Merge remote-tracking branch 'qatar/master'

* qatar/master:
  FATE: add a test for the interlace filter
  lavfi: new interlace filter

Conflicts:
	Changelog
	configure
	doc/filters.texi
	libavfilter/Makefile
	libavfilter/allfilters.c
	tests/fate/filter.mak

Merged-by: Michael Niedermayer <michaelni@gmx.at>

8 files changed, 320 insertions, 0 deletions

diff --git a/Changelog b/Changelog
index 51f91a918b..22a216bec7 100644
--- a/Changelog
+++ b/Changelog
@@ -20,6 +20,7 @@ version <next>:
 - libquvi demuxer
 - uniform options syntax across all filters
 - telecine filter
+- new interlace filter
 
 
 version 1.2:
diff --git a/configure b/configure
index fe976fd1b4..d6b8dd3497 100755
--- a/configure
+++ b/configure
@@ -2133,6 +2133,7 @@ geq_filter_deps="gpl"
 histeq_filter_deps="gpl"
 hqdn3d_filter_deps="gpl"
 hue_filter_deps="gpl"
+interlace_filter_deps="gpl"
 kerndeint_filter_deps="gpl"
 movie_filter_deps="avcodec avformat"
 mp_filter_deps="gpl avcodec swscale inline_asm"
diff --git a/doc/filters.texi b/doc/filters.texi
index a10d2fc8aa..419b0f39be 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -3774,6 +3774,36 @@ Default value is @code{none}.
 Swap luma/chroma/alpha fields. Exchange even & odd lines. Default value is @code{0}.
 @end table
 
+@section interlace
+
+Simple interlacing filter from progressive contents. This interleaves upper (or
+lower) lines from odd frames with lower (or upper) lines from even frames,
+halving the frame rate and preserving image height.
+
+@example
+   Original        Original             New Frame
+   Frame 'j'      Frame 'j+1'             (tff)
+  ==========      ===========       ==================
+    Line 0  -------------------->    Frame 'j' Line 0
+    Line 1          Line 1  ---->   Frame 'j+1' Line 1
+    Line 2 --------------------->    Frame 'j' Line 2
+    Line 3          Line 3  ---->   Frame 'j+1' Line 3
+     ...             ...                   ...
+New Frame + 1 will be generated by Frame 'j+2' and Frame 'j+3' and so on
+@end example
+
+It accepts the following optional parameters:
+
+@table @option
+@item scan
+determines whether the interlaced frame is taken from the even (tff - default)
+or odd (bff) lines of the progressive frame.
+
+@item lowpass
+Enable (default) or disable the vertical lowpass filter to avoid twitter
+interlacing and reduce moire patterns.
+@end table
+
 @section kerndeint
 
