avfilter: add hstack & vstack filter

Signed-off-by: Paul B Mahol <onemda@gmail.com>

6 files changed, 308 insertions, 1 deletions

diff --git a/Changelog b/Changelog
index d1fea74e29..73a23ab2cc 100644
--- a/Changelog
+++ b/Changelog
@@ -34,6 +34,7 @@ version <next>:
 - showfreqs filter
 - vectorscope filter
 - waveform filter
+- hstack and vstack filter
 
 
 version 2.7:
diff --git a/doc/filters.texi b/doc/filters.texi
index 2f7b0fa913..178252f12d 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -6589,6 +6589,21 @@ Set the scaling dimension: @code{2} for @code{hq2x}, @code{3} for
 Default is @code{3}.
 @end table
 
+@section hstack
+Stack input videos horizontally.
+
+All streams must be of same pixel format and of same height.
+
+Note that this filter is faster than using @ref{overlay} and @ref{pad} filter
+to create same output.
+
+The filter accept the following option:
+
+@table @option
+@item nb_inputs
+Set number of input streams. Default is 2.
+@end table
+
 @section hue
 
 Modify the hue and/or the saturation of the input.
@@ -7736,6 +7751,7 @@ Set chroma strength.
 Must be a double value in the range 0-1000, default is @code{1.0}.
 @end table
 
+@anchor{pad}
 @section pad
 
 Add paddings to the input image, and place the original input at the
@@ -10892,6 +10908,21 @@ vignette='PI/4+random(1)*PI/50':eval=frame
 
 @end itemize
 
+@section vstack
+Stack input videos vertically.
+
+All streams must be of same pixel format and of same width.
+
+Note that this filter is faster than using @ref{overlay} and @ref{pad} filter
+to create same output.
+
+The filter accept the following option:
+
+@table @option
+@item nb_inputs
+Set number of input streams. Default is 2.
+@end table
+
 @section w3fdif
 
