lavfi: Weston 3 Field Deinterlacing Filter

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

Changelog

@@ -17,6 +17,7 @@ version <next>
 - read EXIF metadata from JPEG
 - DVB teletext decoder
 - phase filter ported from libmpcodecs
+- w3fdif filter
 
 
 version 2.0:

doc/filters.texi

@@ -7830,6 +7830,45 @@ vignette='PI/4+random(1)*PI/50':eval=frame
 
 @end itemize
 
+@section w3fdif
+
+Deinterlace the input video ("w3fdif" stands for "Weston 3 Field
+Deinterlacing Filter").
+
+Based on the process described by Martin Weston for BBC R&D, and
+implemented based on the de-interlace algorithm written by Jim
+Easterbrook for BBC R&D, the Weston 3 field deinterlacing filter
+uses filter coefficients calculated by BBC R&D.
+
+There are two sets of filter coefficients, so called "simple":
+and "complex". Which set of filter coefficients is used can
+be set by passing an optional parameter:
+
+@table @option
+@item filter
+Set the interlacing filter coefficients. Accepts one of the following values:
+
+@table @samp
+@item simple
+Simple filter coefficient set.
+@item complex
+More-complex filter coefficient set.
+@end table
+Default value is @samp{complex}.
+
+@item deint
+Specify which frames to deinterlace. Accept one of the following values:
+
+@table @samp
+@item all
+Deinterlace all frames,
+@item interlaced
+Only deinterlace frames marked as interlaced.
+@end table
+
+Default value is @samp{all}.
+@end table
+
 @anchor{yadif}
 @section yadif
 

libavfilter/Makefile

@@ -203,6 +203,7 @@ 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-$(CONFIG_W3FDIF_FILTER)                 += vf_w3fdif.o
 OBJS-$(CONFIG_YADIF_FILTER)                  += vf_yadif.o
 OBJS-$(CONFIG_ZMQ_FILTER)                    += f_zmq.o
 

libavfilter/allfilters.c

@@ -198,6 +198,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(VIDSTABDETECT,  vidstabdetect,  vf);
     REGISTER_FILTER(VIDSTABTRANSFORM, vidstabtransform, vf);
     REGISTER_FILTER(VIGNETTE,       vignette,       vf);
+    REGISTER_FILTER(W3FDIF,         w3fdif,         vf);
     REGISTER_FILTER(YADIF,          yadif,          vf);
     REGISTER_FILTER(ZMQ,            zmq,            vf);
 

libavfilter/version.h

@@ -30,8 +30,8 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  3
-#define LIBAVFILTER_VERSION_MINOR  83
+#define LIBAVFILTER_VERSION_MINOR  84
-#define LIBAVFILTER_VERSION_MICRO 104
+#define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
                                                LIBAVFILTER_VERSION_MINOR, \

