yading@10: /*
yading@10:  * Copyright (c) 2002 Michael Niedermayer <michaelni@gmx.at>
yading@10:  * Copyright (c) 2011 Stefano Sabatini
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or modify
yading@10:  * it under the terms of the GNU General Public License as published by
yading@10:  * the Free Software Foundation; either version 2 of the License, or
yading@10:  * (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
yading@10:  * GNU General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU General Public License along
yading@10:  * with FFmpeg; if not, write to the Free Software Foundation, Inc.,
yading@10:  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * Apply a boxblur filter to the input video.
yading@10:  * Ported from MPlayer libmpcodecs/vf_boxblur.c.
yading@10:  */
yading@10: 
yading@10: #include "libavutil/avstring.h"
yading@10: #include "libavutil/common.h"
yading@10: #include "libavutil/eval.h"
yading@10: #include "libavutil/opt.h"
yading@10: #include "libavutil/pixdesc.h"
yading@10: #include "avfilter.h"
yading@10: #include "formats.h"
yading@10: #include "internal.h"
yading@10: #include "video.h"
yading@10: 
yading@10: static const char *const var_names[] = {
yading@10:     "w",
yading@10:     "h",
yading@10:     "cw",
yading@10:     "ch",
yading@10:     "hsub",
yading@10:     "vsub",
yading@10:     NULL
yading@10: };
yading@10: 
yading@10: enum var_name {
yading@10:     VAR_W,
yading@10:     VAR_H,
yading@10:     VAR_CW,
yading@10:     VAR_CH,
yading@10:     VAR_HSUB,
yading@10:     VAR_VSUB,
yading@10:     VARS_NB
yading@10: };
yading@10: 
yading@10: typedef struct {
yading@10:     int radius;
yading@10:     int power;
yading@10:     char *radius_expr;
yading@10: } FilterParam;
yading@10: 
yading@10: typedef struct {
yading@10:     const AVClass *class;
yading@10:     FilterParam luma_param;
yading@10:     FilterParam chroma_param;
yading@10:     FilterParam alpha_param;
yading@10: 
yading@10:     int hsub, vsub;
yading@10:     int radius[4];
yading@10:     int power[4];
yading@10:     uint8_t *temp[2]; ///< temporary buffer used in blur_power()
yading@10: } BoxBlurContext;
yading@10: 
yading@10: #define Y 0
yading@10: #define U 1
yading@10: #define V 2
yading@10: #define A 3
yading@10: 
yading@10: static av_cold int init(AVFilterContext *ctx)
yading@10: {
yading@10:     BoxBlurContext *boxblur = ctx->priv;
yading@10: 
yading@10:     if (!boxblur->luma_param.radius_expr) {
yading@10:         av_log(ctx, AV_LOG_ERROR, "Luma radius expression is not set.\n");
yading@10:         return AVERROR(EINVAL);
yading@10:     }
yading@10: 
yading@10:     /* fill missing params */
yading@10:     if (!boxblur->chroma_param.radius_expr) {
yading@10:         boxblur->chroma_param.radius_expr = av_strdup(boxblur->luma_param.radius_expr);
yading@10:         if (!boxblur->chroma_param.radius_expr)
yading@10:             return AVERROR(ENOMEM);
yading@10:     }
yading@10:     if (boxblur->chroma_param.power < 0)
yading@10:         boxblur->chroma_param.power = boxblur->luma_param.power;
yading@10: 
yading@10:     if (!boxblur->alpha_param.radius_expr) {
yading@10:         boxblur->alpha_param.radius_expr = av_strdup(boxblur->luma_param.radius_expr);
yading@10:         if (!boxblur->alpha_param.radius_expr)
yading@10:             return AVERROR(ENOMEM);
yading@10:     }
yading@10:     if (boxblur->alpha_param.power < 0)
yading@10:         boxblur->alpha_param.power = boxblur->luma_param.power;
