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libavfilter/vf_vflip.c

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00001 /*
00002  * Copyright (c) 2007 Bobby Bingham
00003  *
00004  * This file is part of FFmpeg.
00005  *
00006  * FFmpeg is free software; you can redistribute it and/or
00007  * modify it under the terms of the GNU Lesser General Public
00008  * License as published by the Free Software Foundation; either
00009  * version 2.1 of the License, or (at your option) any later version.
00010  *
00011  * FFmpeg is distributed in the hope that it will be useful,
00012  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00014  * Lesser General Public License for more details.
00015  *
00016  * You should have received a copy of the GNU Lesser General Public
00017  * License along with FFmpeg; if not, write to the Free Software
00018  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00019  */
00020 
00026 #include "libavutil/pixdesc.h"
00027 #include "avfilter.h"
00028 
00029 typedef struct {
00030     int vsub;   
00031 } FlipContext;
00032 
00033 static int config_input(AVFilterLink *link)
00034 {
00035     FlipContext *flip = link->dst->priv;
00036 
00037     flip->vsub = av_pix_fmt_descriptors[link->format].log2_chroma_h;
00038 
00039     return 0;
00040 }
00041 
00042 static AVFilterBufferRef *get_video_buffer(AVFilterLink *link, int perms,
00043                                         int w, int h)
00044 {
00045     FlipContext *flip = link->dst->priv;
00046     AVFilterBufferRef *picref;
00047     int i;
00048 
00049     if (!(perms & AV_PERM_NEG_LINESIZES))
00050         return avfilter_default_get_video_buffer(link, perms, w, h);
00051 
00052     picref = avfilter_get_video_buffer(link->dst->outputs[0], perms, w, h);
00053     for (i = 0; i < 4; i ++) {
00054         int vsub = i == 1 || i == 2 ? flip->vsub : 0;
00055 
00056         if (picref->data[i]) {
00057             picref->data[i] += ((h >> vsub)-1) * picref->linesize[i];
00058             picref->linesize[i] = -picref->linesize[i];
00059         }
00060     }
00061 
00062     return picref;
00063 }
00064 
00065 static void start_frame(AVFilterLink *link, AVFilterBufferRef *inpicref)
00066 {
00067     FlipContext *flip = link->dst->priv;
00068     AVFilterBufferRef *outpicref = avfilter_ref_buffer(inpicref, ~0);
00069     int i;
00070 
00071     for (i = 0; i < 4; i ++) {
00072         int vsub = i == 1 || i == 2 ? flip->vsub : 0;
00073 
00074         if (outpicref->data[i]) {
00075             outpicref->data[i] += ((link->h >> vsub)-1) * outpicref->linesize[i];
00076             outpicref->linesize[i] = -outpicref->linesize[i];
00077         }
00078     }
00079 
00080     avfilter_start_frame(link->dst->outputs[0], outpicref);
00081 }
00082 
00083 static void draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
00084 {
00085     AVFilterContext *ctx = link->dst;
00086 
00087     avfilter_draw_slice(ctx->outputs[0], link->h - (y+h), h, -1 * slice_dir);
00088 }
00089 
00090 AVFilter avfilter_vf_vflip = {
00091     .name      = "vflip",
00092     .description = NULL_IF_CONFIG_SMALL("Flip the input video vertically."),
00093 
00094     .priv_size = sizeof(FlipContext),
00095 
00096     .inputs    = (AVFilterPad[]) {{ .name             = "default",
00097                                     .type             = AVMEDIA_TYPE_VIDEO,
00098                                     .get_video_buffer = get_video_buffer,
00099                                     .start_frame      = start_frame,
00100                                     .draw_slice       = draw_slice,
00101                                     .config_props     = config_input, },
00102                                   { .name = NULL}},
00103     .outputs   = (AVFilterPad[]) {{ .name             = "default",
00104                                     .type             = AVMEDIA_TYPE_VIDEO, },
00105                                   { .name = NULL}},
00106 };

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