 Deinterlace input video by applying Donald Graft's adaptive kernel
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index c736ad1205..c3cd753557 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -131,6 +131,7 @@ OBJS-$(CONFIG_HQDN3D_FILTER)                 += vf_hqdn3d.o
 OBJS-$(CONFIG_HUE_FILTER)                    += vf_hue.o
 OBJS-$(CONFIG_IDET_FILTER)                   += vf_idet.o
 OBJS-$(CONFIG_IL_FILTER)                     += vf_il.o
+OBJS-$(CONFIG_INTERLACE_FILTER)              += vf_interlace.o
 OBJS-$(CONFIG_KERNDEINT_FILTER)              += vf_kerndeint.o
 OBJS-$(CONFIG_LUT_FILTER)                    += vf_lut.o
 OBJS-$(CONFIG_LUTRGB_FILTER)                 += vf_lut.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 4c8f2b4a59..7e875f68e5 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -129,6 +129,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(HUE,            hue,            vf);
     REGISTER_FILTER(IDET,           idet,           vf);
     REGISTER_FILTER(IL,             il,             vf);
+    REGISTER_FILTER(INTERLACE,      interlace,      vf);
     REGISTER_FILTER(KERNDEINT,      kerndeint,      vf);
     REGISTER_FILTER(LUT,            lut,            vf);
     REGISTER_FILTER(LUTRGB,         lutrgb,         vf);
diff --git a/libavfilter/vf_interlace.c b/libavfilter/vf_interlace.c
new file mode 100755
index 0000000000..8a3a43c50f
--- /dev/null
+++ b/libavfilter/vf_interlace.c
@@ -0,0 +1,257 @@
+/*
+ * Copyright (c) 2003 Michael Zucchi <notzed@ximian.com>
+ * Copyright (c) 2010 Baptiste Coudurier
+ * Copyright (c) 2011 Stefano Sabatini
+ * Copyright (c) 2013 Vittorio Giovara <vittorio.giovara@gmail.com>
+ *
+ * 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
+ * progressive to interlaced content filter, inspired by heavy debugging of tinterlace filter
+ */
+
+#include "libavutil/common.h"
+#include "libavutil/opt.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/avassert.h"
+
+#include "formats.h"
+#include "avfilter.h"
+#include "internal.h"
+#include "video.h"
+
+enum ScanMode {
+    MODE_TFF = 0,
+    MODE_BFF = 1,
+};
+
+enum FieldType {
+    FIELD_UPPER = 0,
+    FIELD_LOWER = 1,
+};
+
+typedef struct {
+    const AVClass *class;
+    enum ScanMode scan;    // top or bottom field first scanning
+    int lowpass;           // enable or disable low pass filterning
+    AVFrame *cur, *next;   // the two frames from which the new one is obtained
+    int got_output;        // signal an output frame is reday to request_frame()
+} InterlaceContext;
+
+#define OFFSET(x) offsetof(InterlaceContext, x)
+#define V AV_OPT_FLAG_VIDEO_PARAM
+static const AVOption options[] = {
+    { "scan", "scanning mode", OFFSET(scan),
+        AV_OPT_TYPE_INT,   {.i64 = MODE_TFF }, 0, 1, .flags = V, .unit = "scan" },
+    { "tff", "top field first", 0,
+        AV_OPT_TYPE_CONST, {.i64 = MODE_TFF }, INT_MIN, INT_MAX, .flags = V, .unit = "scan" },
+    { "bff", "bottom field first", 0,
+        AV_OPT_TYPE_CONST, {.i64 = MODE_BFF }, INT_MIN, INT_MAX, .flags = V, .unit = "scan" },
+    { "lowpass", "enable vertical low-pass filter", OFFSET(lowpass),
+        AV_OPT_TYPE_INT,   {.i64 = 1 },        0, 1, .flags = V },
+    { NULL }
+};
+
+static const AVClass class = {
+    .class_name = "interlace filter",
+    .item_name  = av_default_item_name,
+    .option     = options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
+
+static const enum AVPixelFormat formats_supported[] = {
+    AV_PIX_FMT_YUV420P,  AV_PIX_FMT_YUV422P,  AV_PIX_FMT_YUV444P,
+    AV_PIX_FMT_YUV444P,  AV_PIX_FMT_YUV410P,  AV_PIX_FMT_YUVA420P,
+    AV_PIX_FMT_GRAY8,    AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P,
+    AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_NONE
+};
+
+static int query_formats(AVFilterContext *ctx)
+{
+    ff_set_common_formats(ctx, ff_make_format_list(formats_supported));
+    return 0;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    InterlaceContext *s = ctx->priv;
+
+    av_frame_free(&s->cur);
+    av_frame_free(&s->next);
+
+    av_opt_free(s);
+}
+
+static int config_out_props(AVFilterLink *outlink)
+{
+    AVFilterContext *ctx = outlink->src;
+    AVFilterLink *inlink = outlink->src->inputs[0];
+    InterlaceContext *s = ctx->priv;
+
+    if (inlink->h < 2) {
+        av_log(ctx, AV_LOG_ERROR, "input video height is too small\n");
+        return AVERROR_INVALIDDATA;
+    }
+    // same input size
+    outlink->w = inlink->w;
+    outlink->h = inlink->h;
+    outlink->time_base = inlink->time_base;
+    // half framerate
+    outlink->time_base.num *= 2;
+
+    av_log(ctx, AV_LOG_VERBOSE, "%s interlacing %s lowpass filter\n",
