1/* 2 * Copyright (c) 2011 Mark Himsley 3 * 4 * This file is part of Libav. 5 * 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. 10 * 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. 15 * 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 19 */ 20 21/** 22 * @file 23 * video field order filter, heavily influenced by vf_pad.c 24 */ 25 26/* #define DEBUG */ 27 28#include "libavutil/imgutils.h" 29#include "libavutil/pixdesc.h" 30#include "avfilter.h" 31 32typedef struct 33{ 34 unsigned int dst_tff; ///< output bff/tff 35 int line_size[4]; ///< bytes of pixel data per line for each plane 36} FieldOrderContext; 37 38static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque) 39{ 40 FieldOrderContext *fieldorder = ctx->priv; 41 42 const char *tff = "tff"; 43 const char *bff = "bff"; 44 45 if (!args) { 46 fieldorder->dst_tff = 1; 47 } else if (sscanf(args, "%u", &fieldorder->dst_tff) == 1) { 48 fieldorder->dst_tff = !!fieldorder->dst_tff; 49 } else if (!strcmp(tff, args)) { 50 fieldorder->dst_tff = 1; 51 } else if (!strcmp(bff, args)) { 52 fieldorder->dst_tff = 0; 53 } else { 54 av_log(ctx, AV_LOG_ERROR, "Invalid argument '%s'.\n", args); 55 return AVERROR(EINVAL); 56 } 57 58 av_log(ctx, AV_LOG_INFO, "output field order: %s\n", 59 fieldorder->dst_tff ? tff : bff); 60 61 return 0; 62} 63 64static int query_formats(AVFilterContext *ctx) 65{ 66 AVFilterFormats *formats; 67 enum PixelFormat pix_fmt; 68 int ret; 69 70 /** accept any input pixel format that is not hardware accelerated, not 71 * a bitstream format, and does not have vertically sub-sampled chroma */ 72 if (ctx->inputs[0]) { 73 formats = NULL; 74 for (pix_fmt = 0; pix_fmt < PIX_FMT_NB; pix_fmt++) 75 if (!( av_pix_fmt_descriptors[pix_fmt].flags & PIX_FMT_HWACCEL 76 || av_pix_fmt_descriptors[pix_fmt].flags & PIX_FMT_BITSTREAM) 77 && av_pix_fmt_descriptors[pix_fmt].nb_components 78 && !av_pix_fmt_descriptors[pix_fmt].log2_chroma_h 79 && (ret = avfilter_add_format(&formats, pix_fmt)) < 0) { 80 avfilter_formats_unref(&formats); 81 return ret; 82 } 83 avfilter_formats_ref(formats, &ctx->inputs[0]->out_formats); 84 avfilter_formats_ref(formats, &ctx->outputs[0]->in_formats); 85 } 86 87 return 0; 88} 89 90static int config_input(AVFilterLink *inlink) 91{ 92 AVFilterContext *ctx = inlink->dst; 93 FieldOrderContext *fieldorder = ctx->priv; 94 int plane; 95 96 /** full an array with the number of bytes that the video 97 * data occupies per line for each plane of the input video */ 98 for (plane = 0; plane < 4; plane++) { 99 fieldorder->line_size[plane] = av_image_get_linesize( 100 inlink->format, 101 inlink->w, 102 plane); 103 } 104 105 return 0; 106} 107 108static AVFilterBufferRef *get_video_buffer(AVFilterLink *inlink, int perms, int w, int h) 109{ 110 AVFilterContext *ctx = inlink->dst; 111 AVFilterLink *outlink = ctx->outputs[0]; 112 113 return avfilter_get_video_buffer(outlink, perms, w, h); 114} 115 116static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *inpicref) 117{ 118 AVFilterContext *ctx = inlink->dst; 119 AVFilterLink *outlink = ctx->outputs[0]; 120 121 AVFilterBufferRef *outpicref; 122 123 outpicref = avfilter_ref_buffer(inpicref, ~0); 124 outlink->out_buf = outpicref; 125 126 avfilter_start_frame(outlink, outpicref); 127} 128 129static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir) 130{ 131 AVFilterContext *ctx = inlink->dst; 132 FieldOrderContext *fieldorder = ctx->priv; 133 AVFilterLink *outlink = ctx->outputs[0]; 134 135 AVFilterBufferRef *inpicref = inlink->cur_buf; 136 137 /** can only currently do slices if this filter is doing nothing 138 * because this filter is moving picture content, the output 139 * slice will contain different video lines than the input slice 140 * and that complexity will be added later */ 141 if ( !inpicref->video->interlaced 142 || inpicref->video->top_field_first == fieldorder->dst_tff) { 143 avfilter_draw_slice(outlink, y, h, slice_dir); 144 } 145} 146 147static void end_frame(AVFilterLink *inlink) 148{ 149 AVFilterContext *ctx = inlink->dst; 150 FieldOrderContext *fieldorder = ctx->priv; 151 AVFilterLink *outlink = ctx->outputs[0]; 152 153 AVFilterBufferRef *inpicref = inlink->cur_buf; 154 AVFilterBufferRef *outpicref = outlink->out_buf; 155 156 int h, plane, line_step, line_size, line; 157 uint8_t *cpy_src, *cpy_dst; 158 159 if ( inpicref->video->interlaced 160 && inpicref->video->top_field_first != fieldorder->dst_tff) { 161 av_dlog(ctx, 162 "picture will move %s one line\n", 163 fieldorder->dst_tff ? "up" : "down"); 164 h = inpicref->video->h; 165 for (plane = 0; plane < 4 && inpicref->data[plane]; plane++) { 166 line_step = inpicref->linesize[plane]; 167 line_size = fieldorder->line_size[plane]; 168 cpy_src = inpicref->data[plane]; 169 cpy_dst = outpicref->data[plane]; 170 if (fieldorder->dst_tff) { 171 /** Move every line up one line, working from 172 * the top to the bottom of the frame. 173 * The original top line is lost. 174 * The new last line is created as a copy of the 175 * penultimate line from that field. */ 176 for (line = 0; line < h; line++) { 177 if (1 + line < outpicref->video->h) { 178 memcpy(cpy_dst, cpy_src + line_step, line_size); 179 } else { 180 memcpy(cpy_dst, cpy_src - line_step - line_step, line_size); 181 } 182 cpy_src += line_step; 183 cpy_dst += line_step; 184 } 185 } else { 186 /** Move every line down one line, working from 187 * the bottom to the top of the frame. 188 * The original bottom line is lost. 189 * The new first line is created as a copy of the 190 * second line from that field. */ 191 cpy_src += (h - 1) * line_step; 192 cpy_dst += (h - 1) * line_step; 193 for (line = h - 1; line >= 0 ; line--) { 194 if (line > 0) { 195 memcpy(cpy_dst, cpy_src - line_step, line_size); 196 } else { 197 memcpy(cpy_dst, cpy_src + line_step + line_step, line_size); 198 } 199 cpy_src -= line_step; 200 cpy_dst -= line_step; 201 } 202 } 203 } 204 outpicref->video->top_field_first = fieldorder->dst_tff; 205 avfilter_draw_slice(outlink, 0, h, 1); 206 } else { 207 av_dlog(ctx, 208 "not interlaced or field order already correct\n"); 209 } 210 211 avfilter_end_frame(outlink); 212 avfilter_unref_buffer(inpicref); 213} 214 215AVFilter avfilter_vf_fieldorder = { 216 .name = "fieldorder", 217 .description = NULL_IF_CONFIG_SMALL("Set the field order."), 218 .init = init, 219 .priv_size = sizeof(FieldOrderContext), 220 .query_formats = query_formats, 221 .inputs = (AVFilterPad[]) {{ .name = "default", 222 .type = AVMEDIA_TYPE_VIDEO, 223 .config_props = config_input, 224 .start_frame = start_frame, 225 .get_video_buffer = get_video_buffer, 226 .draw_slice = draw_slice, 227 .end_frame = end_frame, 228 .min_perms = AV_PERM_READ, 229 .rej_perms = AV_PERM_REUSE2|AV_PERM_PRESERVE,}, 230 { .name = NULL}}, 231 .outputs = (AVFilterPad[]) {{ .name = "default", 232 .type = AVMEDIA_TYPE_VIDEO, }, 233 { .name = NULL}}, 234}; 235