:
+ R0, R1, R2, R3, R4, R5, R6,R7, P0, P1, P2, P3, P4, P5, A0, A1.
+ Other registers used:
+ I0, I1, I2, I3, B0, B2, B3, M0, M1, L3 registers and LC0.
+
+ Input - r0 - pointer to start of DCTELEM *block
+
+ Output - The DCT output coefficients in the DCTELEM *block
+
+ Register constraint:
+ This code is called from jpeg_encode.
+ R6, R5, R4 if modified should be stored and restored.
+
+
+ Performance: (Timer version 0.6.33)
+ Code Size : 240 Bytes.
+ Memory Required :
+ Input Matrix : 8 * 8 * 2 Bytes.
+ Coefficients : 16 Bytes
+ Temporary matrix: 8 * 8 * 2 Bytes.
+ Cycle Count :26+{18+8*(14+2S)}*2 where S -> Stalls
+ (7.45 c/pel)
+ -----------------------------------------
+ | Size | Forward DCT | Inverse DCT |
+ -----------------------------------------
+ | 8x8 | 284 Cycles | 311 Cycles |
+ -----------------------------------------
+
+Ck = int16(cos(k/16*pi)*32767+.5)/2
+#define C4 23170
+#define C3 13623
+#define C6 6270
+#define C7 3196
+
+Sk = int16(sin(k/16*pi)*32767+.5)/2
+#define S4 11585
+#define S3 9102
+#define S6 15137
+#define S7 16069
+
+the coefficients are ordered as follows:
+short dct_coef[]
+ C4,S4,
+ C6,S6,
+ C7,S7,
+ S3,C3,
+
+-----------------------------------------------------------
+FFMPEG conformance testing results
+-----------------------------------------------------------
+dct-test: modified with the following
+ dct_error("BFINfdct", 0, ff_bfin_fdct, fdct, test);
+produces the following output:
+
+root:/u/ffmpeg/bhead/libavcodec> ./dct-test
+ffmpeg DCT/IDCT test
+
+ 2 -131 -6 -48 -36 33 -83 24
+ 34 52 -24 -15 5 92 57 143
+ -67 -43 -1 74 -16 5 -71 32
+ -78 106 92 -34 -38 81 20 -18
+ 7 -62 40 2 -15 90 -62 -83
+ -83 1 -104 -13 43 -19 7 11
+ -63 31 12 -29 83 72 21 10
+ -17 -63 -15 73 50 -91 159 -14
+DCT BFINfdct: err_inf=2 err2=0.16425938 syserr=0.00795000 maxout=2098 blockSumErr=27
+DCT BFINfdct: 92.1 kdct/s
+root:/u/ffmpeg/bhead/libavcodec>
+
+*/
+
+#include "config_bfin.h"
+
+.section .l1.data.B,"aw",@progbits
+.align 4;
+dct_coeff:
+.short 0x5a82, 0x2d41, 0x187e, 0x3b21, 0x0c7c, 0x3ec5, 0x238e, 0x3537;
+
+.section .l1.data.A,"aw",@progbits
+.align 4
+vtmp: .space 128
+
+DEFUN(fdct,mL1,
+ (DCTELEM *block)):
+ [--SP] = (R7:4, P5:3); // Push the registers onto the stack.
+
+ b0 = r0;
+ r0 = [P3+dct_coeff@GOT17M4];
+ b3 = r0;
+ r0 = [P3+vtmp@GOT17M4];
+ b2 = r0;
+
+ L3 = 16; // L3 is set to 16 to make the coefficient
+ // array Circular.
+
+
+//----------------------------------------------------------------------------
+
+/*
+ * I0, I1, and I2 registers are used to read the input data. I3 register is used
+ * to read the coefficients. P0 and P1 registers are used for writing the output
+ * data.
+ */
+ M0 = 12 (X); // All these initializations are used in the
+ M1 = 16 (X); // modification of address offsets.
+
+ M2 = 128 (X);
+
+ P2 = 16;
+ P3 = 32 (X);
+ P4 = -110 (X);
+ P5 = -62 (X);
+ P0 = 2(X);
+
+
+ // Prescale the input to get the correct precision.
+ i0=b0;
+ i1=b0;
+
+ lsetup (.0, .1) LC0 = P3;
+ r0=[i0++];
+.0: r1=r0<<3 (v) || r0=[i0++] ;
+.1: [i1++]=r1;
+
+ /*
+ * B0 points to the "in" buffer.
+ * B2 points to "temp" buffer in the first iteration.
+ */
+
+ lsetup (.2, .3) LC0 = P0;
+.2:
+ I0 = B0; // I0 points to Input Element (0, 0).
+ I1 = B0; // Element 1 and 0 is read in R0.
+ I1 += M0 || R0 = [I0++]; // I1 points to Input Element (0, 6).
+ I2 = I1; // Element 6 is read into R3.H.
+ I2 -= 4 || R3.H = W[I1++]; // I2 points to Input Element (0, 4).
+
+ I3 = B3; // I3 points to Coefficients.
+ P0 = B2; // P0 points to temporary array Element
+ // (0, 0).
+ P1 = B2; // P1 points to temporary array.
+ R7 = [P1++P2] || R2 = [I2++]; // P1 points to temporary array
+ // Element (1, 0).
+ // R7 is a dummy read. X4,X5
+ // are read into R2.
+ R3.L = W[I1--]; // X7 is read into R3.L.
+ R1.H = W[I0++]; // X2 is read into R1.H.
+
+
+ /*
+ * X0 = (X0 + X7) / 2.
