| /* |
| * Copyright (c) 2010 Stefano Sabatini |
| * Copyright (c) 2010 Baptiste Coudurier |
| * Copyright (c) 2007 Bobby Bingham |
| * |
| * 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 |
| * overlay one video on top of another |
| */ |
| |
| #include "avfilter.h" |
| #include "libavutil/eval.h" |
| #include "libavutil/avstring.h" |
| #include "libavutil/opt.h" |
| #include "libavutil/pixdesc.h" |
| #include "libavutil/imgutils.h" |
| #include "libavutil/mathematics.h" |
| #include "internal.h" |
| #include "drawutils.h" |
| |
| static const char * const var_names[] = { |
| "main_w", "W", ///< width of the main video |
| "main_h", "H", ///< height of the main video |
| "overlay_w", "w", ///< width of the overlay video |
| "overlay_h", "h", ///< height of the overlay video |
| NULL |
| }; |
| |
| enum var_name { |
| VAR_MAIN_W, VAR_MW, |
| VAR_MAIN_H, VAR_MH, |
| VAR_OVERLAY_W, VAR_OW, |
| VAR_OVERLAY_H, VAR_OH, |
| VAR_VARS_NB |
| }; |
| |
| #define MAIN 0 |
| #define OVERLAY 1 |
| |
| #define R 0 |
| #define G 1 |
| #define B 2 |
| #define A 3 |
| |
| #define Y 0 |
| #define U 1 |
| #define V 2 |
| |
| typedef struct { |
| const AVClass *class; |
| int x, y; ///< position of overlayed picture |
| |
| int allow_packed_rgb; |
| uint8_t main_is_packed_rgb; |
| uint8_t main_rgba_map[4]; |
| uint8_t main_has_alpha; |
| uint8_t overlay_is_packed_rgb; |
| uint8_t overlay_rgba_map[4]; |
| uint8_t overlay_has_alpha; |
| |
| AVFilterBufferRef *overpicref; |
| |
| int main_pix_step[4]; ///< steps per pixel for each plane of the main output |
| int overlay_pix_step[4]; ///< steps per pixel for each plane of the overlay |
| int hsub, vsub; ///< chroma subsampling values |
| |
| char *x_expr, *y_expr; |
| } OverlayContext; |
| |
| #define OFFSET(x) offsetof(OverlayContext, x) |
| |
| static const AVOption overlay_options[] = { |
| { "x", "set the x expression", OFFSET(x_expr), AV_OPT_TYPE_STRING, {.str = "0"}, CHAR_MIN, CHAR_MAX }, |
| { "y", "set the y expression", OFFSET(y_expr), AV_OPT_TYPE_STRING, {.str = "0"}, CHAR_MIN, CHAR_MAX }, |
| {"rgb", "force packed RGB in input and output", OFFSET(allow_packed_rgb), AV_OPT_TYPE_INT, {.dbl=0}, 0, 1 }, |
| {NULL}, |
| }; |
| |
| static const char *overlay_get_name(void *ctx) |
| { |
| return "overlay"; |
| } |
| |
| static const AVClass overlay_class = { |
| "OverlayContext", |
| overlay_get_name, |
| overlay_options |
| }; |
| |
| static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque) |
| { |
| OverlayContext *over = ctx->priv; |
| char *args1 = av_strdup(args); |
| char *expr, *bufptr = NULL; |
| int ret = 0; |
| |
| over->class = &overlay_class; |
| av_opt_set_defaults(over); |
| |
| if (expr = av_strtok(args1, ":", &bufptr)) { |
| av_free(over->x_expr); |
| if (!(over->x_expr = av_strdup(expr))) { |
| ret = AVERROR(ENOMEM); |
| goto end; |
| } |
| } |
| if (expr = av_strtok(NULL, ":", &bufptr)) { |
| av_free(over->y_expr); |
| if (!(over->y_expr = av_strdup(expr))) { |
| ret = AVERROR(ENOMEM); |
| goto end; |
| } |
| } |
| |
| if (bufptr && (ret = av_set_options_string(over, bufptr, "=", ":")) < 0) |
| goto end; |
| |
| end: |
| av_free(args1); |
| return ret; |
| } |
| |
| static av_cold void uninit(AVFilterContext *ctx) |
| { |
| OverlayContext *over = ctx->priv; |
| |
| av_freep(&over->x_expr); |
