[PATCH 1/1] Add hflip filter.
Stefano Sabatini
stefano.sabatini-lala
Sat Jul 31 02:05:27 CEST 2010
---
doc/filters.texi | 10 +++
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/vf_hflip.c | 168 ++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 180 insertions(+), 0 deletions(-)
create mode 100644 libavfilter/vf_hflip.c
diff --git a/doc/filters.texi b/doc/filters.texi
index 7f0cb71..380d91d 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -56,6 +56,16 @@ The following command:
will convert the input video to the format ``yuv420p''.
+ at section hflip
+
+Flip the input video horizontally.
+
+For example to horizontally flip the video in input with
+ at file{ffmpeg}:
+ at example
+ffmpeg -i in.avi -vf "hflip" out.avi
+ at end example
+
@section noformat
Force libavfilter not to use any of the specified pixel formats for the
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index feef16c..72c510a 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -17,6 +17,7 @@ OBJS = allfilters.o \
OBJS-$(CONFIG_ASPECT_FILTER) += vf_aspect.o
OBJS-$(CONFIG_CROP_FILTER) += vf_crop.o
OBJS-$(CONFIG_FORMAT_FILTER) += vf_format.o
+OBJS-$(CONFIG_HFLIP_FILTER) += vf_hflip.o
OBJS-$(CONFIG_NOFORMAT_FILTER) += vf_format.o
OBJS-$(CONFIG_NULL_FILTER) += vf_null.o
OBJS-$(CONFIG_PAD_FILTER) += vf_pad.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index e8bc771..15596bd 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -37,6 +37,7 @@ void avfilter_register_all(void)
REGISTER_FILTER (ASPECT, aspect, vf);
REGISTER_FILTER (CROP, crop, vf);
REGISTER_FILTER (FORMAT, format, vf);
+ REGISTER_FILTER (HFLIP, hflip, vf);
REGISTER_FILTER (NOFORMAT, noformat, vf);
REGISTER_FILTER (NULL, null, vf);
REGISTER_FILTER (PAD, pad, vf);
diff --git a/libavfilter/vf_hflip.c b/libavfilter/vf_hflip.c
new file mode 100644
index 0000000..62a31bb
--- /dev/null
+++ b/libavfilter/vf_hflip.c
@@ -0,0 +1,168 @@
+/*
+ * Copyright (c) 2007 Benoit Fouet
+ * Copyright (c) 2010 Stefano Sabatini
+ *
+ * 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
+ */
+
+/**
+ * @flip
+ * horizontal flip filter
+ */
+
+#include "avfilter.h"
+#include "libavutil/pixdesc.h"
+
+typedef struct {
+ int max_step[4]; ///< max pixel step for each plane, expressed as a number of bytes
+ int hsub, vsub; ///< chroma subsampling
+} FlipContext;
+
+static int query_formats(AVFilterContext *ctx)
+{
+ static const enum PixelFormat pix_fmts[] = {
+ PIX_FMT_RGB48BE, PIX_FMT_RGB48LE,
+ PIX_FMT_ARGB, PIX_FMT_RGBA,
+ PIX_FMT_ABGR, PIX_FMT_BGRA,
+ PIX_FMT_RGB24, PIX_FMT_BGR24,
+ PIX_FMT_RGB565BE, PIX_FMT_RGB565LE,
+ PIX_FMT_RGB555BE, PIX_FMT_RGB555LE,
+ PIX_FMT_BGR565BE, PIX_FMT_BGR565LE,
+ PIX_FMT_BGR555BE, PIX_FMT_BGR555LE,
+ PIX_FMT_GRAY16BE, PIX_FMT_GRAY16LE,
+ PIX_FMT_YUV420P16LE, PIX_FMT_YUV420P16BE,
+ PIX_FMT_YUV422P16LE, PIX_FMT_YUV422P16BE,
+ PIX_FMT_YUV444P16LE, PIX_FMT_YUV444P16BE,
+ PIX_FMT_YUV444P, PIX_FMT_YUV422P,
+ PIX_FMT_YUV420P, PIX_FMT_YUV411P,
+ PIX_FMT_YUV410P, PIX_FMT_YUV440P,
+ PIX_FMT_YUVJ444P, PIX_FMT_YUVJ422P,
+ PIX_FMT_YUVJ420P, PIX_FMT_YUVJ440P,
