/* * idct BlackFin * * Copyright (C) 2007 Marc Hoffman <marc.hoffman@analog.com> * * This file is part of Libav. * * Libav 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. * * Libav 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 Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /* This blackfin DSP code implements an 8x8 inverse type II DCT. Prototype : void ff_bfin_idct(DCTELEM *in) Registers Used : A0, A1, R0-R7, I0-I3, B0, B2, B3, M0-M2, L0-L3, P0-P5, LC0. Performance : Code Size : 498 Bytes. Cycle Count : 417 Cycles ----------------------------------------------------------- Libav conformance testing results ----------------------------------------------------------- dct-test: modified with the following dct_error("BFINidct", 1, ff_bfin_idct, idct, test); produces the following output libavcodec> ./dct-test -i Libav DCT/IDCT test 8 15 -2 21 24 17 0 10 2 -10 -5 -5 -3 7 -14 -3 2 -13 -10 -19 18 -6 6 -2 9 4 16 -3 9 12 10 15 15 -9 -2 10 1 16 0 -15 -15 5 7 3 13 0 13 20 -6 -15 24 9 -18 1 9 -22 -8 25 23 2 -7 0 30 13 IDCT BFINidct: err_inf=1 err2=0.01002344 syserr=0.00150000 maxout=266 blockSumErr=64 IDCT BFINidct: 88.3 kdct/s */ #include "config.h" #include "config_bfin.h" #if defined(__FDPIC__) && CONFIG_SRAM .section .l1.data.B,"aw",@progbits #else .data #endif .align 4; coefs: .short 0x5a82; // C4 .short 0x5a82; // C4 .short 0x30FC; //cos(3pi/8) C6 .short 0x7642; //cos(pi/8) C2 .short 0x18F9; //cos(7pi/16) .short 0x7D8A; //cos(pi/16) .short 0x471D; //cos(5pi/16) .short 0x6A6E; //cos(3pi/16) .short 0x18F9; //cos(7pi/16) .short 0x7D8A; //cos(pi/16) #if defined(__FDPIC__) && CONFIG_SRAM .section .l1.data.A,"aw",@progbits #endif vtmp: .space 256 #define TMP0 FP-8 #define TMP1 FP-12 #define TMP2 FP-16 .text DEFUN(idct,mL1, (DCTELEM *block)): /********************** Function Prologue *********************************/ link 16; [--SP] = (R7:4, P5:3); // Push the registers onto the stack. B0 = R0; // Pointer to Input matrix RELOC(R1, P3, coefs); // Pointer to Coefficients RELOC(R2, P3, vtmp); // Pointer to Temporary matrix B3 = R1; B2 = R2; L3 = 20; // L3 is used for making the coefficient array // circular. // MUST BE RESTORED TO ZERO at function exit. M1 = 16 (X); // All these registers are initialized for M3 = 8(X); // modifying address offsets. I0 = B0; // I0 points to Input Element (0, 0). I2 = B0; // I2 points to Input Element (0, 0). I2 += M3 || R0.H = W[I0]; // Element 0 is read into R0.H I1 = I2; // I1 points to input Element (0, 6). I1 += 4 || R0.L = W[I2++]; // I2 points to input Element (0, 4). // Element 4 is read into R0.L. P2 = 8 (X); P3 = 32 (X); P4 = -32 (X); P5 = 98 (X); R7 = 0x8000(Z); I3 = B3; // I3 points to Coefficients