@@ -22,6 +22,7 @@ version <next>:

 - telecine filter

 - new interlace filter

 - smptehdbars source

+- inverse telecine filters (fieldmatch and decimate)

 version 1.2:

@@ -2383,6 +2383,46 @@ curves=vintage

 @end example

 @end itemize

+@anchor{decimate}

+@section decimate

+

+Drop duplicated frames at regular intervals.

+

+The filter accepts the following options:

+

+@table @option

+@item cycle

+Set the number of frames from which one will be dropped. Setting this to

+@var{N} means one frame in every batch of @var{N} frames will be dropped.

+Default is @code{5}.

+

+@item dupthresh

+Set the threshold for duplicate detection. If the difference metric for a frame

+is less than or equal to this value, then it is declared as duplicate. Default

+is @code{1.1}

+

+@item scthresh

+Set scene change threshold. Default is @code{15}.

+

+@item blockx

+@item blocky

+Set the size of the x and y-axis blocks used during metric calculations.

+Larger blocks give better noise suppression, but also give worse detection of

+small movements. Must be a power of two. Default is @code{32}.

+

+@item ppsrc

+Mark main input as a pre-processed input and activate clean source input

+stream. This allows the input to be pre-processed with various filters to help

+the metrics calculation while keeping the frame selection lossless. When set to

+@code{1}, the first stream is for the pre-processed input, and the second

+stream is the clean source from where the kept frames are chosen. Default is

+@code{0}.

+

+@item chroma

+Set whether or not chroma is considered in the metric calculations. Default is

+@code{1}.

+@end table

+

 @section mpdecimate

 Drop frames that do not differ greatly from the previous frame in

@@ -3047,6 +3087,328 @@ Specify whether to extract the top (if the value is @code{0} or

 @code{bottom}).

 @end table

+@section fieldmatch

+

+Field matching filter for inverse telecine. It is meant to reconstruct the

+progressive frames from a telecined stream. The filter does not drop duplicated

+frames, so to achieve a complete inverse telecine @code{fieldmatch} needs to be

+followed by a decimation filter such as @ref{decimate} in the filtergraph.

+

+The separation of the field matching and the decimation is notably motivated by

+the possibility of inserting a de-interlacing filter fallback between the two.

+If the source has mixed telecined and real interlaced content,

+@code{fieldmatch} will not be able to match fields for the interlaced parts.

+But these remaining combed frames will be marked as interlaced, and thus can be

+de-interlaced by a later filter such as @ref{yadif} before decimation.

+

+In addition to the various configuration options, @code{fieldmatch} can take an

+optional second stream, activated through the @option{ppsrc} option. If

+enabled, the frames reconstruction will be based on the fields and frames from

+this second stream. This allows the first input to be pre-processed in order to

+help the various algorithms of the filter, while keeping the output lossless

+(assuming the fields are matched properly). Typically, a field-aware denoiser,

+or brightness/contrast adjustments can help.

+

+Note that this filter uses the same algorithms as TIVTC/TFM (AviSynth project)

+and VIVTC/VFM (VapourSynth project). The later is a light clone of TFM from

+which @code{fieldmatch} is based on. While the semantic and usage are very

+close, some behaviour and options names can differ.

+

+The filter accepts the following options:

+

+@table @option

+@item order

+Specify the assumed field order of the input stream. Available values are:

+

+@table @samp

+@item auto

+Auto detect parity (use FFmpeg's internal parity value).

+@item bff

+Assume bottom field first.

+@item tff

+Assume top field first.

+@end table

+

+Note that it is sometimes recommended not to trust the parity announced by the

+stream.

+

+Default value is @var{auto}.

+

+@item mode

+Set the matching mode or strategy to use. @option{pc} mode is the safest in the

+sense that it wont risk creating jerkiness due to duplicate frames when

+possible, but if there are bad edits or blended fields it will end up

+outputting combed frames when a good match might actually exist. On the other

+hand, @option{pcn_ub} mode is the most risky in terms of creating jerkiness,

+but will almost always find a good frame if there is one. The other values are

+all somewhere in between @option{pc} and @option{pcn_ub} in terms of risking

+jerkiness and creating duplicate frames versus finding good matches in sections

+with bad edits, orphaned fields, blended fields, etc.

+

+More details about p/c/n/u/b are available in @ref{p/c/n/u/b meaning} section.

