[FFmpeg-devel] [PATCH] avfilter: add panorama filter

Paul B Mahol onemda at gmail.com
Thu Dec 3 23:49:39 CET 2015


Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
 libavfilter/Makefile      |   1 +
 libavfilter/allfilters.c  |   1 +
 libavfilter/vf_panorama.c | 304 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 306 insertions(+)
 create mode 100644 libavfilter/vf_panorama.c

diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 740a640..36ade75 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -192,6 +192,7 @@ OBJS-$(CONFIG_OWDENOISE_FILTER)              += vf_owdenoise.o
 OBJS-$(CONFIG_PAD_FILTER)                    += vf_pad.o
 OBJS-$(CONFIG_PALETTEGEN_FILTER)             += vf_palettegen.o
 OBJS-$(CONFIG_PALETTEUSE_FILTER)             += vf_paletteuse.o dualinput.o framesync.o
+OBJS-$(CONFIG_PANORAMA_FILTER)               += vf_panorama.o
 OBJS-$(CONFIG_PERMS_FILTER)                  += f_perms.o
 OBJS-$(CONFIG_PERSPECTIVE_FILTER)            += vf_perspective.o
 OBJS-$(CONFIG_PHASE_FILTER)                  += vf_phase.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 6557612..c2ea7e5 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -213,6 +213,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(PAD,            pad,            vf);
     REGISTER_FILTER(PALETTEGEN,     palettegen,     vf);
     REGISTER_FILTER(PALETTEUSE,     paletteuse,     vf);
+    REGISTER_FILTER(PANORAMA,       panorama,       vf);
     REGISTER_FILTER(PERMS,          perms,          vf);
     REGISTER_FILTER(PERSPECTIVE,    perspective,    vf);
     REGISTER_FILTER(PHASE,          phase,          vf);
diff --git a/libavfilter/vf_panorama.c b/libavfilter/vf_panorama.c
new file mode 100644
index 0000000..4cc0831
--- /dev/null
+++ b/libavfilter/vf_panorama.c
@@ -0,0 +1,304 @@
+/*
+ * 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/avassert.h"
+#include "libavutil/eval.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/pixdesc.h"
+#include "libavutil/opt.h"
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+
+enum Projections {
+    EQUIRECTANGULAR,
+    CUBIC,
+    NB_PROJECTIONS,
+};
+
+struct XYRemap {
+    int vi, ui;
+    int v2, u2;
+    float a, b, c, d;
+};
+
+typedef struct PanoramaContext {
+    const AVClass *class;
+    int in, out;
+
+    int planewidth[4], planeheight[4];
+    int inplanewidth[4], inplaneheight[4];
+    int nb_planes;
+
+    struct XYRemap *remap[4];
+    int (*panorama)(struct PanoramaContext *s,
+                    const uint8_t *src, uint8_t *dst,
+                    int width, int height,
+                    int in_width, int in_height,
+                    int in_linesize, int out_linesize,
+                    struct XYRemap *remap);
+} PanoramaContext;
+
+#define OFFSET(x) offsetof(PanoramaContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
+
+static const AVOption panorama_options[] = {
+    { "i", "set input projection",  OFFSET(in),  AV_OPT_TYPE_INT, {.i64=EQUIRECTANGULAR}, 0, NB_PROJECTIONS-1, FLAGS },
+    { "o", "set output projection", OFFSET(out), AV_OPT_TYPE_INT, {.i64=CUBIC},           0, NB_PROJECTIONS-1, FLAGS },
+    { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(panorama);
+
+static int query_formats(AVFilterContext *ctx)
+{
+    static const enum AVPixelFormat pix_fmts[] = {
+        AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA420P,
+        AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVJ422P,AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ411P,
+        AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P,
