libavfilter/vf_crop.c

   1 /*
   2  * copyright (c) 2007 Bobby Bingham
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * FFmpeg is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with FFmpeg; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 /**
  22  * @file libavfilter/vf_crop.c
  23  * video crop filter
  24  */
  25
  26 #include "avfilter.h"
  27
  28 typedef struct {
  29     int  x;             ///< x offset of the non-cropped area with respect to the input area
  30     int  y;             ///< y offset of the non-cropped area with respect to the input area
  31     int  w;             ///< width of the cropped area
  32     int  h;             ///< height of the cropped area
  33
  34     int bpp;            ///< bits per pixel
  35     int hsub, vsub;     ///< chroma subsampling
  36 } CropContext;
  37
  38 static int query_formats(AVFilterContext *ctx)
  39 {
  40     static const enum PixelFormat pix_fmts[] = {
  41         PIX_FMT_RGB48BE,      PIX_FMT_RGB48LE,
  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
  67     return 0;
  68 }
  69
  70 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
  71 {
  72     CropContext *crop = ctx->priv;
  73
  74     if (args)
  75         sscanf(args, "%d:%d:%d:%d", &crop->x, &crop->y, &crop->w, &crop->h);
  76
  77     return 0;
  78 }
  79
  80 static int config_input(AVFilterLink *link)
  81 {
  82     AVFilterContext *ctx = link->dst;
  83     CropContext *crop = ctx->priv;
  84
  85     switch (link->format) {
  86     case PIX_FMT_RGB48BE:
  87     case PIX_FMT_RGB48LE:
  88         crop->bpp = 48;
  89         break;
  90     case PIX_FMT_ARGB:
  91     case PIX_FMT_RGBA:
  92     case PIX_FMT_ABGR:
  93     case PIX_FMT_BGRA:
  94         crop->bpp = 32;
  95         break;
  96     case PIX_FMT_RGB24:
  97     case PIX_FMT_BGR24:
  98         crop->bpp = 24;
  99         break;
 100     case PIX_FMT_RGB565BE:
 101     case PIX_FMT_RGB565LE:
 102     case PIX_FMT_RGB555BE:
 103     case PIX_FMT_RGB555LE:
 104     case PIX_FMT_BGR565BE:
 105     case PIX_FMT_BGR565LE:
 106     case PIX_FMT_BGR555BE:
 107     case PIX_FMT_BGR555LE:
 108     case PIX_FMT_GRAY16BE:
 109     case PIX_FMT_GRAY16LE:
 110     case PIX_FMT_YUV420P16LE:
 111     case PIX_FMT_YUV420P16BE:
 112     case PIX_FMT_YUV422P16LE:
 113     case PIX_FMT_YUV422P16BE:
 114     case PIX_FMT_YUV444P16LE:
 115     case PIX_FMT_YUV444P16BE:
 116         crop->bpp = 16;
 117         break;
 118     default:
 119         crop->bpp = 8;
 120     }
 121
 122     avcodec_get_chroma_sub_sample(link->format, &crop->hsub, &crop->vsub);
 123
 124     if (crop->w == 0)
 125         crop->w = link->w - crop->x;
 126     if (crop->h == 0)
 127         crop->h = link->h - crop->y;
 128
 129     crop->x &= ~((1 << crop->hsub) - 1);
 130     crop->y &= ~((1 << crop->vsub) - 1);
 131
 132     av_log(link->dst, AV_LOG_INFO, "x:%d y:%d w:%d h:%d\n",
 133            crop->x, crop->y, crop->w, crop->h);
 134
 135     if (crop->x <  0 || crop->y <  0                    ||
 136         crop->w <= 0 || crop->h <= 0                    ||
 137         (unsigned)crop->x + (unsigned)crop->w > link->w ||
 138         (unsigned)crop->y + (unsigned)crop->h > link->h) {
 139         av_log(ctx, AV_LOG_ERROR,
 140                "Output area %d:%d:%d:%d not within the input area 0:0:%d:%d or zero-sized\n",
 141                crop->x, crop->y, crop->w, crop->h, link->w, link->h);
 142         return -1;
 143     }
 144
 145     return 0;
 146 }
 147
 148 static int config_output(AVFilterLink *link)
 149 {
 150     CropContext *crop = link->src->priv;
 151
 152     link->w = crop->w;
 153     link->h = crop->h;
 154
 155     return 0;
 156 }
 157
 158 static AVFilterPicRef *get_video_buffer(AVFilterLink *link, int perms,
 159                                         int w, int h)
 160 {
 161     return avfilter_get_video_buffer(link->dst->outputs[0], perms, w, h);
 162 }
 163
 164 static void start_frame(AVFilterLink *link, AVFilterPicRef *picref)
 165 {
 166     CropContext *crop = link->dst->priv;
 167     AVFilterPicRef *ref2 = avfilter_ref_pic(picref, ~0);
 168     int i;
 169
 170     ref2->w        = crop->w;
 171     ref2->h        = crop->h;
 172
 173     ref2->data[0] += crop->y * ref2->linesize[0];
 174     ref2->data[0] += (crop->x * crop->bpp) >> 3;
 175
 176     if (link->format != PIX_FMT_PAL8      &&
 177         link->format != PIX_FMT_BGR4_BYTE &&
 178         link->format != PIX_FMT_RGB4_BYTE &&
 179         link->format != PIX_FMT_BGR8      &&
 180         link->format != PIX_FMT_RGB8) {
 181         for (i = 1; i < 3; i ++) {
 182             if (ref2->data[i]) {
 183                 ref2->data[i] += (crop->y >> crop->vsub) * ref2->linesize[i];
 184                 ref2->data[i] += ((crop->x * crop->bpp) >> 3) >> crop->hsub;
 185             }
 186         }
 187     }
 188
 189     /* alpha plane */
 190     if (ref2->data[3]) {
 191         ref2->data[3] += crop->y * ref2->linesize[3];
 192         ref2->data[3] += (crop->x * crop->bpp) >> 3;
 193     }
 194
 195     avfilter_start_frame(link->dst->outputs[0], ref2);
 196 }
 197
 198 static void draw_slice(AVFilterLink *link, int y, int h)
 199 {
 200     AVFilterContext *ctx = link->dst;
 201     CropContext *crop = ctx->priv;
 202
 203     if (y >= crop->y + crop->h || y + h <= crop->y)
 204         return;
 205
 206     if (y < crop->y) {
 207         h -= crop->y - y;
 208         y  = crop->y;
 209     }
 210     if (y + h > crop->y + crop->h)
 211         h = crop->y + crop->h - y;
 212
 213     avfilter_draw_slice(ctx->outputs[0], y - crop->y, h);
 214 }
 215
 216 AVFilter avfilter_vf_crop = {
 217     .name      = "crop",
 218     .description = NULL_IF_CONFIG_SMALL("Crop the input video to x:y:width:height."),
 219
 220     .priv_size = sizeof(CropContext),
 221
 222     .query_formats = query_formats,
 223     .init          = init,
 224
 225     .inputs    = (AVFilterPad[]) {{ .name             = "default",
 226                                     .type             = CODEC_TYPE_VIDEO,
 227                                     .start_frame      = start_frame,
 228                                     .draw_slice       = draw_slice,
 229                                     .get_video_buffer = get_video_buffer,
 230                                     .config_props     = config_input, },
 231                                   { .name = NULL}},
 232     .outputs   = (AVFilterPad[]) {{ .name             = "default",
 233                                     .type             = CODEC_TYPE_VIDEO,
 234                                     .config_props     = config_output, },
 235                                   { .name = NULL}},
 236 };