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