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vf_fade: add support to options parsing

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Extend fade syntax, required by a pending patch.

Signed-off-by: Stefano Sabatini <stefasab@gmail.com>
pull/2/head
Mark Himsley 13 years ago committed by Stefano Sabatini
parent dea8f6e18b
commit 0d602615ab
3 changed files with 101 additions and 19 deletions
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  1. 18
      doc/filters.texi
  2. 2
      libavfilter/avfilter.h
  3. 100
      libavfilter/vf_fade.c

18
doc/filters.texi
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@ -1139,7 +1139,7 @@ For more information about libfreetype, check:
Apply fade-in/out effect to input video.
It accepts the parameters:
@var{type}:@var{start_frame}:@var{nb_frames}
@var{type}:@var{start_frame}:@var{nb_frames}[:@var{options}]
@var{type} specifies if the effect type, can be either "in" for
fade-in, or "out" for a fade-out effect.
@ -1152,6 +1152,22 @@ effect has to last. At the end of the fade-in effect the output video
will have the same intensity as the input video, at the end of the
fade-out transition the output video will be completely black.
@var{options} is an optional sequence of @var{key}=@var{value} pairs,
separated by ":". The description of the accepted options follows.
@table @option
@item type, t
See @var{type}.
@item start_frame, s
See @var{start_frame}.
@item nb_frames, n
See @var{nb_frames}.
@end table
A few usage examples follow, usable too as test scenarios.
@example
# fade in first 30 frames of video

2
libavfilter/avfilter.h
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@ -30,7 +30,7 @@
#define LIBAVFILTER_VERSION_MAJOR 2
#define LIBAVFILTER_VERSION_MINOR 47
#define LIBAVFILTER_VERSION_MICRO 0
#define LIBAVFILTER_VERSION_MICRO 1
#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
LIBAVFILTER_VERSION_MINOR, \

100
libavfilter/vf_fade.c
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@ -25,48 +25,113 @@
* based heavily on vf_negate.c by Bobby Bingham
*/
#include "libavutil/avstring.h"
#include "libavutil/eval.h"
#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"
#include "avfilter.h"
#include "drawutils.h"
#include "internal.h"
typedef struct {
const AVClass *class;
int factor, fade_per_frame;
unsigned int frame_index, start_frame, stop_frame;
unsigned int frame_index, start_frame, stop_frame, nb_frames;
int hsub, vsub, bpp;
unsigned int black_level, black_level_scaled;
char *type;
} FadeContext;
#define OFFSET(x) offsetof(FadeContext, x)
static const AVOption fade_options[] = {
{ "type", "set the fade direction", OFFSET(type), AV_OPT_TYPE_STRING, {.str = "in" }, CHAR_MIN, CHAR_MAX },
{ "t", "set the fade direction", OFFSET(type), AV_OPT_TYPE_STRING, {.str = "in" }, CHAR_MIN, CHAR_MAX },
{ "start_frame", "set expression of frame to start fading", OFFSET(start_frame), AV_OPT_TYPE_INT, {.dbl = 0 }, 0, INT_MAX },
{ "s", "set expression of frame to start fading", OFFSET(start_frame), AV_OPT_TYPE_INT, {.dbl = 0 }, 0, INT_MAX },
{ "nb_frames", "set expression for fade duration in frames", OFFSET(nb_frames), AV_OPT_TYPE_INT, {.dbl = 25 }, 0, INT_MAX },
{ "n", "set expression for fade duration in frames", OFFSET(nb_frames), AV_OPT_TYPE_INT, {.dbl = 25 }, 0, INT_MAX },
{NULL},
};
static const char *fade_get_name(void *ctx)
{
return "fade";
}
static const AVClass fade_class = {
"FadeContext",
fade_get_name,
fade_options
};
static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
{
FadeContext *fade = ctx->priv;
unsigned int nb_frames;
char in_out[4];
int ret = 0;
char *args1, *expr, *bufptr = NULL;
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);
fade->class = &fade_class;
av_opt_set_defaults(fade);
if (!(args1 = av_strdup(args))) {
ret = AVERROR(ENOMEM);
goto end;
}
if (expr = av_strtok(args1, ":", &bufptr)) {
if (!(fade->type = av_strdup(expr))) {
ret = AVERROR(ENOMEM);
goto end;
}
}
if (expr = av_strtok(NULL, ":", &bufptr)) {
if ((ret = av_opt_set(fade, "start_frame", expr, 0)) < 0) {
av_log(ctx, AV_LOG_ERROR,
"Invalid value '%s' for start_frame option\n", expr);
return ret;
}
}
if (expr = av_strtok(NULL, ":", &bufptr)) {
if ((ret = av_opt_set(fade, "nb_frames", expr, 0)) < 0) {
av_log(ctx, AV_LOG_ERROR,
"Invalid value '%s' for nb_frames option\n", expr);
return ret;
}
}
if (bufptr && (ret = av_set_options_string(fade, bufptr, "=", ":")) < 0)
goto end;
nb_frames = nb_frames ? nb_frames : 1;
fade->fade_per_frame = (1 << 16) / nb_frames;
if (!strcmp(in_out, "in"))
fade->fade_per_frame = (1 << 16) / fade->nb_frames;
if (!strcmp(fade->type, "in"))
fade->factor = 0;
else if (!strcmp(in_out, "out")) {
else if (!strcmp(fade->type, "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);
"Type argument must be 'in' or 'out' but '%s' was specified\n", fade->type);
ret = AVERROR(EINVAL);
goto end;
}
fade->stop_frame = fade->start_frame + nb_frames;
fade->stop_frame = fade->start_frame + fade->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;
fade->type, fade->start_frame, fade->nb_frames);
end:
av_free(args1);
return ret;
}
static av_cold void uninit(AVFilterContext *ctx)
{
FadeContext *fade = ctx->priv;
av_freep(&fade->type);
}
static int query_formats(AVFilterContext *ctx)
@ -163,6 +228,7 @@ AVFilter avfilter_vf_fade = {
.name = "fade",
.description = NULL_IF_CONFIG_SMALL("Fade in/out input video"),
.init = init,
.uninit = uninit,
.priv_size = sizeof(FadeContext),
.query_formats = query_formats,

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