avfilter: add fieldhint filter

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

Changelog

@@ -3,6 +3,7 @@ releases are sorted from youngest to oldest.
 
 version <next>:
 - DXVA2-accelerated HEVC Main10 decoding
+- fieldhint filter
 
 
 version 3.0:

doc/filters.texi

@@ -6637,6 +6637,50 @@ Specify whether to extract the top (if the value is @code{0} or
 @code{bottom}).
 @end table
 
+@section fieldhint
+
+Create new frames by copying the top and bottom fields from surrounding frames
+supplied as numbers by the hint file.
+
+@table @option
+@item hint
+Set file containing hints: absolute/relative frame numbers.
+
+There must be one line for each frame in a clip. Each line must contain two
+numbers separated by the comma, optionally followed by @code{-} or @code{+}.
+Numbers supplied on each line of file can not be out of [N-1,N+1] where N
+is current frame number for @code{absolute} mode or out of [-1, 1] range
+for @code{relative} mode. First number tells from which frame to pick up top
+field and second number tells from which frame to pick up bottom field.
+
+If optionally followed by @code{+} output frame will be marked as interlaced,
+else if followed by @code{-} output frame will be marked as progressive, else
+it will be marked same as input frame.
+If line starts with @code{#} or @code{;} that line is skipped.
+
+@item mode
+Can be item @code{absolute} or @code{relative}. Default is @code{absolute}.
+@end table
+
+Example of first several lines of @code{hint} file for @code{relative} mode:
+@example
+0,0 - # first frame
+1,0 - # second frame, use third's frame top field and second's frame bottom field
+1,0 - # third frame, use fourth's frame top field and third's frame bottom field
+1,0 -
+0,0 -
+0,0 -
+1,0 -
+1,0 -
+1,0 -
+0,0 -
+0,0 -
+1,0 -
+1,0 -
+1,0 -
+0,0 -
+@end example
+
 @section fieldmatch
 
 Field matching filter for inverse telecine. It is meant to reconstruct the

libavfilter/Makefile

@@ -153,6 +153,7 @@ OBJS-$(CONFIG_EXTRACTPLANES_FILTER)          += vf_extractplanes.o
 OBJS-$(CONFIG_FADE_FILTER)                   += vf_fade.o
 OBJS-$(CONFIG_FFTFILT_FILTER)                += vf_fftfilt.o
 OBJS-$(CONFIG_FIELD_FILTER)                  += vf_field.o
+OBJS-$(CONFIG_FIELDHINT_FILTER)              += vf_fieldhint.o
 OBJS-$(CONFIG_FIELDMATCH_FILTER)             += vf_fieldmatch.o
 OBJS-$(CONFIG_FIELDORDER_FILTER)             += vf_fieldorder.o
 OBJS-$(CONFIG_FIND_RECT_FILTER)              += vf_find_rect.o lavfutils.o

libavfilter/allfilters.c

@@ -174,6 +174,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(FADE,           fade,           vf);
     REGISTER_FILTER(FFTFILT,        fftfilt,        vf);
     REGISTER_FILTER(FIELD,          field,          vf);
+    REGISTER_FILTER(FIELDHINT,      fieldhint,      vf);
     REGISTER_FILTER(FIELDMATCH,     fieldmatch,     vf);
     REGISTER_FILTER(FIELDORDER,     fieldorder,     vf);
     REGISTER_FILTER(FIND_RECT,      find_rect,      vf);

libavfilter/version.h

@@ -30,7 +30,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVFILTER_VERSION_MAJOR   6
-#define LIBAVFILTER_VERSION_MINOR  31
+#define LIBAVFILTER_VERSION_MINOR  32
 #define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \

