1 /*
2  * Copyright (c) 2002 Dieter Shirley
3  *
4  * dct_unquantize_h263_altivec:
5  * Copyright (c) 2003 Romain Dolbeau <romain@dolbeau.org>
6  *
7  * This file is part of FFmpeg.
8  *
9  * FFmpeg is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU Lesser General Public
11  * License as published by the Free Software Foundation; either
12  * version 2.1 of the License, or (at your option) any later version.
13  *
14  * FFmpeg is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  * Lesser General Public License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with FFmpeg; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22  */
23 
24 #include <stdlib.h>
25 #include <stdio.h>
26 #include "dsputil.h"
27 #include "mpegvideo.h"
28 
29 #include "gcc_fixes.h"
30 
31 #include "dsputil_ppc.h"
32 #include "util_altivec.h"
33 // Swaps two variables (used for altivec registers)
34 #define SWAP(a,b) \
35 do { \
36     __typeof__(a) swap_temp=a; \
37     a=b; \
38     b=swap_temp; \
39 } while (0)
40 
41 // transposes a matrix consisting of four vectors with four elements each
42 #define TRANSPOSE4(a,b,c,d) \
43 do { \
44   __typeof__(a) _trans_ach = vec_mergeh(a, c); \
45   __typeof__(a) _trans_acl = vec_mergel(a, c); \
46   __typeof__(a) _trans_bdh = vec_mergeh(b, d); \
47   __typeof__(a) _trans_bdl = vec_mergel(b, d); \
48  \
49   a = vec_mergeh(_trans_ach, _trans_bdh); \
50   b = vec_mergel(_trans_ach, _trans_bdh); \
51   c = vec_mergeh(_trans_acl, _trans_bdl); \
52   d = vec_mergel(_trans_acl, _trans_bdl); \
53 } while (0)
54 
55 
56 // Loads a four-byte value (int or float) from the target address
57 // into every element in the target vector.  Only works if the
58 // target address is four-byte aligned (which should be always).
59 #define LOAD4(vec, address) \
60 { \
61     __typeof__(vec)* _load_addr = (__typeof__(vec)*)(address); \
62     vector unsigned char _perm_vec = vec_lvsl(0,(address)); \
63     vec = vec_ld(0, _load_addr); \
64     vec = vec_perm(vec, vec, _perm_vec); \
65     vec = vec_splat(vec, 0); \
66 }
67 
68 
69 #define FOUROF(a) AVV(a,a,a,a)
70 
dct_quantize_altivec(MpegEncContext * s,DCTELEM * data,int n,int qscale,int * overflow)71 int dct_quantize_altivec(MpegEncContext* s,
72                         DCTELEM* data, int n,
73                         int qscale, int* overflow)
74 {
75     int lastNonZero;
76     vector float row0, row1, row2, row3, row4, row5, row6, row7;
77     vector float alt0, alt1, alt2, alt3, alt4, alt5, alt6, alt7;
78     const vector float zero = (const vector float)FOUROF(0.);
79     // used after quantize step
80     int oldBaseValue = 0;
81 
82     // Load the data into the row/alt vectors
83     {
84         vector signed short data0, data1, data2, data3, data4, data5, data6, data7;
85 
86         data0 = vec_ld(0, data);
87         data1 = vec_ld(16, data);
88         data2 = vec_ld(32, data);
89         data3 = vec_ld(48, data);
90         data4 = vec_ld(64, data);
91         data5 = vec_ld(80, data);
92         data6 = vec_ld(96, data);
93         data7 = vec_ld(112, data);
94 
95         // Transpose the data before we start
96         TRANSPOSE8(data0, data1, data2, data3, data4, data5, data6, data7);
97 
98         // load the data into floating point vectors.  We load
99         // the high half of each row into the main row vectors
100         // and the low half into the alt vectors.
