[FFmpeg-devel] [SOCIS] Porting vf_field.c from libmpcodecs [WIP]

[David Keller]

Hi,

I am in the process of porting the filter vf_field.c from libmpcodecs and
almost done. I just haven't figured out which configuration inputs I should
support and the formats in query_format are presumably not complete.

I have attached the code I've written so far.

David
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diff --git a/libavfilter/vf_field.c b/libavfilter/vf_field.c
new file mode 100644
index 0000000..687b504
--- /dev/null
+++ b/libavfilter/vf_field.c
@@ -0,0 +1,162 @@
+/* This file is part of FFmpeg, ported from MPlayer.
+ *
+ * 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
+ * field filter, ported from MPlayer
+ * libmpcodecs/vf_field.c.
+ */
+
+// Original includes
+/*#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "config.h"
+#include "mp_msg.h"
+
+#include "mp_image.h"
+#include "vf.h"
+*/
+
+#include "libavutil/pixdesc.h"
+#include "avfilter.h"
+#include "libavutil/avassert.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+
+typedef struct {
+    int field;
+} FieldContext;
+
+
+// Still work in progress
+static int config_input(AVFilterLink *inlink)
+{
+    FieldContext *field = inlink->dst->priv;
+
+    return 0;
+}
+
+
+static int end_frame(AVFilterLink *inlink)
+{
+    FieldContext *field = inlink->dst->priv;
+    AVFilterLink *outlink = inlink->dst->outputs[0];
+    AVFilterBufferRef *inpic  = inlink ->cur_buf;
+    AVFilterBufferRef *outpic = outlink->out_buf;
+
+    int ret;
+
+    outpic->data[0] = inpic->data[0] + inpic->linesize[0] * field->field;
+
+    outpic->linesize[0] = 2 * inpic->linesize[0];
+
+//    if (vf->dmpi->flags&MP_IMGFLAG_PLANAR) {
+
+    outpic->data[1] = inpic->data[1];
+
+    inpic->linesize[1] * field->field;
+
+    outpic->linesize[1] = 2 * inpic->linesize[1];
+
+    outpic->data[2] = inpic->data[2] +
+
+                      inpic->linesize[2] * field->field;
+
+    outpic->linesize[2] = 2 * inpic->linesize[2];
+
+/*      else
+        vf->dmpi->planes[1]=mpi->planes[1]; // passthru bgr8 palette!!!
+
+        outpic->data[1] = inpic->data[1]; // passthru bgr8 palette
+*/
+
+    if ((ret = ff_draw_slice(outlink, 0, inpic->video->h, 1)) < 0 ||
+            (ret = ff_end_frame(outlink)) < 0)
+        return ret;
+
+    return 0;
+}
+
+
+static int query_formats(AVFilterContext *ctx)
+{
+    // Presumably not complete
+    static const enum PixelFormat pix_fmts[] = {
+            PIX_FMT_YUV444P,  PIX_FMT_YUV422P,  PIX_FMT_YUV420P,
+            PIX_FMT_YUV411P,  PIX_FMT_YUV410P,
+            PIX_FMT_YUVJ444P, PIX_FMT_YUVJ422P, PIX_FMT_YUVJ420P,
+            PIX_FMT_YUV440P,  PIX_FMT_YUVJ440P
+    };
+
+    ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
+
+    return 0;
+}
+
+/*static void uninit(struct vf_instance *vf)
+{
+        free(vf->priv);
+}*/
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    FieldContext *field = ctx->priv;
+
+    av_freep(&field->field);
+}
+
+static av_cold int init(AVFilterContext *ctx, const char *args)
+{
+    FieldContext *field = ctx->priv;
+
+    if (args)
+        sscanf(args, "%d", field->field);
+
+    return 0;
+}
+
+static int null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
+{
+    return 0;
+}
+
+AVFilter avfilter_vf_field = {
+    .name          = "field",
+    .description   = NULL_IF_CONFIG_SMALL("Extract a single field."),
+
+    .priv_size     = sizeof(FieldContext),
+    .init          = init,
+    .uninit        = uninit,
+    .query_formats = query_formats,
+
+    .inputs    = (const AVFilterPad[]) {
+        { .name             = "default",
+          .type             = AVMEDIA_TYPE_VIDEO,
+          .draw_slice       = null_draw_slice,
+          .config_props     = config_input,
+          .end_frame        = end_frame },
+        { .name = NULL}
+    },
+    .outputs   = (const AVFilterPad[]) {
+        { .name             = "default",
+          .type             = AVMEDIA_TYPE_VIDEO },
+        { .name = NULL}
+    },
+};