/*
* Copyright (c) 2010 Stefano Sabatini
* Copyright (c) 2010 Baptiste Coudurier
* Copyright (c) 2007 Bobby Bingham
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; 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 "formats.h"
#include "libavutil/common.h"
#include "libavutil/eval.h"
#include "libavutil/avstring.h"
#include "libavutil/avassert.h"
#include "libavutil/pixdesc.h"
#include "libavutil/imgutils.h"
#include "libavutil/mathematics.h"
#include "libavutil/opt.h"
#include "internal.h"
#include "video.h"
static const char *const 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
};
enum EOFAction {
EOF_ACTION_REPEAT,
EOF_ACTION_ENDALL,
EOF_ACTION_PASS
};
static const char *eof_action_str[] = {
"repeat", "endall", "pass"
};
#define MAIN 0
#define OVERLAY 1
typedef struct OverlayContext {
const AVClass *class;
int x, y; ///< position of overlaid picture
int max_plane_step[4]; ///< steps per pixel for each plane
int hsub, vsub; ///< chroma subsampling values
char *x_expr, *y_expr;
enum EOFAction eof_action; ///< action to take on EOF from source
AVFrame *main;
AVFrame *over_prev, *over_next;
} OverlayContext;
static av_cold void uninit(AVFilterContext *ctx)
{
OverlayContext *s = ctx->priv;
av_frame_free(&s->main);
av_frame_free(&s->over_prev);
av_frame_free(&s->over_next);
}
static int query_formats(AVFilterContext *ctx)
{
const enum AVPixelFormat inout_pix_fmts[] = { AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE };
const enum AVPixelFormat blend_pix_fmts[] = { AV_PIX_FMT_YUVA420P, AV_PIX_FMT_NONE };
AVFilterFormats *inout_formats = ff_make_format_list(inout_pix_fmts);
AVFilterFormats *blend_formats = ff_make_format_list(blend_pix_fmts);
ff_formats_ref(inout_formats, &ctx->inputs [MAIN ]->out_formats);
ff_formats_ref(blend_formats, &ctx->inputs [OVERLAY]->out_formats);
ff_formats_ref(inout_formats, &ctx->outputs[MAIN ]->in_formats );
return 0;
}
static int config_input_main(AVFilterLink *inlink)
{
OverlayContext *s = inlink->dst->priv;
const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(inlink->format);
av_image_fill_max_pixsteps(s->max_plane_step, NULL, pix_desc);
s->hsub = pix_desc->log2_chroma_w;
s->vsub = pix_desc->log2_chroma_h;
return 0;
}
static int config_input_overlay(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
OverlayContext *s = 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 = s->x_expr), var_names, var_values,
NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
goto fail;
s->x = res;
if ((ret = av_expr_parse_and_eval(&res, (expr = s->y_expr), var_names, var_values,
NULL, NULL, NULL, NULL, NULL, 0, ctx)))
goto fail;
s->y = res;
/* x may depend on y */
if ((ret = av_expr_parse_and_eval(&res, (expr = s->x_expr), var_names, var_values,
NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
goto fail;
s->x = res;
av_log(ctx, AV_LOG_VERBOSE,
"main w:%d h:%d fmt:%s overlay x:%d y:%d w:%d h:%d fmt:%s eof_action:%s\n",
ctx->inputs[MAIN]->w, ctx->inputs[MAIN]->h,
av_get_pix_fmt_name(ctx->inputs[MAIN]->format),
s->x, s->y,
ctx->inputs[OVERLAY]->w, ctx->inputs[OVERLAY]->h,
av_get_pix_fmt_name(ctx->inputs[OVERLAY]->format),
eof_action_str[s->eof_action]);
if (s->x < 0 || s->y < 0 ||
s->x + var_values[VAR_OVERLAY_W] > var_values[VAR_MAIN_W] ||
s->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",
s->x, s->y,
(int)(s->x + var_values[VAR_OVERLAY_W]),
(int)(s->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;
outlink->w = ctx->inputs[MAIN]->w;
outlink->h = ctx->inputs[MAIN]->h;
outlink->time_base = ctx->inputs[MAIN]->time_base;
return 0;
}
static void blend_frame(AVFilterContext *ctx,
AVFrame *dst, AVFrame *src,
int x, int y)
{
OverlayContext *s = ctx->priv;
int i, j, k;
int width, height;
int overlay_end_y = y + src->height;
int end_y, start_y;
width = FFMIN(dst->width - x, src->width);
end_y = FFMIN(dst->height, overlay_end_y);
start_y = FFMAX(y, 0);
height = end_y - start_y;
if (dst->format == AV_PIX_FMT_BGR24 || dst->format == AV_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 == AV_PIX_FMT_BGR24 ? 2 : 0;
int r = dst->format == AV_PIX_FMT_BGR24 ? 0 : 2;
if (y < 0)
sp += -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 ? s->hsub : 0;
int vsub = i ? s->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 (y < 0) {
sp += ((-y) >> vsub) * src->linesize[i];