libavfilter/vf_w3fdif.c

@@ -0,0 +1,382 @@
+/*
+ * Copyright (C) 2012 British Broadcasting Corporation, All Rights Reserved
+ * Author of de-interlace algorithm: Jim Easterbrook for BBC R&D
+ * Based on the process described by Martin Weston for BBC R&D
+ * Author of FFmpeg filter: Mark Himsley for BBC Broadcast Systems Development
+ *
+ * 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/common.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/opt.h"
+#include "libavutil/pixdesc.h"
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+
+typedef struct W3FDIFContext {
+    const AVClass *class;
+    int filter;           ///< 0 is simple, 1 is more complex
+    int deint;            ///< which frames to deinterlace
+    int linesize[4];      ///< bytes of pixel data per line for each plane
+    int planeheight[4];   ///< height of each plane
+    int field;            ///< which field are we on, 0 or 1
+    int eof;
+    int nb_planes;
+    double ts_unit;
+    AVFrame *prev, *cur, *next;  ///< previous, current, next frames
+    int32_t *work_line;   ///< line we are calculating
+} W3FDIFContext;
+
+#define OFFSET(x) offsetof(W3FDIFContext, x)
+#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
+#define CONST(name, help, val, unit) { name, help, 0, AV_OPT_TYPE_CONST, {.i64=val}, 0, 0, FLAGS, unit }
+
+static const AVOption w3fdif_options[] = {
+    { "filter", "specify the filter", OFFSET(filter), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, FLAGS, "filter" },
+    CONST("simple",  NULL, 0, "filter"),
+    CONST("complex", NULL, 1, "filter"),
+    { "deint",  "specify which frames to deinterlace", OFFSET(deint), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS, "deint" },
+    CONST("all",        "deinterlace all frames",                       0, "deint"),
+    CONST("interlaced", "only deinterlace frames marked as interlaced", 1, "deint"),
+    { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(w3fdif);
+
+static int query_formats(AVFilterContext *ctx)
+{
+    static const enum AVPixelFormat pix_fmts[] = {
+        AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV411P,
+        AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P,
+        AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV444P,
+        AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P,
+        AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ420P,
+        AV_PIX_FMT_YUVJ411P,
+        AV_PIX_FMT_YUVA420P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA444P,
+        AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRAP,
+        AV_PIX_FMT_GRAY8,
+        AV_PIX_FMT_NONE
+    };
+
+    ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
+
+    return 0;
+}
+
+static int config_input(AVFilterLink *inlink)
+{
+    W3FDIFContext *s = inlink->dst->priv;
+    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
+    int ret;
+
+    if ((ret = av_image_fill_linesizes(s->linesize, inlink->format, inlink->w)) < 0)
+        return ret;
+
+    s->planeheight[1] = s->planeheight[2] = FF_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h);
+    s->planeheight[0] = s->planeheight[3] = inlink->h;
+
+    s->nb_planes = av_pix_fmt_count_planes(inlink->format);
+    s->work_line = av_calloc(s->linesize[0], sizeof(*s->work_line));
+    if (!s->work_line)
+        return AVERROR(ENOMEM);
+
+    return 0;
+}
+
+static int config_output(AVFilterLink *outlink)
+{
+    AVFilterLink *inlink = outlink->src->inputs[0];
+    W3FDIFContext *s = outlink->src->priv;
+
+    outlink->time_base.num = inlink->time_base.num;
+    outlink->time_base.den = inlink->time_base.den * 2;
+    outlink->frame_rate.num = inlink->frame_rate.num * 2;
+    outlink->frame_rate.den = inlink->frame_rate.den;
+    outlink->flags |= FF_LINK_FLAG_REQUEST_LOOP;
+    s->ts_unit = av_q2d(av_inv_q(av_mul_q(outlink->frame_rate, outlink->time_base)));
+
+    return 0;
+}
+
+/*
+ * Filter coefficients from PH-2071, scaled by 256 * 256.
+ * Each set of coefficients has a set for low-frequencies and high-frequencies.
+ * n_coef_lf[] and n_coef_hf[] are the number of coefs for simple and more-complex.
+ * It is important for later that n_coef_lf[] is even and n_coef_hf[] is odd.
+ * coef_lf[][] and coef_hf[][] are the coefficients for low-frequencies
