libavfilter/vf_hflip.c

   1 /*
   2  * Copyright (c) 2007 Benoit Fouet
   3  * Copyright (c) 2010 Stefano Sabatini
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * Libav is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with Libav; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file
  24  * horizontal flip filter
  25  */
  26
  27 #include "avfilter.h"
  28 #include "libavutil/pixdesc.h"
  29 #include "libavutil/intreadwrite.h"
  30 #include "libavutil/imgutils.h"
  31
  32 typedef struct {
  33     int max_step[4];    ///< max pixel step for each plane, expressed as a number of bytes
  34     int hsub, vsub;     ///< chroma subsampling
  35 } FlipContext;
  36
  37 static int query_formats(AVFilterContext *ctx)
  38 {
  39     static const enum PixelFormat pix_fmts[] = {
  40         PIX_FMT_RGB48BE,      PIX_FMT_RGB48LE,
  41         PIX_FMT_BGR48BE,      PIX_FMT_BGR48LE,
  42         PIX_FMT_ARGB,         PIX_FMT_RGBA,
  43         PIX_FMT_ABGR,         PIX_FMT_BGRA,
  44         PIX_FMT_RGB24,        PIX_FMT_BGR24,
  45         PIX_FMT_RGB565BE,     PIX_FMT_RGB565LE,
  46         PIX_FMT_RGB555BE,     PIX_FMT_RGB555LE,
  47         PIX_FMT_BGR565BE,     PIX_FMT_BGR565LE,
  48         PIX_FMT_BGR555BE,     PIX_FMT_BGR555LE,
  49         PIX_FMT_GRAY16BE,     PIX_FMT_GRAY16LE,
  50         PIX_FMT_YUV420P16LE,  PIX_FMT_YUV420P16BE,
  51         PIX_FMT_YUV422P16LE,  PIX_FMT_YUV422P16BE,
  52         PIX_FMT_YUV444P16LE,  PIX_FMT_YUV444P16BE,
  53         PIX_FMT_YUV444P,      PIX_FMT_YUV422P,
  54         PIX_FMT_YUV420P,      PIX_FMT_YUV411P,
  55         PIX_FMT_YUV410P,      PIX_FMT_YUV440P,
  56         PIX_FMT_YUVJ444P,     PIX_FMT_YUVJ422P,
  57         PIX_FMT_YUVJ420P,     PIX_FMT_YUVJ440P,
  58         PIX_FMT_YUVA420P,
  59         PIX_FMT_RGB8,         PIX_FMT_BGR8,
  60         PIX_FMT_RGB4_BYTE,    PIX_FMT_BGR4_BYTE,
  61         PIX_FMT_PAL8,         PIX_FMT_GRAY8,
  62         PIX_FMT_NONE
  63     };
  64
  65     avfilter_set_common_formats(ctx, avfilter_make_format_list(pix_fmts));
  66     return 0;
  67 }
  68
  69 static int config_props(AVFilterLink *inlink)
  70 {
  71     FlipContext *flip = inlink->dst->priv;
  72     const AVPixFmtDescriptor *pix_desc = &av_pix_fmt_descriptors[inlink->format];
  73
  74     av_image_fill_max_pixsteps(flip->max_step, NULL, pix_desc);
  75     flip->hsub = av_pix_fmt_descriptors[inlink->format].log2_chroma_w;
  76     flip->vsub = av_pix_fmt_descriptors[inlink->format].log2_chroma_h;
  77
  78     return 0;
  79 }
  80
  81 static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
  82 {
  83     FlipContext *flip = inlink->dst->priv;
  84     AVFilterBufferRef *inpic  = inlink->cur_buf;
  85     AVFilterBufferRef *outpic = inlink->dst->outputs[0]->out_buf;
  86     uint8_t *inrow, *outrow;
  87     int i, j, plane, step, hsub, vsub;
  88
  89     for (plane = 0; plane < 4 && inpic->data[plane]; plane++) {
  90         step = flip->max_step[plane];
  91         hsub = (plane == 1 || plane == 2) ? flip->hsub : 0;
  92         vsub = (plane == 1 || plane == 2) ? flip->vsub : 0;
  93
  94         outrow = outpic->data[plane] + (y>>vsub) * outpic->linesize[plane];
  95         inrow  = inpic ->data[plane] + (y>>vsub) * inpic ->linesize[plane] + ((inlink->w >> hsub) - 1) * step;
  96         for (i = 0; i < h>>vsub; i++) {
  97             switch (step) {
  98             case 1:
  99             {
 100                 for (j = 0; j < (inlink->w >> hsub); j++)
 101                     outrow[j] = inrow[-j];
 102             }
 103             break;
 104
 105             case 2:
 106             {
 107                 uint16_t *outrow16 = (uint16_t *)outrow;
 108                 uint16_t * inrow16 = (uint16_t *) inrow;
 109                 for (j = 0; j < (inlink->w >> hsub); j++)
 110                     outrow16[j] = inrow16[-j];
 111             }
 112             break;
 113
 114             case 3:
 115             {
 116                 uint8_t *in  =  inrow;
 117                 uint8_t *out = outrow;
 118                 for (j = 0; j < (inlink->w >> hsub); j++, out += 3, in -= 3) {
 119                     int32_t v = AV_RB24(in);
 120                     AV_WB24(out, v);
 121                 }
 122             }
 123             break;
 124
 125             case 4:
 126             {
 127                 uint32_t *outrow32 = (uint32_t *)outrow;
 128                 uint32_t * inrow32 = (uint32_t *) inrow;
 129                 for (j = 0; j < (inlink->w >> hsub); j++)
 130                     outrow32[j] = inrow32[-j];
 131             }
 132             break;
 133
 134             default:
 135                 for (j = 0; j < (inlink->w >> hsub); j++)
 136                     memcpy(outrow + j*step, inrow - j*step, step);
 137             }
 138
 139             inrow  += inpic ->linesize[plane];
 140             outrow += outpic->linesize[plane];
 141         }
 142     }
 143
 144     avfilter_draw_slice(inlink->dst->outputs[0], y, h, slice_dir);
 145 }
 146
 147 AVFilter avfilter_vf_hflip = {
 148     .name      = "hflip",
 149     .description = NULL_IF_CONFIG_SMALL("Horizontally flip the input video."),
 150     .priv_size = sizeof(FlipContext),
 151     .query_formats = query_formats,
 152
 153     .inputs    = (AVFilterPad[]) {{ .name            = "default",
 154                                     .type            = AVMEDIA_TYPE_VIDEO,
 155                                     .draw_slice      = draw_slice,
 156                                     .config_props    = config_props,
 157                                     .min_perms       = AV_PERM_READ, },
 158                                   { .name = NULL}},
 159     .outputs   = (AVFilterPad[]) {{ .name            = "default",
 160                                     .type            = AVMEDIA_TYPE_VIDEO, },
 161                                   { .name = NULL}},
 162 };