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vf_fieldorder.c
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1 /*
2  * Copyright (c) 2011 Mark Himsley
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
23  * video field order filter, heavily influenced by vf_pad.c
24  */
25 
26 #include "libavutil/imgutils.h"
27 #include "libavutil/internal.h"
28 #include "libavutil/opt.h"
29 #include "libavutil/pixdesc.h"
30 #include "avfilter.h"
31 #include "formats.h"
32 #include "internal.h"
33 #include "video.h"
34 
35 typedef struct FieldOrderContext {
36  const AVClass *class;
37  int dst_tff; ///< output bff/tff
38  int line_size[4]; ///< bytes of pixel data per line for each plane
40 
42 {
45  int ret;
46 
47  /** accept any input pixel format that is not hardware accelerated, not
48  * a bitstream format, and does not have vertically sub-sampled chroma */
49  if (ctx->inputs[0]) {
50  const AVPixFmtDescriptor *desc = NULL;
51  formats = NULL;
52  while ((desc = av_pix_fmt_desc_next(desc))) {
53  pix_fmt = av_pix_fmt_desc_get_id(desc);
54  if (!(desc->flags & AV_PIX_FMT_FLAG_HWACCEL ||
55  desc->flags & AV_PIX_FMT_FLAG_PAL ||
57  desc->nb_components && !desc->log2_chroma_h &&
58  (ret = ff_add_format(&formats, pix_fmt)) < 0) {
59  ff_formats_unref(&formats);
60  return ret;
61  }
62  }
63  ff_formats_ref(formats, &ctx->inputs[0]->out_formats);
64  ff_formats_ref(formats, &ctx->outputs[0]->in_formats);
65  }
66 
67  return 0;
68 }
69 
70 static int config_input(AVFilterLink *inlink)
71 {
72  AVFilterContext *ctx = inlink->dst;
73  FieldOrderContext *s = ctx->priv;
74 
75  return av_image_fill_linesizes(s->line_size, inlink->format, inlink->w);
76 }
77 
78 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
79 {
80  AVFilterContext *ctx = inlink->dst;
81  FieldOrderContext *s = ctx->priv;
82  AVFilterLink *outlink = ctx->outputs[0];
83  int h, plane, src_line_step, dst_line_step, line_size, line;
84  uint8_t *dst, *src;
85  AVFrame *out;
86 
87  if (!frame->interlaced_frame ||
88  frame->top_field_first == s->dst_tff) {
90  "Skipping %s.\n",
91  frame->interlaced_frame ?
92  "frame with same field order" : "progressive frame");
93  return ff_filter_frame(outlink, frame);
94  }
95 
96  if (av_frame_is_writable(frame)) {
97  out = frame;
98  } else {
99  out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
100  if (!out) {
101  av_frame_free(&frame);
102  return AVERROR(ENOMEM);
103  }
104  av_frame_copy_props(out, frame);
105  }
106 
107  av_dlog(ctx,
108  "picture will move %s one line\n",
109  s->dst_tff ? "up" : "down");
110  h = frame->height;
111  for (plane = 0; plane < 4 && frame->data[plane] && frame->linesize[plane]; plane++) {
112  dst_line_step = out->linesize[plane];
113  src_line_step = frame->linesize[plane];
114  line_size = s->line_size[plane];
115  dst = out->data[plane];
116  src = frame->data[plane];
117  if (s->dst_tff) {
118  /** Move every line up one line, working from
119  * the top to the bottom of the frame.
120  * The original top line is lost.
121  * The new last line is created as a copy of the
122  * penultimate line from that field. */
123  for (line = 0; line < h; line++) {
124  if (1 + line < frame->height) {
125  memcpy(dst, src + src_line_step, line_size);
126  } else {
127  memcpy(dst, src - 2 * src_line_step, line_size);
128  }
129  dst += dst_line_step;
130  src += src_line_step;
131  }
132  } else {
133  /** Move every line down one line, working from
134  * the bottom to the top of the frame.
135  * The original bottom line is lost.
136  * The new first line is created as a copy of the
137  * second line from that field. */
138  dst += (h - 1) * dst_line_step;
139  src += (h - 1) * src_line_step;
140  for (line = h - 1; line >= 0 ; line--) {
141  if (line > 0) {
142  memcpy(dst, src - src_line_step, line_size);
143  } else {
144  memcpy(dst, src + 2 * src_line_step, line_size);
145  }
146  dst -= dst_line_step;
147  src -= src_line_step;
148  }
149  }
150  }
151  out->top_field_first = s->dst_tff;
152 
153  if (frame != out)
154  av_frame_free(&frame);
155  return ff_filter_frame(outlink, out);
156 }
157 
158 #define OFFSET(x) offsetof(FieldOrderContext, x)
159 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
160 
161 static const AVOption fieldorder_options[] = {
162  { "order", "output field order", OFFSET(dst_tff), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, FLAGS, "order" },
163  { "bff", "bottom field first", 0, AV_OPT_TYPE_CONST, { .i64 = 0 }, .flags=FLAGS, .unit = "order" },
164  { "tff", "top field first", 0, AV_OPT_TYPE_CONST, { .i64 = 1 }, .flags=FLAGS, .unit = "order" },
165  { NULL }
166 };
167 
168 AVFILTER_DEFINE_CLASS(fieldorder);
169 
171  {
172  .name = "default",
173  .type = AVMEDIA_TYPE_VIDEO,
174  .config_props = config_input,
175  .filter_frame = filter_frame,
176  },
177  { NULL }
178 };
179 
181  {
182  .name = "default",
183  .type = AVMEDIA_TYPE_VIDEO,
184  },
185  { NULL }
186 };
187 
189  .name = "fieldorder",
190  .description = NULL_IF_CONFIG_SMALL("Set the field order."),
191  .priv_size = sizeof(FieldOrderContext),
192  .priv_class = &fieldorder_class,
194  .inputs = avfilter_vf_fieldorder_inputs,
195  .outputs = avfilter_vf_fieldorder_outputs,
197 };