+           s->scan == MODE_TFF ? "tff" : "bff", (s->lowpass) ? "with" : "without");
+
+    return 0;
+}
+
+static void copy_picture_field(AVFrame *src_frame, AVFrame *dst_frame,
+                               AVFilterLink *inlink, enum FieldType field_type,
+                               int lowpass)
+{
+    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
+    int vsub = desc->log2_chroma_h;
+    int plane, i, j;
+
+    for (plane = 0; plane < desc->nb_components; plane++) {
+        int lines = (plane == 1 || plane == 2) ? inlink->h >> vsub : inlink->h;
+        int linesize = av_image_get_linesize(inlink->format, inlink->w, plane);
+        uint8_t *dstp = dst_frame->data[plane];
+        const uint8_t *srcp = src_frame->data[plane];
+
+        av_assert0(linesize >= 0);
+
+        lines /= 2;
+        if (field_type == FIELD_LOWER)
+            srcp += src_frame->linesize[plane];
+        if (field_type == FIELD_LOWER)
+            dstp += dst_frame->linesize[plane];
+        if (lowpass) {
+            int srcp_linesize = src_frame->linesize[plane] * 2;
+            int dstp_linesize = dst_frame->linesize[plane] * 2;
+            for (j = lines; j > 0; j--) {
+                const uint8_t *srcp_above = srcp - src_frame->linesize[plane];
+                const uint8_t *srcp_below = srcp + src_frame->linesize[plane];
+                if (j == lines)
+                    srcp_above = srcp; // there is no line above
+                if (j == 1)
+                    srcp_below = srcp; // there is no line below
+                for (i = 0; i < linesize; i++) {
+                    // this calculation is an integer representation of
+                    // '0.5 * current + 0.25 * above + 0.25 + below'
+                    // '1 +' is for rounding.
+                    dstp[i] = (1 + srcp[i] + srcp[i] + srcp_above[i] + srcp_below[i]) >> 2;
+                }
+                dstp += dstp_linesize;
+                srcp += srcp_linesize;
+            }
+        } else {
+            av_image_copy_plane(dstp, dst_frame->linesize[plane] * 2,
+                                srcp, src_frame->linesize[plane] * 2,
+                                linesize, lines);
+        }
+    }
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
+{
+    AVFilterContext *ctx = inlink->dst;
+    AVFilterLink *outlink = ctx->outputs[0];
+    InterlaceContext *s = ctx->priv;
+    AVFrame *out;
+    int tff, ret;
+
+    av_frame_free(&s->cur);
+    s->cur  = s->next;
+    s->next = buf;
+
+    /* we need at least two frames */
+    if (!s->cur || !s->next)
+        return 0;
+
+    tff = (s->scan == MODE_TFF);
+    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 = 1;
+    out->top_field_first  = tff;
+    out->pts             /= 2;  // adjust pts to new framerate
+
+    /* copy upper/lower field from cur */
+    copy_picture_field(s->cur, out, inlink, tff ? FIELD_UPPER : FIELD_LOWER, s->lowpass);
+    av_frame_free(&s->cur);
+
+    /* copy lower/upper field from next */
+    copy_picture_field(s->next, out, inlink, tff ? FIELD_LOWER : FIELD_UPPER, s->lowpass);
+    av_frame_free(&s->next);
+
+    ret = ff_filter_frame(outlink, out);
+    s->got_output = 1;
+
+    return ret;
+}
+
+static int request_frame(AVFilterLink *outlink)
+{
+    AVFilterContext *ctx = outlink->src;
+    InterlaceContext *s  = ctx->priv;
+    int ret = 0;
+
+    s->got_output = 0;
+    while (ret >= 0 && !s->got_output)
+        ret = ff_request_frame(ctx->inputs[0]);
+
+    return ret;
+}
+
+static const AVFilterPad inputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .filter_frame = filter_frame,
+    },
+    { NULL }
+};
+
+static const AVFilterPad outputs[] = {
+    {
+        .name          = "default",
+        .type          = AVMEDIA_TYPE_VIDEO,
+        .config_props  = config_out_props,
+        .request_frame = request_frame,
+    },
+    { NULL }
+};
+
+AVFilter avfilter_vf_interlace = {
+    .name          = "interlace",
+    .description   = NULL_IF_CONFIG_SMALL("Convert progressive video into interlaced."),
+    .uninit        = uninit,
+
+    .priv_class    = &class,
+    .priv_size     = sizeof(InterlaceContext),
+    .query_formats = query_formats,
+
+    .inputs        = inputs,
+    .outputs       = outputs,
+};
+
diff --git a/tests/fate/filter.mak b/tests/fate/filter.mak
index 43e9fc48f2..721b8840aa 100644
--- a/tests/fate/filter.mak
+++ b/tests/fate/filter.mak
@@ -68,6 +68,9 @@ fate-filter-gradfun: CMD = framecrc -c:v pgmyuv -i $(SRC) -vf gradfun
 FATE_FILTER_VSYNTH-$(CONFIG_HQDN3D_FILTER) += fate-filter-hqdn3d
 fate-filter-hqdn3d: CMD = framecrc -c:v pgmyuv -i $(SRC) -vf hqdn3d
 
