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 * Copyright (c) 2017 Thomas Mundt <tmundt75@gmail.com>
8 * This file is part of FFmpeg.
10 * FFmpeg is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * FFmpeg is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License along
21 * with FFmpeg; if not, write to the Free Software Foundation, Inc.,
22 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
27 * progressive to interlaced content filter, inspired by heavy debugging of tinterlace filter
30 #include "libavutil/common.h"
31 #include "libavutil/opt.h"
32 #include "libavutil/imgutils.h"
33 #include "libavutil/avassert.h"
37 #include "interlace.h"
41 #define OFFSET(x) offsetof(InterlaceContext, x)
42 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
43 static const AVOption interlace_options[] = {
44 { "scan", "scanning mode", OFFSET(scan),
45 AV_OPT_TYPE_INT, {.i64 = MODE_TFF }, 0, 1, .flags = FLAGS, .unit = "scan" },
46 { "tff", "top field first", 0,
47 AV_OPT_TYPE_CONST, {.i64 = MODE_TFF }, INT_MIN, INT_MAX, .flags = FLAGS, .unit = "scan" },
48 { "bff", "bottom field first", 0,
49 AV_OPT_TYPE_CONST, {.i64 = MODE_BFF }, INT_MIN, INT_MAX, .flags = FLAGS, .unit = "scan" },
50 { "lowpass", "set vertical low-pass filter", OFFSET(lowpass),
51 AV_OPT_TYPE_INT, {.i64 = VLPF_LIN }, 0, 2, .flags = FLAGS, .unit = "lowpass" },
52 { "off", "disable vertical low-pass filter", 0,
53 AV_OPT_TYPE_CONST, {.i64 = VLPF_OFF }, INT_MIN, INT_MAX, .flags = FLAGS, .unit = "lowpass" },
54 { "linear", "linear vertical low-pass filter", 0,
55 AV_OPT_TYPE_CONST, {.i64 = VLPF_LIN }, INT_MIN, INT_MAX, .flags = FLAGS, .unit = "lowpass" },
56 { "complex", "complex vertical low-pass filter", 0,
57 AV_OPT_TYPE_CONST, {.i64 = VLPF_CMP }, INT_MIN, INT_MAX, .flags = FLAGS, .unit = "lowpass" },
61 AVFILTER_DEFINE_CLASS(interlace);
63 static void lowpass_line_c(uint8_t *dstp, ptrdiff_t linesize,
65 ptrdiff_t mref, ptrdiff_t pref)
67 const uint8_t *srcp_above = srcp + mref;
68 const uint8_t *srcp_below = srcp + pref;
70 for (i = 0; i < linesize; i++) {
71 // this calculation is an integer representation of
72 // '0.5 * current + 0.25 * above + 0.25 * below'
73 // '1 +' is for rounding.
74 dstp[i] = (1 + srcp[i] + srcp[i] + srcp_above[i] + srcp_below[i]) >> 2;
78 static void lowpass_line_complex_c(uint8_t *dstp, ptrdiff_t linesize,
80 ptrdiff_t mref, ptrdiff_t pref)
82 const uint8_t *srcp_above = srcp + mref;
83 const uint8_t *srcp_below = srcp + pref;
84 const uint8_t *srcp_above2 = srcp + mref * 2;
85 const uint8_t *srcp_below2 = srcp + pref * 2;
87 for (i = 0; i < linesize; i++) {
88 // this calculation is an integer representation of
89 // '0.75 * current + 0.25 * above + 0.25 * below - 0.125 * above2 - 0.125 * below2'
90 // '4 +' is for rounding.
