FFmpeg/libavfilter/vf_fade.c
Mark Himsley b04d1abb40 fade: fix draw_slice() check on fade->factor value
draw_slice() checks that the fade factor is < 65536 and only
calculates the fade if so. But the fade factor is clipped in
end_frame() by av_clip_uint16() to 65535, so the fade is calculated
for every frame.  This patch alters the check so that it compares with
< 65535 (UINT16_MAX).

Signed-off-by: Anton Khirnov <anton@khirnov.net>
2011-04-25 22:45:44 +02:00

171 lines
5.9 KiB
C

/*
* Copyright (c) 2010 Brandon Mintern
* 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
* video fade filter
* based heavily on vf_negate.c by Bobby Bingham
*/
#include "libavutil/pixdesc.h"
#include "avfilter.h"
typedef struct {
int factor, fade_per_frame;
unsigned int frame_index, start_frame, stop_frame;
int hsub, vsub, bpp;
} FadeContext;
static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
{
FadeContext *fade = ctx->priv;
unsigned int nb_frames;
char in_out[4];
if (!args ||
sscanf(args, " %3[^:]:%u:%u", in_out, &fade->start_frame, &nb_frames) != 3) {
av_log(ctx, AV_LOG_ERROR,
"Expected 3 arguments '(in|out):#:#':'%s'\n", args);
return AVERROR(EINVAL);
}
nb_frames = nb_frames ? nb_frames : 1;
fade->fade_per_frame = (1 << 16) / nb_frames;
if (!strcmp(in_out, "in"))
fade->factor = 0;
else if (!strcmp(in_out, "out")) {
fade->fade_per_frame = -fade->fade_per_frame;
fade->factor = (1 << 16);
} else {
av_log(ctx, AV_LOG_ERROR,
"first argument must be 'in' or 'out':'%s'\n", in_out);
return AVERROR(EINVAL);
}
fade->stop_frame = fade->start_frame + nb_frames;
av_log(ctx, AV_LOG_INFO,
"type:%s start_frame:%d nb_frames:%d\n",
in_out, fade->start_frame, nb_frames);
return 0;
}
static int query_formats(AVFilterContext *ctx)
{
const static enum PixelFormat pix_fmts[] = {
PIX_FMT_YUV444P, PIX_FMT_YUV422P, PIX_FMT_YUV420P,
PIX_FMT_YUV411P, PIX_FMT_YUV410P,
PIX_FMT_YUVJ444P, PIX_FMT_YUVJ422P, PIX_FMT_YUVJ420P,
PIX_FMT_YUV440P, PIX_FMT_YUVJ440P,
PIX_FMT_RGB24, PIX_FMT_BGR24,
PIX_FMT_NONE
};
avfilter_set_common_formats(ctx, avfilter_make_format_list(pix_fmts));
return 0;
}
static int config_props(AVFilterLink *inlink)
{
FadeContext *fade = inlink->dst->priv;
const AVPixFmtDescriptor *pixdesc = &av_pix_fmt_descriptors[inlink->format];
fade->hsub = pixdesc->log2_chroma_w;
fade->vsub = pixdesc->log2_chroma_h;
fade->bpp = av_get_bits_per_pixel(pixdesc) >> 3;
return 0;
}
static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
{
FadeContext *fade = inlink->dst->priv;
AVFilterBufferRef *outpic = inlink->cur_buf;
uint8_t *p;
int i, j, plane;
if (fade->factor < UINT16_MAX) {
/* luma or rgb plane */
for (i = 0; i < h; i++) {
p = outpic->data[0] + (y+i) * outpic->linesize[0];
for (j = 0; j < inlink->w * fade->bpp; j++) {
/* fade->factor is using 16 lower-order bits for decimal
* places. 32768 = 1 << 15, it is an integer representation
* of 0.5 and is for rounding. */
*p = (*p * fade->factor + 32768) >> 16;
p++;
}
}
if (outpic->data[1] && outpic->data[2]) {
/* chroma planes */
for (plane = 1; plane < 3; plane++) {
for (i = 0; i < h; i++) {
p = outpic->data[plane] + ((y+i) >> fade->vsub) * outpic->linesize[plane];
for (j = 0; j < inlink->w >> fade->hsub; j++) {
/* 8421367 = ((128 << 1) + 1) << 15. It is an integer
* representation of 128.5. The .5 is for rounding
* purposes. */
*p = ((*p - 128) * fade->factor + 8421367) >> 16;
p++;
}
}
}
}
}
avfilter_draw_slice(inlink->dst->outputs[0], y, h, slice_dir);
}
static void end_frame(AVFilterLink *inlink)
{
FadeContext *fade = inlink->dst->priv;
avfilter_end_frame(inlink->dst->outputs[0]);
if (fade->frame_index >= fade->start_frame &&
fade->frame_index <= fade->stop_frame)
fade->factor += fade->fade_per_frame;
fade->factor = av_clip_uint16(fade->factor);
fade->frame_index++;
}
AVFilter avfilter_vf_fade = {
.name = "fade",
.description = NULL_IF_CONFIG_SMALL("Fade in/out input video"),
.init = init,
.priv_size = sizeof(FadeContext),
.query_formats = query_formats,
.inputs = (AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_props,
.get_video_buffer = avfilter_null_get_video_buffer,
.start_frame = avfilter_null_start_frame,
.draw_slice = draw_slice,
.end_frame = end_frame,
.min_perms = AV_PERM_READ | AV_PERM_WRITE,
.rej_perms = AV_PERM_PRESERVE, },
{ .name = NULL}},
.outputs = (AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO, },
{ .name = NULL}},
};