libavfilter/vf_fieldhint.c

@@ -0,0 +1,280 @@
+/*
+ * Copyright (c) 2016 Paul B Mahol
+ *
+ * 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/imgutils.h"
+#include "libavutil/internal.h"
+#include "libavutil/opt.h"
+#include "libavutil/pixdesc.h"
+#include "avfilter.h"
+#include "internal.h"
+#include "video.h"
+
+typedef struct FieldHintContext {
+    const AVClass *class;
+
+    char *hint_file_str;
+    FILE *hint;
+    int mode;
+
+    AVFrame *frame[3];
+
+    int64_t line;
+    int nb_planes;
+    int eof;
+    int planewidth[4];
+    int planeheight[4];
+} FieldHintContext;
+
+#define OFFSET(x) offsetof(FieldHintContext, x)
+#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
+
+static const AVOption fieldhint_options[] = {
+    { "hint", "set hint file", OFFSET(hint_file_str), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS },
+    { "mode", "set hint mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS, "mode" },
+    {   "absolute", 0, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, FLAGS, "mode" },
+    {   "relative", 0, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, FLAGS, "mode" },
+    { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(fieldhint);
+
+static av_cold int init(AVFilterContext *ctx)
+{
+    FieldHintContext *s = ctx->priv;
+    int ret;
+
+    if (!s->hint_file_str) {
+        av_log(ctx, AV_LOG_ERROR, "Hint file must be set.\n");
+        return AVERROR(EINVAL);
+    }
+    s->hint = fopen(s->hint_file_str, "r");
+    if (!s->hint) {
+        ret = AVERROR(errno);
+        av_log(ctx, AV_LOG_ERROR, "%s: %s\n", s->hint_file_str, av_err2str(ret));
+        return ret;
+    }
+
+    return 0;
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+    AVFilterFormats *pix_fmts = NULL;
+    int fmt, ret;
+
+    for (fmt = 0; av_pix_fmt_desc_get(fmt); fmt++) {
+        const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(fmt);
+        if (!(desc->flags & AV_PIX_FMT_FLAG_HWACCEL ||
+              desc->flags & AV_PIX_FMT_FLAG_PAL     ||
+              desc->flags & AV_PIX_FMT_FLAG_BITSTREAM) &&
+            (ret = ff_add_format(&pix_fmts, fmt)) < 0)
+            return ret;
+    }
+
+    return ff_set_common_formats(ctx, pix_fmts);
+}
+
+static int config_input(AVFilterLink *inlink)
+{
+    FieldHintContext *s = inlink->dst->priv;
+    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
+    int ret;
+
+    if ((ret = av_image_fill_linesizes(s->planewidth, inlink->format, inlink->w)) < 0)
+        return ret;
+
+    s->planeheight[1] = s->planeheight[2] = AV_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);
+
+    return 0;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+    AVFilterContext *ctx = inlink->dst;
+    AVFilterLink *outlink = ctx->outputs[0];
+    FieldHintContext *s = ctx->priv;
+    AVFrame *out, *top, *bottom;
+    char buf[1024] = { 0 };
+    int64_t tf, bf;
+    char hint = '=';
+    int p;
+
+    av_frame_free(&s->frame[0]);
+    s->frame[0] = s->frame[1];
+    s->frame[1] = s->frame[2];
+    s->frame[2] = in;
+    if (!s->frame[1])
+        return 0;
+    else if (!s->frame[0]) {
+        s->frame[0] = av_frame_clone(s->frame[1]);
+        if (!s->frame[0])
+            return AVERROR(ENOMEM);
+    }
+
+    while (1) {
+        if (fgets(buf, sizeof(buf)-1, s->hint)) {
+            s->line++;
+            if (buf[0] == '#' || buf[0] == ';') {
+                continue;
+            } else if (sscanf(buf, "%"PRId64",%"PRId64" %c", &tf, &bf, &hint) == 3) {
+                ;
+            } else if (sscanf(buf, "%"PRId64",%"PRId64"", &tf, &bf) == 2) {
+                ;
+            } else {
+                av_log(ctx, AV_LOG_ERROR, "Invalid entry at line %"PRId64".\n", s->line);
+                return AVERROR_INVALIDDATA;
+            }
+            switch (s->mode) {
+            case 0:
+                if (tf > outlink->frame_count + 1 || tf < FFMAX(0, outlink->frame_count - 1) ||
