[FFmpeg-cvslog] lavfi: add alphaextract and alphamerge filters
Steven Robertson
git at videolan.org
Sun Jul 22 12:20:55 CEST 2012
ffmpeg | branch: master | Steven Robertson <steven at strobe.cc> | Tue Jul 10 22:14:57 2012 -0700| [82ecae8a7069104698d491000b37629cd8d96fd8] | committer: Stefano Sabatini
lavfi: add alphaextract and alphamerge filters
These filters are designed for storing and transmitting video sequences
with alpha using higher-efficiency codecs such as x264 which don't
natively support an alpha channel. 'alphaextract' takes an input stream
with an alpha channel and returns a video containing just the alpha
component as a grayscale value; 'alphamerge' takes an RGB or YUV stream
and adds an alpha channel recovered from a second grayscale stream.
Signed-off-by: Steven Robertson <steven at strobe.cc>
Signed-off-by: Stefano Sabatini <stefasab at gmail.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=82ecae8a7069104698d491000b37629cd8d96fd8
---
Changelog | 1 +
doc/filters.texi | 25 +++++
libavfilter/Makefile | 2 +
libavfilter/allfilters.c | 2 +
libavfilter/version.h | 2 +-
libavfilter/vf_alphaextract.c | 117 +++++++++++++++++++++
libavfilter/vf_alphamerge.c | 212 ++++++++++++++++++++++++++++++++++++++
tests/lavfi-regression.sh | 15 ++-
tests/ref/lavfi/alphaextract_rgb | 1 +
tests/ref/lavfi/alphaextract_yuv | 1 +
tests/ref/lavfi/alphamerge_rgb | 1 +
tests/ref/lavfi/alphamerge_yuv | 1 +
12 files changed, 376 insertions(+), 4 deletions(-)
diff --git a/Changelog b/Changelog
index ab8e704..44e647f 100644
--- a/Changelog
+++ b/Changelog
@@ -34,6 +34,7 @@ version next:
- ffmpeg -(no)stdin option
- Opus decoder using libopus
- caca output device using libcaca
+- alphaextract and alphamerge filters
version 0.11:
diff --git a/doc/filters.texi b/doc/filters.texi
index 4a6c092..2b5cc87 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -1101,6 +1101,31 @@ build.
Below is a description of the currently available video filters.
+ at section alphaextract
+
+Extract the alpha component from the input as a grayscale video. This
+is especially useful with the @var{alphamerge} filter.
+
+ at section alphamerge
+
+Add or replace the alpha component of the primary input with the
+grayscale value of a second input. This is intended for use with
+ at var{alphaextract} to allow the transmission or storage of frame
+sequences that have alpha in a format that doesn't support an alpha
+channel.
+
+For example, to reconstruct full frames from a normal YUV-encoded video
+and a separate video created with @var{alphaextract}, you might use:
+ at example
+movie=in_alpha.mkv [alpha]; [in][alpha] alphamerge [out]
+ at end example
+
+Since this filter is designed for reconstruction, it operates on frame
+sequences without considering timestamps, and terminates when either
+input reaches end of stream. This will cause problems if your encoding
+pipeline drops frames. If you're trying to apply an image as an
+overlay to a video stream, consider the @var{overlay} filter instead.