101         row0 = vec_ctf(vec_unpackh(data0), 0);
102         alt0 = vec_ctf(vec_unpackl(data0), 0);
103         row1 = vec_ctf(vec_unpackh(data1), 0);
104         alt1 = vec_ctf(vec_unpackl(data1), 0);
105         row2 = vec_ctf(vec_unpackh(data2), 0);
106         alt2 = vec_ctf(vec_unpackl(data2), 0);
107         row3 = vec_ctf(vec_unpackh(data3), 0);
108         alt3 = vec_ctf(vec_unpackl(data3), 0);
109         row4 = vec_ctf(vec_unpackh(data4), 0);
110         alt4 = vec_ctf(vec_unpackl(data4), 0);
111         row5 = vec_ctf(vec_unpackh(data5), 0);
112         alt5 = vec_ctf(vec_unpackl(data5), 0);
113         row6 = vec_ctf(vec_unpackh(data6), 0);
114         alt6 = vec_ctf(vec_unpackl(data6), 0);
115         row7 = vec_ctf(vec_unpackh(data7), 0);
116         alt7 = vec_ctf(vec_unpackl(data7), 0);
117     }
118 
119     // The following block could exist as a separate an altivec dct
120                 // function.  However, if we put it inline, the DCT data can remain
121                 // in the vector local variables, as floats, which we'll use during the
122                 // quantize step...
123     {
124         const vector float vec_0_298631336 = (vector float)FOUROF(0.298631336f);
125         const vector float vec_0_390180644 = (vector float)FOUROF(-0.390180644f);
126         const vector float vec_0_541196100 = (vector float)FOUROF(0.541196100f);
127         const vector float vec_0_765366865 = (vector float)FOUROF(0.765366865f);
128         const vector float vec_0_899976223 = (vector float)FOUROF(-0.899976223f);
129         const vector float vec_1_175875602 = (vector float)FOUROF(1.175875602f);
130         const vector float vec_1_501321110 = (vector float)FOUROF(1.501321110f);
131         const vector float vec_1_847759065 = (vector float)FOUROF(-1.847759065f);
132         const vector float vec_1_961570560 = (vector float)FOUROF(-1.961570560f);
133         const vector float vec_2_053119869 = (vector float)FOUROF(2.053119869f);
134         const vector float vec_2_562915447 = (vector float)FOUROF(-2.562915447f);
135         const vector float vec_3_072711026 = (vector float)FOUROF(3.072711026f);
136 
137 
138         int whichPass, whichHalf;
139 
140         for(whichPass = 1; whichPass<=2; whichPass++)
141         {
142             for(whichHalf = 1; whichHalf<=2; whichHalf++)
143             {
144                 vector float tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
145                 vector float tmp10, tmp11, tmp12, tmp13;
146                 vector float z1, z2, z3, z4, z5;
147 
148                 tmp0 = vec_add(row0, row7); // tmp0 = dataptr[0] + dataptr[7];
149                 tmp7 = vec_sub(row0, row7); // tmp7 = dataptr[0] - dataptr[7];
150                 tmp3 = vec_add(row3, row4); // tmp3 = dataptr[3] + dataptr[4];
151                 tmp4 = vec_sub(row3, row4); // tmp4 = dataptr[3] - dataptr[4];
152                 tmp1 = vec_add(row1, row6); // tmp1 = dataptr[1] + dataptr[6];
153                 tmp6 = vec_sub(row1, row6); // tmp6 = dataptr[1] - dataptr[6];
154                 tmp2 = vec_add(row2, row5); // tmp2 = dataptr[2] + dataptr[5];
155                 tmp5 = vec_sub(row2, row5); // tmp5 = dataptr[2] - dataptr[5];
156 
157                 tmp10 = vec_add(tmp0, tmp3); // tmp10 = tmp0 + tmp3;
158                 tmp13 = vec_sub(tmp0, tmp3); // tmp13 = tmp0 - tmp3;
159                 tmp11 = vec_add(tmp1, tmp2); // tmp11 = tmp1 + tmp2;
160                 tmp12 = vec_sub(tmp1, tmp2); // tmp12 = tmp1 - tmp2;
161 
162 
163                 // dataptr[0] = (DCTELEM) ((tmp10 + tmp11) << PASS1_BITS);
164                 row0 = vec_add(tmp10, tmp11);
165 
