2 * Copyright (c) 2011 Stefano Sabatini
3 * Copyright (c) 2010 Baptiste Coudurier
4 * Copyright (c) 2003 Michael Zucchi <notzed@ximian.com>
6 * This file is part of FFmpeg.
8 * FFmpeg is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License along
19 * with FFmpeg if not, write to the Free Software Foundation, Inc.,
20 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
25 * temporal field interlace filter, ported from MPlayer/libmpcodecs
28 #include "libavutil/opt.h"
29 #include "libavutil/imgutils.h"
30 #include "libavutil/avassert.h"
40 MODE_INTERLEAVE_BOTTOM,
47 enum TInterlaceMode mode; ///< interlace mode selected
48 int flags; ///< flags affecting interlacing algorithm
49 int frame; ///< number of the output frame
50 int vsub; ///< chroma vertical subsampling
53 uint8_t *black_data[4]; ///< buffer used to fill padded lines
54 int black_linesize[4];
57 #define OFFSET(x) offsetof(TInterlaceContext, x)
58 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
59 #define TINTERLACE_FLAG_VLPF 01
61 static const AVOption tinterlace_options[] = {
62 {"mode", "select interlace mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=MODE_MERGE}, 0, MODE_NB-1, FLAGS, "mode"},
63 {"merge", "merge fields", 0, AV_OPT_TYPE_CONST, {.i64=MODE_MERGE}, INT_MIN, INT_MAX, FLAGS, "mode"},
64 {"drop_even", "drop even fields", 0, AV_OPT_TYPE_CONST, {.i64=MODE_DROP_EVEN}, INT_MIN, INT_MAX, FLAGS, "mode"},
65 {"drop_odd", "drop odd fields", 0, AV_OPT_TYPE_CONST, {.i64=MODE_DROP_ODD}, INT_MIN, INT_MAX, FLAGS, "mode"},
66 {"pad", "pad alternate lines with black", 0, AV_OPT_TYPE_CONST, {.i64=MODE_PAD}, INT_MIN, INT_MAX, FLAGS, "mode"},
67 {"interleave_top", "interleave top and bottom fields", 0, AV_OPT_TYPE_CONST, {.i64=MODE_INTERLEAVE_TOP}, INT_MIN, INT_MAX, FLAGS, "mode"},
68 {"interleave_bottom", "interleave bottom and top fields", 0, AV_OPT_TYPE_CONST, {.i64=MODE_INTERLEAVE_BOTTOM}, INT_MIN, INT_MAX, FLAGS, "mode"},
69 {"interlacex2", "interlace fields from two consecutive frames", 0, AV_OPT_TYPE_CONST, {.i64=MODE_INTERLACEX2}, INT_MIN, INT_MAX, FLAGS, "mode"},
71 {"flags", "set flags", OFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = 0}, 0, INT_MAX, 0, "flags" },
72 {"low_pass_filter", "enable vertical low-pass filter", 0, AV_OPT_TYPE_CONST, {.i64 = TINTERLACE_FLAG_VLPF}, INT_MIN, INT_MAX, FLAGS, "flags" },
73 {"vlpf", "enable vertical low-pass filter", 0, AV_OPT_TYPE_CONST, {.i64 = TINTERLACE_FLAG_VLPF}, INT_MIN, INT_MAX, FLAGS, "flags" },
78 AVFILTER_DEFINE_CLASS(tinterlace);
80 #define FULL_SCALE_YUVJ_FORMATS \
81 AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P
83 static enum AVPixelFormat full_scale_yuvj_pix_fmts[] = {
84 FULL_SCALE_YUVJ_FORMATS, AV_PIX_FMT_NONE
87 static int query_formats(AVFilterContext *ctx)
89 static const enum AVPixelFormat pix_fmts[] = {
90 AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV444P,
91 AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUVA420P,
92 AV_PIX_FMT_GRAY8, FULL_SCALE_YUVJ_FORMATS,
96 ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
100 static av_cold void uninit(AVFilterContext *ctx)
102 TInterlaceContext *tinterlace = ctx->priv;
104 av_frame_free(&tinterlace->cur );
105 av_frame_free(&tinterlace->next);
106 av_freep(&tinterlace->black_data[0]);
109 static int config_out_props(AVFilterLink *outlink)
111 AVFilterContext *ctx = outlink->src;
112 AVFilterLink *inlink = outlink->src->inputs[0];
113 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(outlink->format);
114 TInterlaceContext *tinterlace = ctx->priv;
116 tinterlace->vsub = desc->log2_chroma_h;
117 outlink->flags |= FF_LINK_FLAG_REQUEST_LOOP;
118 outlink->w = inlink->w;
119 outlink->h = tinterlace->mode == MODE_MERGE || tinterlace->mode == MODE_PAD ?