+
@section ass
Draw ASS (Advanced Substation Alpha) subtitles on top of input video
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index b094f59..a177752 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -76,6 +76,8 @@ OBJS-$(CONFIG_ABUFFERSINK_FILTER) += sink_buffer.o
OBJS-$(CONFIG_ANULLSINK_FILTER) += asink_anullsink.o
OBJS-$(CONFIG_ASS_FILTER) += vf_ass.o
+OBJS-$(CONFIG_ALPHAEXTRACT_FILTER) += vf_alphaextract.o
+OBJS-$(CONFIG_ALPHAMERGE_FILTER) += vf_alphamerge.o
OBJS-$(CONFIG_BBOX_FILTER) += bbox.o vf_bbox.o
OBJS-$(CONFIG_BLACKDETECT_FILTER) += vf_blackdetect.o
OBJS-$(CONFIG_BLACKFRAME_FILTER) += vf_blackframe.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 706405e..aad4534 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -64,6 +64,8 @@ void avfilter_register_all(void)
REGISTER_FILTER (ABUFFERSINK, abuffersink, asink);
REGISTER_FILTER (ANULLSINK, anullsink, asink);
+ REGISTER_FILTER (ALPHAEXTRACT, alphaextract, vf);
+ REGISTER_FILTER (ALPHAMERGE, alphamerge, vf);
REGISTER_FILTER (ASS, ass, vf);
REGISTER_FILTER (BBOX, bbox, vf);
REGISTER_FILTER (BLACKDETECT, blackdetect, vf);
diff --git a/libavfilter/version.h b/libavfilter/version.h
index ea95cf3..96af8d6 100644
--- a/libavfilter/version.h
+++ b/libavfilter/version.h
@@ -29,7 +29,7 @@
#include "libavutil/avutil.h"
#define LIBAVFILTER_VERSION_MAJOR 3
-#define LIBAVFILTER_VERSION_MINOR 2
+#define LIBAVFILTER_VERSION_MINOR 3
#define LIBAVFILTER_VERSION_MICRO 100
#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
diff --git a/libavfilter/vf_alphaextract.c b/libavfilter/vf_alphaextract.c
new file mode 100644
index 0000000..06cbb71
--- /dev/null
+++ b/libavfilter/vf_alphaextract.c
@@ -0,0 +1,117 @@
+/*
+ * Copyright (c) 2012 Steven Robertson
+ *
+ * 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
+ * simple channel-swapping filter to get at the alpha component
+ */
+
+#include <string.h>
+
+#include "libavutil/pixfmt.h"
+#include "avfilter.h"
+#include "drawutils.h"
+#include "formats.h"
+#include "video.h"
+
+enum { Y, U, V, A };
+
+typedef struct {
+ int is_packed_rgb;
+ uint8_t rgba_map[4];
+} AlphaExtractContext;
+
+static int query_formats(AVFilterContext *ctx)
+{
+ enum PixelFormat in_fmts[] = {
+ PIX_FMT_YUVA444P, PIX_FMT_YUVA422P, PIX_FMT_YUVA420P,
+ PIX_FMT_RGBA, PIX_FMT_BGRA, PIX_FMT_ARGB, PIX_FMT_ABGR,
+ PIX_FMT_NONE
+ };
+ enum PixelFormat out_fmts[] = { PIX_FMT_GRAY8, PIX_FMT_NONE };
+ ff_formats_ref(ff_make_format_list(in_fmts), &ctx->inputs[0]->out_formats);
+ ff_formats_ref(ff_make_format_list(out_fmts), &ctx->outputs[0]->in_formats);
+ return 0;
+}
+
+static int config_input(AVFilterLink *inlink)
+{
+ AlphaExtractContext *extract = inlink->dst->priv;
+ extract->is_packed_rgb =
+ ff_fill_rgba_map(extract->rgba_map, inlink->format) >= 0;
+ return 0;
+}
+
+static void draw_slice(AVFilterLink *inlink, int y0, int h, int slice_dir)
+{
+ AlphaExtractContext *extract = inlink->dst->priv;
+ AVFilterBufferRef *cur_buf = inlink->cur_buf;
+ AVFilterBufferRef *out_buf = inlink->dst->outputs[0]->out_buf;
+
+ if (extract->is_packed_rgb) {
+ int x, y;
+ uint8_t *pin, *pout;
+ for (y = y0; y < (y0 + h); y++) {