166                 // dataptr[4] = (DCTELEM) ((tmp10 - tmp11) << PASS1_BITS);
167                 row4 = vec_sub(tmp10, tmp11);
168 
169 
170                 // z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
171                 z1 = vec_madd(vec_add(tmp12, tmp13), vec_0_541196100, (vector float)zero);
172 
173                 // dataptr[2] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp13, FIX_0_765366865),
174                 //                                CONST_BITS-PASS1_BITS);
175                 row2 = vec_madd(tmp13, vec_0_765366865, z1);
176 
177                 // dataptr[6] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp12, - FIX_1_847759065),
178                 //                                CONST_BITS-PASS1_BITS);
179                 row6 = vec_madd(tmp12, vec_1_847759065, z1);
180 
181                 z1 = vec_add(tmp4, tmp7); // z1 = tmp4 + tmp7;
182                 z2 = vec_add(tmp5, tmp6); // z2 = tmp5 + tmp6;
183                 z3 = vec_add(tmp4, tmp6); // z3 = tmp4 + tmp6;
184                 z4 = vec_add(tmp5, tmp7); // z4 = tmp5 + tmp7;
185 
186                 // z5 = MULTIPLY(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */
187                 z5 = vec_madd(vec_add(z3, z4), vec_1_175875602, (vector float)zero);
188 
189                 // z3 = MULTIPLY(z3, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */
190                 z3 = vec_madd(z3, vec_1_961570560, z5);
191 
192                 // z4 = MULTIPLY(z4, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */
193                 z4 = vec_madd(z4, vec_0_390180644, z5);
194 
195                 // The following adds are rolled into the multiplies above
196                 // z3 = vec_add(z3, z5);  // z3 += z5;
197                 // z4 = vec_add(z4, z5);  // z4 += z5;
198 
199                 // z2 = MULTIPLY(z2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */
200                 // Wow!  It's actually more efficient to roll this multiply
201                 // into the adds below, even thought the multiply gets done twice!
202                 // z2 = vec_madd(z2, vec_2_562915447, (vector float)zero);
203 
204                 // z1 = MULTIPLY(z1, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
205                 // Same with this one...
206                 // z1 = vec_madd(z1, vec_0_899976223, (vector float)zero);
207 
208                 // tmp4 = MULTIPLY(tmp4, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
209                 // dataptr[7] = (DCTELEM) DESCALE(tmp4 + z1 + z3, CONST_BITS-PASS1_BITS);
210                 row7 = vec_madd(tmp4, vec_0_298631336, vec_madd(z1, vec_0_899976223, z3));
211 
212                 // tmp5 = MULTIPLY(tmp5, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
213                 // dataptr[5] = (DCTELEM) DESCALE(tmp5 + z2 + z4, CONST_BITS-PASS1_BITS);
214                 row5 = vec_madd(tmp5, vec_2_053119869, vec_madd(z2, vec_2_562915447, z4));
215 
216                 // tmp6 = MULTIPLY(tmp6, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
217                 // dataptr[3] = (DCTELEM) DESCALE(tmp6 + z2 + z3, CONST_BITS-PASS1_BITS);
218                 row3 = vec_madd(tmp6, vec_3_072711026, vec_madd(z2, vec_2_562915447, z3));
219 
220                 // tmp7 = MULTIPLY(tmp7, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
221                 // dataptr[1] = (DCTELEM) DESCALE(tmp7 + z1 + z4, CONST_BITS-PASS1_BITS);
222                 row1 = vec_madd(z1, vec_0_899976223, vec_madd(tmp7, vec_1_501321110, z4));
223 
224                 // Swap the row values with the alts.  If this is the first half,
225                 // this sets up the low values to be acted on in the second half.
