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h264idct_template.c
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1 /*
2  * H.264 IDCT
3  * Copyright (c) 2004-2011 Michael Niedermayer <michaelni@gmx.at>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * H.264 IDCT.
25  * @author Michael Niedermayer <michaelni@gmx.at>
26  */
27 
28 #include "bit_depth_template.c"
29 #include "libavutil/common.h"
30 #include "h264.h"
31 #include "h264idct.h"
32 
33 void FUNCC(ff_h264_idct_add)(uint8_t *_dst, int16_t *_block, int stride)
34 {
35  int i;
36  pixel *dst = (pixel*)_dst;
37  dctcoef *block = (dctcoef*)_block;
38  stride >>= sizeof(pixel)-1;
39 
40  block[0] += 1 << 5;
41 
42  for(i=0; i<4; i++){
43  const int z0= block[i + 4*0] + block[i + 4*2];
44  const int z1= block[i + 4*0] - block[i + 4*2];
45  const int z2= (block[i + 4*1]>>1) - block[i + 4*3];
46  const int z3= block[i + 4*1] + (block[i + 4*3]>>1);
47 
48  block[i + 4*0]= z0 + z3;
49  block[i + 4*1]= z1 + z2;
50  block[i + 4*2]= z1 - z2;
51  block[i + 4*3]= z0 - z3;
52  }
53 
54  for(i=0; i<4; i++){
55  const int z0= block[0 + 4*i] + block[2 + 4*i];
56  const int z1= block[0 + 4*i] - block[2 + 4*i];
57  const int z2= (block[1 + 4*i]>>1) - block[3 + 4*i];
58  const int z3= block[1 + 4*i] + (block[3 + 4*i]>>1);
59 
60  dst[i + 0*stride]= av_clip_pixel(dst[i + 0*stride] + ((z0 + z3) >> 6));
61  dst[i + 1*stride]= av_clip_pixel(dst[i + 1*stride] + ((z1 + z2) >> 6));
62  dst[i + 2*stride]= av_clip_pixel(dst[i + 2*stride] + ((z1 - z2) >> 6));
63  dst[i + 3*stride]= av_clip_pixel(dst[i + 3*stride] + ((z0 - z3) >> 6));
64  }
65 
66  memset(block, 0, 16 * sizeof(dctcoef));
67 }
68 
69 void FUNCC(ff_h264_idct8_add)(uint8_t *_dst, int16_t *_block, int stride){
70  int i;
71  pixel *dst = (pixel*)_dst;
72  dctcoef *block = (dctcoef*)_block;
73  stride >>= sizeof(pixel)-1;
74 
75  block[0] += 32;
76 
77  for( i = 0; i < 8; i++ )
78  {
79  const int a0 = block[i+0*8] + block[i+4*8];
80  const int a2 = block[i+0*8] - block[i+4*8];
81  const int a4 = (block[i+2*8]>>1) - block[i+6*8];
82  const int a6 = (block[i+6*8]>>1) + block[i+2*8];
83 
84  const int b0 = a0 + a6;
85  const int b2 = a2 + a4;
86  const int b4 = a2 - a4;
87  const int b6 = a0 - a6;
88 
89  const int a1 = -block[i+3*8] + block[i+5*8] - block[i+7*8] - (block[i+7*8]>>1);
90  const int a3 = block[i+1*8] + block[i+7*8] - block[i+3*8] - (block[i+3*8]>>1);
91  const int a5 = -block[i+1*8] + block[i+7*8] + block[i+5*8] + (block[i+5*8]>>1);
92  const int a7 = block[i+3*8] + block[i+5*8] + block[i+1*8] + (block[i+1*8]>>1);
93 
94  const int b1 = (a7>>2) + a1;
95  const int b3 = a3 + (a5>>2);
96  const int b5 = (a3>>2) - a5;
97  const int b7 = a7 - (a1>>2);
