From 6310fbd543f0c61b258d3993f28286eb0360ff87 Mon Sep 17 00:00:00 2001 From: Gyan Doshi Date: Tue, 31 Dec 2019 17:10:58 +0530 Subject: avfilter/scale: separate exprs parse and eval Retains parsed expressions which allows for better error-checking and adding animation support. --- libavfilter/vf_scale.c | 264 ++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 242 insertions(+), 22 deletions(-) (limited to 'libavfilter/vf_scale.c') diff --git a/libavfilter/vf_scale.c b/libavfilter/vf_scale.c index 3e97a4592a..64f5eb0642 100644 --- a/libavfilter/vf_scale.c +++ b/libavfilter/vf_scale.c @@ -32,6 +32,7 @@ #include "scale_eval.h" #include "video.h" #include "libavutil/avstring.h" +#include "libavutil/eval.h" #include "libavutil/internal.h" #include "libavutil/mathematics.h" #include "libavutil/opt.h" @@ -41,6 +42,76 @@ #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", + "ohsub", + "ovsub", + 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, + VAR_OHSUB, + VAR_OVSUB, + VARS_NB +}; + +/** + * This must be kept in sync with var_names so that it is always a + * complete list of var_names with the scale2ref specific names + * appended. scale2ref values must appear in the order they appear + * in the var_name_scale2ref enum but also be below all of the + * non-scale2ref specific values. + */ +static const char *const var_names_scale2ref[] = { + "in_w", "iw", + "in_h", "ih", + "out_w", "ow", + "out_h", "oh", + "a", + "sar", + "dar", + "hsub", + "vsub", + "ohsub", + "ovsub", + "main_w", + "main_h", + "main_a", + "main_sar", + "main_dar", "mdar", + "main_hsub", + "main_vsub", + NULL +}; + +enum var_name_scale2ref { + VAR_S2R_MAIN_W, + VAR_S2R_MAIN_H, + VAR_S2R_MAIN_A, + VAR_S2R_MAIN_SAR, + VAR_S2R_MAIN_DAR, VAR_S2R_MDAR, + VAR_S2R_MAIN_HSUB, + VAR_S2R_MAIN_VSUB, + VARS_S2R_NB +}; + enum EvalMode { EVAL_MODE_INIT, EVAL_MODE_FRAME, @@ -72,6 +143,10 @@ typedef struct ScaleContext { char *w_expr; ///< width expression string char *h_expr; ///< height expression string + AVExpr *w_pexpr; + AVExpr *h_pexpr; + double var_values[VARS_NB + VARS_S2R_NB]; + char *flags_str; char *in_color_matrix; @@ -96,6 +171,59 @@ typedef struct ScaleContext { AVFilter ff_vf_scale2ref; +static int config_props(AVFilterLink *outlink); + +static int scale_parse_expr(AVFilterContext *ctx, char *str_expr, AVExpr **pexpr_ptr, const char *var, const char *args) +{ + ScaleContext *scale = ctx->priv; + int ret, is_inited = 0; + char *old_str_expr = NULL; + AVExpr *old_pexpr = NULL; + const char scale2ref = ctx->filter == &ff_vf_scale2ref; + const char *const *names = scale2ref ? var_names_scale2ref : var_names; + + if (str_expr) { + old_str_expr = av_strdup(str_expr); + if (!old_str_expr) + return AVERROR(ENOMEM); + av_opt_set(scale, var, args, 0); + } + + if (*pexpr_ptr) { + old_pexpr = *pexpr_ptr; + *pexpr_ptr = NULL; + is_inited = 1; + } + + ret = av_expr_parse(pexpr_ptr, args, names, + NULL, NULL, NULL, NULL, 0, ctx); + if (ret < 0) { + av_log(ctx, AV_LOG_ERROR, "Cannot parse expression for %s: '%s'\n", var, args); + goto revert; + } + + if (is_inited && (ret = config_props(ctx->outputs[0])) < 0) + goto revert; + + av_expr_free(old_pexpr); + old_pexpr = NULL; + av_freep(&old_str_expr); + + return 0; + +revert: + av_expr_free(*pexpr_ptr); + *pexpr_ptr = NULL; + if (old_str_expr) { + av_opt_set(scale, var, old_str_expr, 0); + av_free(old_str_expr); + } + if (old_pexpr) + *pexpr_ptr = old_pexpr; + + return ret; +} + static av_cold int init_dict(AVFilterContext *ctx, AVDictionary **opts) { ScaleContext *scale = ctx->priv; @@ -127,6 +255,14 @@ static av_cold int init_dict(AVFilterContext *ctx, AVDictionary **opts) if (!scale->h_expr) av_opt_set(scale, "h", "ih", 0); + ret = scale_parse_expr(ctx, NULL, &scale->w_pexpr, "width", scale->w_expr); + if (ret < 0) + return ret; + + ret = scale_parse_expr(ctx, NULL, &scale->h_pexpr, "height", scale->h_expr); + if (ret < 0) + return ret; + av_log(ctx, AV_LOG_VERBOSE, "w:%s h:%s flags:'%s' interl:%d\n", scale->w_expr, scale->h_expr, (char *)av_x_if_null(scale->flags_str, ""), scale->interlaced); @@ -149,6 +285,9 @@ static av_cold int init_dict(AVFilterContext *ctx, AVDictionary **opts) static av_cold void uninit(AVFilterContext *ctx) { ScaleContext *scale = ctx->priv; + av_expr_free(scale->w_pexpr); + av_expr_free(scale->h_pexpr); + scale->w_pexpr = scale->h_pexpr = NULL; sws_freeContext(scale->sws); sws_freeContext(scale->isws[0]); sws_freeContext(scale->isws[1]); @@ -218,6 +357,81 @@ static const int *parse_yuv_type(const char *s, enum AVColorSpace colorspace) return sws_getCoefficients(colorspace); } +static int scale_eval_dimensions(AVFilterContext *ctx) +{ + ScaleContext *scale = ctx->priv; + const char scale2ref = ctx->filter == &ff_vf_scale2ref; + const AVFilterLink *inlink = scale2ref ? ctx->inputs[1] : ctx->inputs[0]; + const AVFilterLink *outlink = ctx->outputs[0]; + const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format); + const AVPixFmtDescriptor *out_desc = av_pix_fmt_desc_get(outlink->format); + char *expr; + int eval_w, eval_h; + int ret; + double res; + const AVPixFmtDescriptor *main_desc; + const AVFilterLink *main_link; + + if (scale2ref) { + main_link = ctx->inputs[0]; + main_desc = av_pix_fmt_desc_get(main_link->format); + } + + scale->var_values[VAR_IN_W] = scale->var_values[VAR_IW] = inlink->w; + scale->var_values[VAR_IN_H] = scale->var_values[VAR_IH] = inlink->h; + scale->var_values[VAR_OUT_W] = scale->var_values[VAR_OW] = NAN; + scale->var_values[VAR_OUT_H] = scale->var_values[VAR_OH] = NAN; + scale->var_values[VAR_A] = (double) inlink->w / inlink->h; + scale->var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ? + (double) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1; + scale->var_values[VAR_DAR] = scale->var_values[VAR_A] * scale->var_values[VAR_SAR]; + scale->var_values[VAR_HSUB] = 1 << desc->log2_chroma_w; + scale->var_values[VAR_VSUB] = 1 << desc->log2_chroma_h; + scale->var_values[VAR_OHSUB] = 1 << out_desc->log2_chroma_w; + scale->var_values[VAR_OVSUB] = 1 << out_desc->log2_chroma_h; + + if (scale2ref) { + scale->var_values[VARS_NB + VAR_S2R_MAIN_W] = main_link->w; + scale->var_values[VARS_NB + VAR_S2R_MAIN_H] = main_link->h; + scale->var_values[VARS_NB + VAR_S2R_MAIN_A] = (double) main_link->w / main_link->h; + scale->var_values[VARS_NB + VAR_S2R_MAIN_SAR] = main_link->sample_aspect_ratio.num ? + (double) main_link->sample_aspect_ratio.num / main_link->sample_aspect_ratio.den : 1; + scale->var_values[VARS_NB + VAR_S2R_MAIN_DAR] = scale->var_values[VARS_NB + VAR_S2R_MDAR] = + scale->var_values[VARS_NB + VAR_S2R_MAIN_A] * scale->var_values[VARS_NB + VAR_S2R_MAIN_SAR]; + scale->var_values[VARS_NB + VAR_S2R_MAIN_HSUB] = 1 << main_desc->log2_chroma_w; + scale->var_values[VARS_NB + VAR_S2R_MAIN_VSUB] = 