226                 // If this is the second half, it puts the high values back in
227                 // the row values where they are expected to be when we're done.
228                 SWAP(row0, alt0);
229                 SWAP(row1, alt1);
230                 SWAP(row2, alt2);
231                 SWAP(row3, alt3);
232                 SWAP(row4, alt4);
233                 SWAP(row5, alt5);
234                 SWAP(row6, alt6);
235                 SWAP(row7, alt7);
236             }
237 
238             if (whichPass == 1)
239             {
240                 // transpose the data for the second pass
241 
242                 // First, block transpose the upper right with lower left.
243                 SWAP(row4, alt0);
244                 SWAP(row5, alt1);
245                 SWAP(row6, alt2);
246                 SWAP(row7, alt3);
247 
248                 // Now, transpose each block of four
249                 TRANSPOSE4(row0, row1, row2, row3);
250                 TRANSPOSE4(row4, row5, row6, row7);
251                 TRANSPOSE4(alt0, alt1, alt2, alt3);
252                 TRANSPOSE4(alt4, alt5, alt6, alt7);
253             }
254         }
255     }
256 
257     // perform the quantize step, using the floating point data
258     // still in the row/alt registers
259     {
260         const int* biasAddr;
261         const vector signed int* qmat;
262         vector float bias, negBias;
263 
264         if (s->mb_intra)
265         {
266             vector signed int baseVector;
267 
268             // We must cache element 0 in the intra case
269             // (it needs special handling).
270             baseVector = vec_cts(vec_splat(row0, 0), 0);
271             vec_ste(baseVector, 0, &oldBaseValue);
272 
273             qmat = (vector signed int*)s->q_intra_matrix[qscale];
274             biasAddr = &(s->intra_quant_bias);
275         }
276         else
277         {
278             qmat = (vector signed int*)s->q_inter_matrix[qscale];
279             biasAddr = &(s->inter_quant_bias);
280         }
281 
282         // Load the bias vector (We add 0.5 to the bias so that we're
283                                 // rounding when we convert to int, instead of flooring.)
284         {
285             vector signed int biasInt;
286             const vector float negOneFloat = (vector float)FOUROF(-1.0f);
287             LOAD4(biasInt, biasAddr);
288             bias = vec_ctf(biasInt, QUANT_BIAS_SHIFT);
289             negBias = vec_madd(bias, negOneFloat, zero);
290         }
291 
292         {
293             vector float q0, q1, q2, q3, q4, q5, q6, q7;
294 
295             q0 = vec_ctf(qmat[0], QMAT_SHIFT);
296             q1 = vec_ctf(qmat[2], QMAT_SHIFT);
297             q2 = vec_ctf(qmat[4], QMAT_SHIFT);
298             q3 = vec_ctf(qmat[6], QMAT_SHIFT);
299             q4 = vec_ctf(qmat[8], QMAT_SHIFT);
300             q5 = vec_ctf(qmat[10], QMAT_SHIFT);
301             q6 = vec_ctf(qmat[12], QMAT_SHIFT);
302             q7 = vec_ctf(qmat[14], QMAT_SHIFT);
303 
304             row0 = vec_sel(vec_madd(row0, q0, negBias), vec_madd(row0, q0, bias),
305                     vec_cmpgt(row0, zero));
306             row1 = vec_sel(vec_madd(row1, q1, negBias), vec_madd(row1, q1, bias),
307                     vec_cmpgt(row1, zero));
308             row2 = vec_sel(vec_madd(row2, q2, negBias), vec_madd(row2, q2, bias),
309                     vec_cmpgt(row2, zero));
310             row3 = vec_sel(vec_madd(row3, q3, negBias), vec_madd(row3, q3, bias),
311                     vec_cmpgt(row3, zero));
312             row4 = vec_sel(vec_madd(row4, q4, negBias), vec_madd(row4, q4, bias),
313                     vec_cmpgt(row4, zero));
314             row5 = vec_sel(vec_madd(row5, q5, negBias), vec_madd(row5, q5, bias),