+        AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRAP, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE
+    };
+
+    AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
+    if (!fmts_list)
+        return AVERROR(ENOMEM);
+    return ff_set_common_formats(ctx, fmts_list);
+}
+
+static void to_xyz(int i, int j, int face, float edge, float *x, float *y, float *z)
+{
+    float a = 2.0 * i / edge;
+    float b = 2.0 * j / edge;
+
+    if (face == 0) { // back
+        *x = -1.0;
+        *y = 1.0 - a;
+        *z = 3.0 - b;
+    } else if (face == 1) { // left
+        *x = a - 3.0;
+        *y = -1.0;
+        *z = 3.0 - b;
+    } else if (face == 2) { // front
+        *x = 1.0;
+        *y = a - 5.0;
+        *z = 3.0 - b;
+    } else if (face == 3) { // right
+        *x = 7.0 - a;
+        *y = 1.0;
+        *z = 3.0 - b;
+    } else if (face == 4) { // top
+        *x = b - 1.0;
+        *y = a - 5.0;
+        *z = 1.0;
+    } else if (face == 5) { // bottom
+        *x = 5.0 - b;
+        *y = a - 5.0;
+        *z = -1.0;
+    }
+}
+
+static int config_output(AVFilterLink *outlink)
+{
+    AVFilterContext *ctx = outlink->src;
+    AVFilterLink *inlink = ctx->inputs[0];
+    PanoramaContext *s = ctx->priv;
+    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
+    int p;
+
+    if (s->in == EQUIRECTANGULAR && s->out == CUBIC) {
+        int w = inlink->w;
+        int h = inlink->w * 3 / 4;
+
+        s->planeheight[1] = s->planeheight[2] = FF_CEIL_RSHIFT(h, desc->log2_chroma_h);
+        s->planeheight[0] = s->planeheight[3] = h;
+        s->planewidth[1] = s->planewidth[2] = FF_CEIL_RSHIFT(w, desc->log2_chroma_w);
+        s->planewidth[0] = s->planewidth[3] = w;
+        outlink->h = h;
+        outlink->w = w;
+    } else {
+        av_assert0(0);
+    }
+
+    s->inplaneheight[1] = s->inplaneheight[2] = FF_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h);
+    s->inplaneheight[0] = s->inplaneheight[3] = inlink->h;
+    s->inplanewidth[1]  = s->inplanewidth[2]  = FF_CEIL_RSHIFT(inlink->w, desc->log2_chroma_w);
+    s->inplanewidth[0]  = s->inplanewidth[3]  = inlink->w;
+    s->nb_planes = av_pix_fmt_count_planes(inlink->format);
+
+    for (p = 0; p < s->nb_planes; p++)
+        s->remap[p] = av_calloc(s->planewidth[p] * s->planeheight[p], sizeof(struct XYRemap));
+
+    for (p = 0; p < s->nb_planes; p++) {
+        int face, face2, start, end, ui, vi, u2, v2;
+        float theta, R, phi, uf, vf, mu, nu, x, y, z;
+        int edge = s->planewidth[p] / 4;
+        int width = s->planewidth[p];
+        int in_width = s->inplanewidth[p];
+        int in_height = s->inplaneheight[p];
+        int i, j;
+
+        for (i = 0; i < width; i++) {
+            face = i / edge; // 0 - back, 1 - left 2 - front, 3 - right
+            if (face == 2) {
+                start = 0;
+                end = edge * 3;
+            } else {
+                start = edge;
+                end = edge * 2;
+            }
+
+            for (j = start; j < end; j++) {
+                struct XYRemap *r = &s->remap[p][j * width + i];
+
+                if (j < edge)
+                    face2 = 4; // top
+                else if (j >= 2 * edge)
+                    face2 = 5; // bottom
+                else
+                    face2 = face;
+
+                to_xyz(i, j, face2, edge, &x, &y, &z);
+                theta = atan2(y, x);
+                R = hypot(x , y);
+                phi = atan2(z , R);
+                uf = (2.0 * edge * (theta + M_PI) / M_PI);
+                vf = (2.0 * edge * (M_PI/2 - phi) / M_PI);
+
+                ui = floor(uf);  // coord of pixel to bottom left