98 
99  block[i+0*8] = b0 + b7;
100  block[i+7*8] = b0 - b7;
101  block[i+1*8] = b2 + b5;
102  block[i+6*8] = b2 - b5;
103  block[i+2*8] = b4 + b3;
104  block[i+5*8] = b4 - b3;
105  block[i+3*8] = b6 + b1;
106  block[i+4*8] = b6 - b1;
107  }
108  for( i = 0; i < 8; i++ )
109  {
110  const int a0 = block[0+i*8] + block[4+i*8];
111  const int a2 = block[0+i*8] - block[4+i*8];
112  const int a4 = (block[2+i*8]>>1) - block[6+i*8];
113  const int a6 = (block[6+i*8]>>1) + block[2+i*8];
114 
115  const int b0 = a0 + a6;
116  const int b2 = a2 + a4;
117  const int b4 = a2 - a4;
118  const int b6 = a0 - a6;
119 
120  const int a1 = -block[3+i*8] + block[5+i*8] - block[7+i*8] - (block[7+i*8]>>1);
121  const int a3 = block[1+i*8] + block[7+i*8] - block[3+i*8] - (block[3+i*8]>>1);
122  const int a5 = -block[1+i*8] + block[7+i*8] + block[5+i*8] + (block[5+i*8]>>1);
123  const int a7 = block[3+i*8] + block[5+i*8] + block[1+i*8] + (block[1+i*8]>>1);
124 
125  const int b1 = (a7>>2) + a1;
126  const int b3 = a3 + (a5>>2);
127  const int b5 = (a3>>2) - a5;
128  const int b7 = a7 - (a1>>2);
129 
130  dst[i + 0*stride] = av_clip_pixel( dst[i + 0*stride] + ((b0 + b7) >> 6) );
131  dst[i + 1*stride] = av_clip_pixel( dst[i + 1*stride] + ((b2 + b5) >> 6) );
132  dst[i + 2*stride] = av_clip_pixel( dst[i + 2*stride] + ((b4 + b3) >> 6) );
133  dst[i + 3*stride] = av_clip_pixel( dst[i + 3*stride] + ((b6 + b1) >> 6) );
134  dst[i + 4*stride] = av_clip_pixel( dst[i + 4*stride] + ((b6 - b1) >> 6) );
135  dst[i + 5*stride] = av_clip_pixel( dst[i + 5*stride] + ((b4 - b3) >> 6) );
136  dst[i + 6*stride] = av_clip_pixel( dst[i + 6*stride] + ((b2 - b5) >> 6) );
137  dst[i + 7*stride] = av_clip_pixel( dst[i + 7*stride] + ((b0 - b7) >> 6) );
138  }
139 
140  memset(block, 0, 64 * sizeof(dctcoef));
141 }
142 
143 // assumes all AC coefs are 0
144 void FUNCC(ff_h264_idct_dc_add)(uint8_t *_dst, int16_t *_block, int stride){
145  int i, j;
146  pixel *dst = (pixel*)_dst;
147  dctcoef *block = (dctcoef*)_block;
148  int dc = (block[0] + 32) >> 6;
149  stride /= sizeof(pixel);
150  block[0] = 0;
151  for( j = 0; j < 4; j++ )
152  {
153  for( i = 0; i < 4; i++ )
154  dst[i] = av_clip_pixel( dst[i] + dc );
155  dst += stride;
156  }
157 }
158 
159 void FUNCC(ff_h264_idct8_dc_add)(uint8_t *_dst, int16_t *_block, int stride){
160  int i, j;
161  pixel *dst = (pixel*)_dst;
162  dctcoef *block = (dctcoef*)_block;
163  int dc = (block[0] + 32) >> 6;
164  block[0] = 0;
165  stride /= sizeof(pixel);
166  for( j = 0; j < 8; j++ )
167  {
168  for( i = 0; i < 8; i++ )
169  dst[i] = av_clip_pixel( dst[i] + dc );
170  dst += stride;
171  }
172 }
173 
