FFmpeg: libavfilter/vf_crop.c Source File

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 "avfilter.h"
00027 #include "libavutil/pixdesc.h"
00028 
00029 typedef struct {
00030     int  x;             
00031     int  y;             
00032     int  w;             
00033     int  h;             
00034 
00035     int bpp;            
00036     int hsub, vsub;     
00037 } CropContext;
00038 
00039 static int query_formats(AVFilterContext *ctx)
00040 {
00041     static const enum PixelFormat pix_fmts[] = {
00042         PIX_FMT_RGB48BE,      PIX_FMT_RGB48LE,
00043         PIX_FMT_ARGB,         PIX_FMT_RGBA,
00044         PIX_FMT_ABGR,         PIX_FMT_BGRA,
00045         PIX_FMT_RGB24,        PIX_FMT_BGR24,
00046         PIX_FMT_RGB565BE,     PIX_FMT_RGB565LE,
00047         PIX_FMT_RGB555BE,     PIX_FMT_RGB555LE,
00048         PIX_FMT_BGR565BE,     PIX_FMT_BGR565LE,
00049         PIX_FMT_BGR555BE,     PIX_FMT_BGR555LE,
00050         PIX_FMT_GRAY16BE,     PIX_FMT_GRAY16LE,
00051         PIX_FMT_YUV420P16LE,  PIX_FMT_YUV420P16BE,
00052         PIX_FMT_YUV422P16LE,  PIX_FMT_YUV422P16BE,
00053         PIX_FMT_YUV444P16LE,  PIX_FMT_YUV444P16BE,
00054         PIX_FMT_YUV444P,      PIX_FMT_YUV422P,
00055         PIX_FMT_YUV420P,      PIX_FMT_YUV411P,
00056         PIX_FMT_YUV410P,      PIX_FMT_YUV440P,
00057         PIX_FMT_YUVJ444P,     PIX_FMT_YUVJ422P,
00058         PIX_FMT_YUVJ420P,     PIX_FMT_YUVJ440P,
00059         PIX_FMT_YUVA420P,
00060         PIX_FMT_RGB8,         PIX_FMT_BGR8,
00061         PIX_FMT_RGB4_BYTE,    PIX_FMT_BGR4_BYTE,
00062         PIX_FMT_PAL8,         PIX_FMT_GRAY8,
00063         PIX_FMT_NONE
00064     };
00065 
00066     avfilter_set_common_formats(ctx, avfilter_make_format_list(pix_fmts));
00067 
00068     return 0;
00069 }
00070 
00071 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
00072 {
00073     CropContext *crop = ctx->priv;
00074 
00075     if (args)
00076         sscanf(args, "%d:%d:%d:%d", &crop->x, &crop->y, &crop->w, &crop->h);
00077 
00078     return 0;
00079 }
00080 
00081 static int config_input(AVFilterLink *link)
00082 {
00083     AVFilterContext *ctx = link->dst;
00084     CropContext *crop = ctx->priv;
00085 
00086     switch (link->format) {
00087     case PIX_FMT_RGB48BE:
00088     case PIX_FMT_RGB48LE:
00089         crop->bpp = 48;
00090         break;
00091     case PIX_FMT_ARGB:
00092     case PIX_FMT_RGBA:
00093     case PIX_FMT_ABGR:
00094     case PIX_FMT_BGRA:
00095         crop->bpp = 32;
00096         break;
00097     case PIX_FMT_RGB24:
00098     case PIX_FMT_BGR24:
00099         crop->bpp = 24;
00100         break;
00101     case PIX_FMT_RGB565BE:
00102     case PIX_FMT_RGB565LE:
00103     case PIX_FMT_RGB555BE:
00104     case PIX_FMT_RGB555LE:
00105     case PIX_FMT_BGR565BE:
00106     case PIX_FMT_BGR565LE:
00107     case PIX_FMT_BGR555BE:
00108     case PIX_FMT_BGR555LE:
00109     case PIX_FMT_GRAY16BE:
00110     case PIX_FMT_GRAY16LE:
00111     case PIX_FMT_YUV420P16LE:
00112     case PIX_FMT_YUV420P16BE:
00113     case PIX_FMT_YUV422P16LE:
00114     case PIX_FMT_YUV422P16BE:
00115     case PIX_FMT_YUV444P16LE:
00116     case PIX_FMT_YUV444P16BE:
00117         crop->bpp = 16;
00118         break;
00119     default:
00120         crop->bpp = 8;
00121     }
00122 
00123     avcodec_get_chroma_sub_sample(link->format, &crop->hsub, &crop->vsub);
00124 
00125     if (crop->w == 0)
00126         crop->w = link->w - crop->x;
00127     if (crop->h == 0)
00128         crop->h = link->h - crop->y;
00129 
00130     crop->x &= ~((1 << crop->hsub) - 1);
00131     crop->y &= ~((1 << crop->vsub) - 1);
00132 
