2 * Copyright (c) 2010 Stefano Sabatini
3 * Copyright (c) 2010 Baptiste Coudurier
4 * Copyright (c) 2007 Bobby Bingham
6 * This file is part of Libav.
8 * Libav is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * Libav is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with Libav; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 * overlay one video on top of another
30 #include "libavutil/common.h"
31 #include "libavutil/eval.h"
32 #include "libavutil/avstring.h"
33 #include "libavutil/avassert.h"
34 #include "libavutil/pixdesc.h"
35 #include "libavutil/imgutils.h"
36 #include "libavutil/mathematics.h"
37 #include "libavutil/opt.h"
41 static const char *const var_names[] = {
45 "main_w", "W", ///< width of the main video
46 "main_h", "H", ///< height of the main video
47 "overlay_w", "w", ///< width of the overlay video
48 "overlay_h", "h", ///< height of the overlay video
58 VAR_OVERLAY_W, VAR_OW,
59 VAR_OVERLAY_H, VAR_OH,
68 int x, y; ///< position of overlayed picture
70 int max_plane_step[4]; ///< steps per pixel for each plane
71 int hsub, vsub; ///< chroma subsampling values
73 char *x_expr, *y_expr;
76 AVFrame *over_prev, *over_next;
79 static av_cold void uninit(AVFilterContext *ctx)
81 OverlayContext *s = ctx->priv;
83 av_frame_free(&s->main);
84 av_frame_free(&s->over_prev);
85 av_frame_free(&s->over_next);
88 static int query_formats(AVFilterContext *ctx)
90 const enum AVPixelFormat inout_pix_fmts[] = { AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE };
91 const enum AVPixelFormat blend_pix_fmts[] = { AV_PIX_FMT_YUVA420P, AV_PIX_FMT_NONE };
92 AVFilterFormats *inout_formats = ff_make_format_list(inout_pix_fmts);
93 AVFilterFormats *blend_formats = ff_make_format_list(blend_pix_fmts);
95 ff_formats_ref(inout_formats, &ctx->inputs [MAIN ]->out_formats);
96 ff_formats_ref(blend_formats, &ctx->inputs [OVERLAY]->out_formats);
97 ff_formats_ref(inout_formats, &ctx->outputs[MAIN ]->in_formats );
102 static int config_input_main(AVFilterLink *inlink)
104 OverlayContext *s = inlink->dst->priv;
105 const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(inlink->format);
107 av_image_fill_max_pixsteps(s->max_plane_step, NULL, pix_desc);
108 s->hsub = pix_desc->log2_chroma_w;
109 s->vsub = pix_desc->log2_chroma_h;
114 static int config_input_overlay(AVFilterLink *inlink)
116 AVFilterContext *ctx = inlink->dst;
117 OverlayContext *s = inlink->dst->priv;
119 double var_values[VAR_VARS_NB], res;
122 /* Finish the configuration by evaluating the expressions
123 now when both inputs are configured. */
124 var_values[VAR_E ] = M_E;
125 var_values[VAR_PHI] = M_PHI;
126 var_values[VAR_PI ] = M_PI;
128 var_values[VAR_MAIN_W ] = var_values[VAR_MW] = ctx->inputs[MAIN ]->w;
129 var_values[VAR_MAIN_H ] = var_values[VAR_MH] = ctx->inputs[MAIN ]->h;
130 var_values[VAR_OVERLAY_W] = var_values[VAR_OW] = ctx->inputs[OVERLAY]->w;
131 var_values[VAR_OVERLAY_H] = var_values[VAR_OH] = ctx->inputs[OVERLAY]->h;
133 if ((ret = av_expr_parse_and_eval(&res, (expr = s->x_expr), var_names, var_values,
134 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
137 if ((ret = av_expr_parse_and_eval(&res, (expr = s->y_expr), var_names, var_values,