+

+Available values are:

+

+@table @samp

+@item pc

+2-way matching (p/c)

+@item pc_n

+2-way matching, and trying 3rd match if still combed (p/c + n)

+@item pc_u

+2-way matching, and trying 3rd match (same order) if still combed (p/c + u)

+@item pc_n_ub

+2-way matching, trying 3rd match if still combed, and trying 4th/5th matches if

+still combed (p/c + n + u/b)

+@item pcn

+3-way matching (p/c/n)

+@item pcn_ub

+3-way matching, and trying 4th/5th matches if all 3 of the original matches are

+detected as combed (p/c/n + u/b)

+@end table

+

+The parenthesis at the end indicate the matches that would be used for that

+mode assuming @option{order}=@var{tff} (and @option{field} on @var{auto} or

+@var{top}).

+

+In terms of speed @option{pc} mode is by far the fastest and @option{pcn_ub} is

+the slowest.

+

+Default value is @var{pc_n}.

+

+@item ppsrc

+Mark the main input stream as a pre-processed input, and enable the secondary

+input stream as the clean source to pick the fields from. See the filter

+introduction for more details. It is similar to the @option{clip2} feature from

+VFM/TFM.

+

+Default value is @code{0} (disabled).

+

+@item field

+Set the field to match from. It is recommended to set this to the same value as

+@option{order} unless you experience matching failures with that setting. In

+certain circumstances changing the field that is used to match from can have a

+large impact on matching performance. Available values are:

+

+@table @samp

+@item auto

+Automatic (same value as @option{order}).

+@item bottom

+Match from the bottom field.

+@item top

+Match from the top field.

+@end table

+

+Default value is @var{auto}.

+

+@item mchroma

+Set whether or not chroma is included during the match comparisons. In most

+cases it is recommended to leave this enabled. You should set this to @code{0}

+only if your clip has bad chroma problems such as heavy rainbowing or other

+artifacts. Setting this to @code{0} could also be used to speed things up at

+the cost of some accuracy.

+

+Default value is @code{1}.

+

+@item y0

+@item y1

+These define an exclusion band which excludes the lines between @option{y0} and

+@option{y1} from being included in the field matching decision. An exclusion

+band can be used to ignore subtitles, a logo, or other things that may

+interfere with the matching. @option{y0} sets the starting scan line and

+@option{y1} sets the ending line; all lines in between @option{y0} and

+@option{y1} (including @option{y0} and @option{y1}) will be ignored. Setting

+@option{y0} and @option{y1} to the same value will disable the feature.

+@option{y0} and @option{y1} defaults to @code{0}.

+

+@item scthresh

+Set the scene change detection threshold as a percentage of maximum change on

+the luma plane. Good values are in the @code{[8.0, 14.0]} range. Scene change

+detection is only relevant in case @option{combmatch}=@var{sc}.  The range for

+@option{scthresh} is @code{[0.0, 100.0]}.

+

+Default value is @code{12.0}.

+

+@item combmatch

+When @option{combatch} is not @var{none}, @code{fieldmatch} will take into

+account the combed scores of matches when deciding what match to use as the

+final match. Available values are:

+

+@table @samp

+@item none

+No final matching based on combed scores.

+@item sc

+Combed scores are only used when a scene change is detected.

+@item full

+Use combed scores all the time.

+@end table

+

+Default is @var{sc}.

+

+@item combdbg

+Force @code{fieldmatch} to calculate the combed metrics for certain matches and

+print them. This setting is known as @option{micout} in TFM/VFM vocabulary.

+Available values are:

+

+@table @samp

+@item none

+No forced calculation.

+@item pcn

+Force p/c/n calculations.

+@item pcnub

+Force p/c/n/u/b calculations.

+@end table

+

+Default value is @var{none}.

+

+@item cthresh

+This is the area combing threshold used for combed frame detection. This

+essentially controls how "strong" or "visible" combing must be to be detected.

+Larger values mean combing must be more visible and smaller values mean combing

+can be less visible or strong and still be detected. Valid settings are from

+@code{-1} (every pixel will be detected as combed) to @code{255} (no pixel will

+be detected as combed). This is basically a pixel difference value. A good

+range is @code{[8, 12]}.

+

+Default value is @code{9}.