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static av_cold void uninit(AVFilterContext *ctx)
yading@10: {
yading@10:     BoxBlurContext *boxblur = ctx->priv;
yading@10: 
yading@10:     av_freep(&boxblur->temp[0]);
yading@10:     av_freep(&boxblur->temp[1]);
yading@10: }
yading@10: 
yading@10: static int query_formats(AVFilterContext *ctx)
yading@10: {
yading@10:     static const enum AVPixelFormat pix_fmts[] = {
yading@10:         AV_PIX_FMT_YUV444P,  AV_PIX_FMT_YUV422P,  AV_PIX_FMT_YUV420P,
yading@10:         AV_PIX_FMT_YUV411P,  AV_PIX_FMT_YUV410P,  AV_PIX_FMT_YUVA420P,
yading@10:         AV_PIX_FMT_YUV440P,  AV_PIX_FMT_GRAY8,
yading@10:         AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ420P,
yading@10:         AV_PIX_FMT_YUVJ440P,
yading@10:         AV_PIX_FMT_NONE
yading@10:     };
yading@10: 
yading@10:     ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int config_input(AVFilterLink *inlink)
yading@10: {
yading@10:     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
yading@10:     AVFilterContext    *ctx = inlink->dst;
yading@10:     BoxBlurContext *boxblur = ctx->priv;
yading@10:     int w = inlink->w, h = inlink->h;
yading@10:     int cw, ch;
yading@10:     double var_values[VARS_NB], res;
yading@10:     char *expr;
yading@10:     int ret;
yading@10: 
yading@10:     if (!(boxblur->temp[0] = av_malloc(FFMAX(w, h))) ||
yading@10:         !(boxblur->temp[1] = av_malloc(FFMAX(w, h))))
yading@10:         return AVERROR(ENOMEM);
yading@10: 
yading@10:     boxblur->hsub = desc->log2_chroma_w;
yading@10:     boxblur->vsub = desc->log2_chroma_h;
yading@10: 
yading@10:     var_values[VAR_W]       = inlink->w;
yading@10:     var_values[VAR_H]       = inlink->h;
yading@10:     var_values[VAR_CW] = cw = w>>boxblur->hsub;
yading@10:     var_values[VAR_CH] = ch = h>>boxblur->vsub;
yading@10:     var_values[VAR_HSUB]    = 1<<boxblur->hsub;
yading@10:     var_values[VAR_VSUB]    = 1<<boxblur->vsub;
yading@10: 
yading@10: #define EVAL_RADIUS_EXPR(comp)                                          \
yading@10:     expr = boxblur->comp##_param.radius_expr;                           \
yading@10:     ret = av_expr_parse_and_eval(&res, expr, var_names, var_values,     \
yading@10:                                  NULL, NULL, NULL, NULL, NULL, 0, ctx); \
yading@10:     boxblur->comp##_param.radius = res;                                 \
yading@10:     if (ret < 0) {                                                      \
yading@10:         av_log(NULL, AV_LOG_ERROR,                                      \
yading@10:                "Error when evaluating " #comp " radius expression '%s'\n", expr); \
yading@10:         return ret;                                                     \
yading@10:     }
yading@10:     EVAL_RADIUS_EXPR(luma);
yading@10:     EVAL_RADIUS_EXPR(chroma);
yading@10:     EVAL_RADIUS_EXPR(alpha);
yading@10: 
yading@10:     av_log(ctx, AV_LOG_VERBOSE,
yading@10:            "luma_radius:%d luma_power:%d "
yading@10:            "chroma_radius:%d chroma_power:%d "
yading@10:            "alpha_radius:%d alpha_power:%d "
yading@10:            "w:%d chroma_w:%d h:%d chroma_h:%d\n",
yading@10:            boxblur->luma_param  .radius, boxblur->luma_param  .power,
yading@10:            boxblur->chroma_param.radius, boxblur->chroma_param.power,
yading@10:            boxblur->alpha_param .radius, boxblur->alpha_param .power,
