| 1 | /* |
| 2 | * Copyright (c) 2003 Rich Felker |
| 3 | * Copyright (c) 2012 Stefano Sabatini |
| 4 | * |
| 5 | * This file is part of FFmpeg. |
| 6 | * |
| 7 | * FFmpeg is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU Lesser General Public |
| 9 | * License as published by the Free Software Foundation; either |
| 10 | * version 2.1 of the License, or (at your option) any later version. |
| 11 | * |
| 12 | * FFmpeg is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 15 | * Lesser General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU Lesser General Public |
| 18 | * License along with FFmpeg; if not, write to the Free Software |
| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 20 | */ |
| 21 | |
| 22 | /** |
| 23 | * @file |
| 24 | * field filter, based on libmpcodecs/vf_field.c by Rich Felker |
| 25 | */ |
| 26 | |
| 27 | #include "libavutil/opt.h" |
| 28 | #include "libavutil/pixdesc.h" |
| 29 | #include "avfilter.h" |
| 30 | #include "internal.h" |
| 31 | |
| 32 | enum FieldType { FIELD_TYPE_TOP = 0, FIELD_TYPE_BOTTOM }; |
| 33 | |
| 34 | typedef struct { |
| 35 | const AVClass *class; |
| 36 | enum FieldType type; |
| 37 | int nb_planes; ///< number of planes of the current format |
| 38 | } FieldContext; |
| 39 | |
| 40 | #define OFFSET(x) offsetof(FieldContext, x) |
| 41 | #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM |
| 42 | |
| 43 | static const AVOption field_options[] = { |
| 44 | {"type", "set field type (top or bottom)", OFFSET(type), AV_OPT_TYPE_INT, {.i64=FIELD_TYPE_TOP}, 0, 1, FLAGS, "field_type" }, |
| 45 | {"top", "select top field", 0, AV_OPT_TYPE_CONST, {.i64=FIELD_TYPE_TOP}, INT_MIN, INT_MAX, FLAGS, "field_type"}, |
| 46 | {"bottom", "select bottom field", 0, AV_OPT_TYPE_CONST, {.i64=FIELD_TYPE_BOTTOM}, INT_MIN, INT_MAX, FLAGS, "field_type"}, |
| 47 | {NULL} |
| 48 | }; |
| 49 | |
| 50 | AVFILTER_DEFINE_CLASS(field); |
| 51 | |
| 52 | static int config_props_output(AVFilterLink *outlink) |
| 53 | { |
| 54 | AVFilterContext *ctx = outlink->src; |
| 55 | FieldContext *field = ctx->priv; |
| 56 | AVFilterLink *inlink = ctx->inputs[0]; |
| 57 | |
| 58 | field->nb_planes = av_pix_fmt_count_planes(outlink->format); |
| 59 | |
| 60 | outlink->w = inlink->w; |
| 61 | outlink->h = (inlink->h + (field->type == FIELD_TYPE_TOP)) / 2; |
| 62 | |
| 63 | av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d type:%s -> w:%d h:%d\n", |
| 64 | inlink->w, inlink->h, field->type == FIELD_TYPE_BOTTOM ? "bottom" : "top", |
| 65 | outlink->w, outlink->h); |
| 66 | return 0; |
| 67 | } |
| 68 | |
| 69 | static int filter_frame(AVFilterLink *inlink, AVFrame *inpicref) |
| 70 | { |
| 71 | FieldContext *field = inlink->dst->priv; |
| 72 | AVFilterLink *outlink = inlink->dst->outputs[0]; |
| 73 | int i; |
| 74 | |
| 75 | inpicref->height = outlink->h; |
| 76 | inpicref->interlaced_frame = 0; |
| 77 | |
| 78 | for (i = 0; i < field->nb_planes; i++) { |
| 79 | if (field->type == FIELD_TYPE_BOTTOM) |
| 80 | inpicref->data[i] = inpicref->data[i] + inpicref->linesize[i]; |
| 81 | inpicref->linesize[i] = 2 * inpicref->linesize[i]; |
| 82 | } |
| 83 | return ff_filter_frame(outlink, inpicref); |
| 84 | } |
| 85 | |
| 86 | static const AVFilterPad field_inputs[] = { |
| 87 | { |
| 88 | .name = "default", |
| 89 | .type = AVMEDIA_TYPE_VIDEO, |
| 90 | .filter_frame = filter_frame, |
| 91 | }, |
| 92 | { NULL } |
| 93 | }; |
| 94 | |
| 95 | static const AVFilterPad field_outputs[] = { |
| 96 | { |
| 97 | .name = "default", |
| 98 | .type = AVMEDIA_TYPE_VIDEO, |
| 99 | .config_props = config_props_output, |
| 100 | }, |
| 101 | { NULL } |
| 102 | }; |
| 103 | |
| 104 | AVFilter ff_vf_field = { |
| 105 | .name = "field", |
| 106 | .description = NULL_IF_CONFIG_SMALL("Extract a field from the input video."), |
| 107 | .priv_size = sizeof(FieldContext), |
| 108 | .inputs = field_inputs, |
| 109 | .outputs = field_outputs, |
| 110 | .priv_class = &field_class, |
| 111 | }; |