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-rw-r--r--libavfilter/vf_geq.c239
1 files changed, 239 insertions, 0 deletions
diff --git a/libavfilter/vf_geq.c b/libavfilter/vf_geq.c
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--- /dev/null
+++ b/libavfilter/vf_geq.c
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+/*
+ * 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,
+};
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-04 03:56:36 +0000