| av_freep(&over->y_expr); |
| |
| if (over->overpicref) |
| avfilter_unref_buffer(over->overpicref); |
| } |
| |
| static int query_formats(AVFilterContext *ctx) |
| { |
| OverlayContext *over = ctx->priv; |
| |
| /* overlay formats contains alpha, for avoiding conversion with alpha information loss */ |
| const enum PixelFormat main_pix_fmts_yuv[] = { PIX_FMT_YUV420P, PIX_FMT_NONE }; |
| const enum PixelFormat overlay_pix_fmts_yuv[] = { PIX_FMT_YUVA420P, PIX_FMT_NONE }; |
| const enum PixelFormat main_pix_fmts_rgb[] = { |
| PIX_FMT_ARGB, PIX_FMT_RGBA, |
| PIX_FMT_ABGR, PIX_FMT_BGRA, |
| PIX_FMT_RGB24, PIX_FMT_BGR24, |
| PIX_FMT_NONE |
| }; |
| const enum PixelFormat overlay_pix_fmts_rgb[] = { |
| PIX_FMT_ARGB, PIX_FMT_RGBA, |
| PIX_FMT_ABGR, PIX_FMT_BGRA, |
| PIX_FMT_NONE |
| }; |
| |
| AVFilterFormats *main_formats; |
| AVFilterFormats *overlay_formats; |
| |
| if (over->allow_packed_rgb) { |
| main_formats = avfilter_make_format_list(main_pix_fmts_rgb); |
| overlay_formats = avfilter_make_format_list(overlay_pix_fmts_rgb); |
| } else { |
| main_formats = avfilter_make_format_list(main_pix_fmts_yuv); |
| overlay_formats = avfilter_make_format_list(overlay_pix_fmts_yuv); |
| } |
| |
| avfilter_formats_ref(main_formats, &ctx->inputs [MAIN ]->out_formats); |
| avfilter_formats_ref(overlay_formats, &ctx->inputs [OVERLAY]->out_formats); |
| avfilter_formats_ref(main_formats, &ctx->outputs[MAIN ]->in_formats ); |
| |
| return 0; |
| } |
| |
| static const enum PixelFormat alpha_pix_fmts[] = { |
| PIX_FMT_YUVA420P, PIX_FMT_ARGB, PIX_FMT_ABGR, PIX_FMT_RGBA, |
| PIX_FMT_BGRA, PIX_FMT_NONE |
| }; |
| |
| static int config_input_main(AVFilterLink *inlink) |
| { |
| OverlayContext *over = inlink->dst->priv; |
| const AVPixFmtDescriptor *pix_desc = &av_pix_fmt_descriptors[inlink->format]; |
| |
| av_image_fill_max_pixsteps(over->main_pix_step, NULL, pix_desc); |
| |
| over->hsub = pix_desc->log2_chroma_w; |
| over->vsub = pix_desc->log2_chroma_h; |
| |
| over->main_is_packed_rgb = |
| ff_fill_rgba_map(over->main_rgba_map, inlink->format) >= 0; |
| over->main_has_alpha = ff_fmt_is_in(inlink->format, alpha_pix_fmts); |
| return 0; |
| } |
| |
| static int config_input_overlay(AVFilterLink *inlink) |
| { |
| AVFilterContext *ctx = inlink->dst; |
| OverlayContext *over = inlink->dst->priv; |
| char *expr; |
| double var_values[VAR_VARS_NB], res; |
| int ret; |
| const AVPixFmtDescriptor *pix_desc = &av_pix_fmt_descriptors[inlink->format]; |
| |
| av_image_fill_max_pixsteps(over->overlay_pix_step, NULL, pix_desc); |
| |
| /* Finish the configuration by evaluating the expressions |
| now when both inputs are configured. */ |
| var_values[VAR_MAIN_W ] = var_values[VAR_MW] = ctx->inputs[MAIN ]->w; |
| var_values[VAR_MAIN_H ] = var_values[VAR_MH] = ctx->inputs[MAIN ]->h; |
| var_values[VAR_OVERLAY_W] = var_values[VAR_OW] = ctx->inputs[OVERLAY]->w; |
| var_values[VAR_OVERLAY_H] = var_values[VAR_OH] = ctx->inputs[OVERLAY]->h; |
| |
| if ((ret = av_expr_parse_and_eval(&res, (expr = over->x_expr), var_names, var_values, |
| NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0) |
| goto fail; |
| over->x = res; |
| if ((ret = av_expr_parse_and_eval(&res, (expr = over->y_expr), var_names, var_values, |
| NULL, NULL, NULL, NULL, NULL, 0, ctx))) |
| goto fail; |
| over->y = res; |
