mirror of https://git.ffmpeg.org/ffmpeg.git
210 lines
6.8 KiB
C
210 lines
6.8 KiB
C
/*
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* copyright (c) 2007 Bobby Bingham
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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 libavfilter/vf_scale.c
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* scale video filter
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*/
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#include "avfilter.h"
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#include "libavutil/pixdesc.h"
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#include "libswscale/swscale.h"
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typedef struct {
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struct SwsContext *sws; ///< software scaler context
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/**
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* New dimensions. Special values are:
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* 0 = original width/height
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* -1 = keep original aspect
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*/
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int w, h;
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int hsub, vsub; ///< chroma subsampling
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int slice_y; ///< top of current output slice
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int input_is_pal; ///< set to 1 if the input format is paletted
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} ScaleContext;
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static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
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{
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ScaleContext *scale = ctx->priv;
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if (args)
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sscanf(args, "%d:%d", &scale->w, &scale->h);
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/* sanity check params */
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if (scale->w < -1 || scale->h < -1) {
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av_log(ctx, AV_LOG_ERROR, "Size values less than -1 are not acceptable.\n");
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return -1;
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}
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if (scale->w == -1 && scale->h == -1)
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scale->w = scale->h = 0;
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return 0;
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}
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static av_cold void uninit(AVFilterContext *ctx)
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{
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ScaleContext *scale = ctx->priv;
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sws_freeContext(scale->sws);
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scale->sws = NULL;
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}
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static int query_formats(AVFilterContext *ctx)
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{
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AVFilterFormats *formats;
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enum PixelFormat pix_fmt;
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int ret;
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if (ctx->inputs[0]) {
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formats = NULL;
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for (pix_fmt = 0; pix_fmt < PIX_FMT_NB; pix_fmt++)
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if ( sws_isSupportedInput(pix_fmt)
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&& (ret = avfilter_add_colorspace(&formats, pix_fmt)) < 0) {
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avfilter_formats_unref(&formats);
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return ret;
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}
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avfilter_formats_ref(formats, &ctx->inputs[0]->out_formats);
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}
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if (ctx->outputs[0]) {
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formats = NULL;
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for (pix_fmt = 0; pix_fmt < PIX_FMT_NB; pix_fmt++)
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if ( sws_isSupportedOutput(pix_fmt)
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&& (ret = avfilter_add_colorspace(&formats, pix_fmt)) < 0) {
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avfilter_formats_unref(&formats);
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return ret;
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}
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avfilter_formats_ref(formats, &ctx->outputs[0]->in_formats);
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}
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return 0;
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}
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static int config_props(AVFilterLink *outlink)
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{
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AVFilterContext *ctx = outlink->src;
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AVFilterLink *inlink = outlink->src->inputs[0];
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ScaleContext *scale = ctx->priv;
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int64_t w, h;
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if (!(w = scale->w))
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w = inlink->w;
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if (!(h = scale->h))
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h = inlink->h;
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if (w == -1)
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w = av_rescale(h, inlink->w, inlink->h);
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if (h == -1)
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h = av_rescale(w, inlink->h, inlink->w);
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if (w > INT_MAX || h > INT_MAX ||
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(h * inlink->w) > INT_MAX ||
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(w * inlink->h) > INT_MAX)
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av_log(ctx, AV_LOG_ERROR, "Rescaled value for width or height is too big.\n");
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outlink->w = w;
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outlink->h = h;
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/* TODO: make algorithm configurable */
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scale->sws = sws_getContext(inlink ->w, inlink ->h, inlink ->format,
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outlink->w, outlink->h, outlink->format,
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SWS_BILINEAR, NULL, NULL, NULL);
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av_log(ctx, AV_LOG_INFO, "w:%d h:%d fmt:%s\n",
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outlink->w, outlink->h, av_pix_fmt_descriptors[outlink->format].name);
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scale->input_is_pal = av_pix_fmt_descriptors[inlink->format].flags & PIX_FMT_PAL;
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return !scale->sws;
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}
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static void start_frame(AVFilterLink *link, AVFilterPicRef *picref)
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{
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ScaleContext *scale = link->dst->priv;
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AVFilterLink *outlink = link->dst->outputs[0];
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AVFilterPicRef *outpicref;
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scale->hsub = av_pix_fmt_descriptors[link->format].log2_chroma_w;
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scale->vsub = av_pix_fmt_descriptors[link->format].log2_chroma_h;
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outpicref = avfilter_get_video_buffer(outlink, AV_PERM_WRITE, outlink->w, outlink->h);
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outpicref->pts = picref->pts;
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outpicref->pos = picref->pos;
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outlink->outpic = outpicref;
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av_reduce(&outpicref->pixel_aspect.num, &outpicref->pixel_aspect.den,
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(int64_t)picref->pixel_aspect.num * outlink->h * link->w,
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(int64_t)picref->pixel_aspect.den * outlink->w * link->h,
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INT_MAX);
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scale->slice_y = 0;
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avfilter_start_frame(outlink, avfilter_ref_pic(outpicref, ~0));
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}
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static void draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
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{
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ScaleContext *scale = link->dst->priv;
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int out_h;
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AVFilterPicRef *cur_pic = link->cur_pic;
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uint8_t *data[4];
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if (scale->slice_y == 0 && slice_dir == -1)
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scale->slice_y = link->dst->outputs[0]->h;
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data[0] = cur_pic->data[0] + y * cur_pic->linesize[0];
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data[1] = scale->input_is_pal ?
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cur_pic->data[1] :
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cur_pic->data[1] + (y>>scale->vsub) * cur_pic->linesize[1];
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data[2] = cur_pic->data[2] + (y>>scale->vsub) * cur_pic->linesize[2];
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data[3] = cur_pic->data[3] + y * cur_pic->linesize[3];
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out_h = sws_scale(scale->sws, data, cur_pic->linesize, y, h,
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link->dst->outputs[0]->outpic->data,
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link->dst->outputs[0]->outpic->linesize);
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if (slice_dir == -1)
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scale->slice_y -= out_h;
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avfilter_draw_slice(link->dst->outputs[0], scale->slice_y, out_h, slice_dir);
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if (slice_dir == 1)
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scale->slice_y += out_h;
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}
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AVFilter avfilter_vf_scale = {
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.name = "scale",
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.description = "Scale the input video to width:height size and/or convert the image format.",
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.init = init,
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.uninit = uninit,
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.query_formats = query_formats,
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.priv_size = sizeof(ScaleContext),
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.inputs = (AVFilterPad[]) {{ .name = "default",
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.type = CODEC_TYPE_VIDEO,
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.start_frame = start_frame,
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.draw_slice = draw_slice,
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.min_perms = AV_PERM_READ, },
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{ .name = NULL}},
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.outputs = (AVFilterPad[]) {{ .name = "default",
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.type = CODEC_TYPE_VIDEO,
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.config_props = config_props, },
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{ .name = NULL}},
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};
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