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path: root/libavfilter/vf_interlace.c (plain)
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1/*
2 * Copyright (c) 2003 Michael Zucchi <notzed@ximian.com>
3 * Copyright (c) 2010 Baptiste Coudurier
4 * Copyright (c) 2011 Stefano Sabatini
5 * Copyright (c) 2013 Vittorio Giovara <vittorio.giovara@gmail.com>
6 *
7 * This file is part of FFmpeg.
8 *
9 * FFmpeg is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with FFmpeg; if not, write to the Free Software Foundation, Inc.,
21 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
22 */
23
24/**
25 * @file
26 * progressive to interlaced content filter, inspired by heavy debugging of tinterlace filter
27 */
28
29#include "libavutil/common.h"
30#include "libavutil/opt.h"
31#include "libavutil/imgutils.h"
32#include "libavutil/avassert.h"
33
34#include "formats.h"
35#include "avfilter.h"
36#include "interlace.h"
37#include "internal.h"
38#include "video.h"
39
40#define OFFSET(x) offsetof(InterlaceContext, x)
41#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
42static const AVOption interlace_options[] = {
43 { "scan", "scanning mode", OFFSET(scan),
44 AV_OPT_TYPE_INT, {.i64 = MODE_TFF }, 0, 1, .flags = FLAGS, .unit = "scan" },
45 { "tff", "top field first", 0,
46 AV_OPT_TYPE_CONST, {.i64 = MODE_TFF }, INT_MIN, INT_MAX, .flags = FLAGS, .unit = "scan" },
47 { "bff", "bottom field first", 0,
48 AV_OPT_TYPE_CONST, {.i64 = MODE_BFF }, INT_MIN, INT_MAX, .flags = FLAGS, .unit = "scan" },
49 { "lowpass", "set vertical low-pass filter", OFFSET(lowpass),
50 AV_OPT_TYPE_BOOL, {.i64 = 1 }, 0, 1, .flags = FLAGS },
51 { NULL }
52};
53
54AVFILTER_DEFINE_CLASS(interlace);
55
56static void lowpass_line_c(uint8_t *dstp, ptrdiff_t linesize,
57 const uint8_t *srcp,
58 const uint8_t *srcp_above,
59 const uint8_t *srcp_below)
60{
61 int i;
62 for (i = 0; i < linesize; i++) {
63 // this calculation is an integer representation of
64 // '0.5 * current + 0.25 * above + 0.25 * below'
65 // '1 +' is for rounding.
66 dstp[i] = (1 + srcp[i] + srcp[i] + srcp_above[i] + srcp_below[i]) >> 2;
67 }
68}
69
70static const enum AVPixelFormat formats_supported[] = {
71 AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV444P,
72 AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUVA420P,
73 AV_PIX_FMT_GRAY8, AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P,
74 AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_NONE
75};
76
77static int query_formats(AVFilterContext *ctx)
78{
79 AVFilterFormats *fmts_list = ff_make_format_list(formats_supported);
80 if (!fmts_list)
81 return AVERROR(ENOMEM);
82 return ff_set_common_formats(ctx, fmts_list);
83}
84
85static av_cold void uninit(AVFilterContext *ctx)
86{
87 InterlaceContext *s = ctx->priv;
88
89 av_frame_free(&s->cur);
90 av_frame_free(&s->next);
91}
92
93static int config_out_props(AVFilterLink *outlink)
94{
95 AVFilterContext *ctx = outlink->src;
96 AVFilterLink *inlink = outlink->src->inputs[0];
97 InterlaceContext *s = ctx->priv;
98
99 if (inlink->h < 2) {
100 av_log(ctx, AV_LOG_ERROR, "input video height is too small\n");
101 return AVERROR_INVALIDDATA;
102 }
103
104 if (!s->lowpass)
105 av_log(ctx, AV_LOG_WARNING, "Lowpass filter is disabled, "
106 "the resulting video will be aliased rather than interlaced.\n");
107
108 // same input size
109 outlink->w = inlink->w;
110 outlink->h = inlink->h;
111 outlink->time_base = inlink->time_base;
112 outlink->frame_rate = inlink->frame_rate;
113 // half framerate
114 outlink->time_base.num *= 2;
115 outlink->frame_rate.den *= 2;
116
117
118 if (s->lowpass) {
119 s->lowpass_line = lowpass_line_c;
120 if (ARCH_X86)
121 ff_interlace_init_x86(s);
122 }
123
124 av_log(ctx, AV_LOG_VERBOSE, "%s interlacing %s lowpass filter\n",