+

+@item chroma

+Sets whether or not chroma is considered in the combed frame decision.  Only

+disable this if your source has chroma problems (rainbowing, etc.) that are

+causing problems for the combed frame detection with chroma enabled. Actually,

+using @option{chroma}=@var{0} is usually more reliable, except for the case

+where there is chroma only combing in the source.

+

+Default value is @code{0}.

+

+@item blockx

+@item blocky

+Respectively set the x-axis and y-axis size of the window used during combed

+frame detection. This has to do with the size of the area in which

+@option{combpel} pixels are required to be detected as combed for a frame to be

+declared combed. See the @option{combpel} parameter description for more info.

+Possible values are any number that is a power of 2 starting at 4 and going up

+to 512.

+

+Default value is @code{16}.

+

+@item combpel

+The number of combed pixels inside any of the @option{blocky} by

+@option{blockx} size blocks on the frame for the frame to be detected as

+combed. While @option{cthresh} controls how "visible" the combing must be, this

+setting controls "how much" combing there must be in any localized area (a

+window defined by the @option{blockx} and @option{blocky} settings) on the

+frame. Minimum value is @code{0} and maximum is @code{blocky x blockx} (at

+which point no frames will ever be detected as combed). This setting is known

+as @option{MI} in TFM/VFM vocabulary.

+

+Default value is @code{80}.

+@end table

+

+@anchor{p/c/n/u/b meaning}

+@subsection p/c/n/u/b meaning

+

+@subsubsection p/c/n

+

+We assume the following telecined stream:

+

+@example

+Top fields:     1 2 2 3 4

+Bottom fields:  1 2 3 4 4

+@end example

+

+The numbers correspond to the progressive frame the fields relate to. Here, the

+first two frames are progressive, the 3rd and 4th are combed, and so on.

+

+When @code{fieldmatch} is configured to run a matching from bottom

+(@option{field}=@var{bottom}) this is how this input stream get transformed:

+

+@example

+Input stream:

+                T     1 2 2 3 4

+                B     1 2 3 4 4   <-- matching reference

+

+Matches:              c c n n c

+

+Output stream:

+                T     1 2 3 4 4

+                B     1 2 3 4 4

+@end example

+

+As a result of the field matching, we can see that some frames get duplicated.

+To perform a complete inverse telecine, you need to rely on a decimation filter

+after this operation. See for instance the @ref{decimate} filter.

+

+The same operation now matching from top fields (@option{field}=@var{top})

+looks like this:

+

+@example

+Input stream:

+                T     1 2 2 3 4   <-- matching reference

+                B     1 2 3 4 4

+

+Matches:              c c p p c

+

+Output stream:

+                T     1 2 2 3 4

+                B     1 2 2 3 4

+@end example

+

+In these examples, we can see what @var{p}, @var{c} and @var{n} mean;

+basically, they refer to the frame and field of the opposite parity:

+

+@itemize

+@item @var{p} matches the field of the opposite parity in the previous frame

+@item @var{c} matches the field of the opposite parity in the current frame

+@item @var{n} matches the field of the opposite parity in the next frame

+@end itemize

+

+@subsubsection u/b

+

+The @var{u} and @var{b} matching are a bit special in the sense that they match

+from the opposite parity flag. In the following examples, we assume that we are

+currently matching the 2nd frame (Top:2, bottom:2). According to the match, a

+'x' is placed above and below each matched fields.

+

+With bottom matching (@option{field}=@var{bottom}):

+@example

+Match:           c         p           n          b          u

+

+                 x       x               x        x          x

+  Top          1 2 2     1 2 2       1 2 2      1 2 2      1 2 2

+  Bottom       1 2 3     1 2 3       1 2 3      1 2 3      1 2 3

+                 x         x           x        x              x

+

+Output frames:

+                 2          1          2          2          2

+                 2          2          2          1          3

+@end example

+

+With top matching (@option{field}=@var{top}):

+@example

+Match:           c         p           n          b          u

+

+                 x         x           x        x              x

+  Top          1 2 2     1 2 2       1 2 2      1 2 2      1 2 2

+  Bottom       1 2 3     1 2 3       1 2 3      1 2 3      1 2 3

+                 x       x               x        x          x

+

+Output frames:

+                 2          2          2          1          2

+                 2          1          3          2          2

+@end example

+

+@subsection Examples

+

+Simple IVTC of a top field first telecined stream:

+@example

+fieldmatch=order=tff:combmatch=none, decimate

+@end example

+

+Advanced IVTC, with fallback on @ref{yadif} for still combed frames:

+@example

+fieldmatch=order=tff:combmatch=full, yadif=deint=interlaced, decimate

+@end example

+

 @section fieldorder

 Transform the field order of the input video.