138 NULL, NULL, NULL, NULL, NULL, 0, ctx)))
141 /* x may depend on y */
142 if ((ret = av_expr_parse_and_eval(&res, (expr = s->x_expr), var_names, var_values,
143 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
147 av_log(ctx, AV_LOG_VERBOSE,
148 "main w:%d h:%d fmt:%s overlay x:%d y:%d w:%d h:%d fmt:%s\n",
149 ctx->inputs[MAIN]->w, ctx->inputs[MAIN]->h,
150 av_get_pix_fmt_name(ctx->inputs[MAIN]->format),
152 ctx->inputs[OVERLAY]->w, ctx->inputs[OVERLAY]->h,
153 av_get_pix_fmt_name(ctx->inputs[OVERLAY]->format));
155 if (s->x < 0 || s->y < 0 ||
156 s->x + var_values[VAR_OVERLAY_W] > var_values[VAR_MAIN_W] ||
157 s->y + var_values[VAR_OVERLAY_H] > var_values[VAR_MAIN_H]) {
158 av_log(ctx, AV_LOG_ERROR,
159 "Overlay area (%d,%d)<->(%d,%d) not within the main area (0,0)<->(%d,%d) or zero-sized\n",
161 (int)(s->x + var_values[VAR_OVERLAY_W]),
162 (int)(s->y + var_values[VAR_OVERLAY_H]),
163 (int)var_values[VAR_MAIN_W], (int)var_values[VAR_MAIN_H]);
164 return AVERROR(EINVAL);
169 av_log(NULL, AV_LOG_ERROR,
170 "Error when evaluating the expression '%s'\n", expr);
174 static int config_output(AVFilterLink *outlink)
176 AVFilterContext *ctx = outlink->src;
178 outlink->w = ctx->inputs[MAIN]->w;
179 outlink->h = ctx->inputs[MAIN]->h;
180 outlink->time_base = ctx->inputs[MAIN]->time_base;
185 static void blend_frame(AVFilterContext *ctx,
186 AVFrame *dst, AVFrame *src,
189 OverlayContext *s = ctx->priv;
192 int overlay_end_y = y + src->height;
195 width = FFMIN(dst->width - x, src->width);
196 end_y = FFMIN(dst->height, overlay_end_y);
197 start_y = FFMAX(y, 0);
198 height = end_y - start_y;
200 if (dst->format == AV_PIX_FMT_BGR24 || dst->format == AV_PIX_FMT_RGB24) {
201 uint8_t *dp = dst->data[0] + x * 3 + start_y * dst->linesize[0];
202 uint8_t *sp = src->data[0];
203 int b = dst->format == AV_PIX_FMT_BGR24 ? 2 : 0;
204 int r = dst->format == AV_PIX_FMT_BGR24 ? 0 : 2;
206 sp += -y * src->linesize[0];
207 for (i = 0; i < height; i++) {
208 uint8_t *d = dp, *s = sp;
209 for (j = 0; j < width; j++) {
210 d[r] = (d[r] * (0xff - s[3]) + s[0] * s[3] + 128) >> 8;
211 d[1] = (d[1] * (0xff - s[3]) + s[1] * s[3] + 128) >> 8;
212 d[b] = (d[b] * (0xff - s[3]) + s[2] * s[3] + 128) >> 8;
216 dp += dst->linesize[0];
217 sp += src->linesize[0];
220 for (i = 0; i < 3; i++) {
221 int hsub = i ? s->hsub : 0;
222 int vsub = i ? s->vsub : 0;
223 uint8_t *dp = dst->data[i] + (x >> hsub) +
224 (start_y >> vsub) * dst->linesize[i];
225 uint8_t *sp = src->data[i];
226 uint8_t *ap = src->data[3];
227 int wp = FFALIGN(width, 1<<hsub) >> hsub;
228 int hp = FFALIGN(height, 1<<vsub) >> vsub;
230 sp += ((-y) >> vsub) * src->linesize[i];
231 ap += -y * src->linesize[3];
233 for (j = 0; j < hp; j++) {
234 uint8_t *d = dp, *s = sp, *a = ap;
235 for (k = 0; k < wp; k++) {
236 // average alpha for color components, improve quality
237 int alpha_v, alpha_h, alpha;
238 if (hsub && vsub && j+1 < hp && k+1 < wp) {
239 alpha = (a[0] + a[src->linesize[3]] +
240 a[1] + a[src->linesize[3]+1]) >> 2;
241 } else if (hsub || vsub) {
242 alpha_h = hsub && k+1 < wp ?
243 (a[0] + a[1]) >> 1 : a[0];
244 alpha_v = vsub && j+1 < hp ?