yading@10:            w, cw, h, ch);
yading@10: 
yading@10: #define CHECK_RADIUS_VAL(w_, h_, comp)                                  \
yading@10:     if (boxblur->comp##_param.radius < 0 ||                             \
yading@10:         2*boxblur->comp##_param.radius > FFMIN(w_, h_)) {               \
yading@10:         av_log(ctx, AV_LOG_ERROR,                                       \
yading@10:                "Invalid " #comp " radius value %d, must be >= 0 and <= %d\n", \
yading@10:                boxblur->comp##_param.radius, FFMIN(w_, h_)/2);          \
yading@10:         return AVERROR(EINVAL);                                         \
yading@10:     }
yading@10:     CHECK_RADIUS_VAL(w,  h,  luma);
yading@10:     CHECK_RADIUS_VAL(cw, ch, chroma);
yading@10:     CHECK_RADIUS_VAL(w,  h,  alpha);
yading@10: 
yading@10:     boxblur->radius[Y] = boxblur->luma_param.radius;
yading@10:     boxblur->radius[U] = boxblur->radius[V] = boxblur->chroma_param.radius;
yading@10:     boxblur->radius[A] = boxblur->alpha_param.radius;
yading@10: 
yading@10:     boxblur->power[Y] = boxblur->luma_param.power;
yading@10:     boxblur->power[U] = boxblur->power[V] = boxblur->chroma_param.power;
yading@10:     boxblur->power[A] = boxblur->alpha_param.power;
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static inline void blur(uint8_t *dst, int dst_step, const uint8_t *src, int src_step,
yading@10:                         int len, int radius)
yading@10: {
yading@10:     /* Naive boxblur would sum source pixels from x-radius .. x+radius
yading@10:      * for destination pixel x. That would be O(radius*width).
yading@10:      * If you now look at what source pixels represent 2 consecutive
yading@10:      * output pixels, then you see they are almost identical and only
yading@10:      * differ by 2 pixels, like:
yading@10:      * src0       111111111
yading@10:      * dst0           1
yading@10:      * src1        111111111
yading@10:      * dst1            1
yading@10:      * src0-src1  1       -1
yading@10:      * so when you know one output pixel you can find the next by just adding
yading@10:      * and subtracting 1 input pixel.
yading@10:      * The following code adopts this faster variant.
yading@10:      */
yading@10:     const int length = radius*2 + 1;
yading@10:     const int inv = ((1<<16) + length/2)/length;
yading@10:     int x, sum = 0;
yading@10: 
yading@10:     for (x = 0; x < radius; x++)
yading@10:         sum += src[x*src_step]<<1;
yading@10:     sum += src[radius*src_step];
yading@10: 
yading@10:     for (x = 0; x <= radius; x++) {
yading@10:         sum += src[(radius+x)*src_step] - src[(radius-x)*src_step];
yading@10:         dst[x*dst_step] = (sum*inv + (1<<15))>>16;
yading@10:     }
yading@10: 
yading@10:     for (; x < len-radius; x++) {
yading@10:         sum += src[(radius+x)*src_step] - src[(x-radius-1)*src_step];
yading@10:         dst[x*dst_step] = (sum*inv + (1<<15))>>16;
yading@10:     }
yading@10: 
yading@10:     for (; x < len; x++) {
yading@10:         sum += src[(2*len-radius-x-1)*src_step] - src[(x-radius-1)*src_step];
yading@10:         dst[x*dst_step] = (sum*inv + (1<<15))>>16;
yading@10:     }
yading@10: }
yading@10: 
yading@10: static inline void blur_power(uint8_t *dst, int dst_step, const uint8_t *src, int src_step,
yading@10:                               int len, int radius, int power, uint8_t *temp[2])
yading@10: {
