0,0 → 1,101 |
/* |
* 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 framestep filter, inspired on libmpcodecs/vf_framestep.c by |
* Daniele Fornighieri <guru AT digitalfantasy it>. |
*/ |
|
#include "libavutil/opt.h" |
#include "avfilter.h" |
#include "internal.h" |
#include "video.h" |
|
typedef struct { |
const AVClass *class; |
int frame_step; |
} FrameStepContext; |
|
#define OFFSET(x) offsetof(FrameStepContext, x) |
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM |
|
static const AVOption framestep_options[] = { |
{ "step", "set frame step", OFFSET(frame_step), AV_OPT_TYPE_INT, {.i64=1}, 1, INT_MAX, FLAGS}, |
{ NULL }, |
}; |
|
AVFILTER_DEFINE_CLASS(framestep); |
|
static int config_output_props(AVFilterLink *outlink) |
{ |
AVFilterContext *ctx = outlink->src; |
FrameStepContext *framestep = ctx->priv; |
AVFilterLink *inlink = ctx->inputs[0]; |
|
outlink->flags |= FF_LINK_FLAG_REQUEST_LOOP; |
outlink->frame_rate = |
av_div_q(inlink->frame_rate, (AVRational){framestep->frame_step, 1}); |
|
av_log(ctx, AV_LOG_VERBOSE, "step:%d frame_rate:%d/%d(%f) -> frame_rate:%d/%d(%f)\n", |
framestep->frame_step, |
inlink->frame_rate.num, inlink->frame_rate.den, av_q2d(inlink->frame_rate), |
outlink->frame_rate.num, outlink->frame_rate.den, av_q2d(outlink->frame_rate)); |
return 0; |
} |
|
static int filter_frame(AVFilterLink *inlink, AVFrame *ref) |
{ |
FrameStepContext *framestep = inlink->dst->priv; |
|
if (!(inlink->frame_count % framestep->frame_step)) { |
return ff_filter_frame(inlink->dst->outputs[0], ref); |
} else { |
av_frame_free(&ref); |
return 0; |
} |
} |
|
static const AVFilterPad framestep_inputs[] = { |
{ |
.name = "default", |
.type = AVMEDIA_TYPE_VIDEO, |
.filter_frame = filter_frame, |
}, |
{ NULL } |
}; |
|
static const AVFilterPad framestep_outputs[] = { |
{ |
.name = "default", |
.type = AVMEDIA_TYPE_VIDEO, |
.config_props = config_output_props, |
}, |
{ NULL } |
}; |
|
AVFilter avfilter_vf_framestep = { |
.name = "framestep", |
.description = NULL_IF_CONFIG_SMALL("Select one frame every N frames."), |
.priv_size = sizeof(FrameStepContext), |
.priv_class = &framestep_class, |
.inputs = framestep_inputs, |
.outputs = framestep_outputs, |
.flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC, |
}; |