/*
* 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/pixdesc.h"
#include "libavutil/imgutils.h"
#include "internal.h"
static const char *var_names[] = {
"E",
"PHI",
"PI",
"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_E,
VAR_PHI,
VAR_PI,
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
typedef struct {
int x, y; ///< position of overlayed picture
AVFilterBufferRef *overpicref;
int max_plane_step[4]; ///< steps per pixel for each plane
int hsub, vsub; ///< chroma subsampling values
char x_expr[256], y_expr[256];
} OverlayContext;
static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
{
OverlayContext *over = ctx->priv;
av_strlcpy(over->x_expr, "0", sizeof(over->x_expr));
av_strlcpy(over->y_expr, "0", sizeof(over->y_expr));
if (args)
sscanf(args, "%255[^:]:%255[^:]", over->x_expr, over->y_expr);
return 0;
}
static av_cold void uninit(AVFilterContext *ctx)
{
OverlayContext *over = ctx->priv;
if (over->overpicref)
avfilter_unref_buffer(over->overpicref);
}
static int query_formats(AVFilterContext *ctx)
{
const enum PixelFormat inout_pix_fmts[] = { PIX_FMT_YUV420P, PIX_FMT_NONE };
const enum PixelFormat blend_pix_fmts[] = { PIX_FMT_YUVA420P, PIX_FMT_NONE };
AVFilterFormats *inout_formats = avfilter_make_format_list(inout_pix_fmts);
AVFilterFormats *blend_formats = avfilter_make_format_list(blend_pix_fmts);
avfilter_formats_ref(inout_formats, &ctx->inputs [MAIN ]->out_formats);
avfilter_formats_ref(blend_formats, &ctx->inputs [OVERLAY]->out_formats);
avfilter_formats_ref(inout_formats, &ctx->outputs[MAIN ]->in_formats );
return 0;
}
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->max_plane_step, NULL, pix_desc);
over->hsub = pix_desc->log2_chroma_w;
over->vsub = pix_desc->log2_chroma_h;
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;
/* Finish the configuration by evaluating the expressions
now when both inputs are configured. */
var_values[VAR_E ] = M_E;
var_values[VAR_PHI] = M_PHI;
var_values[VAR_PI ] = M_PI;
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;
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);
}
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 (dst->format == PIX_FMT_BGR24 || dst->format == PIX_FMT_RGB24) {
uint8_t *dp = dst->data[0] + x * 3 + start_y * dst->linesize[0];
uint8_t *sp = src->data[0];
int b = dst->format == PIX_FMT_BGR24 ? 2 : 0;
int r = dst->format == PIX_FMT_BGR24 ? 0 : 2;
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++) {
d[r] = (d[r] * (0xff - s[3]) + s[0] * s[3] + 128) >> 8;
d[1] = (d[1] * (0xff - s[3]) + s[1] * s[3] + 128) >> 8;
d[b] = (d[b] * (0xff - s[3]) + s[2] * s[3] + 128) >> 8;
d += 3;
s += 4;
}
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 = (*d * (0xff - alpha) + *s++ * alpha + 128) >> 8;
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 = (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 = (AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_output, },
{ .name = NULL}},
};