315                     vec_cmpgt(row5, zero));
316             row6 = vec_sel(vec_madd(row6, q6, negBias), vec_madd(row6, q6, bias),
317                     vec_cmpgt(row6, zero));
318             row7 = vec_sel(vec_madd(row7, q7, negBias), vec_madd(row7, q7, bias),
319                     vec_cmpgt(row7, zero));
320 
321             q0 = vec_ctf(qmat[1], QMAT_SHIFT);
322             q1 = vec_ctf(qmat[3], QMAT_SHIFT);
323             q2 = vec_ctf(qmat[5], QMAT_SHIFT);
324             q3 = vec_ctf(qmat[7], QMAT_SHIFT);
325             q4 = vec_ctf(qmat[9], QMAT_SHIFT);
326             q5 = vec_ctf(qmat[11], QMAT_SHIFT);
327             q6 = vec_ctf(qmat[13], QMAT_SHIFT);
328             q7 = vec_ctf(qmat[15], QMAT_SHIFT);
329 
330             alt0 = vec_sel(vec_madd(alt0, q0, negBias), vec_madd(alt0, q0, bias),
331                     vec_cmpgt(alt0, zero));
332             alt1 = vec_sel(vec_madd(alt1, q1, negBias), vec_madd(alt1, q1, bias),
333                     vec_cmpgt(alt1, zero));
334             alt2 = vec_sel(vec_madd(alt2, q2, negBias), vec_madd(alt2, q2, bias),
335                     vec_cmpgt(alt2, zero));
336             alt3 = vec_sel(vec_madd(alt3, q3, negBias), vec_madd(alt3, q3, bias),
337                     vec_cmpgt(alt3, zero));
338             alt4 = vec_sel(vec_madd(alt4, q4, negBias), vec_madd(alt4, q4, bias),
339                     vec_cmpgt(alt4, zero));
340             alt5 = vec_sel(vec_madd(alt5, q5, negBias), vec_madd(alt5, q5, bias),
341                     vec_cmpgt(alt5, zero));
342             alt6 = vec_sel(vec_madd(alt6, q6, negBias), vec_madd(alt6, q6, bias),
343                     vec_cmpgt(alt6, zero));
344             alt7 = vec_sel(vec_madd(alt7, q7, negBias), vec_madd(alt7, q7, bias),
345                     vec_cmpgt(alt7, zero));
346         }
347 
348 
349     }
350 
351     // Store the data back into the original block
352     {
353         vector signed short data0, data1, data2, data3, data4, data5, data6, data7;
354 
355         data0 = vec_pack(vec_cts(row0, 0), vec_cts(alt0, 0));
356         data1 = vec_pack(vec_cts(row1, 0), vec_cts(alt1, 0));
357         data2 = vec_pack(vec_cts(row2, 0), vec_cts(alt2, 0));
358         data3 = vec_pack(vec_cts(row3, 0), vec_cts(alt3, 0));
359         data4 = vec_pack(vec_cts(row4, 0), vec_cts(alt4, 0));
360         data5 = vec_pack(vec_cts(row5, 0), vec_cts(alt5, 0));
361         data6 = vec_pack(vec_cts(row6, 0), vec_cts(alt6, 0));
362         data7 = vec_pack(vec_cts(row7, 0), vec_cts(alt7, 0));
363 
364         {
365             // Clamp for overflow
366             vector signed int max_q_int, min_q_int;
367             vector signed short max_q, min_q;
368 
369             LOAD4(max_q_int, &(s->max_qcoeff));
370             LOAD4(min_q_int, &(s->min_qcoeff));
371 
372             max_q = vec_pack(max_q_int, max_q_int);
373             min_q = vec_pack(min_q_int, min_q_int);
374 
375             data0 = vec_max(vec_min(data0, max_q), min_q);
376             data1 = vec_max(vec_min(data1, max_q), min_q);
377             data2 = vec_max(vec_min(data2, max_q), min_q);
378             data4 = vec_max(vec_min(data4, max_q), min_q);
379             data5 = vec_max(vec_min(data5, max_q), min_q);
380             data6 = vec_max(vec_min(data6, max_q), min_q);
381             data7 = vec_max(vec_min(data7, max_q), min_q);
382         }
383 
384         {
385         vector bool char zero_01, zero_23, zero_45, zero_67;
386         vector signed char scanIndices_01, scanIndices_23, scanIndices_45, scanIndices_67;
387         vector signed char negOne = vec_splat_s8(-1);
388         vector signed char* scanPtr =
389                 (vector signed char*)(s->intra_scantable.inverse);
390         signed char lastNonZeroChar;
391 
392         // Determine the largest non-zero index.