+                vi = floor(vf);
+                u2 = ui + 1;     // coords of pixel to top right
+                v2 = vi + 1;
+                mu = uf - ui;    // fraction of way across pixel
+                nu = vf - vi;
+                r->vi = av_clip(vi, 0, in_height - 1);
+                r->ui = ui % in_width;
+                r->v2 = av_clip(v2, 0, in_height - 1);
+                r->u2 = u2 % in_width;
+                r->a = (1-mu)*(1-nu);
+                r->b = (mu)*(1-nu);
+                r->c = (1-mu)*nu;
+                r->d = mu*nu;
+            }
+        }
+    }
+
+    return 0;
+}
+
+static int erect2cubic(PanoramaContext *s,
+                       const uint8_t *src, uint8_t *dst,
+                       int width, int height,
+                       int in_width, int in_height,
+                       int in_linesize, int out_linesize,
+                       struct XYRemap *remap)
+{
+    int i, j, edge = width / 4;   // the length of each edge in pixels
+    int face, start, end;
+    float A, B, C, D;
+
+    for (i = 0; i < width; i++) {
+        face = i / edge; // 0 - back, 1 - left 2 - front, 3 - right
+        if (face == 2) {
+            start = 0;
+            end = edge * 3;
+        } else {
+            start = edge;
+            end = edge * 2;
+        }
+
+        for (j = start; j < end; j++) {
+            struct XYRemap *r = &remap[j * width + i];
+            A = src[r->vi * in_linesize + r->ui];
+            B = src[r->vi * in_linesize + r->u2];
+            C = src[r->v2 * in_linesize + r->ui];
+            D = src[r->v2 * in_linesize + r->u2];
+            dst[j * out_linesize + i] = A * r->a + B * r->b + C * r->c + D * r->d;
+        }
+    }
+    return 0;
+}
+
+static av_cold int init(AVFilterContext *ctx)
+{
+    PanoramaContext *s = ctx->priv;
+
+    if (s->in == EQUIRECTANGULAR && s->out == CUBIC) {
+        s->panorama = erect2cubic;
+    } else {
+        av_log(ctx, AV_LOG_ERROR, "Unsupported input and output combination!\n");
+    }
+
+    return 0;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+    AVFilterContext *ctx = inlink->dst;
+    AVFilterLink *outlink = ctx->outputs[0];
+    PanoramaContext *s = ctx->priv;
+    AVFrame *out;
+    int plane;
+
+    out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+    if (!out) {
+        av_frame_free(&in);
+        return AVERROR(ENOMEM);
+    }
+    av_frame_copy_props(out, in);
+
+    for (plane = 0; plane < s->nb_planes; plane++) {
+        s->panorama(s, in->data[plane], out->data[plane],
+                    s->planewidth[plane], s->planeheight[plane],
+                    s->inplanewidth[plane], s->inplaneheight[plane],
+                    in->linesize[plane], out->linesize[plane],
+                    s->remap[plane]);
+    }
+
+    av_frame_free(&in);
+    return ff_filter_frame(outlink, out);
+}
+
+static const AVFilterPad inputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .filter_frame = filter_frame,
+    },
+    { NULL }
+};
+
+static const AVFilterPad outputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .config_props = config_output,
+    },
+    { NULL }
+};
+
+AVFilter ff_vf_panorama = {
+    .name          = "panorama",
+    .description   = NULL_IF_CONFIG_SMALL("Convert panorama projection of video."),
+    .priv_size     = sizeof(PanoramaContext),
+    .init          = init,
+    .query_formats = query_formats,
+    .inputs        = inputs,
+    .outputs       = outputs,
+    .priv_class    = &panorama_class,
+};
-- 
1.9.1



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