120 inlink->h*2 : inlink->h;
122 if (tinterlace->mode == MODE_PAD) {
123 uint8_t black[4] = { 16, 128, 128, 16 };
125 if (ff_fmt_is_in(outlink->format, full_scale_yuvj_pix_fmts))
126 black[0] = black[3] = 0;
127 ret = av_image_alloc(tinterlace->black_data, tinterlace->black_linesize,
128 outlink->w, outlink->h, outlink->format, 1);
132 /* fill black picture with black */
133 for (i = 0; i < 4 && tinterlace->black_data[i]; i++) {
134 int h = i == 1 || i == 2 ? FF_CEIL_RSHIFT(outlink->h, desc->log2_chroma_h) : outlink->h;
135 memset(tinterlace->black_data[i], black[i],
136 tinterlace->black_linesize[i] * h);
139 if ((tinterlace->flags & TINTERLACE_FLAG_VLPF)
140 && !(tinterlace->mode == MODE_INTERLEAVE_TOP
141 || tinterlace->mode == MODE_INTERLEAVE_BOTTOM)) {
142 av_log(ctx, AV_LOG_WARNING, "low_pass_filter flag ignored with mode %d\n",
144 tinterlace->flags &= ~TINTERLACE_FLAG_VLPF;
146 av_log(ctx, AV_LOG_VERBOSE, "mode:%d filter:%s h:%d -> h:%d\n",
147 tinterlace->mode, (tinterlace->flags & TINTERLACE_FLAG_VLPF) ? "on" : "off",
148 inlink->h, outlink->h);
153 #define FIELD_UPPER 0
154 #define FIELD_LOWER 1
155 #define FIELD_UPPER_AND_LOWER 2
158 * Copy picture field from src to dst.
160 * @param src_field copy from upper, lower field or both
161 * @param interleave leave a padding line between each copied line
162 * @param dst_field copy to upper or lower field,
163 * only meaningful when interleave is selected
164 * @param flags context flags
167 void copy_picture_field(uint8_t *dst[4], int dst_linesize[4],
168 const uint8_t *src[4], int src_linesize[4],
169 enum AVPixelFormat format, int w, int src_h,
170 int src_field, int interleave, int dst_field,
173 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(format);
174 int plane, vsub = desc->log2_chroma_h;
175 int k = src_field == FIELD_UPPER_AND_LOWER ? 1 : 2;
178 for (plane = 0; plane < desc->nb_components; plane++) {
179 int lines = plane == 1 || plane == 2 ? FF_CEIL_RSHIFT(src_h, vsub) : src_h;
180 int linesize = av_image_get_linesize(format, w, plane);
181 uint8_t *dstp = dst[plane];
182 const uint8_t *srcp = src[plane];
187 lines = (lines + (src_field == FIELD_UPPER)) / k;
188 if (src_field == FIELD_LOWER)
189 srcp += src_linesize[plane];
190 if (interleave && dst_field == FIELD_LOWER)
191 dstp += dst_linesize[plane];
192 if (flags & TINTERLACE_FLAG_VLPF) {
193 // Low-pass filtering is required when creating an interlaced destination from
194 // a progressive source which contains high-frequency vertical detail.
195 // Filtering will reduce interlace 'twitter' and Moire patterning.
196 int srcp_linesize = src_linesize[plane] * k;
197 int dstp_linesize = dst_linesize[plane] * (interleave ? 2 : 1);
198 for (h = lines; h > 0; h--) {
199 const uint8_t *srcp_above = srcp - src_linesize[plane];
200 const uint8_t *srcp_below = srcp + src_linesize[plane];
201 if (h == lines) srcp_above = srcp; // there is no line above
202 if (h == 1) srcp_below = srcp; // there is no line below
203 for (i = 0; i < linesize; i++) {
204 // this calculation is an integer representation of
205 // '0.5 * current + 0.25 * above + 0.25 * below'
206 // '1 +' is for rounding. */
207 dstp[i] = (1 + srcp[i] + srcp[i] + srcp_above[i] + srcp_below[i]) >> 2;
209 dstp += dstp_linesize;
210 srcp += srcp_linesize;
213 av_image_copy_plane(dstp, dst_linesize[plane] * (interleave ? 2 : 1),
214 srcp, src_linesize[plane]*k, linesize, lines);
219 static int filter_frame(AVFilterLink *inlink, AVFrame *picref)
221 AVFilterContext *ctx = inlink->dst;
222 AVFilterLink *outlink = ctx->outputs[0];
223 TInterlaceContext *tinterlace = ctx->priv;
224 AVFrame *cur, *next, *out;
227 av_frame_free(&tinterlace->cur);
228 tinterlace->cur = tinterlace->next;
229 tinterlace->next = picref;
231 cur = tinterlace->cur;
232 next = tinterlace->next;
233 /* we need at least two frames */
234 if (!tinterlace->cur)
237 switch (tinterlace->mode) {
238 case MODE_MERGE: /* move the odd frame into the upper field of the new image, even into
239 * the lower field, generating a double-height video at half framerate */
240 out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
242 return AVERROR(ENOMEM);
243 av_frame_copy_props(out, cur);
244 out->height = outlink->h;
245 out->interlaced_frame = 1;
246 out->top_field_first = 1;
248 /* write odd frame lines into the upper field of the new frame */
249 copy_picture_field(out->data, out->linesize,