P0 = B2; // P0 points to array Element (0, 0) of temp P1 = B2; R7 = [I3++] || [TMP2]=R7; // Coefficient C4 is read into R7.H and R7.L. MNOP; NOP; /* * A1 = Y0 * cos(pi/4) * A0 = Y0 * cos(pi/4) * A1 = A1 + Y4 * cos(pi/4) * A0 = A0 - Y4 * cos(pi/4) * load: * R1=(Y2,Y6) * R7=(C2,C6) * res: * R3=Y0, R2=Y4 */ A1=R7.H*R0.H, A0=R7.H*R0.H (IS) || I0+= 4 || R1.L=W[I1++]; R3=(A1+=R7.H*R0.L), R2=(A0-=R7.H*R0.L) (IS) || R1.H=W[I0--] || R7=[I3++]; LSETUP (.0, .1) LC0 = P2; // perform 8 1d idcts P2 = 112 (X); P1 = P1 + P2; // P1 points to element (7, 0) of temp buffer. P2 = -94(X); .0: /* * A1 = Y2 * cos(3pi/8) * A0 = Y2 * cos(pi/8) * A1 = A1 - Y6 * cos(pi/8) * A0 = A0 + Y6 * cos(3pi/8) * R5 = (Y1,Y7) * R7 = (C1,C7) * res: * R1=Y2, R0=Y6 */ A1=R7.L*R1.H, A0=R7.H*R1.H (IS) || I0+=4 || R5.H=W[I0]; R1=(A1-=R7.H*R1.L), R0=(A0+=R7.L*R1.L) (IS) || R5.L=W[I1--] || R7=[I3++]; /* * Y0 = Y0 + Y6. * Y4 = Y4 + Y2. * Y2 = Y4 - Y2. * Y6 = Y0 - Y6. * R3 is saved * R6.l=Y3 * note: R3: Y0, R2: Y4, R1: Y2, R0: Y6 */ R3=R3+R0, R0=R3-R0; R2=R2+R1, R1=R2-R1 || [TMP0]=R3 || R6.L=W[I0--]; /* * Compute the odd portion (1,3,5,7) even is done. * * Y1 = C7 * Y1 - C1 * Y7 + C3 * Y5 - C5 * Y3. * Y7 = C1 * Y1 + C7 * Y7 + C5 * Y5 + C3 * Y3. * Y5 = C5 * Y1 + C3 * Y7 + C7 * Y5 - C1 * Y3. * Y3 = C3 * Y1 - C5 * Y7 - C1 * Y5 - C7 * Y3. */ // R5=(Y1,Y7) R6=(Y5,Y3) // R7=(C1,C7) A1 =R7.L*R5.H, A0 =R7.H*R5.H (IS) || [TMP1]=R2 || R6.H=W[I2--]; A1-=R7.H*R5.L, A0+=R7.L*R5.L (IS) || I0-=4 || R7=[I3++]; A1+=R7.H*R6.H, A0+=R7.L*R6.H (IS) || I0+=M1; // R7=(C3,C5) R3 =(A1-=R7.L*R6.L), R2 =(A0+=R7.H*R6.L) (IS); A1 =R7.L*R5.H, A0 =R7.H*R5.H (IS) || R4=[TMP0]; A1+=R7.H*R5.L, A0-=R7.L*R5.L (IS) || I1+=M1 || R7=[I3++]; // R7=(C1,C7) A1+=R7.L*R6.H, A0-=R7.H*R6.H (IS); R7 =(A1-=R7.H*R6.L), R6 =(A0-=R7.L*R6.L) (IS) || I2+=M1; // R3=Y1, R2=Y7, R7=Y5, R6=Y3 /* Transpose write column. */ R5.H=R4+R2 (RND12); // Y0=Y0+Y7 R5.L=R4-R2 (RND12) || R4 = [TMP1]; // Y7=Y7-Y0 R2.H=R1+R7 (RND12) || W[P0++P3]=R5.H; // Y2=Y2+Y5 st Y0 R2.L=R1-R7 (RND12) || W[P1++P4]=R5.L || R7=[I3++]; // Y5=Y2-Y5 st Y7 R5.H=R0-R3 (RND12) || W[P0++P3]=R2.H || R1.L=W[I1++]; // Y1=Y6-Y1 st Y2 R5.L=R0+R3 (RND12) || W[P1++P4]=R2.L || R0.H=W[I0++]; // Y6=Y6+Y1 st Y5 R3.H=R4-R6 (RND12) || W[P0++P3]=R5.H || R0.L=W[I2++]; // Y3=Y3-Y4 st Y1 R3.L=R4+R6 (RND12) || W[P1++P4]=R5.L || R1.H=W[I0++]; // Y4=Y3+Y4 st Y6 /* pipeline loop start, + drain Y3, Y4 */ A1=R7.H*R0.H, A0=R7.H*R0.H (IS) || W[P0++P2]= R3.H || R1.H = W[I0--]; .1: R3=(A1+=R7.H*R0.L), R2=(A0-=R7.H*R0.L) (IS) || W[P1++P5]= R3.L || R7 = [I3++]; I0 = B2; // I0 points to Input Element (0, 0) I2 = B2; // I2 points to Input Element (0, 0) I2 += M3 || R0.H = W[I0]; // Y0 is read in R0.H I1 = I2; // I1 