393         zero_01 = vec_pack(vec_cmpeq(data0, (vector signed short)zero),
394                 vec_cmpeq(data1, (vector signed short)zero));
395         zero_23 = vec_pack(vec_cmpeq(data2, (vector signed short)zero),
396                 vec_cmpeq(data3, (vector signed short)zero));
397         zero_45 = vec_pack(vec_cmpeq(data4, (vector signed short)zero),
398                 vec_cmpeq(data5, (vector signed short)zero));
399         zero_67 = vec_pack(vec_cmpeq(data6, (vector signed short)zero),
400                 vec_cmpeq(data7, (vector signed short)zero));
401 
402         // 64 biggest values
403         scanIndices_01 = vec_sel(scanPtr[0], negOne, zero_01);
404         scanIndices_23 = vec_sel(scanPtr[1], negOne, zero_23);
405         scanIndices_45 = vec_sel(scanPtr[2], negOne, zero_45);
406         scanIndices_67 = vec_sel(scanPtr[3], negOne, zero_67);
407 
408         // 32 largest values
409         scanIndices_01 = vec_max(scanIndices_01, scanIndices_23);
410         scanIndices_45 = vec_max(scanIndices_45, scanIndices_67);
411 
412         // 16 largest values
413         scanIndices_01 = vec_max(scanIndices_01, scanIndices_45);
414 
415         // 8 largest values
416         scanIndices_01 = vec_max(vec_mergeh(scanIndices_01, negOne),
417                 vec_mergel(scanIndices_01, negOne));
418 
419         // 4 largest values
420         scanIndices_01 = vec_max(vec_mergeh(scanIndices_01, negOne),
421                 vec_mergel(scanIndices_01, negOne));
422 
423         // 2 largest values
424         scanIndices_01 = vec_max(vec_mergeh(scanIndices_01, negOne),
425                 vec_mergel(scanIndices_01, negOne));
426 
427         // largest value
428         scanIndices_01 = vec_max(vec_mergeh(scanIndices_01, negOne),
429                 vec_mergel(scanIndices_01, negOne));
430 
431         scanIndices_01 = vec_splat(scanIndices_01, 0);
432 
433 
434         vec_ste(scanIndices_01, 0, &lastNonZeroChar);
435 
436         lastNonZero = lastNonZeroChar;
437 
438         // While the data is still in vectors we check for the transpose IDCT permute
439         // and handle it using the vector unit if we can.  This is the permute used
440         // by the altivec idct, so it is common when using the altivec dct.