 Deinterlace the input video ("w3fdif" stands for "Weston 3 Field
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index aa34d8b368..58f990a925 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -153,6 +153,7 @@ OBJS-$(CONFIG_HISTEQ_FILTER)                 += vf_histeq.o
 OBJS-$(CONFIG_HISTOGRAM_FILTER)              += vf_histogram.o
 OBJS-$(CONFIG_HQDN3D_FILTER)                 += vf_hqdn3d.o
 OBJS-$(CONFIG_HQX_FILTER)                    += vf_hqx.o
+OBJS-$(CONFIG_HSTACK_FILTER)                 += vf_stack.o framesync.o
 OBJS-$(CONFIG_HUE_FILTER)                    += vf_hue.o
 OBJS-$(CONFIG_IDET_FILTER)                   += vf_idet.o
 OBJS-$(CONFIG_IL_FILTER)                     += vf_il.o
@@ -231,6 +232,7 @@ OBJS-$(CONFIG_VFLIP_FILTER)                  += vf_vflip.o
 OBJS-$(CONFIG_VIDSTABDETECT_FILTER)          += vidstabutils.o vf_vidstabdetect.o
 OBJS-$(CONFIG_VIDSTABTRANSFORM_FILTER)       += vidstabutils.o vf_vidstabtransform.o
 OBJS-$(CONFIG_VIGNETTE_FILTER)               += vf_vignette.o
+OBJS-$(CONFIG_VSTACK_FILTER)                 += vf_stack.o framesync.o
 OBJS-$(CONFIG_W3FDIF_FILTER)                 += vf_w3fdif.o
 OBJS-$(CONFIG_WAVEFORM_FILTER)               += vf_waveform.o
 OBJS-$(CONFIG_XBR_FILTER)                    += vf_xbr.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 353a1dc2bb..0a1bdfdf46 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -169,6 +169,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(HISTOGRAM,      histogram,      vf);
     REGISTER_FILTER(HQDN3D,         hqdn3d,         vf);
     REGISTER_FILTER(HQX,            hqx,            vf);
+    REGISTER_FILTER(HSTACK,         hstack,         vf);
     REGISTER_FILTER(HUE,            hue,            vf);
     REGISTER_FILTER(IDET,           idet,           vf);
     REGISTER_FILTER(IL,             il,             vf);
@@ -246,6 +247,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(VIDSTABDETECT,  vidstabdetect,  vf);
     REGISTER_FILTER(VIDSTABTRANSFORM, vidstabtransform, vf);
     REGISTER_FILTER(VIGNETTE,       vignette,       vf);
+    REGISTER_FILTER(VSTACK,         vstack,         vf);
     REGISTER_FILTER(W3FDIF,         w3fdif,         vf);
     REGISTER_FILTER(WAVEFORM,       waveform,       vf);
     REGISTER_FILTER(XBR,            xbr,            vf);
diff --git a/libavfilter/version.h b/libavfilter/version.h
index 5572b1c7a0..6b836d394d 100644
--- a/libavfilter/version.h
+++ b/libavfilter/version.h
@@ -30,7 +30,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  5
-#define LIBAVFILTER_VERSION_MINOR  37
+#define LIBAVFILTER_VERSION_MINOR  38
 #define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
diff --git a/libavfilter/vf_stack.c b/libavfilter/vf_stack.c
new file mode 100644
index 0000000000..6342e3fbc5
--- /dev/null
+++ b/libavfilter/vf_stack.c
@@ -0,0 +1,271 @@
+/*
+ * Copyright (c) 2015 Paul B. Mahol
+ *
+ * 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
+ */
+
+#include "libavutil/avstring.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/opt.h"
+#include "libavutil/pixdesc.h"
+
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "framesync.h"
+#include "video.h"
+
+typedef struct StackContext {
+    const AVClass *class;
+    const AVPixFmtDescriptor *desc;
+    int nb_inputs;
+    int is_vertical;
+    int nb_planes;
+
+    AVFrame **frames;
+    FFFrameSync fs;
+} StackContext;
+
+static int query_formats(AVFilterContext *ctx)
+{
+    AVFilterFormats *pix_fmts = NULL;
+    int fmt;
+
+    for (fmt = 0; av_pix_fmt_desc_get(fmt); fmt++) {
+        const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(fmt);
+        if (!(desc->flags & AV_PIX_FMT_FLAG_PAL ||
+              desc->flags & AV_PIX_FMT_FLAG_HWACCEL ||
+              desc->flags & AV_PIX_FMT_FLAG_BITSTREAM))
+            ff_add_format(&pix_fmts, fmt);
+    }
+
+    return ff_set_common_formats(ctx, pix_fmts);
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+    StackContext *s = inlink->dst->priv;
+    return ff_framesync_filter_frame(&s->fs, inlink, in);
+}
+
+static av_cold int init(AVFilterContext *ctx)
+{
+    StackContext *s = ctx->priv;
+    int i, ret;
+
+    if (!strcmp(ctx->filter->name, "vstack"))
+        s->is_vertical = 1;
+
+    s->frames = av_calloc(s->nb_inputs, sizeof(*s->frames));
+    if (!s->frames)
+        return AVERROR(ENOMEM);
+
+    for (i = 0; i < s->nb_inputs; i++) {
+        AVFilterPad pad = { 0 };
+
+        pad.type = AVMEDIA_TYPE_VIDEO;
+        pad.name = av_asprintf("input%d", i);
+        if (!pad.name)
+            return AVERROR(ENOMEM);
+        pad.filter_frame = filter_frame;
+
+        if ((ret = ff_insert_inpad(ctx, i, &pad)) < 0) {
+            av_freep(&pad.name);
+            return ret;
+        }
+    }
+
+    return 0;
+}
+
+static int process_frame(FFFrameSync *fs)
+{
+    AVFilterContext *ctx = fs->parent;
+    AVFilterLink *outlink = ctx->outputs[0];
+    StackContext *s = fs->opaque;
+    AVFrame **in = s->frames;
+    AVFrame *out;
+    int i, p, ret, offset[4] = { 0 };
+
+    for (i = 0; i < s->nb_inputs; i++) {
+        if ((ret = ff_framesync_get_frame(&s->fs, i, &in[i], 0)) < 0)
+            return ret;
+    }
+