+ * and high-frequencies for simple and more-complex mode.
+ */
+static const int8_t   n_coef_lf[2] = { 2, 4 };
+static const int32_t coef_lf[2][4] = {{ 32768, 32768,     0,     0},
+                                      { -1704, 34472, 34472, -1704}};
+static const int8_t   n_coef_hf[2] = { 3, 5 };
+static const int32_t coef_hf[2][5] = {{ -4096,  8192, -4096,     0,     0},
+                                      {  2032, -7602, 11140, -7602,  2032}};
+
+static void deinterlace_plane(AVFilterContext *ctx, AVFrame *out,
+                              const AVFrame *cur, const AVFrame *adj,
+                              const int filter, const int plane)
+{
+    W3FDIFContext *s = ctx->priv;
+    uint8_t *in_line, *in_lines_cur[5], *in_lines_adj[5];
+    uint8_t *out_line, *out_pixel;
+    int32_t *work_line, *work_pixel;
+    uint8_t *cur_data = cur->data[plane];
+    uint8_t *adj_data = adj->data[plane];
+    uint8_t *dst_data = out->data[plane];
+    const int linesize = s->linesize[plane];
+    const int height   = s->planeheight[plane];
+    const int cur_line_stride = cur->linesize[plane];
+    const int adj_line_stride = adj->linesize[plane];
+    const int dst_line_stride = out->linesize[plane];
+    int i, j, y_in, y_out;
+
+    /* copy unchanged the lines of the field */
+    y_out = s->field == cur->top_field_first;
+
+    in_line  = cur_data + (y_out * cur_line_stride);
+    out_line = dst_data + (y_out * dst_line_stride);
+
+    while (y_out < height) {
+        memcpy(out_line, in_line, linesize);
+        y_out += 2;
+        in_line  += cur_line_stride * 2;
+        out_line += dst_line_stride * 2;
+    }
+
+    /* interpolate other lines of the field */
+    y_out = s->field != cur->top_field_first;
+
+    out_line = dst_data + (y_out * dst_line_stride);
+
+    while (y_out < height) {
+        /* clear workspace */
+        memset(s->work_line, 0, sizeof(*s->work_line) * linesize);
+
+        /* get low vertical frequencies from current field */
+        for (j = 0; j < n_coef_lf[filter]; j++) {
+            y_in = (y_out + 1) + (j * 2) - n_coef_lf[filter];
+
+            while (y_in < 0)
+                y_in += 2;
+            while (y_in >= height)
+                y_in -= 2;
+
+            in_lines_cur[j] = cur_data + (y_in * cur_line_stride);
+        }
+
+        work_line = s->work_line;
+        switch (n_coef_lf[filter]) {
+        case 2:
+            for (i = 0; i < linesize; i++) {
+                *work_line   += *in_lines_cur[0]++ * coef_lf[filter][0];
+                *work_line++ += *in_lines_cur[1]++ * coef_lf[filter][1];
+            }
+            break;
+        case 4:
+            for (i = 0; i < linesize; i++) {
+                *work_line   += *in_lines_cur[0]++ * coef_lf[filter][0];
+                *work_line   += *in_lines_cur[1]++ * coef_lf[filter][1];
+                *work_line   += *in_lines_cur[2]++ * coef_lf[filter][2];
+                *work_line++ += *in_lines_cur[3]++ * coef_lf[filter][3];
+            }
+        }
+
+        /* get high vertical frequencies from adjacent fields */
+        for (j = 0; j < n_coef_hf[filter]; j++) {
+            y_in = (y_out + 1) + (j * 2) - n_coef_hf[filter];
+
+            while (y_in < 0)
+                y_in += 2;
+            while (y_in >= height)
+                y_in -= 2;
+
+            in_lines_cur[j] = cur_data + (y_in * cur_line_stride);
+            in_lines_adj[j] = adj_data + (y_in * adj_line_stride);
+        }
+
+        work_line = s->work_line;
+        switch (n_coef_hf[filter]) {
+        case 3:
+            for (i = 0; i < linesize; i++) {
+                *work_line   += *in_lines_cur[0]++ * coef_hf[filter][0];
+                *work_line   += *in_lines_adj[0]++ * coef_hf[filter][0];
+                *work_line   += *in_lines_cur[1]++ * coef_hf[filter][1];
+                *work_line   += *in_lines_adj[1]++ * coef_hf[filter][1];
+                *work_line   += *in_lines_cur[2]++ * coef_hf[filter][2];
+                *work_line++ += *in_lines_adj[2]++ * coef_hf[filter][2];
+            }
+            break;
+        case 5:
+            for (i = 0; i < linesize; i++) {
+                *work_line   += *in_lines_cur[0]++ * coef_hf[filter][0];
+                *work_line   += *in_lines_adj[0]++ * coef_hf[filter][0];