+ pin = cur_buf->data[0] + y * cur_buf->linesize[0] + extract->rgba_map[A];
+ pout = out_buf->data[0] + y * out_buf->linesize[0];
+ for (x = 0; x < out_buf->video->w; x++) {
+ *pout = *pin;
+ pout += 1;
+ pin += 4;
+ }
+ }
+ } else if (cur_buf->linesize[A] == out_buf->linesize[Y]) {
+ const int linesize = cur_buf->linesize[A];
+ memcpy(out_buf->data[Y] + y0 * linesize,
+ cur_buf->data[A] + y0 * linesize,
+ linesize * h);
+ } else {
+ const int linesize = FFMIN(out_buf->linesize[Y], cur_buf->linesize[A]);
+ int y;
+ for (y = y0; y < (y0 + h); y++) {
+ memcpy(out_buf->data[Y] + y * out_buf->linesize[Y],
+ cur_buf->data[A] + y * cur_buf->linesize[A],
+ linesize);
+ }
+ }
+ ff_draw_slice(inlink->dst->outputs[0], y0, h, slice_dir);
+}
+
+AVFilter avfilter_vf_alphaextract = {
+ .name = "alphaextract",
+ .description = NULL_IF_CONFIG_SMALL("Extract an alpha channel as a "
+ "grayscale image component."),
+ .priv_size = sizeof(AlphaExtractContext),
+ .query_formats = query_formats,
+
+ .inputs = (const AVFilterPad[]) {
+ { .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .config_props = config_input,
+ .draw_slice = draw_slice,
+ .min_perms = AV_PERM_READ },
+ { .name = NULL }
+ },
+ .outputs = (const AVFilterPad[]) {
+ { .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO, },
+ { .name = NULL }
+ },
+};
diff --git a/libavfilter/vf_alphamerge.c b/libavfilter/vf_alphamerge.c
new file mode 100644
index 0000000..67422a1
--- /dev/null
+++ b/libavfilter/vf_alphamerge.c
@@ -0,0 +1,212 @@
+/*
+ * Copyright (c) 2012 Steven Robertson
+ *
+ * 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
+ * copy an alpha component from another video's luma
+ */
+
+#include <string.h>
+
+#include "libavutil/pixfmt.h"
+#include "avfilter.h"
+#include "bufferqueue.h"
+#include "drawutils.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+
+enum { Y, U, V, A };
+
+typedef struct {
+ int frame_requested;
+ int is_packed_rgb;
+ uint8_t rgba_map[4];
+ struct FFBufQueue queue_main;
+ struct FFBufQueue queue_alpha;
+} AlphaMergeContext;
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+ AlphaMergeContext *merge = ctx->priv;
+ ff_bufqueue_discard_all(&merge->queue_main);
+ ff_bufqueue_discard_all(&merge->queue_alpha);
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+ enum PixelFormat main_fmts[] = {
+ PIX_FMT_YUVA444P, PIX_FMT_YUVA422P, PIX_FMT_YUVA420P,
+ PIX_FMT_RGBA, PIX_FMT_BGRA, PIX_FMT_ARGB, PIX_FMT_ABGR,
+ PIX_FMT_NONE
+ };
+ enum PixelFormat alpha_fmts[] = { PIX_FMT_GRAY8, PIX_FMT_NONE };
+ AVFilterFormats *main_formats = ff_make_format_list(main_fmts);
+ AVFilterFormats *alpha_formats = ff_make_format_list(alpha_fmts);
+ ff_formats_ref(main_formats, &ctx->inputs[0]->out_formats);
+ ff_formats_ref(alpha_formats, &ctx->inputs[1]->out_formats);
+ ff_formats_ref(main_formats, &ctx->outputs[0]->in_formats);
+ return 0;
+}
+
+static int config_input_main(AVFilterLink *inlink)
+{
+ AlphaMergeContext *merge = inlink->dst->priv;
+ merge->is_packed_rgb =
+ ff_fill_rgba_map(merge->rgba_map, inlink->format) >= 0;
+ return 0;
+}
+
+static int config_output(AVFilterLink *outlink)
+{
+ AVFilterContext *ctx = outlink->src;
+ AVFilterLink *mainlink = ctx->inputs[0];
