libavfilter/vf_fieldorder.c

   1 /*
   2  * Copyright (c) 2011 Mark Himsley
   3  *
   4  * This file is part of Libav.
   5  *
   6  * Libav 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  * Libav 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 Libav; 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
  23  * video field order filter, heavily influenced by vf_pad.c
  24  */
  25
  26 #include <stdio.h>
  27 #include <string.h>
  28
  29 #include "libavutil/imgutils.h"
  30 #include "libavutil/internal.h"
  31 #include "libavutil/opt.h"
  32 #include "libavutil/pixdesc.h"
  33 #include "avfilter.h"
  34 #include "formats.h"
  35 #include "internal.h"
  36 #include "video.h"
  37
  38 typedef struct FieldOrderContext {
  39     const AVClass *class;
  40     int dst_tff;               ///< output bff/tff
  41     int          line_size[4]; ///< bytes of pixel data per line for each plane
  42 } FieldOrderContext;
  43
  44 static int query_formats(AVFilterContext *ctx)
  45 {
  46     AVFilterFormats  *formats;
  47     enum AVPixelFormat pix_fmt;
  48     int              ret;
  49
  50     /** accept any input pixel format that is not hardware accelerated, not
  51      *  a bitstream format, and does not have vertically sub-sampled chroma */
  52     if (ctx->inputs[0]) {
  53         const AVPixFmtDescriptor *desc = NULL;
  54         formats = NULL;
  55         while ((desc = av_pix_fmt_desc_next(desc))) {
  56             pix_fmt = av_pix_fmt_desc_get_id(desc);
  57             if (!(desc->flags & AV_PIX_FMT_FLAG_HWACCEL ||
  58                   desc->flags & AV_PIX_FMT_FLAG_BITSTREAM) &&
  59                 desc->nb_components && !desc->log2_chroma_h &&
  60                 (ret = ff_add_format(&formats, pix_fmt)) < 0) {
  61                 ff_formats_unref(&formats);
  62                 return ret;
  63             }
  64         }
  65         ff_formats_ref(formats, &ctx->inputs[0]->out_formats);
  66         ff_formats_ref(formats, &ctx->outputs[0]->in_formats);
  67     }
  68
  69     return 0;
  70 }
  71
  72 static int config_input(AVFilterLink *inlink)
  73 {
  74     AVFilterContext   *ctx = inlink->dst;
  75     FieldOrderContext *s   = ctx->priv;
  76     int               plane;
  77
  78     /** full an array with the number of bytes that the video
  79      *  data occupies per line for each plane of the input video */
  80     for (plane = 0; plane < 4; plane++) {
  81         s->line_size[plane] = av_image_get_linesize(inlink->format, inlink->w,
  82                                                     plane);
  83     }
  84
  85     return 0;
  86 }
  87
  88 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
  89 {
  90     AVFilterContext   *ctx     = inlink->dst;
  91     FieldOrderContext *s       = ctx->priv;
  92     AVFilterLink      *outlink = ctx->outputs[0];
  93     int h, plane, line_step, line_size, line;
  94     uint8_t *data;
  95
  96     if (!frame->interlaced_frame ||
  97         frame->top_field_first == s->dst_tff) {
  98         av_log(ctx, AV_LOG_VERBOSE,
  99                "Skipping %s.\n",
 100                frame->interlaced_frame ?
 101                "frame with same field order" : "progressive frame");
 102         return ff_filter_frame(outlink, frame);
 103     }
 104
 105     av_log(ctx, AV_LOG_TRACE,
 106             "picture will move %s one line\n",
 107             s->dst_tff ? "up" : "down");
 108     h = frame->height;
 109     for (plane = 0; plane < 4 && frame->data[plane]; plane++) {
 110         line_step = frame->linesize[plane];
 111         line_size = s->line_size[plane];
 112         data = frame->data[plane];
 113         if (s->dst_tff) {
 114             /** Move every line up one line, working from
 115              *  the top to the bottom of the frame.
 116              *  The original top line is lost.
 117              *  The new last line is created as a copy of the
 118              *  penultimate line from that field. */
 119             for (line = 0; line < h; line++) {
 120                 if (1 + line < frame->height) {
 121                     memcpy(data, data + line_step, line_size);
 122                 } else {
 123                     memcpy(data, data - line_step - line_step, line_size);
 124                 }
 125                 data += line_step;
 126             }
 127         } else {
 128             /** Move every line down one line, working from
 129              *  the bottom to the top of the frame.
 130              *  The original bottom line is lost.
 131              *  The new first line is created as a copy of the
 132              *  second line from that field. */
 133             data += (h - 1) * line_step;
 134             for (line = h - 1; line >= 0 ; line--) {
 135                 if (line > 0) {
 136                     memcpy(data, data - line_step, line_size);
 137                 } else {
 138                     memcpy(data, data + line_step + line_step, line_size);
 139                 }
 140                 data -= line_step;
 141             }
 142         }
 143     }
 144     frame->top_field_first = s->dst_tff;
 145
 146     return ff_filter_frame(outlink, frame);
 147 }
 148
 149 #define OFFSET(x) offsetof(FieldOrderContext, x)
 150 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM
 151 static const AVOption options[] = {
 152     { "order", "output field order", OFFSET(dst_tff), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, FLAGS, "order" },
 153         { "bff", "bottom field first", 0, AV_OPT_TYPE_CONST, { .i64 = 0 }, .unit = "order" },
 154         { "tff", "top field first",    0, AV_OPT_TYPE_CONST, { .i64 = 1 }, .unit = "order" },
 155     { NULL },
 156 };
 157
 158 static const AVClass fieldorder_class = {
 159     .class_name = "fieldorder",
 160     .item_name  = av_default_item_name,
 161     .option     = options,
 162     .version    = LIBAVUTIL_VERSION_INT,
 163 };
 164
 165 static const AVFilterPad avfilter_vf_fieldorder_inputs[] = {
 166     {
 167         .name             = "default",
 168         .type             = AVMEDIA_TYPE_VIDEO,
 169         .config_props     = config_input,
 170         .filter_frame     = filter_frame,
 171         .needs_writable   = 1,
 172     },
 173     { NULL }
 174 };
 175
 176 static const AVFilterPad avfilter_vf_fieldorder_outputs[] = {
 177     {
 178         .name = "default",
 179         .type = AVMEDIA_TYPE_VIDEO,
 180     },
 181     { NULL }
 182 };
 183
 184 AVFilter ff_vf_fieldorder = {
 185     .name          = "fieldorder",
 186     .description   = NULL_IF_CONFIG_SMALL("Set the field order."),
 187     .priv_size     = sizeof(FieldOrderContext),
 188     .priv_class    = &fieldorder_class,
 189     .query_formats = query_formats,
 190     .inputs        = avfilter_vf_fieldorder_inputs,
 191     .outputs       = avfilter_vf_fieldorder_outputs,
 192 };