@@ -5670,6 +6032,7 @@ Flip the input video vertically.

 ffmpeg -i in.avi -vf "vflip" out.avi

 @end example

+@anchor{yadif}

 @section yadif

 Deinterlace the input video ("yadif" means "yet another deinterlacing

@@ -109,6 +109,7 @@ OBJS-$(CONFIG_COPY_FILTER)                   += vf_copy.o

 OBJS-$(CONFIG_CROP_FILTER)                   += vf_crop.o

 OBJS-$(CONFIG_CROPDETECT_FILTER)             += vf_cropdetect.o

 OBJS-$(CONFIG_CURVES_FILTER)                 += vf_curves.o

+OBJS-$(CONFIG_DECIMATE_FILTER)               += vf_decimate.o

 OBJS-$(CONFIG_DELOGO_FILTER)                 += vf_delogo.o

 OBJS-$(CONFIG_DESHAKE_FILTER)                += vf_deshake.o

 OBJS-$(CONFIG_DRAWBOX_FILTER)                += vf_drawbox.o

@@ -116,6 +117,7 @@ OBJS-$(CONFIG_DRAWTEXT_FILTER)               += vf_drawtext.o

 OBJS-$(CONFIG_EDGEDETECT_FILTER)             += vf_edgedetect.o

 OBJS-$(CONFIG_FADE_FILTER)                   += vf_fade.o

 OBJS-$(CONFIG_FIELD_FILTER)                  += vf_field.o

+OBJS-$(CONFIG_FIELDMATCH_FILTER)             += vf_fieldmatch.o

 OBJS-$(CONFIG_FIELDORDER_FILTER)             += vf_fieldorder.o

 OBJS-$(CONFIG_FORMAT_FILTER)                 += vf_format.o

 OBJS-$(CONFIG_FRAMESTEP_FILTER)              += vf_framestep.o

@@ -107,6 +107,7 @@ void avfilter_register_all(void)

     REGISTER_FILTER(CROP,           crop,           vf);

     REGISTER_FILTER(CROPDETECT,     cropdetect,     vf);

     REGISTER_FILTER(CURVES,         curves,         vf);

+    REGISTER_FILTER(DECIMATE,       decimate,       vf);

     REGISTER_FILTER(DELOGO,         delogo,         vf);

     REGISTER_FILTER(DESHAKE,        deshake,        vf);

     REGISTER_FILTER(DRAWBOX,        drawbox,        vf);

@@ -114,6 +115,7 @@ void avfilter_register_all(void)

     REGISTER_FILTER(EDGEDETECT,     edgedetect,     vf);

     REGISTER_FILTER(FADE,           fade,           vf);

     REGISTER_FILTER(FIELD,          field,          vf);

+    REGISTER_FILTER(FIELDMATCH,     fieldmatch,     vf);

     REGISTER_FILTER(FIELDORDER,     fieldorder,     vf);

     REGISTER_FILTER(FORMAT,         format,         vf);

     REGISTER_FILTER(FPS,            fps,            vf);

@@ -29,7 +29,7 @@

 #include "libavutil/avutil.h"

 #define LIBAVFILTER_VERSION_MAJOR  3

-#define LIBAVFILTER_VERSION_MINOR  55

+#define LIBAVFILTER_VERSION_MINOR  56

 #define LIBAVFILTER_VERSION_MICRO 100

 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \

new file mode 100644

@@ -0,0 +1,398 @@

+/*

+ * Copyright (c) 2012 Fredrik Mellbin

+ * Copyright (c) 2013 Clément Bœsch

+ *

+ * 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/opt.h"

+#include "libavutil/pixdesc.h"

+#include "libavutil/timestamp.h"

+#include "avfilter.h"

+#include "internal.h"

+

+#define INPUT_MAIN     0

+#define INPUT_CLEANSRC 1

+

+struct qitem {

+    AVFrame *frame;

+    int64_t maxbdiff;

+    int64_t totdiff;

