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
51 AVFilterBufferRef *cur;
52 AVFilterBufferRef *next;
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 int init(AVFilterContext *ctx, const char *args)
102 TInterlaceContext *tinterlace = ctx->priv;
103 static const char *shorthand[] = { "mode", NULL };
105 tinterlace->class = &tinterlace_class;
106 av_opt_set_defaults(tinterlace);
108 return av_opt_set_from_string(tinterlace, args, shorthand, "=", ":");
111 static av_cold void uninit(AVFilterContext *ctx)
113 TInterlaceContext *tinterlace = ctx->priv;
115 avfilter_unref_bufferp(&tinterlace->cur );
116 avfilter_unref_bufferp(&tinterlace->next);
118 av_opt_free(tinterlace);
119 av_freep(&tinterlace->black_data[0]);
122 static int config_out_props(AVFilterLink *outlink)
124 AVFilterContext *ctx = outlink->src;
125 AVFilterLink *inlink = outlink->src->inputs[0];
126 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(outlink->format);
127 TInterlaceContext *tinterlace = ctx->priv;
129 tinterlace->vsub = desc->log2_chroma_h;
130 outlink->w = inlink->w;
131 outlink->h = tinterlace->mode == MODE_MERGE || tinterlace->mode == MODE_PAD ?
132 inlink->h*2 : inlink->h;
134 if (tinterlace->mode == MODE_PAD) {
135 uint8_t black[4] = { 16, 128, 128, 16 };
137 if (ff_fmt_is_in(outlink->format, full_scale_yuvj_pix_fmts))
138 black[0] = black[3] = 0;
139 ret = av_image_alloc(tinterlace->black_data, tinterlace->black_linesize,
140 outlink->w, outlink->h, outlink->format, 1);
144 /* fill black picture with black */
145 for (i = 0; i < 4 && tinterlace->black_data[i]; i++) {
146 int h = i == 1 || i == 2 ? outlink->h >> desc->log2_chroma_h : outlink->h;
147 memset(tinterlace->black_data[i], black[i],
148 tinterlace->black_linesize[i] * h);
151 if ((tinterlace->flags & TINTERLACE_FLAG_VLPF)
152 && !(tinterlace->mode == MODE_INTERLEAVE_TOP
153 || tinterlace->mode == MODE_INTERLEAVE_BOTTOM)) {
154 av_log(ctx, AV_LOG_WARNING, "low_pass_filter flag ignored with mode %d\n",
156 tinterlace->flags &= ~TINTERLACE_FLAG_VLPF;
158 av_log(ctx, AV_LOG_VERBOSE, "mode:%d filter:%s h:%d -> h:%d\n",
159 tinterlace->mode, (tinterlace->flags & TINTERLACE_FLAG_VLPF) ? "on" : "off",
160 inlink->h, outlink->h);
165 #define FIELD_UPPER 0
166 #define FIELD_LOWER 1
167 #define FIELD_UPPER_AND_LOWER 2
170 * Copy picture field from src to dst.
172 * @param src_field copy from upper, lower field or both
173 * @param interleave leave a padding line between each copied line
174 * @param dst_field copy to upper or lower field,
175 * only meaningful when interleave is selected
176 * @param flags context flags
179 void copy_picture_field(uint8_t *dst[4], int dst_linesize[4],
180 const uint8_t *src[4], int src_linesize[4],
181 enum AVPixelFormat format, int w, int src_h,
182 int src_field, int interleave, int dst_field,
185 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(format);
186 int plane, vsub = desc->log2_chroma_h;
187 int k = src_field == FIELD_UPPER_AND_LOWER ? 1 : 2;
190 for (plane = 0; plane < desc->nb_components; plane++) {
191 int lines = plane == 1 || plane == 2 ? src_h >> vsub : src_h;
192 int linesize = av_image_get_linesize(format, w, plane);
193 uint8_t *dstp = dst[plane];
194 const uint8_t *srcp = src[plane];
200 if (src_field == FIELD_LOWER)
201 srcp += src_linesize[plane];
202 if (interleave && dst_field == FIELD_LOWER)
203 dstp += dst_linesize[plane];
204 if (flags & TINTERLACE_FLAG_VLPF) {
205 // Low-pass filtering is required when creating an interlaced destination from
206 // a progressive source which contains high-frequency vertical detail.