91 dstp[i] = av_clip_uint8((4 + (srcp[i] << 2)
92 + ((srcp[i] + srcp_above[i] + srcp_below[i]) << 1)
93 - srcp_above2[i] - srcp_below2[i]) >> 3);
97 static const enum AVPixelFormat formats_supported[] = {
98 AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV444P,
99 AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUVA420P,
100 AV_PIX_FMT_GRAY8, AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P,
101 AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_NONE
104 static int query_formats(AVFilterContext *ctx)
106 AVFilterFormats *fmts_list = ff_make_format_list(formats_supported);
108 return AVERROR(ENOMEM);
109 return ff_set_common_formats(ctx, fmts_list);
112 static av_cold void uninit(AVFilterContext *ctx)
114 InterlaceContext *s = ctx->priv;
116 av_frame_free(&s->cur);
117 av_frame_free(&s->next);
120 static int config_out_props(AVFilterLink *outlink)
122 AVFilterContext *ctx = outlink->src;
123 AVFilterLink *inlink = outlink->src->inputs[0];
124 InterlaceContext *s = ctx->priv;
127 av_log(ctx, AV_LOG_ERROR, "input video height is too small\n");
128 return AVERROR_INVALIDDATA;
132 av_log(ctx, AV_LOG_WARNING, "Lowpass filter is disabled, "
133 "the resulting video will be aliased rather than interlaced.\n");
136 outlink->w = inlink->w;
137 outlink->h = inlink->h;
138 outlink->time_base = inlink->time_base;
139 outlink->frame_rate = inlink->frame_rate;
141 outlink->time_base.num *= 2;
142 outlink->frame_rate.den *= 2;
146 if (s->lowpass == VLPF_LIN)
147 s->lowpass_line = lowpass_line_c;
148 else if (s->lowpass == VLPF_CMP)
149 s->lowpass_line = lowpass_line_complex_c;
151 ff_interlace_init_x86(s);
154 av_log(ctx, AV_LOG_VERBOSE, "%s interlacing %s lowpass filter\n",
155 s->scan == MODE_TFF ? "tff" : "bff", (s->lowpass) ? "with" : "without");
160 static void copy_picture_field(InterlaceContext *s,
161 AVFrame *src_frame, AVFrame *dst_frame,
162 AVFilterLink *inlink, enum FieldType field_type,
165 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
166 int hsub = desc->log2_chroma_w;
167 int vsub = desc->log2_chroma_h;
170 for (plane = 0; plane < desc->nb_components; plane++) {
171 int cols = (plane == 1 || plane == 2) ? -(-inlink->w) >> hsub : inlink->w;
172 int lines = (plane == 1 || plane == 2) ? AV_CEIL_RSHIFT(inlink->h, vsub) : inlink->h;
173 uint8_t *dstp = dst_frame->data[plane];
174 const uint8_t *srcp = src_frame->data[plane];
176 av_assert0(cols >= 0 || lines >= 0);
178 lines = (lines + (field_type == FIELD_UPPER)) / 2;
179 if (field_type == FIELD_LOWER) {
180 srcp += src_frame->linesize[plane];
181 dstp += dst_frame->linesize[plane];
183 if (lowpass == VLPF_LIN) {
184 int srcp_linesize = src_frame->linesize[plane] * 2;
185 int dstp_linesize = dst_frame->linesize[plane] * 2;
186 for (j = lines; j > 0; j--) {
187 ptrdiff_t pref = src_frame->linesize[plane];
188 ptrdiff_t mref = -pref;
190 mref = 0; // there is no line above
192 pref = 0; // there is no line below
193 s->lowpass_line(dstp, cols, srcp, mref, pref);
194 dstp += dstp_linesize;
195 srcp += srcp_linesize;
197 } else if (lowpass == VLPF_CMP) {
198 int srcp_linesize = src_frame->linesize[plane] * 2;
199 int dstp_linesize = dst_frame->linesize[plane] * 2;
200 for (j = lines; j > 0; j--) {
201 ptrdiff_t pref = src_frame->linesize[plane];
202 ptrdiff_t mref = -pref;
203 if (j >= (lines - 1))
207 s->lowpass_line(dstp, cols, srcp, mref, pref);
208 dstp += dstp_linesize;
209 srcp += srcp_linesize;
212 av_image_copy_plane(dstp, dst_frame->linesize[plane] * 2,
213 srcp, src_frame->linesize[plane] * 2,
219 static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
221 AVFilterContext *ctx = inlink->dst;
222 AVFilterLink *outlink = ctx->outputs[0];
223 InterlaceContext *s = ctx->priv;
227 av_frame_free(&s->cur);
231 /* we need at least two frames */
232 if (!s->cur || !s->next)
235 if (s->cur->interlaced_frame) {
236 av_log(ctx, AV_LOG_WARNING,
237 "video is already interlaced, adjusting framerate only\n");
238 out = av_frame_clone(s->cur);
240 return AVERROR(ENOMEM);
241 out->pts /= 2; // adjust pts to new framerate
242 ret = ff_filter_frame(outlink, out);
246 tff = (s->scan == MODE_TFF);
247 out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
249 return AVERROR(ENOMEM);
251 av_frame_copy_props(out, s->cur);
252 out->interlaced_frame = 1;
253 out->top_field_first = tff;
254 out->pts /= 2; // adjust pts to new framerate
256 /* copy upper/lower field from cur */
257 copy_picture_field(s, s->cur, out, inlink, tff ? FIELD_UPPER : FIELD_LOWER, s->lowpass);
258 av_frame_free(&s->cur);
260 /* copy lower/upper field from next */
261 copy_picture_field(s, s->next, out, inlink, tff ? FIELD_LOWER : FIELD_UPPER, s->lowpass);
262 av_frame_free(&s->next);
264 ret = ff_filter_frame(outlink, out);
269 static const AVFilterPad inputs[] = {
272 .type = AVMEDIA_TYPE_VIDEO,
273 .filter_frame = filter_frame,
278 static const AVFilterPad outputs[] = {
281 .type = AVMEDIA_TYPE_VIDEO,
282 .config_props = config_out_props,
287 AVFilter ff_vf_interlace = {
289 .description = NULL_IF_CONFIG_SMALL("Convert progressive video into interlaced."),
291 .priv_class = &interlace_class,
292 .priv_size = sizeof(InterlaceContext),
293 .query_formats = query_formats,