+};

+

+typedef struct {

+    const AVClass *class;

+    struct qitem *queue;    ///< window of cycle frames and the associated data diff

+    int fid;                ///< current frame id in the queue

+    int filled;             ///< 1 if the queue is filled, 0 otherwise

+    AVFrame *last;          ///< last frame from the previous queue

+    int64_t frame_count;    ///< output frame counter

+    AVFrame **clean_src;    ///< frame queue for the clean source

+    int got_frame[2];       ///< frame request flag for each input stream

+    double ts_unit;         ///< timestamp units for the output frames

+    uint32_t eof;           ///< bitmask for end of stream

+    int hsub, vsub;         ///< chroma subsampling values

+    int depth;

+    int nxblocks, nyblocks;

+    int bdiffsize;

+    int64_t *bdiffs;

+

+    /* options */

+    int cycle;

+    double dupthresh_flt;

+    double scthresh_flt;

+    int64_t dupthresh;

+    int64_t scthresh;

+    int blockx, blocky;

+    int ppsrc;

+    int chroma;

+} DecimateContext;

+

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

+#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM

+

+static const AVOption decimate_options[] = {

+    { "cycle",     "set the number of frame from which one will be dropped", OFFSET(cycle), AV_OPT_TYPE_INT, {.i64 = 5}, 2, 25, FLAGS },

+    { "dupthresh", "set duplicate threshold",    OFFSET(dupthresh_flt), AV_OPT_TYPE_DOUBLE, {.dbl =  1.1}, 0, 100, FLAGS },

+    { "scthresh",  "set scene change threshold", OFFSET(scthresh_flt),  AV_OPT_TYPE_DOUBLE, {.dbl = 15.0}, 0, 100, FLAGS },

+    { "blockx",    "set the size of the x-axis blocks used during metric calculations", OFFSET(blockx), AV_OPT_TYPE_INT, {.i64 = 32}, 4, 1<<9, FLAGS },

+    { "blocky",    "set the size of the y-axis blocks used during metric calculations", OFFSET(blocky), AV_OPT_TYPE_INT, {.i64 = 32}, 4, 1<<9, FLAGS },

+    { "ppsrc",     "mark main input as a pre-processed input and activate clean source input stream", OFFSET(ppsrc), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS },

+    { "chroma",    "set whether or not chroma is considered in the metric calculations", OFFSET(chroma), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, FLAGS },

+    { NULL }

+};

+

+AVFILTER_DEFINE_CLASS(decimate);

+

+static void calc_diffs(const DecimateContext *dm, struct qitem *q,

+                       const AVFrame *f1, const AVFrame *f2)

+{

+    int64_t maxdiff = -1;

+    int64_t *bdiffs = dm->bdiffs;

+    int plane, i, j;

+

+    memset(bdiffs, 0, dm->bdiffsize * sizeof(*bdiffs));

+

+    for (plane = 0; plane < (dm->chroma ? 3 : 1); plane++) {

+        int x, y, xl;

+        const int linesize1 = f1->linesize[plane];

+        const int linesize2 = f2->linesize[plane];

+        const uint8_t *f1p = f1->data[plane];

+        const uint8_t *f2p = f2->data[plane];

+        int width    = plane ? f1->width  >> dm->hsub : f1->width;

+        int height   = plane ? f1->height >> dm->vsub : f1->height;

+        int hblockx  = dm->blockx / 2;

+        int hblocky  = dm->blocky / 2;

+

+        if (plane) {

+            hblockx >>= dm->hsub;

+            hblocky >>= dm->vsub;

+        }

+

+        for (y = 0; y < height; y++) {

+            int ydest = y / hblocky;

+            int xdest = 0;

+

+#define CALC_DIFF(nbits) do {                               \

+    for (x = 0; x < width; x += hblockx) {                  \

+        int64_t acc = 0;                                    \

+        int m = FFMIN(width, x + hblockx);                  \

+        for (xl = x; xl < m; xl++)                          \

+            acc += abs(((const uint##nbits##_t *)f1p)[xl] - \

+                       ((const uint##nbits##_t *)f2p)[xl]); \

+        bdiffs[ydest * dm->nxblocks + xdest] += acc;        \

+        xdest++;                                            \

+    }                                                       \

+} while (0)

+            if (dm->depth == 8) CALC_DIFF(8);