441 
442         if ((lastNonZero > 0) && (s->dsp.idct_permutation_type == FF_TRANSPOSE_IDCT_PERM))
443         {
444             TRANSPOSE8(data0, data1, data2, data3, data4, data5, data6, data7);
445         }
446 
447         vec_st(data0, 0, data);
448         vec_st(data1, 16, data);
449         vec_st(data2, 32, data);
450         vec_st(data3, 48, data);
451         vec_st(data4, 64, data);
452         vec_st(data5, 80, data);
453         vec_st(data6, 96, data);
454         vec_st(data7, 112, data);
455         }
456     }
457 
458     // special handling of block[0]
459     if (s->mb_intra)
460     {
461         if (!s->h263_aic)
462         {
463             if (n < 4)
464                 oldBaseValue /= s->y_dc_scale;
465             else
466                 oldBaseValue /= s->c_dc_scale;
467         }
468 
469         // Divide by 8, rounding the result
470         data[0] = (oldBaseValue + 4) >> 3;
471     }
472 
473     // We handled the transpose permutation above and we don't
474     // need to permute the "no" permutation case.
475     if ((lastNonZero > 0) &&
476         (s->dsp.idct_permutation_type != FF_TRANSPOSE_IDCT_PERM) &&
477         (s->dsp.idct_permutation_type != FF_NO_IDCT_PERM))
478     {
479         ff_block_permute(data, s->dsp.idct_permutation,
480                 s->intra_scantable.scantable, lastNonZero);
481     }
482 
483     return lastNonZero;
484 }
485 
486 /*
487   AltiVec version of dct_unquantize_h263
488   this code assumes `block' is 16 bytes-aligned
489 */
dct_unquantize_h263_altivec(MpegEncContext * s,DCTELEM * block,int n,int qscale)490 void dct_unquantize_h263_altivec(MpegEncContext *s,
491                                  DCTELEM *block, int n, int qscale)
492 {
493 POWERPC_PERF_DECLARE(altivec_dct_unquantize_h263_num, 1);
494     int i, level, qmul, qadd;
495     int nCoeffs;
496 
497     assert(s->block_last_index[n]>=0);
498 
499 POWERPC_PERF_START_COUNT(altivec_dct_unquantize_h263_num, 1);
500 
501     qadd = (qscale - 1) | 1;
502     qmul = qscale << 1;
503 
504     if (s->mb_intra) {
505         if (!s->h263_aic) {
506             if (n < 4)
507                 block[0] = block[0] * s->y_dc_scale;
508             else
509                 block[0] = block[0] * s->c_dc_scale;
510         }else
511             qadd = 0;
512         i = 1;
513         nCoeffs= 63; //does not always use zigzag table
514     } else {
515         i = 0;
516         nCoeffs= s->intra_scantable.raster_end[ s->block_last_index[n] ];
517     }
518 
519     {
520       register const vector signed short vczero = (const vector signed short)vec_splat_s16(0);
521       DECLARE_ALIGNED_16(short, qmul8[]) =
522           {
523             qmul, qmul, qmul, qmul,
524             qmul, qmul, qmul, qmul
525           };
526       DECLARE_ALIGNED_16(short, qadd8[]) =
527           {
528             qadd, qadd, qadd, qadd,
529             qadd, qadd, qadd, qadd
530           };
531       DECLARE_ALIGNED_16(short, nqadd8[]) =
532           {
533             -qadd, -qadd, -qadd, -qadd,
534             -qadd, -qadd, -qadd, -qadd
535           };
536       register vector signed short blockv, qmulv, qaddv, nqaddv, temp1;
537       register vector bool short blockv_null, blockv_neg;
538       register short backup_0 = block[0];
539       register int j = 0;
540 
541       qmulv = vec_ld(0, qmul8);
542       qaddv = vec_ld(0, qadd8);
543       nqaddv = vec_ld(0, nqadd8);
544 
545 #if 0 // block *is* 16 bytes-aligned, it seems.
