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
28 #include "libavutil/imgutils.h"
29 #include "libavutil/pixdesc.h"
35 unsigned int dst_tff; ///< output bff/tff
36 int line_size[4]; ///< bytes of pixel data per line for each plane
39 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
41 FieldOrderContext *fieldorder = ctx->priv;
43 const char *tff = "tff";
44 const char *bff = "bff";
47 fieldorder->dst_tff = 1;
48 } else if (sscanf(args, "%u", &fieldorder->dst_tff) == 1) {
49 fieldorder->dst_tff = !!fieldorder->dst_tff;
50 } else if (!strcmp(tff, args)) {
51 fieldorder->dst_tff = 1;
52 } else if (!strcmp(bff, args)) {
53 fieldorder->dst_tff = 0;
55 av_log(ctx, AV_LOG_ERROR, "Invalid argument '%s'.\n", args);
56 return AVERROR(EINVAL);
59 av_log(ctx, AV_LOG_INFO, "output field order: %s\n",
60 fieldorder->dst_tff ? tff : bff);
65 static int query_formats(AVFilterContext *ctx)
67 AVFilterFormats *formats;
68 enum PixelFormat pix_fmt;
71 /** accept any input pixel format that is not hardware accelerated, not
72 * a bitstream format, and does not have vertically sub-sampled chroma */
75 for (pix_fmt = 0; pix_fmt < PIX_FMT_NB; pix_fmt++)
76 if (!( av_pix_fmt_descriptors[pix_fmt].flags & PIX_FMT_HWACCEL
77 || av_pix_fmt_descriptors[pix_fmt].flags & PIX_FMT_BITSTREAM)
78 && av_pix_fmt_descriptors[pix_fmt].nb_components
79 && !av_pix_fmt_descriptors[pix_fmt].log2_chroma_h
80 && (ret = ff_add_format(&formats, pix_fmt)) < 0) {
81 ff_formats_unref(&formats);
84 ff_formats_ref(formats, &ctx->inputs[0]->out_formats);
85 ff_formats_ref(formats, &ctx->outputs[0]->in_formats);
91 static int config_input(AVFilterLink *inlink)
93 AVFilterContext *ctx = inlink->dst;
94 FieldOrderContext *fieldorder = ctx->priv;
97 /** full an array with the number of bytes that the video
98 * data occupies per line for each plane of the input video */
99 for (plane = 0; plane < 4; plane++) {
100 fieldorder->line_size[plane] = av_image_get_linesize(
109 static AVFilterBufferRef *get_video_buffer(AVFilterLink *inlink, int perms, int w, int h)
111 AVFilterContext *ctx = inlink->dst;
112 AVFilterLink *outlink = ctx->outputs[0];
114 return avfilter_get_video_buffer(outlink, perms, w, h);
117 static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *inpicref)
119 AVFilterContext *ctx = inlink->dst;
120 AVFilterLink *outlink = ctx->outputs[0];
122 AVFilterBufferRef *outpicref;
124 outpicref = avfilter_ref_buffer(inpicref, ~0);
125 outlink->out_buf = outpicref;
127 avfilter_start_frame(outlink, outpicref);
130 static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
132 AVFilterContext *ctx = inlink->dst;
133 FieldOrderContext *fieldorder = ctx->priv;
134 AVFilterLink *outlink = ctx->outputs[0];
136 AVFilterBufferRef *inpicref = inlink->cur_buf;
138 /** can only currently do slices if this filter is doing nothing
139 * because this filter is moving picture content, the output
140 * slice will contain different video lines than the input slice
141 * and that complexity will be added later */
142 if ( !inpicref->video->interlaced
143 || inpicref->video->top_field_first == fieldorder->dst_tff) {
144 avfilter_draw_slice(outlink, y, h, slice_dir);
148 static void end_frame(AVFilterLink *inlink)
150 AVFilterContext *ctx = inlink->dst;
151 FieldOrderContext *fieldorder = ctx->priv;
152 AVFilterLink *outlink = ctx->outputs[0];
154 AVFilterBufferRef *inpicref = inlink->cur_buf;
155 AVFilterBufferRef *outpicref = outlink->out_buf;
157 int h, plane, line_step, line_size, line;
158 uint8_t *cpy_src, *cpy_dst;
160 if ( inpicref->video->interlaced
161 && inpicref->video->top_field_first != fieldorder->dst_tff) {
163 "picture will move %s one line\n",
164 fieldorder->dst_tff ? "up" : "down");
165 h = inpicref->video->h;
166 for (plane = 0; plane < 4 && inpicref->data[plane]; plane++) {
167 line_step = inpicref->linesize[plane];
168 line_size = fieldorder->line_size[plane];
169 cpy_src = inpicref->data[plane];
170 cpy_dst = outpicref->data[plane];
171 if (fieldorder->dst_tff) {
172 /** Move every line up one line, working from
173 * the top to the bottom of the frame.
174 * The original top line is lost.
175 * The new last line is created as a copy of the
176 * penultimate line from that field. */
177 for (line = 0; line < h; line++) {
178 if (1 + line < outpicref->video->h) {
179 memcpy(cpy_dst, cpy_src + line_step, line_size);
181 memcpy(cpy_dst, cpy_src - line_step - line_step, line_size);
183 cpy_src += line_step;
184 cpy_dst += line_step;
187 /** Move every line down one line, working from
188 * the bottom to the top of the frame.
189 * The original bottom line is lost.
190 * The new first line is created as a copy of the
191 * second line from that field. */
192 cpy_src += (h - 1) * line_step;
193 cpy_dst += (h - 1) * line_step;
194 for (line = h - 1; line >= 0 ; line--) {
196 memcpy(cpy_dst, cpy_src - line_step, line_size);
198 memcpy(cpy_dst, cpy_src + line_step + line_step, line_size);
200 cpy_src -= line_step;
201 cpy_dst -= line_step;
205 outpicref->video->top_field_first = fieldorder->dst_tff;
206 avfilter_draw_slice(outlink, 0, h, 1);
209 "not interlaced or field order already correct\n");
212 avfilter_end_frame(outlink);
213 avfilter_unref_buffer(inpicref);
216 AVFilter avfilter_vf_fieldorder = {
217 .name = "fieldorder",
218 .description = NULL_IF_CONFIG_SMALL("Set the field order."),
220 .priv_size = sizeof(FieldOrderContext),
221 .query_formats = query_formats,
222 .inputs = (AVFilterPad[]) {{ .name = "default",
223 .type = AVMEDIA_TYPE_VIDEO,
224 .config_props = config_input,
225 .start_frame = start_frame,
226 .get_video_buffer = get_video_buffer,
227 .draw_slice = draw_slice,
228 .end_frame = end_frame,
229 .min_perms = AV_PERM_READ,
230 .rej_perms = AV_PERM_REUSE2|AV_PERM_PRESERVE,},
232 .outputs = (AVFilterPad[]) {{ .name = "default",
233 .type = AVMEDIA_TYPE_VIDEO, },