Add hflip filter.

Originally committed as revision 24806 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 167 insertions, 0 deletions

diff --git a/libavfilter/vf_hflip.c b/libavfilter/vf_hflip.c
new file mode 100644
index 0000000000..3c1c3e347e
--- /dev/null
+++ b/libavfilter/vf_hflip.c
@@ -0,0 +1,167 @@
+/*
+ * 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"
+#include "libavutil/intreadwrite.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) {
+                    int32_t v = AV_RB24(in);
+                    AV_WB24(out, v);
+                }
+            }
+            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}},
+};