/* * Copyright (c) 2010 Nolan Lum <nol888@gmail.com> * Copyright (c) 2009 Loren Merritt <lorenm@u.washington.edu> * * This file is part of FFmpeg. * * FFmpeg 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. * * FFmpeg 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 FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * gradfun debanding filter, ported from MPlayer * libmpcodecs/vf_gradfun.c * * Apply a boxblur debanding algorithm (based on the gradfun2db * AviSynth filter by prunedtree). * Foreach pixel, if it's within threshold of the blurred value, make it closer. * So now we have a smoothed and higher bitdepth version of all the shallow * gradients, while leaving detailed areas untouched. * Dither it back to 8bit. */ #include "libavutil/imgutils.h" #include "libavutil/common.h" #include "libavutil/cpu.h" #include "libavutil/opt.h" #include "libavutil/pixdesc.h" #include "avfilter.h" #include "formats.h" #include "gradfun.h" #include "internal.h" #include "video.h" DECLARE_ALIGNED(16, static const uint16_t, dither)[8][8] = { {0x00,0x60,0x18,0x78,0x06,0x66,0x1E,0x7E}, {0x40,0x20,0x58,0x38,0x46,0x26,0x5E,0x3E}, {0x10,0x70,0x08,0x68,0x16,0x76,0x0E,0x6E}, {0x50,0x30,0x48,0x28,0x56,0x36,0x4E,0x2E}, {0x04,0x64,0x1C,0x7C,0x02,0x62,0x1A,0x7A}, {0x44,0x24,0x5C,0x3C,0x42,0x22,0x5A,0x3A}, {0x14,0x74,0x0C,0x6C,0x12,0x72,0x0A,0x6A}, {0x54,0x34,0x4C,0x2C,0x52,0x32,0x4A,0x2A}, }; void ff_gradfun_filter_line_c(uint8_t *dst, const uint8_t *src, const uint16_t *dc, int width, int thresh, const uint16_t *dithers) { int x; for (x = 0; x < width; dc += x & 1, x++) { int pix = src[x] << 7; int delta = dc[0] - pix; int m = abs(delta) * thresh >> 16; m = FFMAX(0, 127 - m); m = m * m * delta >> 14; pix += m + dithers[x & 7]; dst[x] = av_clip_uint8(pix >> 7); } } void ff_gradfun_blur_line_c(uint16_t *dc, uint16_t *buf, const uint16_t *buf1, const uint8_t *src, int src_linesize, int width) { int x, v, old; for (x = 0; x < width; x++) { v = buf1[x] + src[2 * x] + src[2 * x + 1] + src[2 * x + src_linesize] + src[2 * x + 1 + src_linesize]; old = buf[x]; buf[x] = v; dc[x] = v - old; } } static void filter(GradFunContext *ctx, uint8_t *dst, const uint8_t *src, int width, int height, int dst_linesize, int src_linesize, int r) { int bstride = FFALIGN(width, 16) / 2; int y; uint32_t dc_factor = (1 << 21) / (r * r); uint16_t *dc = ctx->buf + 16; uint16_t *buf = ctx->buf + bstride + 32; int thresh = ctx->thresh; memset(dc, 0, (bstride + 16) * sizeof(*buf)); for (y = 0; y < r; y++) ctx->blur_line(dc, buf + y * bstride, buf + (y - 1) * bstride, src + 2 * y * src_linesize, src_linesize, width / 2); for (;;) { if (y < height - r) { int mod = ((y + r) / 2) % r; uint16_t *buf0 = buf + mod * bstride; uint16_t *buf1 = buf + (mod ? mod - 1 : r - 1) * bstride; int x, v; ctx->blur_line(dc, buf0, buf1, src + (y + r) * src_linesize, src_linesize, width / 2); for (x = v = 0; x < r; x++) v += dc[x]; for (; x < width / 2; x++) { v += dc[x] - dc[x-r]; dc[x-r] = v * dc_factor >> 16; } for (; x < (width + r + 1) / 2; x++) dc[x-r] = v * dc_factor >> 16; for (x = -r / 2; x < 0; x++) dc[x] = dc[0]; } if (y == r) { for (y = 0; y < r; y++) ctx->filter_line(dst + y * dst_linesize, src + y * src_linesize, dc - r / 2, width, thresh, dither[y & 7]); } ctx->filter_line(dst + y * dst_linesize, src + y * src_linesize, dc - r / 2, width, thresh, dither[y & 7]); if (++y >= height) break; ctx->filter_line(dst + y * dst_linesize, src + y * src_linesize, dc - r / 2, width, thresh, dither[y & 7]); if (++y >= height) break; } emms_c(); } static av_cold int init(AVFilterContext *ctx) { GradFunContext *s = ctx->priv; s->thresh = (1 << 15) / s->strength; s->radius = av_clip((s->radius + 1) & ~1, 4, 32); s->blur_line = ff_gradfun_blur_line_c; s->filter_line = ff_gradfun_filter_line_c; if (ARCH_X86) ff_gradfun_init_x86(s); av_log(ctx, AV_LOG_VERBOSE, "threshold:%.2f radius:%d\n", s->strength, s->radius); return 0; } static av_cold void uninit(AVFilterContext *ctx) { GradFunContext *s = ctx->priv; av_freep(&s->buf); } static int query_formats(AVFilterContext *ctx) { static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV420P, AV_PIX_FMT_GRAY8, AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV440P, AV_PIX_FMT_GBRP, AV_PIX_FMT_NONE }; ff_set_common_formats(ctx, ff_make_format_list(pix_fmts)); return 0; } static int config_input(AVFilterLink *inlink) { GradFunContext *s = inlink->dst->priv; const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format); int hsub = desc->log2_chroma_w; int vsub = desc->log2_chroma_h; av_freep(&s->buf); s->buf = av_calloc((FFALIGN(inlink->w, 16) * (s->radius + 1) / 2 + 32), sizeof(*s->buf)); if (!s->buf) return AVERROR(ENOMEM); s->chroma_w = FF_CEIL_RSHIFT(inlink->w, hsub); s->chroma_h = FF_CEIL_RSHIFT(inlink->h, vsub); s->chroma_r = av_clip(((((s->radius >> hsub) + (s->radius >> vsub)) / 2 ) + 1) & ~1, 4, 32); return 0; } static int filter_frame(AVFilterLink *inlink, AVFrame *in) { GradFunContext *s = inlink->dst->priv; AVFilterLink *outlink = inlink->dst->outputs[0]; AVFrame *out; int p, direct; if (av_frame_is_writable(in)) { direct = 1; out = in; } else { direct = 0; out = ff_get_video_buffer(outlink, outlink->w, outlink->h); if (!out) { av_frame_free(&in); return AVERROR(ENOMEM); } av_frame_copy_props(out, in); } for (p = 0; p < 4 && in->data[p] && in->linesize[p]; p++) { int w = inlink->w; int h = inlink->h; int r = s->radius; if (p) { w = s->chroma_w; h = s->chroma_h; r = s->chroma_r; } if (FFMIN(w, h) > 2 * r) filter(s, out->data[p], in->data[p], w, h, out->linesize[p], in->linesize[p], r); else if (out->data[p] != in->data[p]) av_image_copy_plane(out->data[p], out->linesize[p], in->data[p], in->linesize[p], w, h); } if (!direct) av_frame_free(&in); return ff_filter_frame(outlink, out); } #define OFFSET(x) offsetof(GradFunContext, x) #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM static const AVOption gradfun_options[] = { { "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 }, { "radius", "The neighborhood to fit the gradient to.", OFFSET(radius), AV_OPT_TYPE_INT, { .i64 = 16 }, 4, 32, FLAGS }, { NULL } }; AVFILTER_DEFINE_CLASS(gradfun); static const AVFilterPad avfilter_vf_gradfun_inputs[] = { { .name = "default", .type = AVMEDIA_TYPE_VIDEO, .config_props = config_input, .filter_frame = filter_frame, }, { NULL } }; static const AVFilterPad avfilter_vf_gradfun_outputs[] = { { .name = "default", .type = AVMEDIA_TYPE_VIDEO, }, { NULL } }; AVFilter ff_vf_gradfun = { .name = "gradfun", .description = NULL_IF_CONFIG_SMALL("Debands video quickly using gradients."), .priv_size = sizeof(GradFunContext), .priv_class = &gradfun_class, .init = init, .uninit = uninit, .query_formats = query_formats, .inputs = avfilter_vf_gradfun_inputs, .outputs = avfilter_vf_gradfun_outputs, .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC, };