diff options
Diffstat (limited to 'libavfilter/vf_field.c')
-rw-r--r-- | libavfilter/vf_field.c | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/libavfilter/vf_field.c b/libavfilter/vf_field.c new file mode 100644 index 0000000..ed12379 --- /dev/null +++ b/libavfilter/vf_field.c @@ -0,0 +1,111 @@ +/* + * Copyright (c) 2003 Rich Felker + * Copyright (c) 2012 Stefano Sabatini + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/** + * @file + * field filter, based on libmpcodecs/vf_field.c by Rich Felker + */ + +#include "libavutil/opt.h" +#include "libavutil/pixdesc.h" +#include "avfilter.h" +#include "internal.h" + +enum FieldType { FIELD_TYPE_TOP = 0, FIELD_TYPE_BOTTOM }; + +typedef struct { + const AVClass *class; + enum FieldType type; + int nb_planes; ///< number of planes of the current format +} FieldContext; + +#define OFFSET(x) offsetof(FieldContext, x) +#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM + +static const AVOption field_options[] = { + {"type", "set field type (top or bottom)", OFFSET(type), AV_OPT_TYPE_INT, {.i64=FIELD_TYPE_TOP}, 0, 1, FLAGS, "field_type" }, + {"top", "select top field", 0, AV_OPT_TYPE_CONST, {.i64=FIELD_TYPE_TOP}, INT_MIN, INT_MAX, FLAGS, "field_type"}, + {"bottom", "select bottom field", 0, AV_OPT_TYPE_CONST, {.i64=FIELD_TYPE_BOTTOM}, INT_MIN, INT_MAX, FLAGS, "field_type"}, + {NULL} +}; + +AVFILTER_DEFINE_CLASS(field); + +static int config_props_output(AVFilterLink *outlink) +{ + AVFilterContext *ctx = outlink->src; + FieldContext *field = ctx->priv; + AVFilterLink *inlink = ctx->inputs[0]; + + field->nb_planes = av_pix_fmt_count_planes(outlink->format); + + outlink->w = inlink->w; + outlink->h = (inlink->h + (field->type == FIELD_TYPE_TOP)) / 2; + + av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d type:%s -> w:%d h:%d\n", + inlink->w, inlink->h, field->type == FIELD_TYPE_BOTTOM ? "bottom" : "top", + outlink->w, outlink->h); + return 0; +} + +static int filter_frame(AVFilterLink *inlink, AVFrame *inpicref) +{ + FieldContext *field = inlink->dst->priv; + AVFilterLink *outlink = inlink->dst->outputs[0]; + int i; + + inpicref->height = outlink->h; + inpicref->interlaced_frame = 0; + + for (i = 0; i < field->nb_planes; i++) { + if (field->type == FIELD_TYPE_BOTTOM) + inpicref->data[i] = inpicref->data[i] + inpicref->linesize[i]; + inpicref->linesize[i] = 2 * inpicref->linesize[i]; + } + return ff_filter_frame(outlink, inpicref); +} + +static const AVFilterPad field_inputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + .filter_frame = filter_frame, + }, + { NULL } +}; + +static const AVFilterPad field_outputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + .config_props = config_props_output, + }, + { NULL } +}; + +AVFilter ff_vf_field = { + .name = "field", + .description = NULL_IF_CONFIG_SMALL("Extract a field from the input video."), + .priv_size = sizeof(FieldContext), + .inputs = field_inputs, + .outputs = field_outputs, + .priv_class = &field_class, +}; |