+                *work_line   += *in_lines_cur[1]++ * coef_hf[filter][1];
+                *work_line   += *in_lines_adj[1]++ * coef_hf[filter][1];
+                *work_line   += *in_lines_cur[2]++ * coef_hf[filter][2];
+                *work_line   += *in_lines_adj[2]++ * coef_hf[filter][2];
+                *work_line   += *in_lines_cur[3]++ * coef_hf[filter][3];
+                *work_line   += *in_lines_adj[3]++ * coef_hf[filter][3];
+                *work_line   += *in_lines_cur[4]++ * coef_hf[filter][4];
+                *work_line++ += *in_lines_adj[4]++ * coef_hf[filter][4];
+            }
+        }
+
+        /* save scaled result to the output frame, scaling down by 256 * 256 */
+        work_pixel = s->work_line;
+        out_pixel = out_line;
+
+        for (j = 0; j < linesize; j++, out_pixel++, work_pixel++)
+             *out_pixel = av_clip(*work_pixel, 0, 255 * 256 * 256) >> 16;
+
+        /* move on to next line */
+        y_out += 2;
+        out_line += dst_line_stride * 2;
+    }
+}
+
+static int filter(AVFilterContext *ctx)
+{
+    W3FDIFContext *s = ctx->priv;
+    AVFilterLink *outlink = ctx->outputs[0];
+    AVFrame *out, *adj;
+    int plane;
+
+    out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+    if (!out)
+        return AVERROR(ENOMEM);
+    av_frame_copy_props(out, s->cur);
+    out->interlaced_frame = 0;
+    out->pts = outlink->frame_count * s->ts_unit;
+
+    adj = s->field ? s->next : s->prev;
+    for (plane = 0; plane < s->nb_planes; plane++)
+        deinterlace_plane(ctx, out, s->cur, adj, s->filter, plane);
+
+    s->field = !s->field;
+
+    return ff_filter_frame(outlink, out);
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
+{
+    AVFilterContext *ctx = inlink->dst;
+    W3FDIFContext *s = ctx->priv;
+    int ret;
+
+    av_frame_free(&s->prev);
+    s->prev = s->cur;
+    s->cur  = s->next;
+    s->next = frame;
+
+    if (!s->cur) {
+        s->cur = av_frame_clone(s->next);
+        if (!s->cur)
+            return AVERROR(ENOMEM);
+    }
+
+    if ((s->deint && !s->cur->interlaced_frame) || ctx->is_disabled) {
+        AVFrame *out = av_frame_clone(s->cur);
+        if (!out)
+            return AVERROR(ENOMEM);
+
+        av_frame_free(&s->prev);
+        out->pts = ctx->outputs[0]->frame_count * s->ts_unit;
+        return ff_filter_frame(ctx->outputs[0], out);
+    }
+
+    if (!s->prev)
+        return 0;
+
+    ret = filter(ctx);
+    if (ret < 0)
+        return ret;
+
+    return filter(ctx);
+}
+
+static int request_frame(AVFilterLink *outlink)
+{
+    AVFilterContext *ctx = outlink->src;
+    W3FDIFContext *s = ctx->priv;
+
+    do {
+        int ret;
+
+        if (s->eof)
+            return AVERROR_EOF;
+
+        ret = ff_request_frame(ctx->inputs[0]);
+
+        if (ret == AVERROR_EOF && s->cur) {
+            AVFrame *next = av_frame_clone(s->next);
+            if (!next)
+                return AVERROR(ENOMEM);
+            filter_frame(ctx->inputs[0], next);
+            s->eof = 1;
+        } else if (ret < 0) {
+            return ret;
+        }
+    } while (!s->cur);
+
+    return 0;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    W3FDIFContext *s = ctx->priv;
+
+    av_frame_free(&s->prev);
+    av_frame_free(&s->cur );
+    av_frame_free(&s->next);
+    av_freep(&s->work_line);
+}
+
+static const AVFilterPad w3fdif_inputs[] = {
+    {
+        .name          = "default",
+        .type          = AVMEDIA_TYPE_VIDEO,
+        .filter_frame  = filter_frame,
+        .config_props  = config_input,
+    },
+    { NULL }
+};
+
+static const AVFilterPad w3fdif_outputs[] = {
+    {
+        .name          = "default",
+        .type          = AVMEDIA_TYPE_VIDEO,
+        .config_props  = config_output,
+        .request_frame = request_frame,
+    },
+    { NULL }
+};
+
+AVFilter avfilter_vf_w3fdif = {
+    .name          = "w3fdif",
+    .description   = NULL_IF_CONFIG_SMALL("Apply Martin Weston three field deinterlace."),
+    .priv_size     = sizeof(W3FDIFContext),
+    .priv_class    = &w3fdif_class,
+    .uninit        = uninit,
+    .query_formats = query_formats,
+    .inputs        = w3fdif_inputs,
+    .outputs       = w3fdif_outputs,
+    .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL,
+};