207 // Filtering will reduce interlace 'twitter' and Moire patterning.
208 int srcp_linesize = src_linesize[plane] * k;
209 int dstp_linesize = dst_linesize[plane] * (interleave ? 2 : 1);
210 for (h = lines; h > 0; h--) {
211 const uint8_t *srcp_above = srcp - src_linesize[plane];
212 const uint8_t *srcp_below = srcp + src_linesize[plane];
213 if (h == lines) srcp_above = srcp; // there is no line above
214 if (h == 1) srcp_below = srcp; // there is no line below
215 for (i = 0; i < linesize; i++) {
216 // this calculation is an integer representation of
217 // '0.5 * current + 0.25 * above + 0.25 + below'
218 // '1 +' is for rounding. */
219 dstp[i] = (1 + srcp[i] + srcp[i] + srcp_above[i] + srcp_below[i]) >> 2;
221 dstp += dstp_linesize;
222 srcp += srcp_linesize;
225 av_image_copy_plane(dstp, dst_linesize[plane] * (interleave ? 2 : 1),
226 srcp, src_linesize[plane]*k, linesize, lines);
231 static int filter_frame(AVFilterLink *inlink, AVFilterBufferRef *picref)
233 AVFilterContext *ctx = inlink->dst;
234 AVFilterLink *outlink = ctx->outputs[0];
235 TInterlaceContext *tinterlace = ctx->priv;
236 AVFilterBufferRef *cur, *next, *out;
239 avfilter_unref_buffer(tinterlace->cur);
240 tinterlace->cur = tinterlace->next;
241 tinterlace->next = picref;
243 cur = tinterlace->cur;
244 next = tinterlace->next;
245 /* we need at least two frames */
246 if (!tinterlace->cur)
249 switch (tinterlace->mode) {
250 case MODE_MERGE: /* move the odd frame into the upper field of the new image, even into
251 * the lower field, generating a double-height video at half framerate */
252 out = ff_get_video_buffer(outlink, AV_PERM_WRITE, outlink->w, outlink->h);
254 return AVERROR(ENOMEM);
255 avfilter_copy_buffer_ref_props(out, cur);
256 out->video->h = outlink->h;
257 out->video->interlaced = 1;
258 out->video->top_field_first = 1;
260 /* write odd frame lines into the upper field of the new frame */
261 copy_picture_field(out->data, out->linesize,
262 (const uint8_t **)cur->data, cur->linesize,
263 inlink->format, inlink->w, inlink->h,
264 FIELD_UPPER_AND_LOWER, 1, FIELD_UPPER, tinterlace->flags);
265 /* write even frame lines into the lower field of the new frame */
266 copy_picture_field(out->data, out->linesize,
267 (const uint8_t **)next->data, next->linesize,
268 inlink->format, inlink->w, inlink->h,
269 FIELD_UPPER_AND_LOWER, 1, FIELD_LOWER, tinterlace->flags);
270 avfilter_unref_bufferp(&tinterlace->next);
273 case MODE_DROP_ODD: /* only output even frames, odd frames are dropped; height unchanged, half framerate */
274 case MODE_DROP_EVEN: /* only output odd frames, even frames are dropped; height unchanged, half framerate */
275 out = avfilter_ref_buffer(tinterlace->mode == MODE_DROP_EVEN ? cur : next, AV_PERM_READ);
276 avfilter_unref_bufferp(&tinterlace->next);
279 case MODE_PAD: /* expand each frame to double height, but pad alternate
280 * lines with black; framerate unchanged */
281 out = ff_get_video_buffer(outlink, AV_PERM_WRITE, outlink->w, outlink->h);
282 avfilter_copy_buffer_ref_props(out, cur);
283 out->video->h = outlink->h;
285 field = (1 + tinterlace->frame) & 1 ? FIELD_UPPER : FIELD_LOWER;
286 /* copy upper and lower fields */
287 copy_picture_field(out->data, out->linesize,
288 (const uint8_t **)cur->data, cur->linesize,
289 inlink->format, inlink->w, inlink->h,
290 FIELD_UPPER_AND_LOWER, 1, field, tinterlace->flags);