ap += -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 int filter_frame_main(AVFilterLink *inlink, AVFrame *frame)
{
OverlayContext *s = inlink->dst->priv;
av_assert0(!s->main);
s->main = frame;
return 0;
}
static int filter_frame_overlay(AVFilterLink *inlink, AVFrame *frame)
{
OverlayContext *s = inlink->dst->priv;
av_assert0(!s->over_next);
s->over_next = frame;
return 0;
}
static int output_frame(AVFilterContext *ctx)
{
OverlayContext *s = ctx->priv;
AVFilterLink *outlink = ctx->outputs[0];
int ret = ff_filter_frame(outlink, s->main);
s->main = NULL;
return ret;
}
static int handle_overlay_eof(AVFilterContext *ctx)
{
OverlayContext *s = ctx->priv;
/* Repeat previous frame on secondary input */
if (s->over_prev && s->eof_action == EOF_ACTION_REPEAT)
blend_frame(ctx, s->main, s->over_prev, s->x, s->y);
/* End both streams */
else if (s->eof_action == EOF_ACTION_ENDALL)
return AVERROR_EOF;
return output_frame(ctx);
}
static int request_frame(AVFilterLink *outlink)
{
AVFilterContext *ctx = outlink->src;
OverlayContext *s = ctx->priv;
AVRational tb_main = ctx->inputs[MAIN]->time_base;
AVRational tb_over = ctx->inputs[OVERLAY]->time_base;
int ret = 0;
/* get a frame on the main input */
if (!s->main) {
ret = ff_request_frame(ctx->inputs[MAIN]);
if (ret < 0)
return ret;
}
/* get a new frame on the overlay input, on EOF check setting 'eof_action' */
if (!s->over_next) {
ret = ff_request_frame(ctx->inputs[OVERLAY]);
if (ret == AVERROR_EOF)
return handle_overlay_eof(ctx);
else if (ret < 0)
return ret;
}
while (s->main->pts != AV_NOPTS_VALUE &&
s->over_next->pts != AV_NOPTS_VALUE &&
av_compare_ts(s->over_next->pts, tb_over, s->main->pts, tb_main) < 0) {
av_frame_free(&s->over_prev);
FFSWAP(AVFrame*, s->over_prev, s->over_next);
ret = ff_request_frame(ctx->inputs[OVERLAY]);
if (ret == AVERROR_EOF)
return handle_overlay_eof(ctx);
else if (ret < 0)
return ret;
}
if (s->main->pts == AV_NOPTS_VALUE ||
s->over_next->pts == AV_NOPTS_VALUE ||
!av_compare_ts(s->over_next->pts, tb_over, s->main->pts, tb_main)) {
blend_frame(ctx, s->main, s->over_next, s->x, s->y);
av_frame_free(&s->over_prev);
FFSWAP(AVFrame*, s->over_prev, s->over_next);
} else if (s->over_prev) {
blend_frame(ctx, s->main, s->over_prev, s->x, s->y);
}
return output_frame(ctx);
}
#define OFFSET(x) offsetof(OverlayContext, x)
#define FLAGS AV_OPT_FLAG_VIDEO_PARAM
static const AVOption options[] = {
{ "x", "Horizontal position of the left edge of the overlaid video on the "
"main video.", OFFSET(x_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
{ "y", "Vertical position of the top edge of the overlaid video on the "
"main video.", OFFSET(y_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
{ "eof_action", "Action to take when encountering EOF from secondary input ",
OFFSET(eof_action), AV_OPT_TYPE_INT, { .i64 = EOF_ACTION_REPEAT },
EOF_ACTION_REPEAT, EOF_ACTION_PASS, .flags = FLAGS, "eof_action" },
{ "repeat", "Repeat the previous frame.", 0, AV_OPT_TYPE_CONST, { .i64 = EOF_ACTION_REPEAT }, .flags = FLAGS, "eof_action" },
{ "endall", "End both streams.", 0, AV_OPT_TYPE_CONST, { .i64 = EOF_ACTION_ENDALL }, .flags = FLAGS, "eof_action" },
{ "pass", "Pass through the main input.", 0, AV_OPT_TYPE_CONST, { .i64 = EOF_ACTION_PASS }, .flags = FLAGS, "eof_action" },
{ NULL },
};
static const AVClass overlay_class = {
.class_name = "overlay",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
static const AVFilterPad avfilter_vf_overlay_inputs[] = {
{
.name = "main",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_input_main,
.filter_frame = filter_frame_main,
.needs_writable = 1,
.needs_fifo = 1,
},
{
.name = "overlay",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_input_overlay,
.filter_frame = filter_frame_overlay,
.needs_fifo = 1,
},
{ NULL }
};
static const AVFilterPad avfilter_vf_overlay_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_output,
.request_frame = request_frame,
},
{ NULL }
};
AVFilter ff_vf_overlay = {
.name = "overlay",
.description = NULL_IF_CONFIG_SMALL("Overlay a video source on top of the input."),
.uninit = uninit,
.priv_size = sizeof(OverlayContext),
.priv_class = &overlay_class,
.query_formats = query_formats,
.inputs = avfilter_vf_overlay_inputs,
.outputs = avfilter_vf_overlay_outputs,
};