diff options
Diffstat (limited to 'libavfilter/vf_geq.c')
-rw-r--r-- | libavfilter/vf_geq.c | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/libavfilter/vf_geq.c b/libavfilter/vf_geq.c new file mode 100644 index 0000000..2f7b50b --- /dev/null +++ b/libavfilter/vf_geq.c @@ -0,0 +1,239 @@ +/* + * Copyright (C) 2006 Michael Niedermayer <michaelni@gmx.at> + * Copyright (C) 2012 Clément Bœsch <ubitux@gmail.com> + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 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 General Public License for more details. + * + * You should have received a copy of the GNU 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 + * Generic equation change filter + * Originally written by Michael Niedermayer for the MPlayer project, and + * ported by Clément Bœsch for FFmpeg. + */ + +#include "libavutil/avstring.h" +#include "libavutil/eval.h" +#include "libavutil/opt.h" +#include "libavutil/pixdesc.h" +#include "internal.h" + +typedef struct { + const AVClass *class; + AVExpr *e[3]; ///< expressions for each plane + char *expr_str[3]; ///< expression strings for each plane + int framenum; ///< frame counter + AVFilterBufferRef *picref; ///< current input buffer + int hsub, vsub; ///< chroma subsampling +} GEQContext; + +#define OFFSET(x) offsetof(GEQContext, x) +#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM + +static const AVOption geq_options[] = { + { "lum_expr", "set luminance expression", OFFSET(expr_str), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS }, + { "cb_expr", "set chroma blue expression", OFFSET(expr_str) + sizeof(char*), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS }, + { "cr_expr", "set chroma red expression", OFFSET(expr_str) + 2*sizeof(char*), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS }, + {NULL}, +}; + +AVFILTER_DEFINE_CLASS(geq); + +static inline double getpix(void *priv, double x, double y, int plane) +{ + int xi, yi; + GEQContext *geq = priv; + AVFilterBufferRef *picref = geq->picref; + const uint8_t *src = picref->data[plane]; + const int linesize = picref->linesize[plane]; + const int w = picref->video->w >> (plane ? geq->hsub : 0); + const int h = picref->video->h >> (plane ? geq->vsub : 0); + + xi = x = av_clipf(x, 0, w - 2); + yi = y = av_clipf(y, 0, h - 2); + + x -= xi; + y -= yi; + + return (1-y)*((1-x)*src[xi + yi * linesize] + x*src[xi + 1 + yi * linesize]) + + y *((1-x)*src[xi + (yi+1) * linesize] + x*src[xi + 1 + (yi+1) * linesize]); +} + +//TODO: cubic interpolate +//TODO: keep the last few frames +static double lum(void *priv, double x, double y) { return getpix(priv, x, y, 0); } +static double cb(void *priv, double x, double y) { return getpix(priv, x, y, 1); } +static double cr(void *priv, double x, double y) { return getpix(priv, x, y, 2); } + +static const char *const var_names[] = { "X", "Y", "W", "H", "N", "SW", "SH", "T", NULL }; +enum { VAR_X, VAR_Y, VAR_W, VAR_H, VAR_N, VAR_SW, VAR_SH, VAR_T, VAR_VARS_NB }; + +static av_cold int geq_init(AVFilterContext *ctx, const char *args) +{ + GEQContext *geq = ctx->priv; + int plane, ret = 0; + static const char *shorthand[] = { "lum_expr", "cb_expr", "cr_expr", NULL }; + + geq->class = &geq_class; + av_opt_set_defaults(geq); + + if ((ret = av_opt_set_from_string(geq, args, shorthand, "=", ":")) < 0) + return ret; + + if (!geq->expr_str[0]) { + av_log(ctx, AV_LOG_ERROR, "Luminance expression is mandatory\n"); + ret = AVERROR(EINVAL); + goto end; + } + + if (!geq->expr_str[1] && !geq->expr_str[2]) { + /* No chroma