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 /* #define DEBUG */
  27
  28 #include <stdio.h>
  29 #include <string.h>
  30
  31 #include "libavutil/imgutils.h"
  32 #include "libavutil/internal.h"
  33 #include "libavutil/pixdesc.h"
  34 #include "avfilter.h"
  35 #include "formats.h"
  36 #include "internal.h"
  37 #include "video.h"
  38
  39 typedef struct
  40 {
  41     unsigned int dst_tff;      ///< output bff/tff
  42     int          line_size[4]; ///< bytes of pixel data per line for each plane
  43 } FieldOrderContext;
  44
  45 static av_cold int init(AVFilterContext *ctx, const char *args)
  46 {
  47     FieldOrderContext *fieldorder = ctx->priv;
  48
  49     const char *tff = "tff";
  50     const char *bff = "bff";
  51
  52     if (!args) {
  53         fieldorder->dst_tff = 1;
  54     } else if (sscanf(args, "%u", &fieldorder->dst_tff) == 1) {
  55         fieldorder->dst_tff = !!fieldorder->dst_tff;
  56     } else if (!strcmp(tff, args)) {
  57         fieldorder->dst_tff = 1;
  58     } else if (!strcmp(bff, args)) {
  59         fieldorder->dst_tff = 0;
  60     } else {
  61         av_log(ctx, AV_LOG_ERROR, "Invalid argument '%s'.\n", args);
  62         return AVERROR(EINVAL);
  63     }
  64
  65     av_log(ctx, AV_LOG_VERBOSE, "output field order: %s\n",
  66             fieldorder->dst_tff ? tff : bff);
  67
  68     return 0;
  69 }
  70
  71 static int query_formats(AVFilterContext *ctx)
  72 {
  73     AVFilterFormats  *formats;
  74     enum AVPixelFormat pix_fmt;
  75     int              ret;
  76
  77     /** accept any input pixel format that is not hardware accelerated, not
  78      *  a bitstream format, and does not have vertically sub-sampled chroma */
  79     if (ctx->inputs[0]) {
  80         formats = NULL;
  81         for (pix_fmt = 0; pix_fmt < AV_PIX_FMT_NB; pix_fmt++) {
  82             const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
  83             if (!(desc->flags & PIX_FMT_HWACCEL ||
  84                   desc->flags & PIX_FMT_BITSTREAM) &&
  85                 desc->nb_components && !desc->log2_chroma_h &&
  86                 (ret = ff_add_format(&formats, pix_fmt)) < 0) {
  87                 ff_formats_unref(&formats);
  88                 return ret;
  89             }
  90         }
  91         ff_formats_ref(formats, &ctx->inputs[0]->out_formats);
  92         ff_formats_ref(formats, &ctx->outputs[0]->in_formats);
  93     }
  94
  95     return 0;
  96 }
  97
  98 static int config_input(AVFilterLink *inlink)
  99 {
 100     AVFilterContext   *ctx        = inlink->dst;
 101     FieldOrderContext *fieldorder = ctx->priv;
 102     int               plane;
 103
 104     /** full an array with the number of bytes that the video
 105      *  data occupies per line for each plane of the input video */
 106     for (plane = 0; plane < 4; plane++) {
 107         fieldorder->line_size[plane] = av_image_get_linesize(
 108                 inlink->format,
 109                 inlink->w,
 110                 plane);
 111     }
 112
 113     return 0;
 114 }
 115
 116 static AVFrame *get_video_buffer(AVFilterLink *inlink, int w, int h)
 117 {
 118     AVFilterContext   *ctx        = inlink->dst;
 119     AVFilterLink      *outlink    = ctx->outputs[0];
 120
 121     return ff_get_video_buffer(outlink, w, h);
 122 }
 123
 124 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
 125 {
 126     AVFilterContext   *ctx     = inlink->dst;
 127     FieldOrderContext *s       = ctx->priv;
 128     AVFilterLink      *outlink = ctx->outputs[0];
 129     int h, plane, line_step, line_size, line;
 130     uint8_t *data;
 131
 132     if (!frame->interlaced_frame ||
 133         frame->top_field_first == s->dst_tff)
 134         return ff_filter_frame(outlink, frame);
 135
 136     av_dlog(ctx,
 137             "picture will move %s one line\n",
 138             s->dst_tff ? "up" : "down");
 139     h = frame->height;
 140     for (plane = 0; plane < 4 && frame->data[plane]; plane++) {
 141         line_step = frame->linesize[plane];
 142         line_size = s->line_size[plane];
 143         data = frame->data[plane];
 144         if (s->dst_tff) {
 145             /** Move every line up one line, working from
 146              *  the top to the bottom of the frame.
 147              *  The original top line is lost.
 148              *  The new last line is created as a copy of the
 149              *  penultimate line from that field. */
 150             for (line = 0; line < h; line++) {
 151                 if (1 + line < frame->height) {
 152                     memcpy(data, data + line_step, line_size);
 153                 } else {
 154                     memcpy(data, data - line_step - line_step, line_size);
 155                 }
 156                 data += line_step;
 157             }
 158         } else {
 159             /** Move every line down one line, working from
 160              *  the bottom to the top of the frame.
 161              *  The original bottom line is lost.
 162              *  The new first line is created as a copy of the
 163              *  second line from that field. */
 164             data += (h - 1) * line_step;
 165             for (line = h - 1; line >= 0 ; line--) {
 166                 if (line > 0) {
 167                     memcpy(data, data - line_step, line_size);
 168                 } else {
 169                     memcpy(data, data + line_step + line_step, line_size);
 170                 }
 171                 data -= line_step;
 172             }
 173         }
 174     }
 175     frame->top_field_first = s->dst_tff;
 176
 177     return ff_filter_frame(outlink, frame);
 178 }
 179
 180 static const AVFilterPad avfilter_vf_fieldorder_inputs[] = {
 181     {
 182         .name             = "default",
 183         .type             = AVMEDIA_TYPE_VIDEO,
 184         .config_props     = config_input,
 185         .get_video_buffer = get_video_buffer,
 186         .filter_frame     = filter_frame,
 187         .needs_writable   = 1,
 188     },
 189     { NULL }
 190 };
 191
 192 static const AVFilterPad avfilter_vf_fieldorder_outputs[] = {
 193     {
 194         .name = "default",
 195         .type = AVMEDIA_TYPE_VIDEO,
 196     },
 197     { NULL }
 198 };
 199
 200 AVFilter avfilter_vf_fieldorder = {
 201     .name          = "fieldorder",
 202     .description   = NULL_IF_CONFIG_SMALL("Set the field order."),
 203     .init          = init,
 204     .priv_size     = sizeof(FieldOrderContext),
 205     .query_formats = query_formats,
 206     .inputs        = avfilter_vf_fieldorder_inputs,
 207     .outputs       = avfilter_vf_fieldorder_outputs,
 208 };