+            else                CALC_DIFF(16);

+

+            f1p += linesize1;

+            f2p += linesize2;

+        }

+    }

+

+    for (i = 0; i < dm->nyblocks - 1; i++) {

+        for (j = 0; j < dm->nxblocks - 1; j++) {

+            int64_t tmp = bdiffs[      i * dm->nxblocks + j    ]

+                        + bdiffs[      i * dm->nxblocks + j + 1]

+                        + bdiffs[(i + 1) * dm->nxblocks + j    ]

+                        + bdiffs[(i + 1) * dm->nxblocks + j + 1];

+            if (tmp > maxdiff)

+                maxdiff = tmp;

+        }

+    }

+

+    q->totdiff = 0;

+    for (i = 0; i < dm->bdiffsize; i++)

+        q->totdiff += bdiffs[i];

+    q->maxbdiff = maxdiff;

+}

+

+static int filter_frame(AVFilterLink *inlink, AVFrame *in)

+{

+    int scpos = -1, duppos = -1;

+    int drop = INT_MIN, i, lowest = 0, ret;

+    AVFilterContext *ctx  = inlink->dst;

+    AVFilterLink *outlink = ctx->outputs[0];

+    DecimateContext *dm   = ctx->priv;

+    AVFrame *prv;

+

+    /* update frames queue(s) */

+    if (FF_INLINK_IDX(inlink) == INPUT_MAIN) {

+        dm->queue[dm->fid].frame = in;

+        dm->got_frame[INPUT_MAIN] = 1;

+    } else {

+        dm->clean_src[dm->fid] = in;

+        dm->got_frame[INPUT_CLEANSRC] = 1;

+    }

+    if (!dm->got_frame[INPUT_MAIN] || (dm->ppsrc && !dm->got_frame[INPUT_CLEANSRC]))

+        return 0;

+    dm->got_frame[INPUT_MAIN] = dm->got_frame[INPUT_CLEANSRC] = 0;

+

+    if (in) {

+        /* update frame metrics */

+        prv = dm->fid ? dm->queue[dm->fid - 1].frame : dm->last;

+        if (!prv)

+            prv = in;

+        calc_diffs(dm, &dm->queue[dm->fid], prv, in);

+        if (++dm->fid != dm->cycle)

+            return 0;

+        av_frame_free(&dm->last);

+        dm->last = av_frame_clone(in);

+        dm->fid = 0;

+

+        /* we have a complete cycle, select the frame to drop */

+        lowest = 0;

+        for (i = 0; i < dm->cycle; i++) {

+            if (dm->queue[i].totdiff > dm->scthresh)

+                scpos = i;

+            if (dm->queue[i].maxbdiff < dm->queue[lowest].maxbdiff)

+                lowest = i;

+        }

+        if (dm->queue[lowest].maxbdiff < dm->dupthresh)

+            duppos = lowest;

+        drop = scpos >= 0 && duppos < 0 ? scpos : lowest;

+    }

+

+    /* metrics debug */

+    if (av_log_get_level() >= AV_LOG_DEBUG) {

+        av_log(ctx, AV_LOG_DEBUG, "1/%d frame drop:\n", dm->cycle);

+        for (i = 0; i < dm->cycle && dm->queue[i].frame; i++) {

+            av_log(ctx, AV_LOG_DEBUG,"  #%d: totdiff=%08"PRIx64" maxbdiff=%08"PRIx64"%s%s%s%s\n",

+                   i + 1, dm->queue[i].totdiff, dm->queue[i].maxbdiff,

+                   i == scpos  ? " sc"     : "",

+                   i == duppos ? " dup"    : "",

+                   i == lowest ? " lowest" : "",

+                   i == drop   ? " [DROP]" : "");

+        }

+    }

+

+    /* push all frames except the drop */

+    ret = 0;

+    for (i = 0; i < dm->cycle && dm->queue[i].frame; i++) {

+        if (i == drop) {

+            if (dm->ppsrc)

+                av_frame_free(&dm->clean_src[i]);

+            av_frame_free(&dm->queue[i].frame);

+        } else {

+            AVFrame *frame = dm->queue[i].frame;

+            if (dm->ppsrc) {

+                av_frame_free(&frame);

+                frame = dm->clean_src[i];

+            }

+            frame->pts = dm->frame_count++ * dm->ts_unit;