+ AVFilterLink *alphalink = ctx->inputs[1];
+ if (mainlink->w != alphalink->w || mainlink->h != alphalink->h) {
+ av_log(ctx, AV_LOG_ERROR,
+ "Input frame sizes do not match (%dx%d vs %dx%d).\n",
+ mainlink->w, mainlink->h,
+ alphalink->w, alphalink->h);
+ return AVERROR(EINVAL);
+ }
+
+ outlink->w = mainlink->w;
+ outlink->h = mainlink->h;
+ outlink->time_base = mainlink->time_base;
+ outlink->sample_aspect_ratio = mainlink->sample_aspect_ratio;
+ outlink->frame_rate = mainlink->frame_rate;
+ return 0;
+}
+
+static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *picref) {}
+static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir) {}
+
+static void draw_frame(AVFilterContext *ctx,
+ AVFilterBufferRef *main_buf,
+ AVFilterBufferRef *alpha_buf)
+{
+ AlphaMergeContext *merge = ctx->priv;
+ int h = main_buf->video->h;
+
+ if (merge->is_packed_rgb) {
+ int x, y;
+ uint8_t *pin, *pout;
+ for (y = 0; y < h; y++) {
+ pin = alpha_buf->data[0] + y * alpha_buf->linesize[0];
+ pout = main_buf->data[0] + y * main_buf->linesize[0] + merge->rgba_map[A];
+ for (x = 0; x < main_buf->video->w; x++) {
+ *pout = *pin;
+ pin += 1;
+ pout += 4;
+ }
+ }
+ } else {
+ int y;
+ const int main_linesize = main_buf->linesize[A];
+ const int alpha_linesize = alpha_buf->linesize[Y];
+ for (y = 0; y < h && y < alpha_buf->video->h; y++) {
+ memcpy(main_buf->data[A] + y * main_linesize,
+ alpha_buf->data[Y] + y * alpha_linesize,
+ FFMIN(main_linesize, alpha_linesize));
+ }
+ }
+ ff_draw_slice(ctx->outputs[0], 0, h, 1);
+}
+
+static void end_frame(AVFilterLink *inlink)
+{
+ AVFilterContext *ctx = inlink->dst;
+ AlphaMergeContext *merge = ctx->priv;
+
+ int is_alpha = (inlink == ctx->inputs[1]);
+ struct FFBufQueue *queue =
+ (is_alpha ? &merge->queue_alpha : &merge->queue_main);
+ ff_bufqueue_add(ctx, queue, inlink->cur_buf);
+ inlink->cur_buf = NULL;
+
+ while (1) {
+ AVFilterBufferRef *main_buf, *alpha_buf;
+
+ if (!ff_bufqueue_peek(&merge->queue_main, 0) ||
+ !ff_bufqueue_peek(&merge->queue_alpha, 0)) break;
+
+ main_buf = ff_bufqueue_get(&merge->queue_main);
+ alpha_buf = ff_bufqueue_get(&merge->queue_alpha);
+
+ ctx->outputs[0]->out_buf = main_buf;
+ ff_start_frame(ctx->outputs[0], avfilter_ref_buffer(main_buf, ~0));
+ merge->frame_requested = 0;
+ draw_frame(ctx, main_buf, alpha_buf);
+ ff_end_frame(ctx->outputs[0]);
+ avfilter_unref_buffer(alpha_buf);
+ }
+}
+
+static int request_frame(AVFilterLink *outlink)
+{
+ AVFilterContext *ctx = outlink->src;
+ AlphaMergeContext *merge = ctx->priv;
+ int in, ret;
+
+ merge->frame_requested = 1;
+ while (merge->frame_requested) {
+ in = ff_bufqueue_peek(&merge->queue_main, 0) ? 0 : 1;
+ ret = ff_request_frame(ctx->inputs[in]);
+ if (ret < 0)
+ return ret;
+ }
+ return 0;
+}
+
+AVFilter avfilter_vf_alphamerge = {
+ .name = "alphamerge",
+ .description = NULL_IF_CONFIG_SMALL("Copy the luma value of the second "
+ "input into the alpha channel of the first input."),
+ .uninit = uninit,
+ .priv_size = sizeof(AlphaMergeContext),
+ .query_formats = query_formats,
+
+ .inputs = (const AVFilterPad[]) {
+ { .name = "main",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .config_props = config_input_main,