| /* x may depend on y */ |
| if ((ret = av_expr_parse_and_eval(&res, (expr = over->x_expr), var_names, var_values, |
| NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0) |
| goto fail; |
| over->x = res; |
| |
| over->overlay_is_packed_rgb = |
| ff_fill_rgba_map(over->overlay_rgba_map, inlink->format) >= 0; |
| over->overlay_has_alpha = ff_fmt_is_in(inlink->format, alpha_pix_fmts); |
| |
| av_log(ctx, AV_LOG_INFO, |
| "main w:%d h:%d fmt:%s overlay x:%d y:%d w:%d h:%d fmt:%s\n", |
| ctx->inputs[MAIN]->w, ctx->inputs[MAIN]->h, |
| av_pix_fmt_descriptors[ctx->inputs[MAIN]->format].name, |
| over->x, over->y, |
| ctx->inputs[OVERLAY]->w, ctx->inputs[OVERLAY]->h, |
| av_pix_fmt_descriptors[ctx->inputs[OVERLAY]->format].name); |
| |
| if (over->x < 0 || over->y < 0 || |
| over->x + var_values[VAR_OVERLAY_W] > var_values[VAR_MAIN_W] || |
| over->y + var_values[VAR_OVERLAY_H] > var_values[VAR_MAIN_H]) { |
| av_log(ctx, AV_LOG_ERROR, |
| "Overlay area (%d,%d)<->(%d,%d) not within the main area (0,0)<->(%d,%d) or zero-sized\n", |
| over->x, over->y, |
| (int)(over->x + var_values[VAR_OVERLAY_W]), |
| (int)(over->y + var_values[VAR_OVERLAY_H]), |
| (int)var_values[VAR_MAIN_W], (int)var_values[VAR_MAIN_H]); |
| return AVERROR(EINVAL); |
| } |
| return 0; |
| |
| fail: |
| av_log(NULL, AV_LOG_ERROR, |
| "Error when evaluating the expression '%s'\n", expr); |
| return ret; |
| } |
| |
| static int config_output(AVFilterLink *outlink) |
| { |
| AVFilterContext *ctx = outlink->src; |
| int exact; |
| // common timebase computation: |
| AVRational tb1 = ctx->inputs[MAIN ]->time_base; |
| AVRational tb2 = ctx->inputs[OVERLAY]->time_base; |
| AVRational *tb = &ctx->outputs[0]->time_base; |
| exact = av_reduce(&tb->num, &tb->den, |
| av_gcd((int64_t)tb1.num * tb2.den, |
| (int64_t)tb2.num * tb1.den), |
| (int64_t)tb1.den * tb2.den, INT_MAX); |
| av_log(ctx, AV_LOG_INFO, |
| "main_tb:%d/%d overlay_tb:%d/%d -> tb:%d/%d exact:%d\n", |
| tb1.num, tb1.den, tb2.num, tb2.den, tb->num, tb->den, exact); |
| if (!exact) |
| av_log(ctx, AV_LOG_WARNING, |
| "Timestamp conversion inexact, timestamp information loss may occurr\n"); |
| |
| outlink->w = ctx->inputs[MAIN]->w; |
| outlink->h = ctx->inputs[MAIN]->h; |
| |
| return 0; |
| } |
| |
| static AVFilterBufferRef *get_video_buffer(AVFilterLink *link, int perms, int w, int h) |
| { |
| return avfilter_get_video_buffer(link->dst->outputs[0], perms, w, h); |
| } |
| |
| static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *inpicref) |
| { |
| AVFilterBufferRef *outpicref = avfilter_ref_buffer(inpicref, ~0); |
| AVFilterContext *ctx = inlink->dst; |
| OverlayContext *over = ctx->priv; |
| |
| inlink->dst->outputs[0]->out_buf = outpicref; |
| outpicref->pts = av_rescale_q(outpicref->pts, ctx->inputs[MAIN]->time_base, |
| ctx->outputs[0]->time_base); |
| |
| if (!over->overpicref || over->overpicref->pts < outpicref->pts) { |
| AVFilterBufferRef *old = over->overpicref; |
| over->overpicref = NULL; |
| avfilter_request_frame(ctx->inputs[OVERLAY]); |
| if (over->overpicref) { |
| if (old) |
| avfilter_unref_buffer(old); |
| } else |
| over->overpicref = old; |
| } |
| |
| avfilter_start_frame(inlink->dst->outputs[0], outpicref); |
| } |
| |
| static void start_frame_overlay(AVFilterLink *inlink, AVFilterBufferRef *inpicref) |