+ * X1 = (X1 + X6) / 2.
+ * X6 = (X1 - X6) / 2.
+ * X7 = (X0 - X7) / 2.
+ * It reads the data 3 in R1.L.
+ */
+
+ R0 = R0 +|+ R3, R3 = R0 -|- R3 || R1.L = W[I0++] || NOP;
+
+ /*
+ * X2 = (X2 + X5) / 2.
+ * X3 = (X3 + X4) / 2.
+ * X4 = (X3 - X4) / 2.
+ * X5 = (X2 - X5) / 2.
+ * R7 = C4 = cos(4*pi/16)
+ */
+
+ R1 = R1 +|+ R2, R2 = R1 -|- R2 (CO) || NOP || R7 = [I3++];
+
+ /*
+ * At the end of stage 1 R0 has (1,0), R1 has (2,3), R2 has (4, 5) and
+ * R3 has (6,7).
+ * Where the notation (x, y) represents uper/lower half pairs.
+ */
+
+ /*
+ * X0 = X0 + X3.
+ * X1 = X1 + X2.
+ * X2 = X1 - X2.
+ * X3 = X0 - X3.
+ */
+ R0 = R0 +|+ R1, R1 = R0 -|- R1;
+
+ lsetup (.row0, .row1) LC1 = P2 >> 1; // 1d dct, loops 8x
+.row0:
+
+ /*
+ * This is part 2 computation continued.....
+ * A1 = X6 * cos(pi/4)
+ * A0 = X6 * cos(pi/4)
+ * A1 = A1 - X5 * cos(pi/4)
+ * A0 = A0 + X5 * cos(pi/4).
+ * The instruction W[I0] = R3.L is used for packing it to R2.L.
+ */
+
+ A1=R3.H*R7.l, A0=R3.H*R7.l || I1+=M1 || W[I0] = R3.L;
+ R4.H=(A1-=R2.L*R7.l), R4.L=(A0+=R2.L*R7.l) || I2+=M0 || NOP;
+
+ /* R0 = (X1,X0) R1 = (X2,X3) R4 = (X5, X6). */
+
+ /*
+ * A1 = X0 * cos(pi/4)
+ * A0 = X0 * cos(pi/4)
+ * A1 = A1 - X1 * cos(pi/4)
+ * A0 = A0 + X1 * cos(pi/4)
+ * R7 = (C2,C6)
+ */
+ A1=R0.L*R7.h, A0=R0.L*R7.h || NOP || R3.H=W[I1++];
+ R5.H=(A1-=R0.H*R7.h),R5.L=(A0+=R0.H*R7.h) || R7=[I3++] || NOP;
+
+ /*
+ * A1 = X2 * cos(3pi/8)
+ * A0 = X3 * cos(3pi/8)
+ * A1 = A1 + X3 * cos(pi/8)
+ * A0 = A0 - X2 * cos(pi/8)
+ * R3 = cos(pi/4)
+ * R7 = (cos(7pi/8),cos(pi/8))
+ * X4 = X4 + X5.
+ * X5 = X4 - X5.
+ * X6 = X7 - X6.
+ * X7 = X7 + X6.
+ */
+ A1=R1.H*R7.L, A0=R1.L*R7.L || W[P0++P3]=R5.L || R2.L=W[I0];
+ R2=R2+|+R4, R4=R2-|-R4 || I0+=4 || R3.L=W[I1--];
+ R6.H=(A1+=R1.L*R7.H),R6.L=(A0 -= R1.H * R7.H) || I0+=4 || R7=[I3++];
+
+ /* R2 = (X4, X7) R4 = (X5,X6) R5 = (X1, X0) R6 = (X2,X3). */
+
+ /*
+ * A1 = X4 * cos(7pi/16)
+ * A0 = X7 * cos(7pi/16)
+ * A1 = A1 + X7 * cos(pi/16)
+ * A0 = A0 - X4 * cos(pi/16)
+ */
+
+ A1=R2.H*R7.L, A0=R2.L*R7.L || W[P0++P3]=R6.H || R0=[I0++];
+ R2.H=(A1+=R2.L*R7.H),R2.L=(A0-=R2.H*R7.H) || W[P0++P3]=R5.H || R7=[I3++];
+
+ /*
+ * A1 = X5 * cos(3pi/16)
+ * A0 = X6 * cos(3pi/16)
+ * A1 = A1 + X6 * cos(5pi/16)
+ * A0 = A0 - X5 * cos(5pi/16)
+ * The output values are written.
+ */
+
+ A1=R4.H*R7.H, A0=R4.L*R7.H || W[P0++P2]=R6.L || R1.H=W[I0++];
+ R4.H=(A1+=R4.L*R7.L),R4.L=(A0-=R4.H*R7.L) || W[P0++P4]=R2.L || R1.L=W[I0++];
+
+
+ /* Beginning of next stage, **pipelined** + drain and store the
+ rest of the column store. */
+
+ R0=R0+|+R3,R3=R0-|-R3 || W[P1++P3]=R2.H || R2=[I2++];
+ R1=R1+|+R2,R2=R1-|-R2 (CO) || W[P1++P3]=R4.L || R7=[I3++];
+.row1: R0=R0+|+R1,R1=R0-|-R1 || W[P1++P5]=R4.H || NOP;
+
+ // Exchange input with output.
+ B1 = B0;
+ B0 = B2;
+.3: B2 = B1;
+
+ L3=0;
+ (r7:4,p5:3) = [sp++];
+ RTS;
+