+ PIX_FMT_YUVA420P,
+ PIX_FMT_RGB8, PIX_FMT_BGR8,
+ PIX_FMT_RGB4_BYTE, PIX_FMT_BGR4_BYTE,
+ PIX_FMT_PAL8, PIX_FMT_GRAY8,
+ PIX_FMT_NONE
+ };
+
+ avfilter_set_common_formats(ctx, avfilter_make_format_list(pix_fmts));
+ return 0;
+}
+
+static int config_props(AVFilterLink *inlink)
+{
+ FlipContext *flip = inlink->dst->priv;
+ const AVPixFmtDescriptor *pix_desc = &av_pix_fmt_descriptors[inlink->format];
+ int i;
+
+ memset(flip->max_step, 0, sizeof(flip->max_step));
+ for (i = 0; i < 4; i++) {
+ const AVComponentDescriptor *comp = &(pix_desc->comp[i]);
+ if ((comp->step_minus1+1) > flip->max_step[comp->plane])
+ flip->max_step[comp->plane] = comp->step_minus1+1;
+ }
+
+ flip->hsub = av_pix_fmt_descriptors[inlink->format].log2_chroma_w;
+ flip->vsub = av_pix_fmt_descriptors[inlink->format].log2_chroma_h;
+
+ return 0;
+}
+
+static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
+{
+ FlipContext *flip = inlink->dst->priv;
+ AVFilterBufferRef *inpic = inlink->cur_buf;
+ AVFilterBufferRef *outpic = inlink->dst->outputs[0]->out_buf;
+ uint8_t *inrow, *outrow;
+ int i, j, plane, step, hsub, vsub;
+
+ for (plane = 0; plane < 4 && inpic->data[plane]; plane++) {
+ step = flip->max_step[plane];
+ hsub = (plane == 1 || plane == 2) ? flip->hsub : 0;
+ vsub = (plane == 1 || plane == 2) ? flip->vsub : 0;
+
+ outrow = outpic->data[plane] + (y>>vsub) * outpic->linesize[plane];
+ inrow = inpic ->data[plane] + (y>>vsub) * inpic ->linesize[plane] + ((inlink->w >> hsub) - 1) * step;
+ for (i = 0; i < h>>vsub; i++) {
+ switch (step) {
+ case 1:
+ {
+ for (j = 0; j < (inlink->w >> hsub); j++)
+ outrow[j] = inrow[-j];
+ }
+ break;
+
+ case 2:
+ {
+ uint16_t *outrow16 = (uint16_t *)outrow;
+ uint16_t * inrow16 = (uint16_t *) inrow;
+ for (j = 0; j < (inlink->w >> hsub); j++)
+ outrow16[j] = inrow16[-j];
+ }
+ break;
+
+ case 3:
+ {
+ uint8_t *in = inrow;
+ uint8_t *out = outrow;
+ for (j = 0; j < (inlink->w >> hsub); j++, out += 3, in -= 3) {
+ out[0] = in[0];
+ out[1] = in[1];
+ out[2] = in[2];
+ }
+ }
+ break;
+
+ case 4:
+ {
+ uint32_t *outrow32 = (uint32_t *)outrow;
+ uint32_t * inrow32 = (uint32_t *) inrow;
+ for (j = 0; j < (inlink->w >> hsub); j++)
+ outrow32[j] = inrow32[-j];
+ }
+ break;
+
+ default:
+ for (j = 0; j < (inlink->w >> hsub); j++)
+ memcpy(outrow + j*step, inrow - j*step, step);
+ }
+
+ inrow += inpic ->linesize[plane];
+ outrow += outpic->linesize[plane];
+ }
+ }
+
+ avfilter_draw_slice(inlink->dst->outputs[0], y, h, slice_dir);
+}
+
+AVFilter avfilter_vf_hflip = {
+ .name = "hflip",
+ .description = NULL_IF_CONFIG_SMALL("Horizontally flip the input video"),
+ .priv_size = sizeof(FlipContext),
+ .query_formats = query_formats,
+
+ .inputs = (AVFilterPad[]) {{ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .draw_slice = draw_slice,
+ .config_props = config_props,
+ .min_perms = AV_PERM_READ, },
+ { .name = NULL}},
+ .outputs = (AVFilterPad[]) {{ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO, },
+ { .name = NULL}},
+};
+
--
1.7.0.4
--qMm9M+Fa2AknHoGS--
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