| { |
| AVFilterContext *ctx = inlink->dst; |
| OverlayContext *over = ctx->priv; |
| |
| over->overpicref = inpicref; |
| over->overpicref->pts = av_rescale_q(inpicref->pts, ctx->inputs[OVERLAY]->time_base, |
| ctx->outputs[0]->time_base); |
| } |
| |
| // divide by 255 and round to nearest |
| // apply a fast variant: (X+127)/255 = ((X+127)*257+257)>>16 = ((X+128)*257)>>16 |
| #define FAST_DIV255(x) ((((x) + 128) * 257) >> 16) |
| |
| static void blend_slice(AVFilterContext *ctx, |
| AVFilterBufferRef *dst, AVFilterBufferRef *src, |
| int x, int y, int w, int h, |
| int slice_y, int slice_w, int slice_h) |
| { |
| OverlayContext *over = ctx->priv; |
| int i, j, k; |
| int width, height; |
| int overlay_end_y = y+h; |
| int slice_end_y = slice_y+slice_h; |
| int end_y, start_y; |
| |
| width = FFMIN(slice_w - x, w); |
| end_y = FFMIN(slice_end_y, overlay_end_y); |
| start_y = FFMAX(y, slice_y); |
| height = end_y - start_y; |
| |
| if (over->main_is_packed_rgb) { |
| uint8_t *dp = dst->data[0] + x * over->main_pix_step[0] + |
| start_y * dst->linesize[0]; |
| uint8_t *sp = src->data[0]; |
| uint8_t alpha; ///< the amount of overlay to blend on to main |
| const int dr = over->main_rgba_map[R]; |
| const int dg = over->main_rgba_map[G]; |
| const int db = over->main_rgba_map[B]; |
| const int da = over->main_rgba_map[A]; |
| const int dstep = over->main_pix_step[0]; |
| const int sr = over->overlay_rgba_map[R]; |
| const int sg = over->overlay_rgba_map[G]; |
| const int sb = over->overlay_rgba_map[B]; |
| const int sa = over->overlay_rgba_map[A]; |
| const int sstep = over->overlay_pix_step[0]; |
| const int main_has_alpha = over->main_has_alpha; |
| if (slice_y > y) |
| sp += (slice_y - y) * src->linesize[0]; |
| for (i = 0; i < height; i++) { |
| uint8_t *d = dp, *s = sp; |
| for (j = 0; j < width; j++) { |
| alpha = s[sa]; |
| |
| // if the main channel has an alpha channel, alpha has to be calculated |
| // to create an un-premultiplied (straight) alpha value |
| if (main_has_alpha && alpha != 0 && alpha != 255) { |
| // apply the general equation: |
| // alpha = alpha_overlay / ( (alpha_main + alpha_overlay) - (alpha_main * alpha_overlay) ) |
| alpha = |
| // the next line is a faster version of: 255 * 255 * alpha |
| ( (alpha << 16) - (alpha << 9) + alpha ) |
| / |
| // the next line is a faster version of: 255 * (alpha + d[da]) |
| ( ((alpha + d[da]) << 8 ) - (alpha + d[da]) |
| - d[da] * alpha ); |
| } |
| |
| switch (alpha) { |
| case 0: |
| break; |
| case 255: |
| d[dr] = s[sr]; |
| d[dg] = s[sg]; |
| d[db] = s[sb]; |
| break; |
| default: |
| // main_value = main_value * (1 - alpha) + overlay_value * alpha |
| // since alpha is in the range 0-255, the result must divided by 255 |
| d[dr] = FAST_DIV255(d[dr] * (255 - alpha) + s[sr] * alpha); |
| d[dg] = FAST_DIV255(d[dg] * (255 - alpha) + s[sg] * alpha); |
| d[db] = FAST_DIV255(d[db] * (255 - alpha) + s[sb] * alpha); |
| } |
| if (main_has_alpha) { |
| switch (alpha) { |
| case 0: |
| break; |
| case 255: |
| d[da] = s[sa]; |
| break; |
| default: |
| // apply alpha compositing: main_alpha += (1-main_alpha) * overlay_alpha |
| d[da] += FAST_DIV255((255 - d[da]) * s[sa]); |
| } |
| } |
| d += dstep; |
| s += sstep; |
| } |
| dp += dst->linesize[0]; |
| sp += src->linesize[0]; |
