@@ -11,6 +11,7 @@ version next:

 - ID3v2 attached pictures reading and writing

 - WMA Lossless decoder

 - bluray protocol

+- blackdetect filter

 version 0.10:

@@ -761,6 +761,60 @@ video, use the command:

 ass=sub.ass

 @end example

+@section blackdetect

+

+Detect video intervals that are (almost) completely black. Can be

+useful to detect chapter transitions, commercials, or invalid

+recordings. Output lines contains the time for the start, end and

+duration of the detected black interval expressed in seconds.

+

+In order to display the output lines, you need to set the loglevel at

+least to the AV_LOG_INFO value.

+

+This filter accepts a list of options in the form of

+@var{key}=@var{value} pairs separated by ":". A description of the

+accepted options follows.

+

+@table @option

+@item black_min_duration, d

+Set the minimum detected black duration expressed in seconds. It must

+be a non-negative floating point number.

+

+Default value is 2.0.

+

+@item picture_black_ratio_th, pic_th

+Set the threshold for considering a picture "black".

+Express the minimum value for the ratio:

+@example

+@var{nb_black_pixels} / @var{nb_pixels}

+@end example

+

+for which a picture is considered black.

+Default value is 0.98.

+

+@item pixel_black_th, pix_th

+Set the threshold for considering a pixel "black".

+

+The threshold expresses the maximum pixel luminance value for which a

+pixel is considered "black". The provided value is scaled according to

+the following equation:

+@example

+@var{absolute_threshold} = @var{luminance_minimum_value} + @var{pixel_black_th} * @var{luminance_range_size}

+@end example

+

+@var{luminance_range_size} and @var{luminance_minimum_value} depend on

+the input video format, the range is [0-255] for YUV full-range

+formats and [16-235] for YUV non full-range formats.

+

+Default value is 0.10.

+@end table

+

+The following example sets the maximum pixel threshold to the minimum

+value, and detects only black intervals of 2 or more seconds:

+@example

+blackdetect=d=2:pix_th=0.00

+@end example

+

 @section blackframe

 Detect frames that are (almost) completely black. Can be useful to

@@ -48,6 +48,7 @@ OBJS-$(CONFIG_ABUFFERSINK_FILTER)            += sink_buffer.o

 OBJS-$(CONFIG_ANULLSINK_FILTER)              += asink_anullsink.o

 OBJS-$(CONFIG_ASS_FILTER)                    += vf_ass.o

+OBJS-$(CONFIG_BLACKDETECT_FILTER)            += vf_blackdetect.o

 OBJS-$(CONFIG_BLACKFRAME_FILTER)             += vf_blackframe.o

 OBJS-$(CONFIG_BOXBLUR_FILTER)                += vf_boxblur.o

 OBJS-$(CONFIG_COPY_FILTER)                   += vf_copy.o

@@ -56,6 +56,7 @@ void avfilter_register_all(void)

     REGISTER_FILTER (ANULLSINK,   anullsink,   asink);

     REGISTER_FILTER (ASS,         ass,  vf);

+    REGISTER_FILTER (BLACKDETECT, blackdetect, vf);

     REGISTER_FILTER (BLACKFRAME,  blackframe,  vf);

     REGISTER_FILTER (BOXBLUR,     boxblur,     vf);

     REGISTER_FILTER (COPY,        copy,        vf);

@@ -29,8 +29,8 @@

 #include "libavutil/avutil.h"

 #define LIBAVFILTER_VERSION_MAJOR  2

-#define LIBAVFILTER_VERSION_MINOR 62

-#define LIBAVFILTER_VERSION_MICRO 101

+#define LIBAVFILTER_VERSION_MINOR 63

+#define LIBAVFILTER_VERSION_MICRO 100

 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \

                                                LIBAVFILTER_VERSION_MINOR, \

new file mode 100644

@@ -0,0 +1,209 @@

+/*

+ * Copyright (c) 2012 Stefano Sabatini

+ *

+ * 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

+ * Video black detector, loosely based on blackframe with extended

+ * syntax and features

+ */

+

+#include <float.h>

+#include "libavutil/opt.h"

+#include "libavutil/timestamp.h"