+                    bf > outlink->frame_count + 1 || bf < FFMAX(0, outlink->frame_count - 1)) {
+                    av_log(ctx, AV_LOG_ERROR, "Out of range frames %"PRId64" and/or %"PRId64" on line %"PRId64" for %"PRId64". input frame.\n", tf, bf, s->line, inlink->frame_count);
+                    return AVERROR_INVALIDDATA;
+                }
+                break;
+            case 1:
+                if (tf > 1 || tf < -1 ||
+                    bf > 1 || bf < -1) {
+                    av_log(ctx, AV_LOG_ERROR, "Out of range %"PRId64" and/or %"PRId64" on line %"PRId64" for %"PRId64". input frame.\n", tf, bf, s->line, inlink->frame_count);
+                    return AVERROR_INVALIDDATA;
+                }
+            };
+            break;
+        } else {
+            av_log(ctx, AV_LOG_ERROR, "Missing entry for %"PRId64". input frame.\n", inlink->frame_count);
+            return AVERROR_INVALIDDATA;
+        }
+    }
+
+    out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+    if (!out)
+        return AVERROR(ENOMEM);
+    av_frame_copy_props(out, s->frame[1]);
+
+    switch (s->mode) {
+    case 0:
+        top    = s->frame[1 + tf - outlink->frame_count];
+        bottom = s->frame[1 + bf - outlink->frame_count];
+        break;
+    case 1:
+        top    = s->frame[1 + tf];
+        bottom = s->frame[1 + bf];
+        break;
+    }
+
+    switch (hint) {
+    case '+':
+        out->interlaced_frame = 1;
+        break;
+    case '-':
+        out->interlaced_frame = 0;
+        break;
+    case '=':
+        break;
+    default:
+        av_log(ctx, AV_LOG_ERROR, "Invalid hint: %c.\n", hint);
+        return AVERROR(EINVAL);
+    }
+
+    for (p = 0; p < s->nb_planes; p++) {
+        av_image_copy_plane(out->data[p],
+                            out->linesize[p] * 2,
+                            top->data[p],
+                            top->linesize[p] * 2,
+                            s->planewidth[p],
+                            (s->planeheight[p] + 1) / 2);
+        av_image_copy_plane(out->data[p] + out->linesize[p],
+                            out->linesize[p] * 2,
+                            bottom->data[p] + bottom->linesize[p],
+                            bottom->linesize[p] * 2,
+                            s->planewidth[p],
+                            (s->planeheight[p] + 1) / 2);
+    }
+
+    return ff_filter_frame(outlink, out);
+}
+
+static int request_frame(AVFilterLink *outlink)
+{
+    AVFilterContext *ctx = outlink->src;
+    FieldHintContext *s = ctx->priv;
+    int ret;
+
+    if (s->eof)
+        return AVERROR_EOF;
+
+    ret = ff_request_frame(ctx->inputs[0]);
+    if (ret == AVERROR_EOF && s->frame[2]) {
+        AVFrame *next = av_frame_clone(s->frame[2]);
+        if (!next)
+            return AVERROR(ENOMEM);
+        ret = filter_frame(ctx->inputs[0], next);
+        s->eof = 1;
+    }
+
+    return ret;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    FieldHintContext *s = ctx->priv;
+
+    if (s->hint)
+        fclose(s->hint);
+    s->hint = NULL;
+
+    av_frame_free(&s->frame[0]);
+    av_frame_free(&s->frame[1]);
+    av_frame_free(&s->frame[2]);
+}
+
+static const AVFilterPad inputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .config_props = config_input,
+        .filter_frame = filter_frame,
+    },
+    { NULL }
+};
+
+static const AVFilterPad outputs[] = {
+    {
+        .name          = "default",
+        .type          = AVMEDIA_TYPE_VIDEO,
+        .request_frame = request_frame,
+    },
+    { NULL }
+};
+
+AVFilter ff_vf_fieldhint = {
+    .name          = "fieldhint",
+    .description   = NULL_IF_CONFIG_SMALL("Field matching using hints."),
+    .priv_size     = sizeof(FieldHintContext),
+    .priv_class    = &fieldhint_class,
+    .init          = init,
+    .uninit        = uninit,
+    .query_formats = query_formats,
+    .inputs        = inputs,
+    .outputs       = outputs,
+};