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101 lines
3.2 KiB
101 lines
3.2 KiB
/* |
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* Copyright (c) 2012 Stefano Sabatini |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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/** |
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* @file framestep filter, inspired on libmpcodecs/vf_framestep.c by |
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* Daniele Fornighieri <guru AT digitalfantasy it>. |
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*/ |
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#include "libavutil/opt.h" |
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#include "avfilter.h" |
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#include "filters.h" |
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#include "video.h" |
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typedef struct NullContext { |
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const AVClass *class; |
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int frame_step; |
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} FrameStepContext; |
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#define OFFSET(x) offsetof(FrameStepContext, x) |
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#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM |
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static const AVOption framestep_options[] = { |
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{ "step", "set frame step", OFFSET(frame_step), AV_OPT_TYPE_INT, {.i64=1}, 1, INT_MAX, FLAGS}, |
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{ NULL }, |
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}; |
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AVFILTER_DEFINE_CLASS(framestep); |
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static int config_output_props(AVFilterLink *outlink) |
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{ |
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AVFilterContext *ctx = outlink->src; |
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FrameStepContext *framestep = ctx->priv; |
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AVFilterLink *inlink = ctx->inputs[0]; |
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FilterLink *il = ff_filter_link(inlink); |
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FilterLink *ol = ff_filter_link(outlink); |
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ol->frame_rate = |
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av_div_q(il->frame_rate, (AVRational){framestep->frame_step, 1}); |
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av_log(ctx, AV_LOG_VERBOSE, "step:%d frame_rate:%d/%d(%f) -> frame_rate:%d/%d(%f)\n", |
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framestep->frame_step, |
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il->frame_rate.num, il->frame_rate.den, av_q2d(il->frame_rate), |
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ol->frame_rate.num, ol->frame_rate.den, av_q2d(ol->frame_rate)); |
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return 0; |
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} |
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static int filter_frame(AVFilterLink *inlink, AVFrame *ref) |
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{ |
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FilterLink *inl = ff_filter_link(inlink); |
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FrameStepContext *framestep = inlink->dst->priv; |
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if (!(inl->frame_count_out % framestep->frame_step)) { |
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return ff_filter_frame(inlink->dst->outputs[0], ref); |
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} else { |
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av_frame_free(&ref); |
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return 0; |
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} |
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} |
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static const AVFilterPad framestep_inputs[] = { |
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{ |
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.name = "default", |
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.type = AVMEDIA_TYPE_VIDEO, |
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.filter_frame = filter_frame, |
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}, |
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}; |
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static const AVFilterPad framestep_outputs[] = { |
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{ |
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.name = "default", |
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.type = AVMEDIA_TYPE_VIDEO, |
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.config_props = config_output_props, |
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}, |
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}; |
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const AVFilter ff_vf_framestep = { |
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.name = "framestep", |
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.description = NULL_IF_CONFIG_SMALL("Select one frame every N frames."), |
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.priv_size = sizeof(FrameStepContext), |
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.priv_class = &framestep_class, |
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FILTER_INPUTS(framestep_inputs), |
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FILTER_OUTPUTS(framestep_outputs), |
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.flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_METADATA_ONLY, |
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};
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