250 (const uint8_t **)cur->data, cur->linesize,
251 inlink->format, inlink->w, inlink->h,
252 FIELD_UPPER_AND_LOWER, 1, FIELD_UPPER, tinterlace->flags);
253 /* write even frame lines into the lower field of the new frame */
254 copy_picture_field(out->data, out->linesize,
255 (const uint8_t **)next->data, next->linesize,
256 inlink->format, inlink->w, inlink->h,
257 FIELD_UPPER_AND_LOWER, 1, FIELD_LOWER, tinterlace->flags);
258 av_frame_free(&tinterlace->next);
261 case MODE_DROP_ODD: /* only output even frames, odd frames are dropped; height unchanged, half framerate */
262 case MODE_DROP_EVEN: /* only output odd frames, even frames are dropped; height unchanged, half framerate */
263 out = av_frame_clone(tinterlace->mode == MODE_DROP_EVEN ? cur : next);
264 av_frame_free(&tinterlace->next);
267 case MODE_PAD: /* expand each frame to double height, but pad alternate
268 * lines with black; framerate unchanged */
269 out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
271 return AVERROR(ENOMEM);
272 av_frame_copy_props(out, cur);
273 out->height = outlink->h;
275 field = (1 + tinterlace->frame) & 1 ? FIELD_UPPER : FIELD_LOWER;
276 /* copy upper and lower fields */
277 copy_picture_field(out->data, out->linesize,
278 (const uint8_t **)cur->data, cur->linesize,
279 inlink->format, inlink->w, inlink->h,
280 FIELD_UPPER_AND_LOWER, 1, field, tinterlace->flags);
281 /* pad with black the other field */
282 copy_picture_field(out->data, out->linesize,
283 (const uint8_t **)tinterlace->black_data, tinterlace->black_linesize,
284 inlink->format, inlink->w, inlink->h,
285 FIELD_UPPER_AND_LOWER, 1, !field, tinterlace->flags);
288 /* interleave upper/lower lines from odd frames with lower/upper lines from even frames,
289 * halving the frame rate and preserving image height */
290 case MODE_INTERLEAVE_TOP: /* top field first */
291 case MODE_INTERLEAVE_BOTTOM: /* bottom field first */
292 tff = tinterlace->mode == MODE_INTERLEAVE_TOP;
293 out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
295 return AVERROR(ENOMEM);
296 av_frame_copy_props(out, cur);
297 out->interlaced_frame = 1;
298 out->top_field_first = tff;
300 /* copy upper/lower field from cur */
301 copy_picture_field(out->data, out->linesize,
302 (const uint8_t **)cur->data, cur->linesize,
303 inlink->format, inlink->w, inlink->h,
304 tff ? FIELD_UPPER : FIELD_LOWER, 1, tff ? FIELD_UPPER : FIELD_LOWER,
306 /* copy lower/upper field from next */
307 copy_picture_field(out->data, out->linesize,
308 (const uint8_t **)next->data, next->linesize,
309 inlink->format, inlink->w, inlink->h,
310 tff ? FIELD_LOWER : FIELD_UPPER, 1, tff ? FIELD_LOWER : FIELD_UPPER,
312 av_frame_free(&tinterlace->next);
314 case MODE_INTERLACEX2: /* re-interlace preserving image height, double frame rate */
315 /* output current frame first */
316 out = av_frame_clone(cur);
318 return AVERROR(ENOMEM);
319 out->interlaced_frame = 1;
321 if ((ret = ff_filter_frame(outlink, out)) < 0)
324 /* output mix of current and next frame */
325 tff = next->top_field_first;
326 out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
328 return AVERROR(ENOMEM);
329 av_frame_copy_props(out, next);
330 out->interlaced_frame = 1;
332 /* write current frame second field lines into the second field of the new frame */
333 copy_picture_field(out->data, out->linesize,
334 (const uint8_t **)cur->data, cur->linesize,
335 inlink->format, inlink->w, inlink->h,
336 tff ? FIELD_LOWER : FIELD_UPPER, 1, tff ? FIELD_LOWER : FIELD_UPPER,
338 /* write next frame first field lines into the first field of the new frame */
339 copy_picture_field(out->data, out->linesize,
340 (const uint8_t **)next->data, next->linesize,
341 inlink->format, inlink->w, inlink->h,
342 tff ? FIELD_UPPER : FIELD_LOWER, 1, tff ? FIELD_UPPER : FIELD_LOWER,
349 ret = ff_filter_frame(outlink, out);
355 static const AVFilterPad tinterlace_inputs[] = {
358 .type = AVMEDIA_TYPE_VIDEO,
359 .filter_frame = filter_frame,
364 static const AVFilterPad tinterlace_outputs[] = {
367 .type = AVMEDIA_TYPE_VIDEO,
368 .config_props = config_out_props,
373 AVFilter avfilter_vf_tinterlace = {
374 .name = "tinterlace",
375 .description = NULL_IF_CONFIG_SMALL("Perform temporal field interlacing."),
376 .priv_size = sizeof(TInterlaceContext),
378 .query_formats = query_formats,
379 .inputs = tinterlace_inputs,
380 .outputs = tinterlace_outputs,
381 .priv_class = &tinterlace_class,