2 * Copyright (c) 2011 Mark Himsley
4 * This file is part of FFmpeg.
6 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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"
36 unsigned int dst_tff; ///< output bff/tff
37 int line_size[4]; ///< bytes of pixel data per line for each plane
40 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
42 FieldOrderContext *fieldorder = ctx->priv;
44 const char *tff = "tff";
45 const char *bff = "bff";
48 fieldorder->dst_tff = 1;
49 } else if (sscanf(args, "%u", &fieldorder->dst_tff) == 1) {
50 fieldorder->dst_tff = !!fieldorder->dst_tff;
51 } else if (!strcmp(tff, args)) {
52 fieldorder->dst_tff = 1;
53 } else if (!strcmp(bff, args)) {
54 fieldorder->dst_tff = 0;
56 av_log(ctx, AV_LOG_ERROR, "Invalid argument '%s'.\n", args);
57 return AVERROR(EINVAL);
60 av_log(ctx, AV_LOG_INFO, "output field order: %s\n",
61 fieldorder->dst_tff ? tff : bff);
66 static int query_formats(AVFilterContext *ctx)
68 AVFilterFormats *formats;
69 enum PixelFormat pix_fmt;
72 /** accept any input pixel format that is not hardware accelerated, not
73 * a bitstream format, and does not have vertically sub-sampled chroma */
76 for (pix_fmt = 0; pix_fmt < PIX_FMT_NB; pix_fmt++)
77 if (!( av_pix_fmt_descriptors[pix_fmt].flags & PIX_FMT_HWACCEL
78 || av_pix_fmt_descriptors[pix_fmt].flags & PIX_FMT_BITSTREAM)
79 && av_pix_fmt_descriptors[pix_fmt].nb_components
80 && !av_pix_fmt_descriptors[pix_fmt].log2_chroma_h
81 && (ret = ff_add_format(&formats, pix_fmt)) < 0) {
82 ff_formats_unref(&formats);
85 ff_formats_ref(formats, &ctx->inputs[0]->out_formats);
86 ff_formats_ref(formats, &ctx->outputs[0]->in_formats);
92 static int config_input(AVFilterLink *inlink)
94 AVFilterContext *ctx = inlink->dst;
95 FieldOrderContext *fieldorder = ctx->priv;
98 /** full an array with the number of bytes that the video
99 * data occupies per line for each plane of the input video */
100 for (plane = 0; plane < 4; plane++) {
101 fieldorder->line_size[plane] = av_image_get_linesize(
110 static AVFilterBufferRef *get_video_buffer(AVFilterLink *inlink, int perms, int w, int h)
112 AVFilterContext *ctx = inlink->dst;
113 AVFilterLink *outlink = ctx->outputs[0];
115 return avfilter_get_video_buffer(outlink, perms, w, h);
118 static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *inpicref)
120 AVFilterContext *ctx = inlink->dst;
121 AVFilterLink *outlink = ctx->outputs[0];
123 AVFilterBufferRef *outpicref;
125 outpicref = avfilter_ref_buffer(inpicref, ~0);
126 outlink->out_buf = outpicref;
128 ff_start_frame(outlink, outpicref);
131 static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
133 AVFilterContext *ctx = inlink->dst;
134 FieldOrderContext *fieldorder = ctx->priv;
135 AVFilterLink *outlink = ctx->outputs[0];
137 AVFilterBufferRef *inpicref = inlink->cur_buf;
139 /** can only currently do slices if this filter is doing nothing
140 * because this filter is moving picture content, the output
141 * slice will contain different video lines than the input slice
142 * and that complexity will be added later */
143 if ( !inpicref->video->interlaced
144 || inpicref->video->top_field_first == fieldorder->dst_tff) {
145 ff_draw_slice(outlink, y, h, slice_dir);
149 static void end_frame(AVFilterLink *inlink)
151 AVFilterContext *ctx = inlink->dst;
152 FieldOrderContext *fieldorder = ctx->priv;
153 AVFilterLink *outlink = ctx->outputs[0];
155 AVFilterBufferRef *inpicref = inlink->cur_buf;
156 AVFilterBufferRef *outpicref = outlink->out_buf;
158 int h, plane, line_step, line_size, line;
159 uint8_t *cpy_src, *cpy_dst;
161 if ( inpicref->video->interlaced
162 && inpicref->video->top_field_first != fieldorder->dst_tff) {
164 "picture will move %s one line\n",
165 fieldorder->dst_tff ? "up" : "down");
166 h = inpicref->video->h;
167 for (plane = 0; plane < 4 && inpicref->data[plane]; plane++) {
168 line_step = inpicref->linesize[plane];
169 line_size = fieldorder->line_size[plane];
170 cpy_src = inpicref->data[plane];
171 cpy_dst = outpicref->data[plane];
172 if (fieldorder->dst_tff) {
173 /** Move every line up one line, working from
174 * the top to the bottom of the frame.
175 * The original top line is lost.
176 * The new last line is created as a copy of the
177 * penultimate line from that field. */
178 for (line = 0; line < h; line++) {
179 if (1 + line < outpicref->video->h) {
180 memcpy(cpy_dst, cpy_src + line_step, line_size);
182 memcpy(cpy_dst, cpy_src - line_step - line_step, line_size);
184 cpy_src += line_step;
185 cpy_dst += line_step;
188 /** Move every line down one line, working from
189 * the bottom to the top of the frame.
190 * The original bottom line is lost.
191 * The new first line is created as a copy of the
192 * second line from that field. */
193 cpy_src += (h - 1) * line_step;
194 cpy_dst += (h - 1) * line_step;
195 for (line = h - 1; line >= 0 ; line--) {
197 memcpy(cpy_dst, cpy_src - line_step, line_size);
199 memcpy(cpy_dst, cpy_src + line_step + line_step, line_size);
201 cpy_src -= line_step;
202 cpy_dst -= line_step;
206 outpicref->video->top_field_first = fieldorder->dst_tff;
207 ff_draw_slice(outlink, 0, h, 1);
210 "not interlaced or field order already correct\n");
213 ff_end_frame(outlink);
214 avfilter_unref_buffer(inpicref);
217 AVFilter avfilter_vf_fieldorder = {
218 .name = "fieldorder",
219 .description = NULL_IF_CONFIG_SMALL("Set the field order."),
221 .priv_size = sizeof(FieldOrderContext),
222 .query_formats = query_formats,
223 .inputs = (const AVFilterPad[]) {{ .name = "default",
224 .type = AVMEDIA_TYPE_VIDEO,
225 .config_props = config_input,
226 .start_frame = start_frame,
227 .get_video_buffer = get_video_buffer,
228 .draw_slice = draw_slice,
229 .end_frame = end_frame,
230 .min_perms = AV_PERM_READ,
231 .rej_perms = AV_PERM_REUSE2|AV_PERM_PRESERVE,},
233 .outputs = (const AVFilterPad[]) {{ .name = "default",
234 .type = AVMEDIA_TYPE_VIDEO, },