174 void FUNCC(ff_h264_idct_add16)(uint8_t *dst, const int *block_offset, int16_t *block, int stride, const uint8_t nnzc[15*8]){
175  int i;
176  for(i=0; i<16; i++){
177  int nnz = nnzc[ scan8[i] ];
178  if(nnz){
179  if(nnz==1 && ((dctcoef*)block)[i*16]) FUNCC(ff_h264_idct_dc_add)(dst + block_offset[i], block + i*16*sizeof(pixel), stride);
180  else FUNCC(ff_h264_idct_add )(dst + block_offset[i], block + i*16*sizeof(pixel), stride);
181  }
182  }
183 }
184 
185 void FUNCC(ff_h264_idct_add16intra)(uint8_t *dst, const int *block_offset, int16_t *block, int stride, const uint8_t nnzc[15*8]){
186  int i;
187  for(i=0; i<16; i++){
188  if(nnzc[ scan8[i] ]) FUNCC(ff_h264_idct_add )(dst + block_offset[i], block + i*16*sizeof(pixel), stride);
189  else if(((dctcoef*)block)[i*16]) FUNCC(ff_h264_idct_dc_add)(dst + block_offset[i], block + i*16*sizeof(pixel), stride);
190  }
191 }
192 
193 void FUNCC(ff_h264_idct8_add4)(uint8_t *dst, const int *block_offset, int16_t *block, int stride, const uint8_t nnzc[15*8]){
194  int i;
195  for(i=0; i<16; i+=4){
196  int nnz = nnzc[ scan8[i] ];
197  if(nnz){
198  if(nnz==1 && ((dctcoef*)block)[i*16]) FUNCC(ff_h264_idct8_dc_add)(dst + block_offset[i], block + i*16*sizeof(pixel), stride);
199  else FUNCC(ff_h264_idct8_add )(dst + block_offset[i], block + i*16*sizeof(pixel), stride);
200  }
201  }
202 }
203 
204 void FUNCC(ff_h264_idct_add8)(uint8_t **dest, const int *block_offset, int16_t *block, int stride, const uint8_t nnzc[15*8]){
205  int i, j;
206  for(j=1; j<3; j++){
207  for(i=j*16; i<j*16+4; i++){
208  if(nnzc[ scan8[i] ])
209  FUNCC(ff_h264_idct_add )(dest[j-1] + block_offset[i], block + i*16*sizeof(pixel), stride);
210  else if(((dctcoef*)block)[i*16])
211  FUNCC(ff_h264_idct_dc_add)(dest[j-1] + block_offset[i], block + i*16*sizeof(pixel), stride);
212  }
213  }
214 }
215 
216 void FUNCC(ff_h264_idct_add8_422)(uint8_t **dest, const int *block_offset, int16_t *block, int stride, const uint8_t nnzc[15*8]){
217  int i, j;
218 
219  for(j=1; j<3; j++){
220  for(i=j*16; i<j*16+4; i++){
221  if(nnzc[ scan8[i] ])
222  FUNCC(ff_h264_idct_add )(dest[j-1] + block_offset[i], block + i*16*sizeof(pixel), stride);
223  else if(((dctcoef*)block)[i*16])
224  FUNCC(ff_h264_idct_dc_add)(dest[j-1] + block_offset[i], block + i*16*sizeof(pixel), stride);
225  }
226  }
227 
228  for(j=1; j<3; j++){
229  for(i=j*16+4; i<j*16+8; i++){
230  if(nnzc[ scan8[i+4] ])
231  FUNCC(ff_h264_idct_add )(dest[j-1] + block_offset[i+4], block + i*16*sizeof(pixel), stride);
232  else if(((dctcoef*)block)[i*16])
233  FUNCC(ff_h264_idct_dc_add)(dest[j-1] + block_offset[i+4], block + i*16*sizeof(pixel), stride);
234  }
235  }
236 }
237 
238 /**
239  * IDCT transforms the 16 dc values and dequantizes them.
