1 /*****************************************************************************
2 * algo_phosphor.c : Phosphor algorithm for the VLC deinterlacer
3 *****************************************************************************
4 * Copyright (C) 2011 the VideoLAN team
7 * Author: Juha Jeronen <juha.jeronen@jyu.fi>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program 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
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
22 *****************************************************************************/
28 #ifdef CAN_COMPILE_MMXEXT
35 #include <vlc_common.h>
37 #include <vlc_picture.h>
38 #include <vlc_filter.h>
40 #include "deinterlace.h" /* filter_sys_t */
41 #include "helpers.h" /* ComposeFrame() */
43 #include "algo_phosphor.h"
45 /*****************************************************************************
47 *****************************************************************************/
50 * Internal helper function: dims (darkens) the given field
51 * of the given picture.
53 * This is used for simulating CRT light output decay in RenderPhosphor().
55 * The strength "1" is recommended. It's a matter of taste,
56 * so it's parametrized.
58 * Note on chroma formats:
59 * - If input is 4:2:2, all planes are processed.
60 * - If input is 4:2:0, only the luma plane is processed, because both fields
61 * have the same chroma. This will distort colours, especially for high
62 * filter strengths, especially for pixels whose U and/or V values are
63 * far away from the origin (which is at 128 in uint8 format).
65 * @param p_dst Input/output picture. Will be modified in-place.
66 * @param i_field Darken which field? 0 = top, 1 = bottom.
67 * @param i_strength Strength of effect: 1, 2 or 3 (division by 2, 4 or 8).
68 * @see RenderPhosphor()
71 static void DarkenField( picture_t *p_dst, const int i_field,
72 const int i_strength )
74 assert( p_dst != NULL );
75 assert( i_field == 0 || i_field == 1 );
76 assert( i_strength >= 1 && i_strength <= 3 );
78 /* Bitwise ANDing with this clears the i_strength highest bits
80 #ifdef CAN_COMPILE_MMXEXT
81 unsigned u_cpu = vlc_CPU();
82 uint64_t i_strength_u64 = i_strength; /* for MMX version (needs to know
85 const uint8_t remove_high_u8 = 0xFF >> i_strength;
86 const uint64_t remove_high_u64 = remove_high_u8 *
87 INT64_C(0x0101010101010101);
91 For luma, the operation is just a shift + bitwise AND, so we vectorize
92 even in the C version.
94 There is an MMX version, too, because it performs about twice faster.
96 int i_plane = Y_PLANE;
97 uint8_t *p_out, *p_out_end;
98 int w = p_dst->p[i_plane].i_visible_pitch;
99 p_out = p_dst->p[i_plane].p_pixels;
100 p_out_end = p_out + p_dst->p[i_plane].i_pitch
101 * p_dst->p[i_plane].i_visible_lines;
103 /* skip first line for bottom field */
105 p_out += p_dst->p[i_plane].i_pitch;
107 int wm8 = w % 8; /* remainder */
108 int w8 = w - wm8; /* part of width that is divisible by 8 */
109 for( ; p_out < p_out_end ; p_out += 2*p_dst->p[i_plane].i_pitch )
111 uint64_t *po = (uint64_t *)p_out;
112 #ifdef CAN_COMPILE_MMXEXT
113 if( u_cpu & CPU_CAPABILITY_MMXEXT )
115 movq_m2r( i_strength_u64, mm1 );
116 movq_m2r( remove_high_u64, mm2 );
117 for( int x = 0 ; x < w8; x += 8 )
119 movq_m2r( (*po), mm0 );
121 psrlq_r2r( mm1, mm0 );
122 pand_r2r( mm2, mm0 );
124 movq_r2m( mm0, (*po++) );
130 for( int x = 0 ; x < w8; x += 8, ++po )
131 (*po) = ( ((*po) >> i_strength) & remove_high_u64 );
132 #ifdef CAN_COMPILE_MMXEXT
135 /* handle the width remainder */
138 uint8_t *po_temp = (uint8_t *)po;
139 for( int x = 0 ; x < wm8; ++x, ++po_temp )
140 (*po_temp) = ( ((*po_temp) >> i_strength) & remove_high_u8 );
144 /* Process chroma if the field chromas are independent.
146 The origin (black) is at YUV = (0, 128, 128) in the uint8 format.
147 The chroma processing is a bit more complicated than luma,
148 and needs MMX for vectorization.