+FATE_FILTER_VSYNTH-$(CONFIG_INTERLACE_FILTER) += fate-filter-interlace
+fate-filter-interlace: CMD = framecrc -c:v pgmyuv -i $(SRC) -vf interlace
+
 #FATE_FILTER-$(call FILTERDEMDECENCMUX, JOIN, WAV, PCM_S16LE, PCM_S16LE, PCM_S16LE) += fate-filter-join
 fate-filter-join: SRC1 = $(TARGET_PATH)/tests/data/asynth-44100-2.wav
 fate-filter-join: SRC2 = $(TARGET_PATH)/tests/data/asynth-44100-3.wav
diff --git a/tests/ref/fate/filter-interlace b/tests/ref/fate/filter-interlace
new file mode 100644
index 0000000000..4fa495ca40
--- /dev/null
+++ b/tests/ref/fate/filter-interlace
@@ -0,0 +1,26 @@
+#tb 0: 1/25
+0,          0,          0,        1,   152064, 0x6077db38
+0,          2,          2,        1,   152064, 0x3d4f1b15
+0,          4,          4,        1,   152064, 0x447594f6
+0,          6,          6,        1,   152064, 0xb6258a38
+0,          8,          8,        1,   152064, 0x296abb09
+0,         10,         10,        1,   152064, 0x0fad069d
+0,         12,         12,        1,   152064, 0x92c78c0d
+0,         14,         14,        1,   152064, 0x645531fd
+0,         16,         16,        1,   152064, 0xe7652880
+0,         18,         18,        1,   152064, 0x496e1151
+0,         20,         20,        1,   152064, 0x7f7cfb06
+0,         22,         22,        1,   152064, 0x45e9affe
+0,         24,         24,        1,   152064, 0xaedb2d3a
+0,         26,         26,        1,   152064, 0x03fd9ae6
+0,         28,         28,        1,   152064, 0x2084e84d
+0,         30,         30,        1,   152064, 0xcf05faf6
+0,         32,         32,        1,   152064, 0x84c746c2
+0,         34,         34,        1,   152064, 0x898a6321
+0,         36,         36,        1,   152064, 0xe12b7fe9
+0,         38,         38,        1,   152064, 0x12feb756
+0,         40,         40,        1,   152064, 0xd813601a
+0,         42,         42,        1,   152064, 0xc0f3d385
+0,         44,         44,        1,   152064, 0xfca3a63f
+0,         46,         46,        1,   152064, 0xa0796f44
+0,         48,         48,        1,   152064, 0x1d26af11