245 (a[0] + a[src->linesize[3]]) >> 1 : a[0];
246 alpha = (alpha_v + alpha_h) >> 1;
249 *d = (*d * (0xff - alpha) + *s++ * alpha + 128) >> 8;
253 dp += dst->linesize[i];
254 sp += src->linesize[i];
255 ap += (1 << vsub) * src->linesize[3];
261 static int filter_frame_main(AVFilterLink *inlink, AVFrame *frame)
263 OverlayContext *s = inlink->dst->priv;
265 av_assert0(!s->main);
271 static int filter_frame_overlay(AVFilterLink *inlink, AVFrame *frame)
273 OverlayContext *s = inlink->dst->priv;
275 av_assert0(!s->over_next);
276 s->over_next = frame;
281 static int output_frame(AVFilterContext *ctx)
283 OverlayContext *s = ctx->priv;
284 AVFilterLink *outlink = ctx->outputs[0];
285 int ret = ff_filter_frame(outlink, s->main);
291 static int handle_overlay_eof(AVFilterContext *ctx)
293 OverlayContext *s = ctx->priv;
295 blend_frame(ctx, s->main, s->over_prev, s->x, s->y);
296 return output_frame(ctx);
299 static int request_frame(AVFilterLink *outlink)
301 AVFilterContext *ctx = outlink->src;
302 OverlayContext *s = ctx->priv;
303 AVRational tb_main = ctx->inputs[MAIN]->time_base;
304 AVRational tb_over = ctx->inputs[OVERLAY]->time_base;
307 /* get a frame on the main input */
309 ret = ff_request_frame(ctx->inputs[MAIN]);
314 /* get a new frame on the overlay input, on EOF
317 ret = ff_request_frame(ctx->inputs[OVERLAY]);
318 if (ret == AVERROR_EOF)
319 return handle_overlay_eof(ctx);
324 while (s->main->pts != AV_NOPTS_VALUE &&
325 s->over_next->pts != AV_NOPTS_VALUE &&
326 av_compare_ts(s->over_next->pts, tb_over, s->main->pts, tb_main) < 0) {
327 av_frame_free(&s->over_prev);
328 FFSWAP(AVFrame*, s->over_prev, s->over_next);
330 ret = ff_request_frame(ctx->inputs[OVERLAY]);
331 if (ret == AVERROR_EOF)
332 return handle_overlay_eof(ctx);
337 if (s->main->pts == AV_NOPTS_VALUE ||
338 s->over_next->pts == AV_NOPTS_VALUE ||
339 !av_compare_ts(s->over_next->pts, tb_over, s->main->pts, tb_main)) {
340 blend_frame(ctx, s->main, s->over_next, s->x, s->y);
341 av_frame_free(&s->over_prev);
342 FFSWAP(AVFrame*, s->over_prev, s->over_next);
343 } else if (s->over_prev) {
344 blend_frame(ctx, s->main, s->over_prev, s->x, s->y);
347 return output_frame(ctx);
350 #define OFFSET(x) offsetof(OverlayContext, x)
351 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM
352 static const AVOption options[] = {
353 { "x", "Horizontal position of the left edge of the overlaid video on the "
354 "main video.", OFFSET(x_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
355 { "y", "Vertical position of the top edge of the overlaid video on the "
356 "main video.", OFFSET(y_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
360 static const AVClass overlay_class = {
361 .class_name = "overlay",
362 .item_name = av_default_item_name,
364 .version = LIBAVUTIL_VERSION_INT,
367 static const AVFilterPad avfilter_vf_overlay_inputs[] = {
370 .type = AVMEDIA_TYPE_VIDEO,
371 .config_props = config_input_main,
372 .filter_frame = filter_frame_main,
378 .type = AVMEDIA_TYPE_VIDEO,
379 .config_props = config_input_overlay,
380 .filter_frame = filter_frame_overlay,
386 static const AVFilterPad avfilter_vf_overlay_outputs[] = {
389 .type = AVMEDIA_TYPE_VIDEO,
390 .config_props = config_output,
391 .request_frame = request_frame,
396 AVFilter avfilter_vf_overlay = {
398 .description = NULL_IF_CONFIG_SMALL("Overlay a video source on top of the input."),
402 .priv_size = sizeof(OverlayContext),
403 .priv_class = &overlay_class,
405 .query_formats = query_formats,
407 .inputs = avfilter_vf_overlay_inputs,
408 .outputs = avfilter_vf_overlay_outputs,