yading@10:     uint8_t *a = temp[0], *b = temp[1];
yading@10: 
yading@10:     if (radius && power) {
yading@10:         blur(a, 1, src, src_step, len, radius);
yading@10:         for (; power > 2; power--) {
yading@10:             uint8_t *c;
yading@10:             blur(b, 1, a, 1, len, radius);
yading@10:             c = a; a = b; b = c;
yading@10:         }
yading@10:         if (power > 1) {
yading@10:             blur(dst, dst_step, a, 1, len, radius);
yading@10:         } else {
yading@10:             int i;
yading@10:             for (i = 0; i < len; i++)
yading@10:                 dst[i*dst_step] = a[i];
yading@10:         }
yading@10:     } else {
yading@10:         int i;
yading@10:         for (i = 0; i < len; i++)
yading@10:             dst[i*dst_step] = src[i*src_step];
yading@10:     }
yading@10: }
yading@10: 
yading@10: static void hblur(uint8_t *dst, int dst_linesize, const uint8_t *src, int src_linesize,
yading@10:                   int w, int h, int radius, int power, uint8_t *temp[2])
yading@10: {
yading@10:     int y;
yading@10: 
yading@10:     if (radius == 0 && dst == src)
yading@10:         return;
yading@10: 
yading@10:     for (y = 0; y < h; y++)
yading@10:         blur_power(dst + y*dst_linesize, 1, src + y*src_linesize, 1,
yading@10:                    w, radius, power, temp);
yading@10: }
yading@10: 
yading@10: static void vblur(uint8_t *dst, int dst_linesize, const uint8_t *src, int src_linesize,
yading@10:                   int w, int h, int radius, int power, uint8_t *temp[2])
yading@10: {
yading@10:     int x;
yading@10: 
yading@10:     if (radius == 0 && dst == src)
yading@10:         return;
yading@10: 
yading@10:     for (x = 0; x < w; x++)
yading@10:         blur_power(dst + x, dst_linesize, src + x, src_linesize,
yading@10:                    h, radius, power, temp);
yading@10: }
yading@10: 
yading@10: static int filter_frame(AVFilterLink *inlink, AVFrame *in)
yading@10: {
yading@10:     AVFilterContext *ctx = inlink->dst;
yading@10:     BoxBlurContext *boxblur = ctx->priv;
yading@10:     AVFilterLink *outlink = inlink->dst->outputs[0];
yading@10:     AVFrame *out;
yading@10:     int plane;
yading@10:     int cw = inlink->w >> boxblur->hsub, ch = in->height >> boxblur->vsub;
yading@10:     int w[4] = { inlink->w, cw, cw, inlink->w };
yading@10:     int h[4] = { in->height, ch, ch, in->height };
yading@10: 
yading@10:     out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
yading@10:     if (!out) {
yading@10:         av_frame_free(&in);
yading@10:         return AVERROR(ENOMEM);
yading@10:     }
yading@10:     av_frame_copy_props(out, in);
yading@10: 
yading@10:     for (plane = 0; in->data[plane] && plane < 4; plane++)
yading@10:         hblur(out->data[plane], out->linesize[plane],
yading@10:               in ->data[plane], in ->linesize[plane],
yading@10:               w[plane], h[plane], boxblur->radius[plane], boxblur->power[plane],
yading@10:               boxblur->temp);
yading@10: 
yading@10:     for (plane = 0; in->data[plane] && plane < 4; plane++)
yading@10:         vblur(out->data[plane], out->linesize[plane],
yading@10:               out->data[plane], out->linesize[plane],
yading@10:               w[plane], h[plane], boxblur->radius[plane], boxblur->power[plane],
yading@10:               boxblur->temp);
yading@10: 
yading@10:     av_frame_free(&in);
yading@10: 
yading@10:     return ff_filter_frame(outlink, out);
yading@10: }
yading@10: 