+            ret = ff_filter_frame(outlink, frame);

+            if (ret < 0)

+                break;

+        }

+    }

+

+    return ret;

+}

+

+static int config_input(AVFilterLink *inlink)

+{

+    int max_value;

+    AVFilterContext *ctx = inlink->dst;

+    DecimateContext *dm = ctx->priv;

+    const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(inlink->format);

+    const int w = inlink->w;

+    const int h = inlink->h;

+

+    dm->hsub      = pix_desc->log2_chroma_w;

+    dm->vsub      = pix_desc->log2_chroma_h;

+    dm->depth     = pix_desc->comp[0].depth_minus1 + 1;

+    max_value     = (1 << dm->depth) - 1;

+    dm->scthresh  = (int64_t)(((int64_t)max_value *          w * h          * dm->scthresh_flt)  / 100);

+    dm->dupthresh = (int64_t)(((int64_t)max_value * dm->blockx * dm->blocky * dm->dupthresh_flt) / 100);

+    dm->nxblocks  = (w + dm->blockx/2 - 1) / (dm->blockx/2);

+    dm->nyblocks  = (h + dm->blocky/2 - 1) / (dm->blocky/2);

+    dm->bdiffsize = dm->nxblocks * dm->nyblocks;

+    dm->bdiffs    = av_malloc(dm->bdiffsize * sizeof(*dm->bdiffs));

+    dm->queue     = av_calloc(dm->cycle, sizeof(*dm->queue));

+

+    if (!dm->bdiffs || !dm->queue)

+        return AVERROR(ENOMEM);

+

+    if (dm->ppsrc) {

+        dm->clean_src = av_calloc(dm->cycle, sizeof(*dm->clean_src));

+        if (!dm->clean_src)

+            return AVERROR(ENOMEM);

+    }

+

+    return 0;

+}

+

+static av_cold int decimate_init(AVFilterContext *ctx)

+{

+    const DecimateContext *dm = ctx->priv;

+    AVFilterPad pad = {

+        .name         = av_strdup("main"),

+        .type         = AVMEDIA_TYPE_VIDEO,

+        .filter_frame = filter_frame,

+        .config_props = config_input,

+    };

+

+    if (!pad.name)

+        return AVERROR(ENOMEM);

+    ff_insert_inpad(ctx, INPUT_MAIN, &pad);

+

+    if (dm->ppsrc) {

+        pad.name = av_strdup("clean_src");

+        pad.config_props = NULL;

+        if (!pad.name)

+            return AVERROR(ENOMEM);

+        ff_insert_inpad(ctx, INPUT_CLEANSRC, &pad);

+    }

+

+    if ((dm->blockx & (dm->blockx - 1)) ||

+        (dm->blocky & (dm->blocky - 1))) {

+        av_log(ctx, AV_LOG_ERROR, "blockx and blocky settings must be power of two\n");

+        return AVERROR(EINVAL);

+    }

+

+    return 0;

+}

+

+static av_cold void decimate_uninit(AVFilterContext *ctx)

+{

+    int i;

+    DecimateContext *dm = ctx->priv;

+

+    av_frame_free(&dm->last);

+    av_freep(&dm->bdiffs);

+    av_freep(&dm->queue);

+    av_freep(&dm->clean_src);

+    for (i = 0; i < ctx->nb_inputs; i++)

+        av_freep(&ctx->input_pads[i].name);

+}

+

+static int request_inlink(AVFilterContext *ctx, int lid)

+{

+    int ret = 0;

+    DecimateContext *dm = ctx->priv;

+

+    if (!dm->got_frame[lid]) {

+        AVFilterLink *inlink = ctx->inputs[lid];

+        ret = ff_request_frame(inlink);

+        if (ret == AVERROR_EOF) { // flushing

+            dm->eof |= 1 << lid;

+            ret = filter_frame(inlink, NULL);

+        }

+    }

+    return ret;

+}

+

+static int request_frame(AVFilterLink *outlink)

+{

+    int ret;

+    AVFilterContext *ctx = outlink->src;

+    DecimateContext *dm = ctx->priv;

+    const uint32_t eof_mask = 1<<INPUT_MAIN | dm->ppsrc<<INPUT_CLEANSRC;

+

+    if ((dm->eof & eof_mask) == eof_mask) // flush done?