150 if( p_dst->format.i_chroma == VLC_CODEC_I422 ||
151 p_dst->format.i_chroma == VLC_CODEC_J422 )
153 for( i_plane = 0 ; i_plane < p_dst->i_planes ; i_plane++ )
155 if( i_plane == Y_PLANE )
156 continue; /* luma already handled */
158 int w = p_dst->p[i_plane].i_visible_pitch;
159 #ifdef CAN_COMPILE_MMXEXT
160 int wm8 = w % 8; /* remainder */
161 int w8 = w - wm8; /* part of width that is divisible by 8 */
163 p_out = p_dst->p[i_plane].p_pixels;
164 p_out_end = p_out + p_dst->p[i_plane].i_pitch
165 * p_dst->p[i_plane].i_visible_lines;
167 /* skip first line for bottom field */
169 p_out += p_dst->p[i_plane].i_pitch;
171 for( ; p_out < p_out_end ; p_out += 2*p_dst->p[i_plane].i_pitch )
173 #ifdef CAN_COMPILE_MMXEXT
174 /* See also easy-to-read C version below. */
175 if( u_cpu & CPU_CAPABILITY_MMXEXT )
177 static const mmx_t b128 = { .uq = 0x8080808080808080ULL };
178 movq_m2r( b128, mm5 );
179 movq_m2r( i_strength_u64, mm6 );
180 movq_m2r( remove_high_u64, mm7 );
182 uint64_t *po = (uint64_t *)p_out;
183 for( int x = 0 ; x < w8; x += 8 )
185 movq_m2r( (*po), mm0 );
187 movq_r2r( mm5, mm2 ); /* 128 */
188 movq_r2r( mm0, mm1 ); /* copy of data */
189 psubusb_r2r( mm2, mm1 ); /* mm1 = max(data - 128, 0) */
190 psubusb_r2r( mm0, mm2 ); /* mm2 = max(128 - data, 0) */
193 psrlq_r2r( mm6, mm1 );
194 psrlq_r2r( mm6, mm2 );
195 pand_r2r( mm7, mm1 );
196 pand_r2r( mm7, mm2 );
198 /* collect results from pos./neg. parts */
199 psubb_r2r( mm2, mm1 );
200 paddb_r2r( mm5, mm1 );
202 movq_r2m( mm1, (*po++) );
205 /* handle the width remainder */
208 /* The output is closer to 128 than the input;
209 the result always fits in uint8. */
210 uint8_t *po8 = (uint8_t *)po;
211 for( int x = 0 ; x < wm8; ++x, ++po8 )
212 (*po8) = 128 + ( ((*po8) - 128) /
219 /* 4:2:2 chroma handler, C version */
221 for( int x = 0 ; x < w; ++x, ++po )
222 (*po) = 128 + ( ((*po) - 128) / (1 << i_strength) );
223 #ifdef CAN_COMPILE_MMXEXT
227 } /* for i_plane... */
230 #ifdef CAN_COMPILE_MMXEXT
231 if( u_cpu & CPU_CAPABILITY_MMXEXT )
236 /*****************************************************************************
238 *****************************************************************************/
240 /* See header for function doc. */
241 int RenderPhosphor( filter_t *p_filter,
243 int i_order, int i_field )
245 assert( p_filter != NULL );
246 assert( p_dst != NULL );
247 assert( i_order >= 0 && i_order <= 2 ); /* 2 = soft field repeat */
248 assert( i_field == 0 || i_field == 1 );
250 filter_sys_t *p_sys = p_filter->p_sys;
252 /* Last two input frames */
253 picture_t *p_in = p_sys->pp_history[HISTORY_SIZE-1];
254 picture_t *p_old = p_sys->pp_history[HISTORY_SIZE-2];
256 /* Use the same input picture as "old" at the first frame after startup */
260 /* If the history mechanism has failed, we can't do anything. */
264 assert( p_old != NULL );
265 assert( p_in != NULL );
267 /* Decide sources for top & bottom fields of output. */
268 picture_t *p_in_top = p_in;
269 picture_t *p_in_bottom = p_in;
270 /* For the first output field this frame,
271 grab "old" field from previous frame. */
274 if( i_field == 0 ) /* rendering top field */
276 else /* i_field == 1, rendering bottom field */
280 compose_chroma_t cc = CC_ALTLINE; /* initialize to prevent compiler warning */
281 switch( p_sys->phosphor.i_chroma_for_420 )
289 else /* i_field == 1 */
290 cc = CC_SOURCE_BOTTOM;
299 /* The above are the only possibilities, if there are no bugs. */
304 ComposeFrame( p_filter, p_dst, p_in_top, p_in_bottom, cc );
306 /* Simulate phosphor light output decay for the old field.
308 The dimmer can also be switched off in the configuration, but that is
309 more of a technical curiosity or an educational toy for advanced users
310 than a useful deinterlacer mode (although it does make telecined
311 material look slightly better than without any filtering).
313 In most use cases the dimmer is used.
315 if( p_sys->phosphor.i_dimmer_strength > 0 )
316 DarkenField( p_dst, !i_field, p_sys->phosphor.i_dimmer_strength );