00133     av_log(link->dst, AV_LOG_INFO, "x:%d y:%d w:%d h:%d\n",
00134            crop->x, crop->y, crop->w, crop->h);
00135 
00136     if (crop->x <  0 || crop->y <  0                    ||
00137         crop->w <= 0 || crop->h <= 0                    ||
00138         (unsigned)crop->x + (unsigned)crop->w > link->w ||
00139         (unsigned)crop->y + (unsigned)crop->h > link->h) {
00140         av_log(ctx, AV_LOG_ERROR,
00141                "Output area %d:%d:%d:%d not within the input area 0:0:%d:%d or zero-sized\n",
00142                crop->x, crop->y, crop->w, crop->h, link->w, link->h);
00143         return -1;
00144     }
00145 
00146     return 0;
00147 }
00148 
00149 static int config_output(AVFilterLink *link)
00150 {
00151     CropContext *crop = link->src->priv;
00152 
00153     link->w = crop->w;
00154     link->h = crop->h;
00155 
00156     return 0;
00157 }
00158 
00159 static void start_frame(AVFilterLink *link, AVFilterPicRef *picref)
00160 {
00161     CropContext *crop = link->dst->priv;
00162     AVFilterPicRef *ref2 = avfilter_ref_pic(picref, ~0);
00163     int i;
00164 
00165     ref2->w        = crop->w;
00166     ref2->h        = crop->h;
00167 
00168     ref2->data[0] += crop->y * ref2->linesize[0];
00169     ref2->data[0] += (crop->x * crop->bpp) >> 3;
00170 
00171     if (!(av_pix_fmt_descriptors[link->format].flags & PIX_FMT_PAL)) {
00172         for (i = 1; i < 3; i ++) {
00173             if (ref2->data[i]) {
00174                 ref2->data[i] += (crop->y >> crop->vsub) * ref2->linesize[i];
00175                 ref2->data[i] += ((crop->x * crop->bpp) >> 3) >> crop->hsub;
00176             }
00177         }
00178     }
00179 
00180     /* alpha plane */
00181     if (ref2->data[3]) {
00182         ref2->data[3] += crop->y * ref2->linesize[3];
00183         ref2->data[3] += (crop->x * crop->bpp) >> 3;
00184     }
00185 
00186     avfilter_start_frame(link->dst->outputs[0], ref2);
00187 }
00188 
00189 static void draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
00190 {
00191     AVFilterContext *ctx = link->dst;
00192     CropContext *crop = ctx->priv;
00193 
00194     if (y >= crop->y + crop->h || y + h <= crop->y)
00195         return;
00196 
00197     if (y < crop->y) {
00198         h -= crop->y - y;
00199         y  = crop->y;
00200     }
00201     if (y + h > crop->y + crop->h)
00202         h = crop->y + crop->h - y;
00203 
00204     avfilter_draw_slice(ctx->outputs[0], y - crop->y, h, slice_dir);
00205 }
00206 
00207 AVFilter avfilter_vf_crop = {
00208     .name      = "crop",
00209     .description = NULL_IF_CONFIG_SMALL("Crop the input video to x:y:width:height."),
00210 
00211     .priv_size = sizeof(CropContext),
00212 
00213     .query_formats = query_formats,
00214     .init          = init,
00215 
00216     .inputs    = (AVFilterPad[]) {{ .name             = "default",
00217                                     .type             = AVMEDIA_TYPE_VIDEO,
00218                                     .start_frame      = start_frame,
00219                                     .draw_slice       = draw_slice,
00220                                     .get_video_buffer = avfilter_null_get_video_buffer,
00221                                     .config_props     = config_input, },
00222                                   { .name = NULL}},
00223     .outputs   = (AVFilterPad[]) {{ .name             = "default",
00224                                     .type             = AVMEDIA_TYPE_VIDEO,
00225                                     .config_props     = config_output, },
00226                                   { .name = NULL}},
00227 };