[FFmpeg-cvslog] vf_fade: add alpha option and alpha fading support
Mark Himsley
git at videolan.org
Thu Nov 10 01:42:47 CET 2011
ffmpeg | branch: master | Mark Himsley <mark at mdsh.com> | Wed Nov 9 01:35:31 2011 +0100| [8c1fb50d077d5f954784b554489cd9915d876b74] | committer: Stefano Sabatini
vf_fade: add alpha option and alpha fading support
Signed-off-by: Stefano Sabatini <stefasab at gmail.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=8c1fb50d077d5f954784b554489cd9915d876b74
---
doc/filters.texi | 6 ++++
libavfilter/avfilter.h | 2 +-
libavfilter/vf_fade.c | 76 ++++++++++++++++++++++++++++++++++++++++-------
3 files changed, 71 insertions(+), 13 deletions(-)
diff --git a/doc/filters.texi b/doc/filters.texi
index 2741f96..b45df57 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -1166,6 +1166,9 @@ See @var{start_frame}.
@item nb_frames, n
See @var{nb_frames}.
+ at item alpha
+If set to 1, fade only alpha channel, if one exists on the input.
+Default value is 0.
@end table
A few usage examples follow, usable too as test scenarios.
@@ -1181,6 +1184,9 @@ fade=in:0:25, fade=out:975:25
# make first 5 frames black, then fade in from frame 5-24
fade=in:5:20
+
+# fade in alpha over first 25 frames of video
+fade=in:0:25:alpha=1
@end example
@section fieldorder
diff --git a/libavfilter/avfilter.h b/libavfilter/avfilter.h
index a651330..5c60425 100644
--- a/libavfilter/avfilter.h
+++ b/libavfilter/avfilter.h
@@ -30,7 +30,7 @@
#define LIBAVFILTER_VERSION_MAJOR 2
#define LIBAVFILTER_VERSION_MINOR 47
-#define LIBAVFILTER_VERSION_MICRO 1
+#define LIBAVFILTER_VERSION_MICRO 2
#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
LIBAVFILTER_VERSION_MINOR, \
diff --git a/libavfilter/vf_fade.c b/libavfilter/vf_fade.c
index 7252a12..d6f292d 100644
--- a/libavfilter/vf_fade.c
+++ b/libavfilter/vf_fade.c
@@ -33,12 +33,24 @@
#include "drawutils.h"
#include "internal.h"
+#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 factor, fade_per_frame;
unsigned int frame_index, start_frame, stop_frame, nb_frames;
int hsub, vsub, bpp;
unsigned int black_level, black_level_scaled;
+ uint8_t is_packed_rgb;
+ uint8_t rgba_map[4];
+ int alpha;
char *type;
} FadeContext;
@@ -52,6 +64,7 @@ static const AVOption fade_options[] = {
{ "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 },
+ { "alpha", "fade alpha if it is available on the input", OFFSET(alpha), AV_OPT_TYPE_INT, {.dbl = 0 }, 0, 1 },
{NULL},
};
@@ -119,8 +132,8 @@ static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
fade->stop_frame = fade->start_frame + fade->nb_frames;
av_log(ctx, AV_LOG_INFO,
- "type:%s start_frame:%d nb_frames:%d\n",
- fade->type, fade->start_frame, fade->nb_frames);
+ "type:%s start_frame:%d nb_frames:%d alpha:%d\n",
+ fade->type, fade->start_frame, fade->nb_frames, fade->alpha);
end:
av_free(args1);
@@ -141,7 +154,10 @@ static int query_formats(AVFilterContext *ctx)
PIX_FMT_YUV411P, PIX_FMT_YUV410P,
PIX_FMT_YUVJ444P, PIX_FMT_YUVJ422P, PIX_FMT_YUVJ420P,
PIX_FMT_YUV440P, PIX_FMT_YUVJ440P,
+ PIX_FMT_YUVA420P,
PIX_FMT_RGB24, PIX_FMT_BGR24,
+ PIX_FMT_ARGB, PIX_FMT_ABGR,
+ PIX_FMT_RGBA, PIX_FMT_BGRA,
PIX_FMT_NONE
};
@@ -156,6 +172,13 @@ const static enum PixelFormat studio_level_pix_fmts[] = {
PIX_FMT_NONE
};
+static 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_props(AVFilterLink *inlink)
{
FadeContext *fade = inlink->dst->priv;
@@ -165,14 +188,37 @@ static int config_props(AVFilterLink *inlink)
fade->vsub = pixdesc->log2_chroma_h;
fade->bpp = av_get_bits_per_pixel(pixdesc) >> 3;
+ fade->alpha = fade->alpha ? ff_fmt_is_in(inlink->format, alpha_pix_fmts) : 0;
+ fade->is_packed_rgb = ff_fill_rgba_map(fade->rgba_map, inlink->format) >= 0;
- fade->black_level = ff_fmt_is_in(inlink->format, studio_level_pix_fmts) ? 16 : 0;
+ /* CCIR601/709 black level unless input is RGB or has alpha */
+ fade->black_level =
+ ff_fmt_is_in(inlink->format, studio_level_pix_fmts) || fade->alpha ? 0 : 16;
/* 32768 = 1 << 15, it is an integer representation
* of 0.5 and is for rounding. */
fade->black_level_scaled = (fade->black_level << 16) + 32768;
return 0;
}
+static void fade_plane(int y, int h, int w,
+ int fade_factor, int black_level, int black_level_scaled,
+ uint8_t offset, uint8_t step, int bytes_per_plane,
+ uint8_t *data, int line_size)
+{
+ uint8_t *p;
+ int i, j;
+
+ /* luma, alpha or rgb plane */
+ for (i = 0; i < h; i++) {
+ p = data + offset + (y+i) * line_size;
+ for (j = 0; j < w * bytes_per_plane; j++) {
+ /* fade->factor is using 16 lower-order bits for decimal places. */
+ *p = ((*p - black_level) * fade_factor + black_level_scaled) >> 16;
+ p+=step;
+ }
+ }
+}
+
static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
{
FadeContext *fade = inlink->dst->priv;
@@ -181,16 +227,21 @@ static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
int i, j, plane;
if (fade->factor < UINT16_MAX) {
+ if (fade->alpha) {
+ // alpha only
+ plane = fade->is_packed_rgb ? 0 : A; // alpha is on plane 0 for packed formats
+ // or plane 3 for planar formats
+ fade_plane(y, h, inlink->w,
+ fade->factor, fade->black_level, fade->black_level_scaled,
+ fade->is_packed_rgb ? fade->rgba_map[A] : 0, // alpha offset for packed formats
+ fade->is_packed_rgb ? 4 : 1, // pixstep for 8 bit packed formats
+ 1, outpic->data[plane], outpic->linesize[plane]);
+ } else {
/* 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. */
- *p = ((*p - fade->black_level) * fade->factor + fade->black_level_scaled) >> 16;
- p++;
- }
- }
-
+ fade_plane(y, h, inlink->w,
+ fade->factor, fade->black_level, fade->black_level_scaled,
+ 0, 1, // offset & pixstep for Y plane or RGB packed format
+ fade->bpp, outpic->data[0], outpic->linesize[0]);
if (outpic->data[1] && outpic->data[2]) {
/* chroma planes */
for (plane = 1; plane < 3; plane++) {
@@ -206,6 +257,7 @@ static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
}
}
}
+ }
}
avfilter_draw_slice(inlink->dst->outputs[0], y, h, slice_dir);
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