+        return AVERROR_EOF;

+    if ((ret = request_inlink(ctx, INPUT_MAIN)) < 0)

+        return ret;

+    if (dm->ppsrc && (ret = request_inlink(ctx, INPUT_CLEANSRC)) < 0)

+        return ret;

+    return 0;

+}

+

+static int query_formats(AVFilterContext *ctx)

+{

+    static const enum AVPixelFormat pix_fmts[] = {

+#define PF_NOALPHA(suf) AV_PIX_FMT_YUV420##suf,  AV_PIX_FMT_YUV422##suf,  AV_PIX_FMT_YUV444##suf

+#define PF_ALPHA(suf)   AV_PIX_FMT_YUVA420##suf, AV_PIX_FMT_YUVA422##suf, AV_PIX_FMT_YUVA444##suf

+#define PF(suf)         PF_NOALPHA(suf), PF_ALPHA(suf)

+        PF(P), PF(P9), PF(P10), PF_NOALPHA(P12), PF_NOALPHA(P14), PF(P16),

+        AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P,

+        AV_PIX_FMT_GRAY8,

+        AV_PIX_FMT_NONE

+    };

+    ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));

+    return 0;

+}

+

+static int config_output(AVFilterLink *outlink)

+{

+    AVFilterContext *ctx = outlink->src;

+    DecimateContext *dm = ctx->priv;

+    const AVFilterLink *inlink =

+        ctx->inputs[dm->ppsrc ? INPUT_CLEANSRC : INPUT_MAIN];

+    AVRational fps = inlink->frame_rate;

+

+    if (!fps.num || !fps.den) {

+        av_log(ctx, AV_LOG_ERROR, "The input needs a constant frame rate; "

+               "current rate of %d/%d is invalid\n", fps.num, fps.den);

+        return AVERROR(EINVAL);

+    }

+    fps = av_mul_q(fps, (AVRational){dm->cycle - 1, dm->cycle});

+    av_log(ctx, AV_LOG_VERBOSE, "FPS: %d/%d -> %d/%d\n",

+           inlink->frame_rate.num, inlink->frame_rate.den, fps.num, fps.den);

+    outlink->flags |= FF_LINK_FLAG_REQUEST_LOOP;

+    outlink->time_base  = inlink->time_base;

+    outlink->frame_rate = fps;

+    outlink->sample_aspect_ratio = inlink->sample_aspect_ratio;

+    outlink->w = inlink->w;

+    outlink->h = inlink->h;

+    dm->ts_unit = av_q2d(av_inv_q(av_mul_q(fps, outlink->time_base)));

+    return 0;

+}

+

+static const AVFilterPad decimate_outputs[] = {

+    {

+        .name          = "default",

+        .type          = AVMEDIA_TYPE_VIDEO,

+        .request_frame = request_frame,

+        .config_props  = config_output,

+    },

+    { NULL }

+};

+

+AVFilter avfilter_vf_decimate = {

+    .name          = "decimate",

+    .description   = NULL_IF_CONFIG_SMALL("Decimate frames (post field matching filter)."),

+    .init          = decimate_init,

+    .uninit        = decimate_uninit,

+    .priv_size     = sizeof(DecimateContext),

+    .query_formats = query_formats,

+    .outputs       = decimate_outputs,

+    .priv_class    = &decimate_class,

+    .flags         = AVFILTER_FLAG_DYNAMIC_INPUTS,

+};

new file mode 100644

@@ -0,0 +1,986 @@

+/*

+ * Copyright (c) 2012 Fredrik Mellbin

+ * Copyright (c) 2013 Clément Bœsch

+ *

+ * 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

+ * Fieldmatching filter, ported from VFM filter (VapouSsynth) by Clément.

+ * Fredrik Mellbin is the author of the VIVTC/VFM filter, which is itself a

+ * light clone of the TIVTC/TFM (AviSynth) filter written by Kevin Stone

+ * (tritical), the original author.

+ *

+ * @see http://bengal.missouri.edu/~kes25c/

+ * @see http://www.vapoursynth.com/about/

+ */

+

+#include <inttypes.h>

+

+#include "libavutil/avassert.h"

+#include "libavutil/imgutils.h"

+#include "libavutil/opt.h"

+#include "libavutil/timestamp.h"

+#include "avfilter.h"

+#include "internal.h"

+