1/* 2 * Copyright (c) 2010 Nolan Lum <nol888@gmail.com> 3 * Copyright (c) 2009 Loren Merritt <lorenm@u.washington.edu> 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 * gradfun debanding filter, ported from MPlayer 25 * libmpcodecs/vf_gradfun.c 26 * 27 * Apply a boxblur debanding algorithm (based on the gradfun2db 28 * AviSynth filter by prunedtree). 29 * Foreach pixel, if it's within threshold of the blurred value, make it closer. 30 * So now we have a smoothed and higher bitdepth version of all the shallow 31 * gradients, while leaving detailed areas untouched. 32 * Dither it back to 8bit. 33 */ 34 35#include "libavutil/imgutils.h" 36#include "libavutil/common.h" 37#include "libavutil/cpu.h" 38#include "libavutil/opt.h" 39#include "libavutil/pixdesc.h" 40#include "avfilter.h" 41#include "formats.h" 42#include "gradfun.h" 43#include "internal.h" 44#include "video.h" 45 46DECLARE_ALIGNED(16, static const uint16_t, dither)[8][8] = { 47 {0x00,0x60,0x18,0x78,0x06,0x66,0x1E,0x7E}, 48 {0x40,0x20,0x58,0x38,0x46,0x26,0x5E,0x3E}, 49 {0x10,0x70,0x08,0x68,0x16,0x76,0x0E,0x6E}, 50 {0x50,0x30,0x48,0x28,0x56,0x36,0x4E,0x2E}, 51 {0x04,0x64,0x1C,0x7C,0x02,0x62,0x1A,0x7A}, 52 {0x44,0x24,0x5C,0x3C,0x42,0x22,0x5A,0x3A}, 53 {0x14,0x74,0x0C,0x6C,0x12,0x72,0x0A,0x6A}, 54 {0x54,0x34,0x4C,0x2C,0x52,0x32,0x4A,0x2A}, 55}; 56 57void ff_gradfun_filter_line_c(uint8_t *dst, const uint8_t *src, const uint16_t *dc, int width, int thresh, const uint16_t *dithers) 58{ 59 int x; 60 for (x = 0; x < width; dc += x & 1, x++) { 61 int pix = src[x] << 7; 62 int delta = dc[0] - pix; 63 int m = abs(delta) * thresh >> 16; 64 m = FFMAX(0, 127 - m); 65 m = m * m * delta >> 14; 66 pix += m + dithers[x & 7]; 67 dst[x] = av_clip_uint8(pix >> 7); 68 } 69} 70 71void ff_gradfun_blur_line_c(uint16_t *dc, uint16_t *buf, const uint16_t *buf1, const uint8_t *src, int src_linesize, int width) 72{ 73 int x, v, old; 74 for (x = 0; x < width; x++) { 75 v = buf1[x] + src[2 * x] + src[2 * x + 1] + src[2 * x + src_linesize] + src[2 * x + 1 + src_linesize]; 76 old = buf[x]; 77 buf[x] = v; 78 dc[x] = v - old; 79 } 80} 81 82static void filter(GradFunContext *ctx, uint8_t *dst, const uint8_t *src, int width, int height, int dst_linesize, int src_linesize, int r) 83{ 84 int bstride = FFALIGN(width, 16) / 2; 85 int y; 86 uint32_t dc_factor = (1 << 21) / (r * r); 87 uint16_t *dc = ctx->buf + 16; 88 uint16_t *buf = ctx->buf + bstride + 32; 89 int thresh = ctx->thresh; 90 91 memset(dc, 0, (bstride + 16) * sizeof(*buf)); 92 for (y = 0; y < r; y++) 93 ctx->blur_line(dc, buf + y * bstride, buf + (y - 1) * bstride, src + 2 * y * src_linesize, src_linesize, width / 2); 94 for (;;) { 95 if (y < height - r) { 96 int mod = ((y + r) / 2) % r; 97 uint16_t *buf0 = buf + mod * bstride; 98 uint16_t *buf1 = buf + (mod ? mod - 1 : r - 1) * bstride; 99 int x, v; 100 ctx->blur_line(dc, buf0, buf1, src + (y + r) * src_linesize, src_linesize, width / 2); 101 for (x = v = 0; x < r; x++) 102 v += dc[x]; 103 for (; x < width / 2; x++) { 104 v += dc[x] - dc[x-r]; 105 dc[x-r] = v * dc_factor >> 16; 106 } 107 for (; x < (width + r + 1) / 2; x++) 108 dc[x-r] = v * dc_factor >> 16; 109 for (x = -r / 2; x < 0; x++) 110 dc[x] = dc[0]; 111 } 112 if (y == r) { 113 for (y = 0; y < r; y++) 114 ctx->filter_line(dst + y * dst_linesize, src + y * src_linesize, dc - r / 2, width, thresh, dither[y & 7]); 115 } 116 ctx->filter_line(dst + y * dst_linesize, src + y * src_linesize, dc - r / 2, width, thresh, dither[y & 7]); 117 if (++y >= height) break; 118 ctx->filter_line(dst + y * dst_linesize, src + y * src_linesize, dc - r / 2, width, thresh, dither[y & 7]); 119 if (++y >= height) break; 120 } 121 emms_c(); 122} 123 124static av_cold int init(AVFilterContext *ctx) 125{ 126 GradFunContext *s = ctx->priv; 127 128 s->thresh = (1 << 15) / s->strength; 129 s->radius = av_clip((s->radius + 1) & ~1, 4, 32); 130 131 s->blur_line = ff_gradfun_blur_line_c; 132 s->filter_line = ff_gradfun_filter_line_c; 133 134 if (ARCH_X86) 135 ff_gradfun_init_x86(s); 136 137 av_log(ctx, AV_LOG_VERBOSE, "threshold:%.2f radius:%d\n", s->strength, s->radius); 138 139 return 0; 140} 141 142static av_cold void uninit(AVFilterContext *ctx) 143{ 144 GradFunContext *s = ctx->priv; 145 av_freep(&s->buf); 146} 147 148static int query_formats(AVFilterContext *ctx) 149{ 150 static const enum AVPixelFormat pix_fmts[] = { 151 AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV420P, 152 AV_PIX_FMT_GRAY8, AV_PIX_FMT_YUV444P, 153 AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV411P, 154 AV_PIX_FMT_YUV440P, 155 AV_PIX_FMT_GBRP, 156 AV_PIX_FMT_NONE 157 }; 158 159 ff_set_common_formats(ctx, ff_make_format_list(pix_fmts)); 160 161 return 0; 162} 163 164static int config_input(AVFilterLink *inlink) 165{ 166 GradFunContext *s = inlink->dst->priv; 167 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format); 168 int hsub = desc->log2_chroma_w; 169 int vsub = desc->log2_chroma_h; 170 171 av_freep(&s->buf); 172 s->buf = av_calloc((FFALIGN(inlink->w, 16) * (s->radius + 1) / 2 + 32), sizeof(*s->buf)); 173 if (!s->buf) 174 return AVERROR(ENOMEM); 175 176 s->chroma_w = FF_CEIL_RSHIFT(inlink->w, hsub); 177 s->chroma_h = FF_CEIL_RSHIFT(inlink->h, vsub); 178 s->chroma_r = av_clip(((((s->radius >> hsub) + (s->radius >> vsub)) / 2 ) + 1) & ~1, 4, 32); 179 180 return 0; 181} 182 183static int filter_frame(AVFilterLink *inlink, AVFrame *in) 184{ 185 GradFunContext *s = inlink->dst->priv; 186 AVFilterLink *outlink = inlink->dst->outputs[0]; 187 AVFrame *out; 188 int p, direct; 189 190 if (av_frame_is_writable(in)) { 191 direct = 1; 192 out = in; 193 } else { 194 direct = 0; 195 out = ff_get_video_buffer(outlink, outlink->w, outlink->h); 196 if (!out) { 197 av_frame_free(&in); 198 return AVERROR(ENOMEM); 199 } 200 av_frame_copy_props(out, in); 201 } 202 203 for (p = 0; p < 4 && in->data[p] && in->linesize[p]; p++) { 204 int w = inlink->w; 205 int h = inlink->h; 206 int r = s->radius; 207 if (p) { 208 w = s->chroma_w; 209 h = s->chroma_h; 210 r = s->chroma_r; 211 } 212 213 if (FFMIN(w, h) > 2 * r) 214 filter(s, out->data[p], in->data[p], w, h, out->linesize[p], in->linesize[p], r); 215 else if (out->data[p] != in->data[p]) 216 av_image_copy_plane(out->data[p], out->linesize[p], in->data[p], in->linesize[p], w, h); 217 } 218 219 if (!direct) 220 av_frame_free(&in); 221 222 return ff_filter_frame(outlink, out); 223} 224 225#define OFFSET(x) offsetof(GradFunContext, x) 226#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM 227 228static const AVOption gradfun_options[] = { 229 { "strength", "The maximum amount by which the filter will change any one pixel.", OFFSET(strength), AV_OPT_TYPE_FLOAT, { .dbl = 1.2 }, 0.51, 64, FLAGS }, 230 { "radius", "The neighborhood to fit the gradient to.", OFFSET(radius), AV_OPT_TYPE_INT, { .i64 = 16 }, 4, 32, FLAGS }, 231 { NULL } 232}; 233 234AVFILTER_DEFINE_CLASS(gradfun); 235 236static const AVFilterPad avfilter_vf_gradfun_inputs[] = { 237 { 238 .name = "default", 239 .type = AVMEDIA_TYPE_VIDEO, 240 .config_props = config_input, 241 .filter_frame = filter_frame, 242 }, 243 { NULL } 244}; 245 246static const AVFilterPad avfilter_vf_gradfun_outputs[] = { 247 { 248 .name = "default", 249 .type = AVMEDIA_TYPE_VIDEO, 250 }, 251 { NULL } 252}; 253 254AVFilter ff_vf_gradfun = { 255 .name = "gradfun", 256 .description = NULL_IF_CONFIG_SMALL("Debands video quickly using gradients."), 257 .priv_size = sizeof(GradFunContext), 258 .priv_class = &gradfun_class, 259 .init = init, 260 .uninit = uninit, 261 .query_formats = query_formats, 262 .inputs = avfilter_vf_gradfun_inputs, 263 .outputs = avfilter_vf_gradfun_outputs, 264 .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC, 265}; 266