1 << main_desc->log2_chroma_h; + } + + res = av_expr_eval(scale->w_pexpr, scale->var_values, NULL); + eval_w = scale->var_values[VAR_OUT_W] = scale->var_values[VAR_OW] = (int) res == 0 ? inlink->w : (int) res; + + res = av_expr_eval(scale->h_pexpr, scale->var_values, NULL); + if (isnan(res)) { + expr = scale->h_expr; + ret = AVERROR(EINVAL); + goto fail; + } + eval_h = scale->var_values[VAR_OUT_H] = scale->var_values[VAR_OH] = (int) res == 0 ? inlink->h : (int) res; + + res = av_expr_eval(scale->w_pexpr, scale->var_values, NULL); + if (isnan(res)) { + expr = scale->w_expr; + ret = AVERROR(EINVAL); + goto fail; + } + eval_w = scale->var_values[VAR_OUT_W] = scale->var_values[VAR_OW] = (int) res == 0 ? inlink->w : (int) res; + + scale->w = eval_w; + scale->h = eval_h; + + return 0; + +fail: + av_log(ctx, AV_LOG_ERROR, + "Error when evaluating the expression '%s'.\n", expr); + return ret; +} + static int config_props(AVFilterLink *outlink) { AVFilterContext *ctx = outlink->src; @@ -228,26 +442,23 @@ static int config_props(AVFilterLink *outlink) enum AVPixelFormat outfmt = outlink->format; const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format); ScaleContext *scale = ctx->priv; - int w, h; int ret; - if ((ret = ff_scale_eval_dimensions(ctx, - scale->w_expr, scale->h_expr, - inlink, outlink, - &w, &h)) < 0) + if ((ret = scale_eval_dimensions(ctx)) < 0) goto fail; - ff_scale_adjust_dimensions(inlink, &w, &h, + ff_scale_adjust_dimensions(inlink, &scale->w, &scale->h, scale->force_original_aspect_ratio, scale->force_divisible_by); - if (w > INT_MAX || h > INT_MAX || - (h * inlink->w) > INT_MAX || - (w * inlink->h) > INT_MAX) + if (scale->w > INT_MAX || + scale->h > INT_MAX || + (scale->h * inlink->w) > INT_MAX || + (scale->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; + outlink->w = scale->w; + outlink->h = scale->h; /* TODO: make algorithm configurable */ @@ -421,6 +632,14 @@ static int scale_frame(AVFilterLink *link, AVFrame *in, AVFrame **frame_out) av_opt_set(scale, "w", buf, 0); snprintf(buf, sizeof(buf)-1, "%d", outlink->h); av_opt_set(scale, "h", buf, 0); + + ret = scale_parse_expr(ctx, NULL, &scale->w_pexpr, "width", scale->w_expr); + if (ret < 0) + return ret; + + ret = scale_parse_expr(ctx, NULL, &scale->h_pexpr, "height", scale->h_expr); + if (ret < 0) + return ret; } link->dst->inputs[0]->format = in->format; @@ -566,23 +785,24 @@ static int process_command(AVFilterContext *ctx, const char *cmd, const char *ar char *res, int res_len, int flags) { ScaleContext *scale = ctx->priv; - int ret; + char *str_expr; + AVExpr **pexpr_ptr; + int ret, w, h; - if ( !strcmp(cmd, "width") || !strcmp(cmd, "w") - || !strcmp(cmd, "height") || !strcmp(cmd, "h")) { + w = !strcmp(cmd, "width") || !strcmp(cmd, "w"); + h = !strcmp(cmd, "height") || !strcmp(cmd, "h"); - int old_w = scale->w; - int old_h = scale->h; - AVFilterLink *outlink = ctx->outputs[0]; + if (w || h) { + str_expr = w ? scale->w_expr : scale->h_expr; + pexpr_ptr = w ? &scale->w_pexpr : &scale->h_pexpr; - av_opt_set(scale, cmd, args, 0); - if ((ret = config_props(outlink)) < 0) { - scale->w = old_w; - scale->h = old_h; - } + ret = scale_parse_expr(ctx, str_expr, pexpr_ptr, cmd, args); } else ret = AVERROR(ENOSYS); + if (ret < 0) + av_log(ctx, AV_LOG_ERROR, "Failed to process command. Continuing with existing parameters.\n"); + return ret; } -- cgit v1.2.3