+ .get_video_buffer = ff_null_get_video_buffer,
+ .start_frame = start_frame,
+ .draw_slice = draw_slice,
+ .end_frame = end_frame,
+ .min_perms = AV_PERM_READ | AV_PERM_WRITE,
+ .rej_perms = AV_PERM_REUSE2 | AV_PERM_PRESERVE },
+ { .name = "alpha",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .start_frame = start_frame,
+ .draw_slice = draw_slice,
+ .end_frame = end_frame,
+ .min_perms = AV_PERM_READ,
+ .rej_perms = AV_PERM_REUSE2 },
+ { .name = NULL }
+ },
+ .outputs = (const AVFilterPad[]) {
+ { .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .config_props = config_output,
+ .request_frame = request_frame },
+ { .name = NULL }
+ },
+};
diff --git a/tests/lavfi-regression.sh b/tests/lavfi-regression.sh
index dd5e2da..6104044 100755
--- a/tests/lavfi-regression.sh
+++ b/tests/lavfi-regression.sh
@@ -13,21 +13,25 @@ eval do_$test=y
do_video_filter() {
label=$1
- filters=$2
+ filters="$2"
shift 2
printf '%-20s' $label
run_avconv $DEC_OPTS -f image2 -vcodec pgmyuv -i $raw_src \
$ENC_OPTS -vf "$filters" -vcodec rawvideo $* -f nut md5:
}
-do_lavfi() {
- vfilters="slicify=random,$2"
+do_lavfi_plain() {
+ vfilters="$2"
if [ $test = $1 ] ; then
do_video_filter $test "$vfilters"
fi
}
+do_lavfi() {
+ do_lavfi_plain $1 "slicify=random,$2"
+}
+
do_lavfi_colormatrix() {
do_lavfi "${1}1" "$1=$4:$5,$1=$5:$3,$1=$3:$4,$1=$4:$3,$1=$3:$5,$1=$5:$2"
do_lavfi "${1}2" "$1=$2:$3,$1=$3:$2,$1=$2:$4,$1=$4:$2,$1=$2:$5,$1=$5:$4"
@@ -60,6 +64,11 @@ do_lavfi "vflip" "vflip"
do_lavfi "vflip_crop" "vflip,crop=iw-100:ih-100:100:100"
do_lavfi "vflip_vflip" "vflip,vflip"
+do_lavfi_plain "alphamerge_rgb" "[in]slicify=random,format=bgra,split,alphamerge[out]"
+do_lavfi_plain "alphamerge_yuv" "[in]slicify=random,format=yuv420p,split,alphamerge[out]"
+do_lavfi_plain "alphaextract_rgb" "[in]slicify=random,format=bgra,split,alphamerge,slicify=random,split[o3][o4];[o4]alphaextract[alpha];[o3][alpha]alphamerge[out]"
+do_lavfi_plain "alphaextract_yuv" "[in]slicify=random,format=yuv420p,split,alphamerge,slicify=random,split[o3][o4];[o4]alphaextract[alpha];[o3][alpha]alphamerge[out]"
+
do_lavfi_colormatrix "colormatrix" bt709 fcc bt601 smpte240m
do_lavfi_pixfmts(){
diff --git a/tests/ref/lavfi/alphaextract_rgb b/tests/ref/lavfi/alphaextract_rgb
new file mode 100644
index 0000000..3b86986
--- /dev/null
+++ b/tests/ref/lavfi/alphaextract_rgb
@@ -0,0 +1 @@
+alphaextract_rgb b706818ea0d324e0d43adbaef9ab3470
diff --git a/tests/ref/lavfi/alphaextract_yuv b/tests/ref/lavfi/alphaextract_yuv
new file mode 100644
index 0000000..7bfcf86
--- /dev/null
+++ b/tests/ref/lavfi/alphaextract_yuv
@@ -0,0 +1 @@
+alphaextract_yuv 430b779a379ad9c38f3b4c190f723cd4
diff --git a/tests/ref/lavfi/alphamerge_rgb b/tests/ref/lavfi/alphamerge_rgb
new file mode 100644
index 0000000..6dc3b9a
--- /dev/null
+++ b/tests/ref/lavfi/alphamerge_rgb
@@ -0,0 +1 @@
+alphamerge_rgb b706818ea0d324e0d43adbaef9ab3470
diff --git a/tests/ref/lavfi/alphamerge_yuv b/tests/ref/lavfi/alphamerge_yuv
new file mode 100644
index 0000000..ecd7bf8
--- /dev/null
+++ b/tests/ref/lavfi/alphamerge_yuv
@@ -0,0 +1 @@
+alphamerge_yuv 430b779a379ad9c38f3b4c190f723cd4
More information about the ffmpeg-cvslog
mailing list