| /* |
| * 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/avstring.h" |
| #include "libavutil/eval.h" |
| #include "libavutil/mathematics.h" |
| #include "libavutil/pixdesc.h" |
| #include "libavutil/avassert.h" |
| #include "libswscale/swscale.h" |
| |
| static const char * const var_names[] = { |
| "in_w", "iw", |
| "in_h", "ih", |
| "out_w", "ow", |
| "out_h", "oh", |
| "a", |
| "sar", |
| "dar", |
| "hsub", |
| "vsub", |
| NULL |
| }; |
| |
| enum var_name { |
| VAR_IN_W, VAR_IW, |
| VAR_IN_H, VAR_IH, |
| VAR_OUT_W, VAR_OW, |
| VAR_OUT_H, VAR_OH, |
| VAR_A, |
| VAR_SAR, |
| VAR_DAR, |
| VAR_HSUB, |
| VAR_VSUB, |
| VARS_NB |
| }; |
| |
| typedef struct { |
| struct SwsContext *sws; ///< software scaler context |
| struct SwsContext *isws[2]; ///< software scaler context for interlaced material |
| |
| /** |
| * 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 |
| int interlaced; |
| |
| char w_expr[256]; ///< width expression string |
| char h_expr[256]; ///< height expression string |
| } ScaleContext; |
| |
| static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque) |
| { |
| ScaleContext *scale = ctx->priv; |
| const char *p; |
| |
| av_strlcpy(scale->w_expr, "iw", sizeof(scale->w_expr)); |
| av_strlcpy(scale->h_expr, "ih", sizeof(scale->h_expr)); |
| |
| scale->flags = SWS_BILINEAR; |
| if (args) { |
| sscanf(args, "%255[^:]:%255[^:]", scale->w_expr, scale->h_expr); |
| p = strstr(args,"flags="); |
| if (p) scale->flags = strtoul(p+6, NULL, 0); |
| if(strstr(args,"interl=1")){ |
| scale->interlaced=1; |
| }else if(strstr(args,"interl=-1")) |
| scale->interlaced=-1; |
| } |
| |
| return 0; |
| } |
| |
| static av_cold void uninit(AVFilterContext *ctx) |
| { |
| ScaleContext *scale = ctx->priv; |
| sws_freeContext(scale->sws); |
| sws_freeContext(scale->isws[0]); |
| sws_freeContext(scale->isws[1]); |
| 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_format(&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) || pix_fmt == PIX_FMT_PAL8) |
| && (ret = avfilter_add_format(&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]; |
| enum PixelFormat outfmt = outlink->format; |
| ScaleContext *scale = ctx->priv; |
| int64_t w, h; |
| double var_values[VARS_NB], res; |
| char *expr; |
| int ret; |
| |
| var_values[VAR_IN_W] = var_values[VAR_IW] = inlink->w; |
| var_values[VAR_IN_H] = var_values[VAR_IH] = inlink->h; |
| var_values[VAR_OUT_W] = var_values[VAR_OW] = NAN; |
| var_values[VAR_OUT_H] = var_values[VAR_OH] = NAN; |
| var_values[VAR_A] = (double) inlink->w / inlink->h; |
| |
| var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ? |
| |
| (double) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1; |
| var_values[VAR_DAR] = var_values[VAR_A] * var_values[VAR_SAR]; |
| var_values[VAR_HSUB] = 1<<av_pix_fmt_descriptors[inlink->format].log2_chroma_w; |
| var_values[VAR_VSUB] = 1<<av_pix_fmt_descriptors[inlink->format].log2_chroma_h; |
| |
| /* evaluate width and height */ |
| av_expr_parse_and_eval(&res, (expr = scale->w_expr), |
| var_names, var_values, |
| NULL, NULL, NULL, NULL, NULL, 0, ctx); |
| scale->w = var_values[VAR_OUT_W] = var_values[VAR_OW] = res; |
| if ((ret = av_expr_parse_and_eval(&res, (expr = scale->h_expr), |
| var_names, var_values, |
| NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0) |
| goto fail; |
| scale->h = var_values[VAR_OUT_H] = var_values[VAR_OH] = res; |
| /* evaluate again the width, as it may depend on the output height */ |
| if ((ret = av_expr_parse_and_eval(&res, (expr = scale->w_expr), |
| var_names, var_values, |
| NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0) |
| goto fail; |
| scale->w = res; |
| |
| w = scale->w; |
| h = scale->h; |
| |
| /* sanity check params */ |
| if (w < -1 || h < -1) { |
| av_log(ctx, AV_LOG_ERROR, "Size values less than -1 are not acceptable.\n"); |
| return AVERROR(EINVAL); |
| } |
| if (w == -1 && h == -1) |
| scale->w = scale->h = 0; |
| |
| 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 */ |
| av_log(ctx, AV_LOG_INFO, "w:%d h:%d fmt:%s -> w:%d h:%d fmt:%s flags:0x%0x\n", |
| inlink ->w, inlink ->h, av_pix_fmt_descriptors[ inlink->format].name, |
| outlink->w, outlink->h, av_pix_fmt_descriptors[outlink->format].name, |
