2 * This file is part of Libav.
4 * Libav is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * Libav is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License along
15 * with Libav; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
21 * progressive to interlaced content filter, inspired by heavy debugging of tinterlace filter
24 #include "libavutil/common.h"
25 #include "libavutil/opt.h"
26 #include "libavutil/imgutils.h"
27 #include "libavutil/avassert.h"
31 #include "interlace.h"
35 #define OFFSET(x) offsetof(InterlaceContext, x)
36 #define V AV_OPT_FLAG_VIDEO_PARAM
37 static const AVOption options[] = {
38 { "scan", "scanning mode", OFFSET(scan),
39 AV_OPT_TYPE_INT, {.i64 = MODE_TFF }, 0, 1, .flags = V, .unit = "scan" },
40 { "tff", "top field first", 0,
41 AV_OPT_TYPE_CONST, {.i64 = MODE_TFF }, INT_MIN, INT_MAX, .flags = V, .unit = "scan" },
42 { "bff", "bottom field first", 0,
43 AV_OPT_TYPE_CONST, {.i64 = MODE_BFF }, INT_MIN, INT_MAX, .flags = V, .unit = "scan" },
44 { "lowpass", "enable vertical low-pass filter", OFFSET(lowpass),
45 AV_OPT_TYPE_INT, {.i64 = 1 }, 0, 1, .flags = V },
49 static const AVClass class = {
50 .class_name = "interlace filter",
51 .item_name = av_default_item_name,
53 .version = LIBAVUTIL_VERSION_INT,
56 static void lowpass_line_c(uint8_t *dstp, ptrdiff_t linesize,
58 const uint8_t *srcp_above,
59 const uint8_t *srcp_below)
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;
70 static 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
77 static int query_formats(AVFilterContext *ctx)
79 ff_set_common_formats(ctx, ff_make_format_list(formats_supported));
83 static av_cold void uninit(AVFilterContext *ctx)
85 InterlaceContext *s = ctx->priv;
87 av_frame_free(&s->cur);
88 av_frame_free(&s->next);
93 static int config_out_props(AVFilterLink *outlink)
95 AVFilterContext *ctx = outlink->src;
96 AVFilterLink *inlink = outlink->src->inputs[0];
97 InterlaceContext *s = ctx->priv;
100 av_log(ctx, AV_LOG_ERROR, "input video height is too small\n");
101 return AVERROR_INVALIDDATA;
105 av_log(ctx, AV_LOG_WARNING, "***warning*** Lowpass filter is disabled, "
106 "the resulting video will be aliased rather than interlaced.\n");
109 outlink->w = inlink->w;
110 outlink->h = inlink->h;
111 outlink->time_base = inlink->time_base;
113 outlink->time_base.num *= 2;
117 s->lowpass_line = lowpass_line_c;
119 ff_interlace_init_x86(s);
122 av_log(ctx, AV_LOG_VERBOSE, "%s interlacing %s lowpass filter\n",
123 s->scan == MODE_TFF ? "tff" : "bff", (s->lowpass) ? "with" : "without");
128 static void copy_picture_field(InterlaceContext *s,
129 AVFrame *src_frame, AVFrame *dst_frame,
130 AVFilterLink *inlink, enum FieldType field_type,
133 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
134 int vsub = desc->log2_chroma_h;
137 for (plane = 0; plane < desc->nb_components; plane++) {
138 int lines = (plane == 1 || plane == 2) ? -(-inlink->h) >> vsub : inlink->h;
139 ptrdiff_t linesize = av_image_get_linesize(inlink->format, inlink->w, plane);
140 uint8_t *dstp = dst_frame->data[plane];
141 const uint8_t *srcp = src_frame->data[plane];
143 av_assert0(linesize >= 0);
145 lines = (lines + (field_type == FIELD_UPPER)) / 2;
146 if (field_type == FIELD_LOWER)
147 srcp += src_frame->linesize[plane];
148 if (field_type == FIELD_LOWER)
149 dstp += dst_frame->linesize[plane];
151 int srcp_linesize = src_frame->linesize[plane] * 2;
152 int dstp_linesize = dst_frame->linesize[plane] * 2;
153 for (j = lines; j > 0; j--) {
154 const uint8_t *srcp_above = srcp - src_frame->linesize[plane];
155 const uint8_t *srcp_below = srcp + src_frame->linesize[plane];
157 srcp_above = srcp; // there is no line above
159 srcp_below = srcp; // there is no line below
160 s->lowpass_line(dstp, linesize, srcp, srcp_above, srcp_below);
161 dstp += dstp_linesize;
162 srcp += srcp_linesize;
165 av_image_copy_plane(dstp, dst_frame->linesize[plane] * 2,
166 srcp, src_frame->linesize[plane] * 2,
172 static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
174 AVFilterContext *ctx = inlink->dst;
175 AVFilterLink *outlink = ctx->outputs[0];
176 InterlaceContext *s = ctx->priv;
180 av_frame_free(&s->cur);
184 /* we need at least two frames */
185 if (!s->cur || !s->next)
188 if (s->cur->interlaced_frame) {
189 av_log(ctx, AV_LOG_WARNING,
190 "video is already interlaced, adjusting framerate only\n");
191 out = av_frame_clone(s->cur);
193 return AVERROR(ENOMEM);
194 out->pts /= 2; // adjust pts to new framerate
195 ret = ff_filter_frame(outlink, out);
200 tff = (s->scan == MODE_TFF);
201 out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
203 return AVERROR(ENOMEM);
205 av_frame_copy_props(out, s->cur);
206 out->interlaced_frame = 1;
207 out->top_field_first = tff;
208 out->pts /= 2; // adjust pts to new framerate
210 /* copy upper/lower field from cur */
211 copy_picture_field(s, s->cur, out, inlink, tff ? FIELD_UPPER : FIELD_LOWER, s->lowpass);
212 av_frame_free(&s->cur);
214 /* copy lower/upper field from next */
215 copy_picture_field(s, s->next, out, inlink, tff ? FIELD_LOWER : FIELD_UPPER, s->lowpass);
216 av_frame_free(&s->next);
218 ret = ff_filter_frame(outlink, out);
224 static int request_frame(AVFilterLink *outlink)
226 AVFilterContext *ctx = outlink->src;
227 InterlaceContext *s = ctx->priv;
231 while (ret >= 0 && !s->got_output)
232 ret = ff_request_frame(ctx->inputs[0]);
237 static const AVFilterPad inputs[] = {
240 .type = AVMEDIA_TYPE_VIDEO,
241 .filter_frame = filter_frame,
246 static const AVFilterPad outputs[] = {
249 .type = AVMEDIA_TYPE_VIDEO,
250 .config_props = config_out_props,
251 .request_frame = request_frame,
256 AVFilter ff_vf_interlace = {
258 .description = NULL_IF_CONFIG_SMALL("Convert progressive video into interlaced."),
261 .priv_class = &class,
262 .priv_size = sizeof(InterlaceContext),
263 .query_formats = query_formats,