at all: fallback on luma */ + geq->expr_str[1] = av_strdup(geq->expr_str[0]); + geq->expr_str[2] = av_strdup(geq->expr_str[0]); + } else { + /* One chroma unspecified, fallback on the other */ + if (!geq->expr_str[1]) geq->expr_str[1] = av_strdup(geq->expr_str[2]); + if (!geq->expr_str[2]) geq->expr_str[2] = av_strdup(geq->expr_str[1]); + } + + if (!geq->expr_str[1] || !geq->expr_str[2]) { + ret = AVERROR(ENOMEM); + goto end; + } + + for (plane = 0; plane < 3; plane++) { + static double (*p[])(void *, double, double) = { lum, cb, cr }; + static const char *const func2_names[] = { "lum", "cb", "cr", "p", NULL }; + double (*func2[])(void *, double, double) = { lum, cb, cr, p[plane], NULL }; + + ret = av_expr_parse(&geq->e[plane], geq->expr_str[plane], var_names, + NULL, NULL, func2_names, func2, 0, ctx); + if (ret < 0) + break; + } + +end: + return ret; +} + +static int geq_query_formats(AVFilterContext *ctx) +{ + static const enum PixelFormat pix_fmts[] = { + AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV420P, + AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV440P, + AV_PIX_FMT_YUVA420P, + AV_PIX_FMT_NONE + }; + ff_set_common_formats(ctx, ff_make_format_list(pix_fmts)); + return 0; +} + +static int geq_config_props(AVFilterLink *inlink) +{ + GEQContext *geq = inlink->dst->priv; + const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format); + + geq->hsub = desc->log2_chroma_w; + geq->vsub = desc->log2_chroma_h; + return 0; +} + +static int geq_filter_frame(AVFilterLink *inlink, AVFilterBufferRef *in) +{ + int plane; + GEQContext *geq = inlink->dst->priv; + AVFilterLink *outlink = inlink->dst->outputs[0]; + AVFilterBufferRef *out; + double values[VAR_VARS_NB] = { + [VAR_N] = geq->framenum++, + [VAR_T] = in->pts == AV_NOPTS_VALUE ? NAN : in->pts * av_q2d(inlink->time_base), + }; + + geq->picref = in; + out = ff_get_video_buffer(outlink, AV_PERM_WRITE, outlink->w, outlink->h); + if (!out) { + avfilter_unref_bufferp(&in); + return AVERROR(ENOMEM); + } + avfilter_copy_buffer_ref_props(out, in); + + for (plane = 0; plane < 3; plane++) { + int x, y; + uint8_t *dst = out->data[plane]; + const int linesize = out->linesize[plane]; + const int w = inlink->w >> (plane ? geq->hsub : 0); + const int h = inlink->h >> (plane ? geq->vsub : 0); + + values[VAR_W] = w; + values[VAR_H] = h; + values[VAR_SW] = w / (double)inlink->w; + values[VAR_SH] = h / (double)inlink->h; + + for (y = 0; y < h; y++) { + values[VAR_Y] = y; + for (x = 0; x < w; x++) { + values[VAR_X] = x; + dst[x] = av_expr_eval(geq->e[plane], values, geq); + } + dst += linesize; + } + } + + avfilter_unref_bufferp(&geq->picref); + return ff_filter_frame(outlink, out); +} + +static av_cold void geq_uninit(AVFilterContext *ctx) +{ + int i; + GEQContext *geq = ctx->priv; + + for (i = 0; i < FF_ARRAY_ELEMS(geq->e); i++) + av_expr_free(geq->e[i]); + av_opt_free(geq); +} + +static const AVFilterPad geq_inputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + .config_props = geq_config_props, + .filter_frame = geq_filter_frame, + .min_perms = AV_PERM_READ, + }, + { NULL } +}; + +static const AVFilterPad geq_outputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + }, + { NULL } +}; + +AVFilter avfilter_vf_geq = { + .name = "geq", + .description = NULL_IF_CONFIG_SMALL("Apply generic equation to each pixel."), + .priv_size = sizeof(GEQContext), + .init = geq_init, + .uninit = geq_uninit, + .query_formats = geq_query_formats, + .inputs = geq_inputs, + .outputs = geq_outputs, + .priv_class = &geq_class, +}; |