points to input Element (0, 6) I1 += 4 || R0.L = W[I2++]; // I2 points to input Element (0, 4) // Y4 is read in R0.L P2 = 8 (X); I3 = B3; // I3 points to Coefficients P0 = B0; // P0 points to array Element (0, 0) for writing // output P1 = B0; R7 = [I3++]; // R7.H = C4 and R7.L = C4 NOP; /* * A1 = Y0 * cos(pi/4) * A0 = Y0 * cos(pi/4) * A1 = A1 + Y4 * cos(pi/4) * A0 = A0 - Y4 * cos(pi/4) * load: * R1=(Y2,Y6) * R7=(C2,C6) * res: * R3=Y0, R2=Y4 */ A1=R7.H*R0.H, A0=R7.H*R0.H (IS) || I0+=4 || R1.L=W[I1++]; R3=(A1+=R7.H*R0.L), R2=(A0-=R7.H*R0.L) (IS) || R1.H=W[I0--] || R7=[I3++]; LSETUP (.2, .3) LC0 = P2; // peform 8 1d idcts P2 = 112 (X); P1 = P1 + P2; P2 = -94(X); .2: /* * A1 = Y2 * cos(3pi/8) * A0 = Y2 * cos(pi/8) * A1 = A1 - Y6 * cos(pi/8) * A0 = A0 + Y6 * cos(3pi/8) * R5 = (Y1,Y7) * R7 = (C1,C7) * res: * R1=Y2, R0=Y6 */ A1=R7.L*R1.H, A0=R7.H*R1.H (IS) || I0+=4 || R5.H=W[I0]; R1=(A1-=R7.H*R1.L), R0=(A0+=R7.L*R1.L) (IS) || R5.L=W[I1--] || R7=[I3++]; /* * Y0 = Y0 + Y6. * Y4 = Y4 + Y2. * Y2 = Y4 - Y2. * Y6 = Y0 - Y6. * R3 is saved * R6.l=Y3 * note: R3: Y0, R2: Y4, R1: Y2, R0: Y6 */ R3=R3+R0, R0=R3-R0; R2=R2+R1, R1=R2-R1 || [TMP0]=R3 || R6.L=W[I0--]; /* * Compute the odd portion (1,3,5,7) even is done. * * Y1 = C7 * Y1 - C1 * Y7 + C3 * Y5 - C5 * Y3. * Y7 = C1 * Y1 + C7 * Y7 + C5 * Y5 + C3 * Y3. * Y5 = C5 * Y1 + C3 * Y7 + C7 * Y5 - C1 * Y3. * Y3 = C3 * Y1 - C5 * Y7 - C1 * Y5 - C7 * Y3. */ // R5=(Y1,Y7) R6=(Y5,Y3) // R7=(C1,C7) A1 =R7.L*R5.H, A0 =R7.H*R5.H (IS) || [TMP1]=R2 || R6.H=W[I2--]; A1-=R7.H*R5.L, A0+=R7.L*R5.L (IS) || I0-=4 || R7=[I3++]; A1+=R7.H*R6.H, A0+=R7.L*R6.H (IS) || I0+=M1; // R7=(C3,C5) R3 =(A1-=R7.L*R6.L), R2 =(A0+=R7.H*R6.L) (IS); A1 =R7.L*R5.H, A0 =R7.H*R5.H (IS) || R4=[TMP0]; A1+=R7.H*R5.L, A0-=R7.L*R5.L (IS) || I1+=M1 || R7=[I3++]; // R7=(C1,C7) A1+=R7.L*R6.H, A0-=R7.H*R6.H (IS); R7 =(A1-=R7.H*R6.L), R6 =(A0-=R7.L*R6.L) (IS) || I2+=M1; // R3=Y1, R2=Y7, R7=Y5, R6=Y3 /* Transpose write column. */ R5.H=R4+R2 (RND20); // Y0=Y0+Y7 R5.L=R4-R2 (RND20) || R4 = [TMP1]; // Y7=Y7-Y0 R2.H=R1+R7 (RND20) || W[P0++P3]=R5.H; // Y2=Y2+Y5 st Y0 R2.L=R1-R7 (RND20) || W[P1++P4]=R5.L || R7=[I3++]; // Y5=Y2-Y5 st Y7 R5.H=R0-R3 (RND20) || W[P0++P3]=R2.H || R1.L=W[I1++]; // Y1=Y6-Y1 st Y2 R5.L=R0+R3 (RND20) || W[P1++P4]=R2.L || R0.H=W[I0++]; // Y6=Y6+Y1 st Y5 R3.H=R4-R6 (RND20) || W[P0++P3]=R5.H || R0.L=W[I2++]; // Y3=Y3-Y4 st Y1 R3.L=R4+R6 (RND20) || W[P1++P4]=R5.L || R1.H=W[I0++]; // Y4=Y3+Y4 st Y6 /* pipeline loop start, + drain Y3, Y4 */ A1=R7.H*R0.H, A0=R7.H*R0.H (IS) || W[P0++P2]= R3.H || R1.H = W[I0--]; .3: R3=(A1+=R7.H*R0.L), R2=(A0-=R7.H*R0.L) (IS) || W[P1++P5]= R3.L || R7 = [I3++]; L3 = 0; (R7:4,P5:3)=[SP++]; unlink; RTS; DEFUN_END(idct)