yading@10: #define OFFSET(x) offsetof(BoxBlurContext, x)
yading@10: #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
yading@10: 
yading@10: static const AVOption boxblur_options[] = {
yading@10:     { "luma_radius", "Radius of the luma blurring box", OFFSET(luma_param.radius_expr), AV_OPT_TYPE_STRING, {.str="2"}, .flags = FLAGS },
yading@10:     { "lr",          "Radius of the luma blurring box", OFFSET(luma_param.radius_expr), AV_OPT_TYPE_STRING, {.str="2"}, .flags = FLAGS },
yading@10:     { "luma_power",  "How many times should the boxblur be applied to luma",  OFFSET(luma_param.power), AV_OPT_TYPE_INT, {.i64=2}, 0, INT_MAX, .flags = FLAGS },
yading@10:     { "lp",          "How many times should the boxblur be applied to luma",  OFFSET(luma_param.power), AV_OPT_TYPE_INT, {.i64=2}, 0, INT_MAX, .flags = FLAGS },
yading@10: 
yading@10:     { "chroma_radius", "Radius of the chroma blurring box", OFFSET(chroma_param.radius_expr), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
yading@10:     { "cr",            "Radius of the chroma blurring box", OFFSET(chroma_param.radius_expr), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
yading@10:     { "chroma_power",  "How many times should the boxblur be applied to chroma",  OFFSET(chroma_param.power), AV_OPT_TYPE_INT, {.i64=-1}, -1, INT_MAX, .flags = FLAGS },
yading@10:     { "cp",            "How many times should the boxblur be applied to chroma",  OFFSET(chroma_param.power), AV_OPT_TYPE_INT, {.i64=-1}, -1, INT_MAX, .flags = FLAGS },
yading@10: 
yading@10:     { "alpha_radius", "Radius of the alpha blurring box", OFFSET(alpha_param.radius_expr), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
yading@10:     { "ar",           "Radius of the alpha blurring box", OFFSET(alpha_param.radius_expr), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
yading@10:     { "alpha_power",  "How many times should the boxblur be applied to alpha",  OFFSET(alpha_param.power), AV_OPT_TYPE_INT, {.i64=-1}, -1, INT_MAX, .flags = FLAGS },
yading@10:     { "ap",           "How many times should the boxblur be applied to alpha",  OFFSET(alpha_param.power), AV_OPT_TYPE_INT, {.i64=-1}, -1, INT_MAX, .flags = FLAGS },
yading@10: 
yading@10:     { NULL }
yading@10: };
yading@10: 
yading@10: AVFILTER_DEFINE_CLASS(boxblur);
yading@10: 
yading@10: static const AVFilterPad avfilter_vf_boxblur_inputs[] = {
yading@10:     {
yading@10:         .name         = "default",
yading@10:         .type         = AVMEDIA_TYPE_VIDEO,
yading@10:         .config_props = config_input,
yading@10:         .filter_frame = filter_frame,
yading@10:     },
yading@10:     { NULL }
yading@10: };
yading@10: 
yading@10: static const AVFilterPad avfilter_vf_boxblur_outputs[] = {
yading@10:     {
yading@10:         .name = "default",
yading@10:         .type = AVMEDIA_TYPE_VIDEO,
yading@10:     },
yading@10:     { NULL }
yading@10: };
yading@10: 
yading@10: AVFilter avfilter_vf_boxblur = {
yading@10:     .name          = "boxblur",
yading@10:     .description   = NULL_IF_CONFIG_SMALL("Blur the input."),
yading@10:     .priv_size     = sizeof(BoxBlurContext),
yading@10:     .priv_class    = &boxblur_class,
yading@10:     .init          = init,
yading@10:     .uninit        = uninit,
yading@10:     .query_formats = query_formats,
yading@10: 
yading@10:     .inputs    = avfilter_vf_boxblur_inputs,
yading@10:     .outputs   = avfilter_vf_boxblur_outputs,
yading@10: };