+#include "avfilter.h"

+#include "internal.h"

+

+typedef struct {

+    const AVClass *class;

+    double  black_min_duration_time; ///< minimum duration of detected black, in seconds

+    int64_t black_min_duration;      ///< minimum duration of detected black, expressed in timebase units

+    int64_t black_start;             ///< pts start time of the first black picture

+    int64_t black_end;               ///< pts end time of the last black picture

+    int black_started;

+

+    double       picture_black_ratio_th;

+    double       pixel_black_th;

+    unsigned int pixel_black_th_i;

+

+    unsigned int frame_count;       ///< frame number

+    unsigned int nb_black_pixels;   ///< number of black pixels counted so far

+} BlackDetectContext;

+

+#define OFFSET(x) offsetof(BlackDetectContext, x)

+static const AVOption blackdetect_options[] = {

+    { "d",                  "set minimum detected black duration in seconds", OFFSET(black_min_duration_time), AV_OPT_TYPE_DOUBLE, {.dbl=2}, 0, DBL_MAX},

+    { "black_min_duration", "set minimum detected black duration in seconds", OFFSET(black_min_duration_time), AV_OPT_TYPE_DOUBLE, {.dbl=2}, 0, DBL_MAX},

+    { "picture_black_ratio_th", "set the picture black ratio threshold", OFFSET(picture_black_ratio_th), AV_OPT_TYPE_DOUBLE, {.dbl=.98}, 0, 1},

+    { "pic_th",                 "set the picture black ratio threshold", OFFSET(picture_black_ratio_th), AV_OPT_TYPE_DOUBLE, {.dbl=.98}, 0, 1},

+    { "pixel_black_th", "set the pixel black threshold", OFFSET(pixel_black_th), AV_OPT_TYPE_DOUBLE, {.dbl=.10}, 0, 1},

+    { "pix_th",         "set the pixel black threshold", OFFSET(pixel_black_th), AV_OPT_TYPE_DOUBLE, {.dbl=.10}, 0, 1},

+    { NULL },

+};

+

+static const char *blackdetect_get_name(void *ctx)

+{

+    return "blackdetect";

+}

+

+static const AVClass blackdetect_class = {

+    .class_name = "BlackDetectContext",

+    .item_name  = blackdetect_get_name,

+    .option     = blackdetect_options,

+};

+

+#define YUVJ_FORMATS \

+    PIX_FMT_YUVJ420P, PIX_FMT_YUVJ422P, PIX_FMT_YUVJ444P, PIX_FMT_YUVJ440P

+

+static enum PixelFormat yuvj_formats[] = {

+    YUVJ_FORMATS, PIX_FMT_NONE

+};

+

+static int query_formats(AVFilterContext *ctx)

+{

+    static const enum PixelFormat pix_fmts[] = {

+        PIX_FMT_YUV410P, PIX_FMT_YUV420P, PIX_FMT_GRAY8, PIX_FMT_NV12,

+        PIX_FMT_NV21, PIX_FMT_YUV444P, PIX_FMT_YUV422P, PIX_FMT_YUV411P,

+        YUVJ_FORMATS,

+        PIX_FMT_NONE

+    };

+

+    avfilter_set_common_pixel_formats(ctx, avfilter_make_format_list(pix_fmts));

+    return 0;

+}

+

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

+{

+    int ret;

+    BlackDetectContext *blackdetect = ctx->priv;

+

+    blackdetect->class = &blackdetect_class;

+    av_opt_set_defaults(blackdetect);

+

+    if ((ret = av_set_options_string(blackdetect, args, "=", ":")) < 0) {

+        av_log(ctx, AV_LOG_ERROR, "Error parsing options string: '%s'\n", args);

+        return ret;

+    }

+

+    return 0;

+}

+

+static int config_input(AVFilterLink *inlink)

+{

+    AVFilterContext *ctx = inlink->dst;

+    BlackDetectContext *blackdetect = ctx->priv;

+

+    blackdetect->black_min_duration =

+        blackdetect->black_min_duration_time / av_q2d(inlink->time_base);

+

+    blackdetect->pixel_black_th_i = ff_fmt_is_in(inlink->format, yuvj_formats) ?