| } |
| } else { |
| for (i = 0; i < 3; i++) { |
| int hsub = i ? over->hsub : 0; |
| int vsub = i ? over->vsub : 0; |
| uint8_t *dp = dst->data[i] + (x >> hsub) + |
| (start_y >> vsub) * dst->linesize[i]; |
| uint8_t *sp = src->data[i]; |
| uint8_t *ap = src->data[3]; |
| int wp = FFALIGN(width, 1<<hsub) >> hsub; |
| int hp = FFALIGN(height, 1<<vsub) >> vsub; |
| if (slice_y > y) { |
| sp += ((slice_y - y) >> vsub) * src->linesize[i]; |
| ap += (slice_y - y) * src->linesize[3]; |
| } |
| for (j = 0; j < hp; j++) { |
| uint8_t *d = dp, *s = sp, *a = ap; |
| for (k = 0; k < wp; k++) { |
| // average alpha for color components, improve quality |
| int alpha_v, alpha_h, alpha; |
| if (hsub && vsub && j+1 < hp && k+1 < wp) { |
| alpha = (a[0] + a[src->linesize[3]] + |
| a[1] + a[src->linesize[3]+1]) >> 2; |
| } else if (hsub || vsub) { |
| alpha_h = hsub && k+1 < wp ? |
| (a[0] + a[1]) >> 1 : a[0]; |
| alpha_v = vsub && j+1 < hp ? |
| (a[0] + a[src->linesize[3]]) >> 1 : a[0]; |
| alpha = (alpha_v + alpha_h) >> 1; |
| } else |
| alpha = a[0]; |
| *d = FAST_DIV255(*d * (255 - alpha) + *s * alpha); |
| s++; |
| d++; |
| a += 1 << hsub; |
| } |
| dp += dst->linesize[i]; |
| sp += src->linesize[i]; |
| ap += (1 << vsub) * src->linesize[3]; |
| } |
| } |
| } |
| } |
| |
| static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir) |
| { |
| AVFilterContext *ctx = inlink->dst; |
| AVFilterLink *outlink = ctx->outputs[0]; |
| AVFilterBufferRef *outpicref = outlink->out_buf; |
| OverlayContext *over = ctx->priv; |
| |
| if (over->overpicref && |
| !(over->x >= outpicref->video->w || over->y >= outpicref->video->h || |
| y+h < over->y || y >= over->y + over->overpicref->video->h)) { |
| blend_slice(ctx, outpicref, over->overpicref, over->x, over->y, |
| over->overpicref->video->w, over->overpicref->video->h, |
| y, outpicref->video->w, h); |
| } |
| avfilter_draw_slice(outlink, y, h, slice_dir); |
| } |
| |
| static void end_frame(AVFilterLink *inlink) |
| { |
| avfilter_end_frame(inlink->dst->outputs[0]); |
| avfilter_unref_buffer(inlink->cur_buf); |
| } |
| |
| static void null_draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir) { } |
| |
| static void null_end_frame(AVFilterLink *inlink) { } |
| |
| AVFilter avfilter_vf_overlay = { |
| .name = "overlay", |
| .description = NULL_IF_CONFIG_SMALL("Overlay a video source on top of the input."), |
| |
| .init = init, |
| .uninit = uninit, |
| |
| .priv_size = sizeof(OverlayContext), |
| |
| .query_formats = query_formats, |
| |
| .inputs = (const AVFilterPad[]) {{ .name = "main", |
| .type = AVMEDIA_TYPE_VIDEO, |
| .start_frame = start_frame, |
| .get_video_buffer= get_video_buffer, |
| .config_props = config_input_main, |
| .draw_slice = draw_slice, |
| .end_frame = end_frame, |
| .min_perms = AV_PERM_READ, |
| .rej_perms = AV_PERM_REUSE2|AV_PERM_PRESERVE, }, |
| { .name = "overlay", |
| .type = AVMEDIA_TYPE_VIDEO, |
| .start_frame = start_frame_overlay, |
| .config_props = config_input_overlay, |
| .draw_slice = null_draw_slice, |
| .end_frame = null_end_frame, |
| .min_perms = AV_PERM_READ, |
| .rej_perms = AV_PERM_REUSE2, }, |
| { .name = NULL}}, |
| .outputs = (const AVFilterPad[]) {{ .name = "default", |
| .type = AVMEDIA_TYPE_VIDEO, |
| .config_props = config_output, }, |
| { .name = NULL}}, |
| }; |