+    out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+    if (!out)
+        return AVERROR(ENOMEM);
+    out->pts = av_rescale_q(s->fs.pts, s->fs.time_base, outlink->time_base);
+
+    for (i = 0; i < s->nb_inputs; i++) {
+        AVFilterLink *inlink = ctx->inputs[i];
+        int linesize[4];
+        int height[4];
+
+        if ((ret = av_image_fill_linesizes(linesize, inlink->format, inlink->w)) < 0)
+            return ret;
+
+        height[1] = height[2] = FF_CEIL_RSHIFT(inlink->h, s->desc->log2_chroma_h);
+        height[0] = height[3] = inlink->h;
+
+        for (p = 0; p < s->nb_planes; p++) {
+            if (s->is_vertical) {
+                av_image_copy_plane(out->data[p] + offset[p] * out->linesize[p],
+                                    out->linesize[p],
+                                    in[i]->data[p],
+                                    in[i]->linesize[p],
+                                    linesize[p], height[p]);
+                offset[p] += height[p];
+            } else {
+                av_image_copy_plane(out->data[p] + offset[p],
+                                    out->linesize[p],
+                                    in[i]->data[p],
+                                    in[i]->linesize[p],
+                                    linesize[p], height[p]);
+                offset[p] += linesize[p];
+            }
+        }
+    }
+
+    return ff_filter_frame(outlink, out);
+}
+
+static int config_output(AVFilterLink *outlink)
+{
+    AVFilterContext *ctx = outlink->src;
+    StackContext *s = ctx->priv;
+    AVRational time_base = ctx->inputs[0]->time_base;
+    AVRational frame_rate = ctx->inputs[0]->frame_rate;
+    int height = ctx->inputs[0]->h;
+    int width = ctx->inputs[0]->w;
+    FFFrameSyncIn *in;
+    int i, ret;
+
+    if (s->is_vertical) {
+        for (i = 1; i < s->nb_inputs; i++) {
+            if (ctx->inputs[i]->w != width) {
+                av_log(ctx, AV_LOG_ERROR, "Input %d width %d does not match input %d width %d.\n", i, ctx->inputs[i]->w, 0, width);
+                return AVERROR(EINVAL);
+            }
+            height += ctx->inputs[i]->h;
+        }
+    } else {
+        for (i = 1; i < s->nb_inputs; i++) {
+            if (ctx->inputs[i]->h != height) {
+                av_log(ctx, AV_LOG_ERROR, "Input %d height %d does not match input %d height %d.\n", i, ctx->inputs[i]->h, 0, height);
+                return AVERROR(EINVAL);
+            }
+            width += ctx->inputs[i]->w;
+        }
+    }
+
+    s->desc = av_pix_fmt_desc_get(outlink->format);
+    if (!s->desc)
+        return AVERROR_BUG;
+    s->nb_planes = av_pix_fmt_count_planes(outlink->format);
+
+    outlink->w          = width;
+    outlink->h          = height;
+    outlink->time_base  = time_base;
+    outlink->frame_rate = frame_rate;
+
+    if ((ret = ff_framesync_init(&s->fs, ctx, s->nb_inputs)) < 0)
+        return ret;
+
+    in = s->fs.in;
+    s->fs.opaque = s;
+    s->fs.on_event = process_frame;
+
+    for (i = 0; i < s->nb_inputs; i++) {
+        AVFilterLink *inlink = ctx->inputs[i];
+
+        in[i].time_base = inlink->time_base;
+        in[i].sync   = 1;
+        in[i].before = EXT_STOP;
+        in[i].after  = EXT_INFINITY;
+    }
+
+    return ff_framesync_configure(&s->fs);
+}
+
+static int request_frame(AVFilterLink *outlink)
+{
+    StackContext *s = outlink->src->priv;
+    return ff_framesync_request_frame(&s->fs, outlink);
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    StackContext *s = ctx->priv;
+    ff_framesync_uninit(&s->fs);
+    av_freep(&s->frames);
+}
+
+#define OFFSET(x) offsetof(StackContext, x)
+#define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_FILTERING_PARAM
+static const AVOption stack_options[] = {
+    { "inputs", "set number of inputs", OFFSET(nb_inputs), AV_OPT_TYPE_INT, {.i64=2}, 2, INT_MAX, .flags = FLAGS },
+    { NULL },
+};
+
+static const AVFilterPad outputs[] = {
+    {
+        .name          = "default",
+        .type          = AVMEDIA_TYPE_VIDEO,
+        .config_props  = config_output,
+        .request_frame = request_frame,
+    },
+    { NULL }
+};
+
+#if CONFIG_HSTACK_FILTER
+
+#define hstack_options stack_options
+AVFILTER_DEFINE_CLASS(hstack);
+
+AVFilter ff_vf_hstack = {
+    .name          = "hstack",
+    .description   = NULL_IF_CONFIG_SMALL("Stack video inputs horizontally."),
+    .priv_size     = sizeof(StackContext),
+    .priv_class    = &hstack_class,
+    .query_formats = query_formats,
+    .outputs       = outputs,
+    .init          = init,
+    .uninit        = uninit,
+    .flags         = AVFILTER_FLAG_DYNAMIC_INPUTS,
+};
+
+#endif /* CONFIG_HSTACK_FILTER */
+
+#if CONFIG_VSTACK_FILTER
+
+#define vstack_options stack_options
+AVFILTER_DEFINE_CLASS(vstack);
+
+AVFilter ff_vf_vstack = {
+    .name          = "vstack",
+    .description   = NULL_IF_CONFIG_SMALL("Stack video inputs vertically."),
+    .priv_size     = sizeof(StackContext),
+    .priv_class    = &vstack_class,
+    .query_formats = query_formats,
+    .outputs       = outputs,
+    .init          = init,
+    .uninit        = uninit,
+    .flags         = AVFILTER_FLAG_DYNAMIC_INPUTS,
+};
+
+#endif /* CONFIG_VSTACK_FILTER */