125 s->scan == MODE_TFF ? "tff" : "bff", (s->lowpass) ? "with" : "without");
126
127 return 0;
128}
129
130static void copy_picture_field(InterlaceContext *s,
131 AVFrame *src_frame, AVFrame *dst_frame,
132 AVFilterLink *inlink, enum FieldType field_type,
133 int lowpass)
134{
135 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
136 int hsub = desc->log2_chroma_w;
137 int vsub = desc->log2_chroma_h;
138 int plane, j;
139
140 for (plane = 0; plane < desc->nb_components; plane++) {
141 int cols = (plane == 1 || plane == 2) ? -(-inlink->w) >> hsub : inlink->w;
142 int lines = (plane == 1 || plane == 2) ? AV_CEIL_RSHIFT(inlink->h, vsub) : inlink->h;
143 uint8_t *dstp = dst_frame->data[plane];
144 const uint8_t *srcp = src_frame->data[plane];
145
146 av_assert0(cols >= 0 || lines >= 0);
147
148 lines = (lines + (field_type == FIELD_UPPER)) / 2;
149 if (field_type == FIELD_LOWER) {
150 srcp += src_frame->linesize[plane];
151 dstp += dst_frame->linesize[plane];
152 }
153 if (lowpass) {
154 int srcp_linesize = src_frame->linesize[plane] * 2;
155 int dstp_linesize = dst_frame->linesize[plane] * 2;
156 for (j = lines; j > 0; j--) {
157 const uint8_t *srcp_above = srcp - src_frame->linesize[plane];
158 const uint8_t *srcp_below = srcp + src_frame->linesize[plane];
159 if (j == lines)
160 srcp_above = srcp; // there is no line above
161 if (j == 1)
162 srcp_below = srcp; // there is no line below
163 s->lowpass_line(dstp, cols, srcp, srcp_above, srcp_below);
164 dstp += dstp_linesize;
165 srcp += srcp_linesize;
166 }
167 } else {
168 av_image_copy_plane(dstp, dst_frame->linesize[plane] * 2,
169 srcp, src_frame->linesize[plane] * 2,
170 cols, lines);
171 }
172 }
173}
174
175static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
176{
177 AVFilterContext *ctx = inlink->dst;
178 AVFilterLink *outlink = ctx->outputs[0];
179 InterlaceContext *s = ctx->priv;
180 AVFrame *out;
181 int tff, ret;
182
183 av_frame_free(&s->cur);
184 s->cur = s->next;
185 s->next = buf;
186
187 /* we need at least two frames */
188 if (!s->cur || !s->next)
189 return 0;
190
191 if (s->cur->interlaced_frame) {
192 av_log(ctx, AV_LOG_WARNING,
193 "video is already interlaced, adjusting framerate only\n");
194 out = av_frame_clone(s->cur);
195 if (!out)
196 return AVERROR(ENOMEM);
197 out->pts /= 2; // adjust pts to new framerate
198 ret = ff_filter_frame(outlink, out);
199 return ret;
200 }
201
202 tff = (s->scan == MODE_TFF);
203 out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
204 if (!out)
205 return AVERROR(ENOMEM);
206
207 av_frame_copy_props(out, s->cur);
208 out->interlaced_frame = 1;
209 out->top_field_first = tff;
210 out->pts /= 2; // adjust pts to new framerate
211
212 /* copy upper/lower field from cur */
213 copy_picture_field(s, s->cur, out, inlink, tff ? FIELD_UPPER : FIELD_LOWER, s->lowpass);
214 av_frame_free(&s->cur);
215
216 /* copy lower/upper field from next */
217 copy_picture_field(s, s->next, out, inlink, tff ? FIELD_LOWER : FIELD_UPPER, s->lowpass);
218 av_frame_free(&s->next);
219
220 ret = ff_filter_frame(outlink, out);
221
222 return ret;
223}
224
225static const AVFilterPad inputs[] = {
226 {
227 .name = "default",
228 .type = AVMEDIA_TYPE_VIDEO,
229 .filter_frame = filter_frame,
230 },
231 { NULL }
232};
233
234static const AVFilterPad outputs[] = {
235 {
236 .name = "default",
237 .type = AVMEDIA_TYPE_VIDEO,
238 .config_props = config_out_props,
239 },
240 { NULL }
241};
242
243AVFilter ff_vf_interlace = {
244 .name = "interlace",
245 .description = NULL_IF_CONFIG_SMALL("Convert progressive video into interlaced."),
246 .uninit = uninit,
247 .priv_class = &interlace_class,
248 .priv_size = sizeof(InterlaceContext),
249 .query_formats = query_formats,
250 .inputs = inputs,
251 .outputs = outputs,
252};
253
generated by cgit at 2024-05-17 02:10:41 (GMT)