240  * @param qmul quantization parameter
241  */
242 void FUNCC(ff_h264_luma_dc_dequant_idct)(int16_t *_output, int16_t *_input, int qmul){
243 #define stride 16
244  int i;
245  int temp[16];
246  static const uint8_t x_offset[4]={0, 2*stride, 8*stride, 10*stride};
247  dctcoef *input = (dctcoef*)_input;
248  dctcoef *output = (dctcoef*)_output;
249 
250  for(i=0; i<4; i++){
251  const int z0= input[4*i+0] + input[4*i+1];
252  const int z1= input[4*i+0] - input[4*i+1];
253  const int z2= input[4*i+2] - input[4*i+3];
254  const int z3= input[4*i+2] + input[4*i+3];
255 
256  temp[4*i+0]= z0+z3;
257  temp[4*i+1]= z0-z3;
258  temp[4*i+2]= z1-z2;
259  temp[4*i+3]= z1+z2;
260  }
261 
262  for(i=0; i<4; i++){
263  const int offset= x_offset[i];
264  const int z0= temp[4*0+i] + temp[4*2+i];
265  const int z1= temp[4*0+i] - temp[4*2+i];
266  const int z2= temp[4*1+i] - temp[4*3+i];
267  const int z3= temp[4*1+i] + temp[4*3+i];
268 
269  output[stride* 0+offset]= ((((z0 + z3)*qmul + 128 ) >> 8));
270  output[stride* 1+offset]= ((((z1 + z2)*qmul + 128 ) >> 8));
271  output[stride* 4+offset]= ((((z1 - z2)*qmul + 128 ) >> 8));
272  output[stride* 5+offset]= ((((z0 - z3)*qmul + 128 ) >> 8));
273  }
274 #undef stride
275 }
276 
277 void FUNCC(ff_h264_chroma422_dc_dequant_idct)(int16_t *_block, int qmul){
278  const int stride= 16*2;
279  const int xStride= 16;
280  int i;
281  int temp[8];
282  static const uint8_t x_offset[2]={0, 16};
283  dctcoef *block = (dctcoef*)_block;
284 
285  for(i=0; i<4; i++){
286  temp[2*i+0] = block[stride*i + xStride*0] + block[stride*i + xStride*1];
287  temp[2*i+1] = block[stride*i + xStride*0] - block[stride*i + xStride*1];
288  }
289 
290  for(i=0; i<2; i++){
291  const int offset= x_offset[i];
292  const int z0= temp[2*0+i] + temp[2*2+i];
293  const int z1= temp[2*0+i] - temp[2*2+i];
294  const int z2= temp[2*1+i] - temp[2*3+i];
295  const int z3= temp[2*1+i] + temp[2*3+i];
296 
297  block[stride*0+offset]= ((z0 + z3)*qmul + 128) >> 8;
298  block[stride*1+offset]= ((z1 + z2)*qmul + 128) >> 8;
299  block[stride*2+offset]= ((z1 - z2)*qmul + 128) >> 8;
300  block[stride*3+offset]= ((z0 - z3)*qmul + 128) >> 8;
301  }
302 }
303 
304 void FUNCC(ff_h264_chroma_dc_dequant_idct)(int16_t *_block, int qmul){
305  const int stride= 16*2;
306  const int xStride= 16;
307  int a,b,c,d,e;
308  dctcoef *block = (dctcoef*)_block;
309 
310  a= block[stride*0 + xStride*0];
311  b= block[stride*0 + xStride*1];
312  c= block[stride*1 + xStride*0];
313  d= block[stride*1 + xStride*1];
314 
315  e= a-b;
316  a= a+b;
317  b= c-d;
318  c= c+d;
319 
320  block[stride*0 + xStride*0]= ((a+c)*qmul) >> 7;
321  block[stride*0 + xStride*1]= ((e+b)*qmul) >> 7;
322  block[stride*1 + xStride*0]= ((a-c)*qmul) >> 7;
323  block[stride*1 + xStride*1]= ((e-b)*qmul) >> 7;
324 }
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