| scale->flags); |
| |
| scale->input_is_pal = av_pix_fmt_descriptors[inlink->format].flags & PIX_FMT_PAL; |
| if (outfmt == PIX_FMT_PAL8) outfmt = PIX_FMT_BGR8; |
| |
| if (scale->sws) |
| sws_freeContext(scale->sws); |
| scale->sws = sws_getContext(inlink ->w, inlink ->h, inlink ->format, |
| outlink->w, outlink->h, outfmt, |
| scale->flags, NULL, NULL, NULL); |
| if (scale->isws[0]) |
| sws_freeContext(scale->isws[0]); |
| scale->isws[0] = sws_getContext(inlink ->w, inlink ->h/2, inlink ->format, |
| outlink->w, outlink->h/2, outfmt, |
| scale->flags, NULL, NULL, NULL); |
| if (scale->isws[1]) |
| sws_freeContext(scale->isws[1]); |
| scale->isws[1] = sws_getContext(inlink ->w, inlink ->h/2, inlink ->format, |
| outlink->w, outlink->h/2, outfmt, |
| scale->flags, NULL, NULL, NULL); |
| if (!scale->sws || !scale->isws[0] || !scale->isws[1]) |
| return AVERROR(EINVAL); |
| |
| if (inlink->sample_aspect_ratio.num){ |
| outlink->sample_aspect_ratio = av_mul_q((AVRational){outlink->h * inlink->w, outlink->w * inlink->h}, inlink->sample_aspect_ratio); |
| } else |
| outlink->sample_aspect_ratio = inlink->sample_aspect_ratio; |
| |
| return 0; |
| |
| fail: |
| av_log(NULL, AV_LOG_ERROR, |
| "Error when evaluating the expression '%s'.\n" |
| "Maybe the expression for out_w:'%s' or for out_h:'%s' is self-referencing.\n", |
| expr, scale->w_expr, scale->h_expr); |
| return ret; |
| } |
| |
| static void start_frame(AVFilterLink *link, AVFilterBufferRef *picref) |
| { |
| ScaleContext *scale = link->dst->priv; |
| AVFilterLink *outlink = link->dst->outputs[0]; |
| AVFilterBufferRef *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|AV_PERM_ALIGN, outlink->w, outlink->h); |
| avfilter_copy_buffer_ref_props(outpicref, picref); |
| outpicref->video->w = outlink->w; |
| outpicref->video->h = outlink->h; |
| |
| outlink->out_buf = outpicref; |
| |
| av_reduce(&outpicref->video->sample_aspect_ratio.num, &outpicref->video->sample_aspect_ratio.den, |
| (int64_t)picref->video->sample_aspect_ratio.num * outlink->h * link->w, |
| (int64_t)picref->video->sample_aspect_ratio.den * outlink->w * link->h, |
| INT_MAX); |
| |
| scale->slice_y = 0; |
| avfilter_start_frame(outlink, avfilter_ref_buffer(outpicref, ~0)); |
| } |
| |
| static int scale_slice(AVFilterLink *link, struct SwsContext *sws, int y, int h, int mul, int field) |
| { |
| ScaleContext *scale = link->dst->priv; |
| AVFilterBufferRef *cur_pic = link->cur_buf; |
| AVFilterBufferRef *out_buf = link->dst->outputs[0]->out_buf; |
| const uint8_t *in[4]; |
| uint8_t *out[4]; |
| int in_stride[4],out_stride[4]; |
| int i; |
| |
| for(i=0; i<4; i++){ |
| int vsub= ((i+1)&2) ? scale->vsub : 0; |
| in_stride[i] = cur_pic->linesize[i] * mul; |
| out_stride[i] = out_buf->linesize[i] * mul; |
| in[i] = cur_pic->data[i] + ((y>>vsub)+field) * cur_pic->linesize[i]; |
| out[i] = out_buf->data[i] + field * out_buf->linesize[i]; |
| } |
| if(scale->input_is_pal){ |
| in[1] = cur_pic->data[1]; |
| out[1] = out_buf->data[1]; |
| } |
| |
| return sws_scale(sws, in, in_stride, y/mul, h, |
| out,out_stride); |
| } |
| |
| static void draw_slice(AVFilterLink *link, int y, int h, int slice_dir) |
| { |
| ScaleContext *scale = link->dst->priv; |
| int out_h; |
| |
| if (scale->slice_y == 0 && slice_dir == -1) |
| scale->slice_y = link->dst->outputs[0]->h; |
| |
| if(scale->interlaced>0 || (scale->interlaced<0 && link->cur_buf->video->interlaced)){ |
| av_assert0(y%(2<<scale->vsub) == 0); |
| out_h = scale_slice(link, scale->isws[0], y, (h+1)/2, 2, 0); |
| out_h+= scale_slice(link, scale->isws[1], y, h /2, 2, 1); |
| }else{ |
| out_h = scale_slice(link, scale->sws, y, h, 1, 0); |
| } |
| |
| 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 = NULL_IF_CONFIG_SMALL("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 = (const AVFilterPad[]) {{ .name = "default", |
| .type = AVMEDIA_TYPE_VIDEO, |
| .start_frame = start_frame, |
| .draw_slice = draw_slice, |
| .min_perms = AV_PERM_READ, }, |
| { .name = NULL}}, |
| .outputs = (const AVFilterPad[]) {{ .name = "default", |
| .type = AVMEDIA_TYPE_VIDEO, |
| .config_props = config_props, }, |
| { .name = NULL}}, |
| }; |