291 /* pad with black the other field */
292 copy_picture_field(out->data, out->linesize,
293 (const uint8_t **)tinterlace->black_data, tinterlace->black_linesize,
294 inlink->format, inlink->w, inlink->h,
295 FIELD_UPPER_AND_LOWER, 1, !field, tinterlace->flags);
298 /* interleave upper/lower lines from odd frames with lower/upper lines from even frames,
299 * halving the frame rate and preserving image height */
300 case MODE_INTERLEAVE_TOP: /* top field first */
301 case MODE_INTERLEAVE_BOTTOM: /* bottom field first */
302 tff = tinterlace->mode == MODE_INTERLEAVE_TOP;
303 out = ff_get_video_buffer(outlink, AV_PERM_WRITE, outlink->w, outlink->h);
305 return AVERROR(ENOMEM);
306 avfilter_copy_buffer_ref_props(out, cur);
307 out->video->interlaced = 1;
308 out->video->top_field_first = tff;
310 /* copy upper/lower field from cur */
311 copy_picture_field(out->data, out->linesize,
312 (const uint8_t **)cur->data, cur->linesize,
313 inlink->format, inlink->w, inlink->h,
314 tff ? FIELD_UPPER : FIELD_LOWER, 1, tff ? FIELD_UPPER : FIELD_LOWER,
316 /* copy lower/upper field from next */
317 copy_picture_field(out->data, out->linesize,
318 (const uint8_t **)next->data, next->linesize,
319 inlink->format, inlink->w, inlink->h,
320 tff ? FIELD_LOWER : FIELD_UPPER, 1, tff ? FIELD_LOWER : FIELD_UPPER,
322 avfilter_unref_bufferp(&tinterlace->next);
324 case MODE_INTERLACEX2: /* re-interlace preserving image height, double frame rate */
325 /* output current frame first */
326 out = avfilter_ref_buffer(cur, ~AV_PERM_WRITE);
328 return AVERROR(ENOMEM);
329 out->video->interlaced = 1;
331 if ((ret = ff_filter_frame(outlink, out)) < 0)
334 /* output mix of current and next frame */
335 tff = next->video->top_field_first;
336 out = ff_get_video_buffer(outlink, AV_PERM_WRITE, outlink->w, outlink->h);
338 return AVERROR(ENOMEM);
339 avfilter_copy_buffer_ref_props(out, next);
340 out->video->interlaced = 1;
342 /* write current frame second field lines into the second field of the new frame */
343 copy_picture_field(out->data, out->linesize,
344 (const uint8_t **)cur->data, cur->linesize,
345 inlink->format, inlink->w, inlink->h,
346 tff ? FIELD_LOWER : FIELD_UPPER, 1, tff ? FIELD_LOWER : FIELD_UPPER,
348 /* write next frame first field lines into the first field of the new frame */
349 copy_picture_field(out->data, out->linesize,
350 (const uint8_t **)next->data, next->linesize,
351 inlink->format, inlink->w, inlink->h,
352 tff ? FIELD_UPPER : FIELD_LOWER, 1, tff ? FIELD_UPPER : FIELD_LOWER,
359 ret = ff_filter_frame(outlink, out);
365 static int request_frame(AVFilterLink *outlink)
367 TInterlaceContext *tinterlace = outlink->src->priv;
368 AVFilterLink *inlink = outlink->src->inputs[0];
373 if ((ret = ff_request_frame(inlink)) < 0)
375 } while (!tinterlace->cur);
380 static const AVFilterPad tinterlace_inputs[] = {
383 .type = AVMEDIA_TYPE_VIDEO,
384 .filter_frame = filter_frame,
389 static const AVFilterPad tinterlace_outputs[] = {
392 .type = AVMEDIA_TYPE_VIDEO,
393 .config_props = config_out_props,
394 .request_frame = request_frame,
399 AVFilter avfilter_vf_tinterlace = {
400 .name = "tinterlace",
401 .description = NULL_IF_CONFIG_SMALL("Perform temporal field interlacing."),
402 .priv_size = sizeof(TInterlaceContext),
405 .query_formats = query_formats,
406 .inputs = tinterlace_inputs,
407 .outputs = tinterlace_outputs,
408 .priv_class = &tinterlace_class,