+        // luminance_minimum_value + pixel_black_th * luminance_range_size

+             blackdetect->pixel_black_th *  255 :

+        16 + blackdetect->pixel_black_th * (235 - 16);

+

+    av_log(blackdetect, AV_LOG_INFO,

+           "black_min_duration:%s pixel_black_th:%f pixel_black_th_i:%d picture_black_ratio_th:%f\n",

+           av_ts2timestr(blackdetect->black_min_duration, &inlink->time_base),

+           blackdetect->pixel_black_th, blackdetect->pixel_black_th_i,

+           blackdetect->picture_black_ratio_th);

+    return 0;

+}

+

+static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)

+{

+    AVFilterContext *ctx = inlink->dst;

+    BlackDetectContext *blackdetect = ctx->priv;

+    AVFilterBufferRef *picref = inlink->cur_buf;

+    int x, i;

+    const uint8_t *p = picref->data[0] + y * picref->linesize[0];

+

+    for (i = 0; i < h; i++) {

+        for (x = 0; x < inlink->w; x++)

+            blackdetect->nb_black_pixels += p[x] <= blackdetect->pixel_black_th_i;

+        p += picref->linesize[0];

+    }

+

+    avfilter_draw_slice(ctx->outputs[0], y, h, slice_dir);

+}

+

+static void end_frame(AVFilterLink *inlink)

+{

+    AVFilterContext *ctx = inlink->dst;

+    BlackDetectContext *blackdetect = ctx->priv;

+    AVFilterBufferRef *picref = inlink->cur_buf;

+    double picture_black_ratio = 0;

+

+    picture_black_ratio = (double)blackdetect->nb_black_pixels / (inlink->w * inlink->h);

+

+    av_log(ctx, AV_LOG_DEBUG,

+           "frame:%u picture_black_ratio:%f pos:%"PRId64" pts:%s t:%s type:%c\n",

+           blackdetect->frame_count, picture_black_ratio,

+           picref->pos, av_ts2str(picref->pts),

+           av_ts2timestr(blackdetect->black_start, &inlink->time_base),

+           av_get_picture_type_char(picref->video->pict_type));

+

+    if (picture_black_ratio >= blackdetect->picture_black_ratio_th) {

+        if (!blackdetect->black_started) {

+            /* black starts here */

+            blackdetect->black_started = 1;

+            blackdetect->black_start = picref->pts;

+        }

+    } else if (blackdetect->black_started) {

+        /* black ends here */

+        blackdetect->black_started = 0;

+        blackdetect->black_end = picref->pts;

+

+        if ((blackdetect->black_end - blackdetect->black_start) >= blackdetect->black_min_duration) {

+            av_log(blackdetect, AV_LOG_INFO,

+                   "black_start:%s black_end:%s black_duration:%s\n",

+                   av_ts2timestr(blackdetect->black_start, &inlink->time_base),

+                   av_ts2timestr(blackdetect->black_end, &inlink->time_base),

+                   av_ts2timestr(blackdetect->black_end - blackdetect->black_start, &inlink->time_base));

+        }

+    }

+

+    blackdetect->frame_count++;

+    blackdetect->nb_black_pixels = 0;

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

+}

+

+AVFilter avfilter_vf_blackdetect = {

+    .name          = "blackdetect",

+    .description   = NULL_IF_CONFIG_SMALL("Detect video intervals that are (almost) black."),

+    .priv_size     = sizeof(BlackDetectContext),

+    .init          = init,

+    .query_formats = query_formats,

+

+    .inputs = (const AVFilterPad[]) {

+        { .name             = "default",

+          .type             = AVMEDIA_TYPE_VIDEO,

+          .config_props     = config_input,

+          .draw_slice       = draw_slice,

+          .get_video_buffer = avfilter_null_get_video_buffer,

+          .start_frame      = avfilter_null_start_frame,

+          .end_frame        = end_frame, },

+        { .name = NULL }

+    },

+

+    .outputs = (const AVFilterPad[]) {

+        { .name             = "default",

+          .type             = AVMEDIA_TYPE_VIDEO },

+        { .name = NULL }

+    },

+};