@@ -45,6 +45,7 @@ version <next>:

 - Demuxer for Leitch/Harris' VR native stream format (LXF)

 - RTP depacketization of the X-QT QuickTime format

 - SAP (Session Announcement Protocol, RFC 2974) muxer

+- cropdetect filter

 version 0.6:

@@ -1399,6 +1399,7 @@ udp_protocol_deps="network"

 # filters

 blackframe_filter_deps="gpl"

+cropdetect_filter_deps="gpl"

 frei0r_filter_deps="frei0r dlopen strtok_r"

 ocv_smooth_filter_deps="libopencv"

 yadif_filter_deps="gpl"

@@ -190,6 +190,41 @@ crop=in_w-100:in_h-100:100:100

 "crop=in_w/2:in_h/2:y:10+10*sin(n/10)"

 @end example

+@section cropdetect

+

+Auto-detect crop size.

+

+Calculate necessary cropping parameters and prints the recommended

+parameters through the logging system. The detected dimensions

+correspond to the non-black area of the input video.

+

+It accepts the syntax:

+@example

+cropdetect[=@var{limit}:@var{round}[:@var{reset}]]

+@end example

+

+@table @option

+

+@item limit

+Threshold, which can be optionally specified from nothing (0) to

+everything (255), defaults to 24.

+

+@item round

+Value which the width/height should be divisible by, defaults to

+16. The offset is automatically adjusted to center the video. Use 2 to

+get only even dimensions (needed for 4:2:2 video). 16 is best when

+encoding to most video codecs.

+

+@item reset

+Counter that determines after how many frames cropdetect will reset

+the previously detected largest video area and start over to detect

+the current optimal crop area. Defaults to 0.

+

+This can be useful when channel logos distort the video area. 0

+indicates never reset and return the largest area encountered during

+playback.

+@end table

+

 @section drawbox

 Draw a colored box on the input image.

@@ -23,6 +23,7 @@ OBJS-$(CONFIG_ANULLSINK_FILTER)              += asink_anullsink.o

 OBJS-$(CONFIG_ASPECT_FILTER)                 += vf_aspect.o

 OBJS-$(CONFIG_BLACKFRAME_FILTER)             += vf_blackframe.o

 OBJS-$(CONFIG_CROP_FILTER)                   += vf_crop.o

+OBJS-$(CONFIG_CROPDETECT_FILTER)             += vf_cropdetect.o

 OBJS-$(CONFIG_DRAWBOX_FILTER)                += vf_drawbox.o

 OBJS-$(CONFIG_FIFO_FILTER)                   += vf_fifo.o

 OBJS-$(CONFIG_FORMAT_FILTER)                 += vf_format.o

@@ -43,6 +43,7 @@ void avfilter_register_all(void)

     REGISTER_FILTER (ASPECT,      aspect,      vf);

     REGISTER_FILTER (BLACKFRAME,  blackframe,  vf);

     REGISTER_FILTER (CROP,        crop,        vf);

+    REGISTER_FILTER (CROPDETECT,  cropdetect,  vf);

     REGISTER_FILTER (DRAWBOX,     drawbox,     vf);

     REGISTER_FILTER (FIFO,        fifo,        vf);

     REGISTER_FILTER (FORMAT,      format,      vf);

@@ -25,8 +25,8 @@

 #include "libavutil/avutil.h"

 #define LIBAVFILTER_VERSION_MAJOR  1

-#define LIBAVFILTER_VERSION_MINOR 50

-#define LIBAVFILTER_VERSION_MICRO  1

+#define LIBAVFILTER_VERSION_MINOR 51

+#define LIBAVFILTER_VERSION_MICRO  0

 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \

                                                LIBAVFILTER_VERSION_MINOR, \

new file mode 100644

@@ -0,0 +1,214 @@

+/*

+ * Copyright (C) 2002 A'rpi

+ * This file is part of FFmpeg.

+ *

+ * FFmpeg is free software; you can redistribute it and/or modify

+ * it under the terms of the GNU General Public License as published by

+ * the Free Software Foundation; either version 2 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 General Public License for more details.

+ *

+ * You should have received a copy of the GNU 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

+ * border detection filter

+ * Ported from MPlayer libmpcodecs/vf_cropdetect.c.

+ */

+

+#include "libavcore/imgutils.h"

+#include "avfilter.h"

+

+typedef struct {

+    int x1, y1, x2, y2;

+    int limit;

+    int round;

+    int reset_count;

+    int frame_nb;

+    int max_pixsteps[4];

+} CropDetectContext;

+

+static int query_formats(AVFilterContext *ctx)

+{

+    static const enum PixelFormat pix_fmts[] = {

+        PIX_FMT_YUV420P, PIX_FMT_YUVJ420P,

+        PIX_FMT_YUV422P, PIX_FMT_YUVJ422P,

+        PIX_FMT_YUV444P, PIX_FMT_YUVJ444P,

+        PIX_FMT_YUV411P, PIX_FMT_GRAY8,

+        PIX_FMT_NV12,    PIX_FMT_NV21,

+        PIX_FMT_NONE

+    };

+

+    avfilter_set_common_formats(ctx, avfilter_make_format_list(pix_fmts));

+    return 0;

+}

+

+static int checkline(void *ctx, const unsigned char *src, int stride, int len, int bpp)

+{

+    int total = 0;

+    int div = len;

+

+    switch (bpp) {

+    case 1:

+        while (--len >= 0) {

+            total += src[0];

+            src += stride;

+        }

+        break;

