2 * Copyright (c) 2011 Mark Himsley
4 * This file is part of Libav.
6 * Libav is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * Libav is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with Libav; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 * video field order filter, heavily influenced by vf_pad.c
31 #include "libavutil/imgutils.h"
32 #include "libavutil/internal.h"
33 #include "libavutil/pixdesc.h"
41 unsigned int dst_tff; ///< output bff/tff
42 int line_size[4]; ///< bytes of pixel data per line for each plane
45 static av_cold int init(AVFilterContext *ctx, const char *args)
47 FieldOrderContext *fieldorder = ctx->priv;
49 const char *tff = "tff";
50 const char *bff = "bff";
53 fieldorder->dst_tff = 1;
54 } else if (sscanf(args, "%u", &fieldorder->dst_tff) == 1) {
55 fieldorder->dst_tff = !!fieldorder->dst_tff;
56 } else if (!strcmp(tff, args)) {
57 fieldorder->dst_tff = 1;
58 } else if (!strcmp(bff, args)) {
59 fieldorder->dst_tff = 0;
61 av_log(ctx, AV_LOG_ERROR, "Invalid argument '%s'.\n", args);
62 return AVERROR(EINVAL);
65 av_log(ctx, AV_LOG_VERBOSE, "output field order: %s\n",
66 fieldorder->dst_tff ? tff : bff);
71 static int query_formats(AVFilterContext *ctx)
73 AVFilterFormats *formats;
74 enum AVPixelFormat pix_fmt;
77 /** accept any input pixel format that is not hardware accelerated, not
78 * a bitstream format, and does not have vertically sub-sampled chroma */
81 for (pix_fmt = 0; pix_fmt < AV_PIX_FMT_NB; pix_fmt++) {
82 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
83 if (!(desc->flags & PIX_FMT_HWACCEL ||
84 desc->flags & PIX_FMT_BITSTREAM) &&
85 desc->nb_components && !desc->log2_chroma_h &&
86 (ret = ff_add_format(&formats, pix_fmt)) < 0) {
87 ff_formats_unref(&formats);
91 ff_formats_ref(formats, &ctx->inputs[0]->out_formats);
92 ff_formats_ref(formats, &ctx->outputs[0]->in_formats);
98 static int config_input(AVFilterLink *inlink)
100 AVFilterContext *ctx = inlink->dst;
101 FieldOrderContext *fieldorder = ctx->priv;
104 /** full an array with the number of bytes that the video
105 * data occupies per line for each plane of the input video */
106 for (plane = 0; plane < 4; plane++) {
107 fieldorder->line_size[plane] = av_image_get_linesize(
116 static AVFilterBufferRef *get_video_buffer(AVFilterLink *inlink, int perms, int w, int h)
118 AVFilterContext *ctx = inlink->dst;
119 AVFilterLink *outlink = ctx->outputs[0];
121 return ff_get_video_buffer(outlink, perms, w, h);
124 static int start_frame(AVFilterLink *inlink, AVFilterBufferRef *inpicref)
126 AVFilterContext *ctx = inlink->dst;
127 AVFilterLink *outlink = ctx->outputs[0];
129 AVFilterBufferRef *outpicref, *for_next_filter;
132 outpicref = avfilter_ref_buffer(inpicref, ~0);
134 return AVERROR(ENOMEM);
136 for_next_filter = avfilter_ref_buffer(outpicref, ~0);
137 if (!for_next_filter) {
138 avfilter_unref_bufferp(&outpicref);
139 return AVERROR(ENOMEM);
142 ret = ff_start_frame(outlink, for_next_filter);
144 avfilter_unref_bufferp(&outpicref);
148 outlink->out_buf = outpicref;
152 static int draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
154 AVFilterContext *ctx = inlink->dst;
155 FieldOrderContext *fieldorder = ctx->priv;
156 AVFilterLink *outlink = ctx->outputs[0];
158 AVFilterBufferRef *inpicref = inlink->cur_buf;
160 /** can only currently do slices if this filter is doing nothing
161 * because this filter is moving picture content, the output
162 * slice will contain different video lines than the input slice
163 * and that complexity will be added later */
164 if ( !inpicref->video->interlaced
165 || inpicref->video->top_field_first == fieldorder->dst_tff) {
166 return ff_draw_slice(outlink, y, h, slice_dir);
171 static int end_frame(AVFilterLink *inlink)
173 AVFilterContext *ctx = inlink->dst;
174 FieldOrderContext *fieldorder = ctx->priv;
175 AVFilterLink *outlink = ctx->outputs[0];
177 AVFilterBufferRef *inpicref = inlink->cur_buf;
178 AVFilterBufferRef *outpicref = outlink->out_buf;
180 int h, plane, line_step, line_size, line;
181 uint8_t *cpy_src, *cpy_dst;
183 if ( inpicref->video->interlaced
184 && inpicref->video->top_field_first != fieldorder->dst_tff) {
186 "picture will move %s one line\n",
187 fieldorder->dst_tff ? "up" : "down");
188 h = inpicref->video->h;
189 for (plane = 0; plane < 4 && inpicref->data[plane]; plane++) {
190 line_step = inpicref->linesize[plane];
191 line_size = fieldorder->line_size[plane];
192 cpy_src = inpicref->data[plane];
193 cpy_dst = outpicref->data[plane];
194 if (fieldorder->dst_tff) {
195 /** Move every line up one line, working from
196 * the top to the bottom of the frame.
197 * The original top line is lost.
198 * The new last line is created as a copy of the
199 * penultimate line from that field. */
200 for (line = 0; line < h; line++) {
201 if (1 + line < outpicref->video->h) {
202 memcpy(cpy_dst, cpy_src + line_step, line_size);
204 memcpy(cpy_dst, cpy_src - line_step - line_step, line_size);
206 cpy_src += line_step;
207 cpy_dst += line_step;
210 /** Move every line down one line, working from
211 * the bottom to the top of the frame.
212 * The original bottom line is lost.
213 * The new first line is created as a copy of the
214 * second line from that field. */
215 cpy_src += (h - 1) * line_step;
216 cpy_dst += (h - 1) * line_step;
217 for (line = h - 1; line >= 0 ; line--) {
219 memcpy(cpy_dst, cpy_src - line_step, line_size);
221 memcpy(cpy_dst, cpy_src + line_step + line_step, line_size);
223 cpy_src -= line_step;
224 cpy_dst -= line_step;
228 outpicref->video->top_field_first = fieldorder->dst_tff;
229 ff_draw_slice(outlink, 0, h, 1);
232 "not interlaced or field order already correct\n");
235 return ff_end_frame(outlink);
238 static const AVFilterPad avfilter_vf_fieldorder_inputs[] = {
241 .type = AVMEDIA_TYPE_VIDEO,
242 .config_props = config_input,
243 .start_frame = start_frame,
244 .get_video_buffer = get_video_buffer,
245 .draw_slice = draw_slice,
246 .end_frame = end_frame,
247 .min_perms = AV_PERM_READ,
248 .rej_perms = AV_PERM_REUSE2 | AV_PERM_PRESERVE,
253 static const AVFilterPad avfilter_vf_fieldorder_outputs[] = {
256 .type = AVMEDIA_TYPE_VIDEO,
261 AVFilter avfilter_vf_fieldorder = {
262 .name = "fieldorder",
263 .description = NULL_IF_CONFIG_SMALL("Set the field order."),
265 .priv_size = sizeof(FieldOrderContext),
266 .query_formats = query_formats,
267 .inputs = avfilter_vf_fieldorder_inputs,
268 .outputs = avfilter_vf_fieldorder_outputs,