546       // first make sure block[j] is 16 bytes-aligned
547       for(j = 0; (j <= nCoeffs) && ((((unsigned long)block) + (j << 1)) & 0x0000000F) ; j++) {
548         level = block[j];
549         if (level) {
550           if (level < 0) {
551                 level = level * qmul - qadd;
552             } else {
553                 level = level * qmul + qadd;
554             }
555             block[j] = level;
556         }
557       }
558 #endif
559 
560       // vectorize all the 16 bytes-aligned blocks
561       // of 8 elements
562       for(; (j + 7) <= nCoeffs ; j+=8)
563       {
564         blockv = vec_ld(j << 1, block);
565         blockv_neg = vec_cmplt(blockv, vczero);
566         blockv_null = vec_cmpeq(blockv, vczero);
567         // choose between +qadd or -qadd as the third operand
568         temp1 = vec_sel(qaddv, nqaddv, blockv_neg);
569         // multiply & add (block{i,i+7} * qmul [+-] qadd)
570         temp1 = vec_mladd(blockv, qmulv, temp1);
571         // put 0 where block[{i,i+7} used to have 0
572         blockv = vec_sel(temp1, blockv, blockv_null);
573         vec_st(blockv, j << 1, block);
574       }
575 
576       // if nCoeffs isn't a multiple of 8, finish the job
577       // using good old scalar units.
578       // (we could do it using a truncated vector,
579       // but I'm not sure it's worth the hassle)
580       for(; j <= nCoeffs ; j++) {
581         level = block[j];
582         if (level) {
583           if (level < 0) {
584                 level = level * qmul - qadd;
585             } else {
586                 level = level * qmul + qadd;
587             }
588             block[j] = level;
589         }
590       }
591 
592       if (i == 1)
593       { // cheat. this avoid special-casing the first iteration
594         block[0] = backup_0;
595       }
596     }
597 POWERPC_PERF_STOP_COUNT(altivec_dct_unquantize_h263_num, nCoeffs == 63);
598 }
599 
600 
601 extern void idct_put_altivec(uint8_t *dest, int line_size, int16_t *block);
602 extern void idct_add_altivec(uint8_t *dest, int line_size, int16_t *block);
603 
MPV_common_init_altivec(MpegEncContext * s)604 void MPV_common_init_altivec(MpegEncContext *s)
605 {
606     if ((mm_flags & MM_ALTIVEC) == 0) return;
607 
608     if (s->avctx->lowres==0)
609     {
610         if ((s->avctx->idct_algo == FF_IDCT_AUTO) ||
611                 (s->avctx->idct_algo == FF_IDCT_ALTIVEC))
612         {
613             s->dsp.idct_put = idct_put_altivec;
614             s->dsp.idct_add = idct_add_altivec;
615             s->dsp.idct_permutation_type = FF_TRANSPOSE_IDCT_PERM;
616         }
617     }
618 
619     // Test to make sure that the dct required alignments are met.
620     if ((((long)(s->q_intra_matrix) & 0x0f) != 0) ||
621         (((long)(s->q_inter_matrix) & 0x0f) != 0))
622     {
623         av_log(s->avctx, AV_LOG_INFO, "Internal Error: q-matrix blocks must be 16-byte aligned "
624                 "to use AltiVec DCT. Reverting to non-AltiVec version.\n");
625         return;
626     }
627 
628     if (((long)(s->intra_scantable.inverse) & 0x0f) != 0)
629     {
630         av_log(s->avctx, AV_LOG_INFO, "Internal Error: scan table blocks must be 16-byte aligned "
631                 "to use AltiVec DCT. Reverting to non-AltiVec version.\n");
632         return;
633     }
634 
635 
636     if ((s->avctx->dct_algo == FF_DCT_AUTO) ||
637             (s->avctx->dct_algo == FF_DCT_ALTIVEC))
638     {
639 #if 0 /* seems to cause trouble under some circumstances */
640         s->dct_quantize = dct_quantize_altivec;
641 #endif
642         s->dct_unquantize_h263_intra = dct_unquantize_h263_altivec;
643         s->dct_unquantize_h263_inter = dct_unquantize_h263_altivec;
644     }
645 }
646