+    case 3:

+    case 4:

+        while (--len >= 0) {

+            total += src[0] + src[1] + src[2];

+            src += stride;

+        }

+        div *= 3;

+        break;

+    }

+    total /= div;

+

+    av_log(ctx, AV_LOG_DEBUG, "total:%d\n", total);

+    return total;

+}

+

+static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)

+{

+    CropDetectContext *cd = ctx->priv;

+

+    cd->limit = 24;

+    cd->round = 0;

+    cd->reset_count = 0;

+    cd->frame_nb = -2;

+

+    if (args)

+        sscanf(args, "%d:%d:%d", &cd->limit, &cd->round, &cd->reset_count);

+

+    av_log(ctx, AV_LOG_INFO, "limit:%d round:%d reset_count:%d\n",

+           cd->limit, cd->round, cd->reset_count);

+

+    return 0;

+}

+

+static int config_input(AVFilterLink *inlink)

+{

+    AVFilterContext *ctx = inlink->dst;

+    CropDetectContext *cd = ctx->priv;

+

+    av_image_fill_max_pixsteps(cd->max_pixsteps, NULL,

+                               &av_pix_fmt_descriptors[inlink->format]);

+

+    cd->x1 = inlink->w - 1;

+    cd->y1 = inlink->h - 1;

+    cd->x2 = 0;

+    cd->y2 = 0;

+

+    return 0;

+}

+

+static void end_frame(AVFilterLink *inlink)

+{

+    AVFilterContext *ctx = inlink->dst;

+    CropDetectContext *cd = ctx->priv;

+    AVFilterBufferRef *picref = inlink->cur_buf;

+    int bpp = cd->max_pixsteps[0];

+    int w, h, x, y, shrink_by;

+

+    // ignore first 2 frames - they may be empty

+    if (++cd->frame_nb > 0) {

+        // Reset the crop area every reset_count frames, if reset_count is > 0

+        if (cd->reset_count > 0 && cd->frame_nb > cd->reset_count) {

+            cd->x1 = picref->video->w-1;

+            cd->y1 = picref->video->h-1;

+            cd->x2 = 0;

+            cd->y2 = 0;

+            cd->frame_nb = 1;

+        }

+

+        for (y = 0; y < cd->y1; y++) {

+            if (checkline(ctx, picref->data[0] + picref->linesize[0] * y, bpp, picref->video->w, bpp) > cd->limit) {

+                cd->y1 = y;

+                break;

+            }

+        }

+

+        for (y = picref->video->h-1; y > cd->y2; y--) {

+            if (checkline(ctx, picref->data[0] + picref->linesize[0] * y, bpp, picref->video->w, bpp) > cd->limit) {

+                cd->y2 = y;

+                break;

+            }

+        }

+

+        for (y = 0; y < cd->x1; y++) {

+            if (checkline(ctx, picref->data[0] + bpp*y, picref->linesize[0], picref->video->h, bpp) > cd->limit) {

+                cd->x1 = y;

+                break;

+            }

+        }

+

+        for (y = picref->video->w-1; y > cd->x2; y--) {

+            if (checkline(ctx, picref->data[0] + bpp*y, picref->linesize[0], picref->video->h, bpp) > cd->limit) {

+                cd->x2 = y;

+                break;

+            }

+        }

+

+        // round x and y (up), important for yuv colorspaces

+        // make sure they stay rounded!

+        x = (cd->x1+1) & ~1;

+        y = (cd->y1+1) & ~1;

+

+        w = cd->x2 - x + 1;

+        h = cd->y2 - y + 1;

+

+        // w and h must be divisible by 2 as well because of yuv

+        // colorspace problems.

+        if (cd->round <= 1)

+            cd->round = 16;

+        if (cd->round % 2)

+            cd->round *= 2;

+

+        shrink_by = w % cd->round;

+        w -= shrink_by;

+        x += (shrink_by/2 + 1) & ~1;

+

+        shrink_by = h % cd->round;

+        h -= shrink_by;

+        y += (shrink_by/2 + 1) & ~1;

+

+        av_log(ctx, AV_LOG_INFO,

+               "x1:%d x2:%d y1:%d y2:%d w:%d h:%d x:%d y:%d pos:%"PRId64" pts:%f crop=%d:%d:%d:%d\n",

+               cd->x1, cd->x2, cd->y1, cd->y2, w, h, x, y, picref->pos,

+               picref->pts == AV_NOPTS_VALUE ? -1 : (double)picref->pts / AV_TIME_BASE,

+               w, h, x, y);

+    }

+

+    avfilter_end_frame(inlink->dst->outputs[0]);

+}

+

+AVFilter avfilter_vf_cropdetect = {

+    .name        = "cropdetect",

+    .description = NULL_IF_CONFIG_SMALL("Auto-detect crop size."),

+

+    .priv_size = sizeof(CropDetectContext),

+    .init      = init,

+

+    .query_formats = query_formats,

+

+    .inputs    = (AVFilterPad[]) {{ .name = "default",

+                                    .type             = AVMEDIA_TYPE_VIDEO,

+                                    .config_props     = config_input,

+                                    .get_video_buffer = avfilter_null_get_video_buffer,

+                                    .start_frame      = avfilter_null_start_frame,

+                                    .end_frame        = end_frame, },

+                                  { .name = NULL}},

+

+    .outputs   = (AVFilterPad[]) {{ .name             = "default",

+                                    .type             = AVMEDIA_TYPE_VIDEO },

+                                  { .name = NULL}},

+};