[FFmpeg-devel] [PATCH 4/5] avfilter/scale: add function to check expressions
Gyan
ffmpeg at gyani.pro
Tue Dec 17 11:26:52 EET 2019
On 15-12-2019 10:37 pm, Gyan wrote:
> 4th of 5 factorized patches; supersedes
> https://patchwork.ffmpeg.org/patch/16272/
Same patch rebased on v2 of 3/5 patch.
Gyan
-------------- next part --------------
From 009e5f6d4c1338261ef7af683e54011b8b1adb30 Mon Sep 17 00:00:00 2001
From: Gyan Doshi <ffmpeg at gyani.pro>
Date: Fri, 13 Dec 2019 00:12:53 +0530
Subject: [PATCH v2 2/3] avfilter/scale: add function to check expressions
Allows finer identification and logging of invalid expressions
and use of a single list for symbols and their index for both
scale and scale2ref.
---
libavfilter/vf_scale.c | 116 ++++++++++++++++++++++++-----------------
1 file changed, 68 insertions(+), 48 deletions(-)
diff --git a/libavfilter/vf_scale.c b/libavfilter/vf_scale.c
index 93d3da807e..8a21cc593a 100644
--- a/libavfilter/vf_scale.c
+++ b/libavfilter/vf_scale.c
@@ -54,6 +54,13 @@ static const char *const var_names[] = {
"vsub",
"ohsub",
"ovsub",
+ "main_w",
+ "main_h",
+ "main_a",
+ "main_sar",
+ "main_dar", "mdar",
+ "main_hsub",
+ "main_vsub",
NULL
};
@@ -69,39 +76,6 @@ enum var_name {
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,
@@ -109,7 +83,7 @@ enum var_name_scale2ref {
VAR_S2R_MAIN_DAR, VAR_S2R_MDAR,
VAR_S2R_MAIN_HSUB,
VAR_S2R_MAIN_VSUB,
- VARS_S2R_NB
+ VARS_NB
};
enum EvalMode {
@@ -145,7 +119,7 @@ typedef struct ScaleContext {
char *h_expr; ///< height expression string
AVExpr *w_pexpr;
AVExpr *h_pexpr;
- double var_values[VARS_NB + VARS_S2R_NB];
+ double var_values[VARS_NB];
char *flags_str;
@@ -171,12 +145,53 @@ typedef struct ScaleContext {
AVFilter ff_vf_scale2ref;
+static int check_exprs(AVFilterContext *ctx)
+{
+ ScaleContext *scale = ctx->priv;
+ unsigned vars_w[VARS_NB] = { 0 }, vars_h[VARS_NB] = { 0 };
+
+ if (!scale->w_pexpr || !scale->h_pexpr)
+ return AVERROR(EINVAL);
+
+ av_expr_count_vars(scale->w_pexpr, vars_w, VARS_NB);
+ av_expr_count_vars(scale->h_pexpr, vars_h, VARS_NB);
+
+ if (vars_w[VAR_OUT_W] || vars_w[VAR_OW]) {
+ av_log(ctx, AV_LOG_ERROR, "Width expression cannot be self-referencing: '%s'.\n", scale->w_expr);
+ return AVERROR(EINVAL);
+ }
+
+ if (vars_h[VAR_OUT_H] || vars_h[VAR_OH]) {
+ av_log(ctx, AV_LOG_ERROR, "Height expression cannot be self-referencing: '%s'.\n", scale->h_expr);
+ return AVERROR(EINVAL);
+ }
+
+ if ((vars_w[VAR_OUT_H] || vars_w[VAR_OH]) &&
+ (vars_h[VAR_OUT_W] || vars_h[VAR_OW])) {
+ av_log(ctx, AV_LOG_ERROR, "Circular expressions invalid for width '%s' and height '%s'.\n", scale->w_expr, scale->h_expr);
+ return AVERROR(EINVAL);
+ }
+
+ if (ctx->filter != &ff_vf_scale2ref &&
+ (vars_w[VAR_S2R_MAIN_W] || vars_h[VAR_S2R_MAIN_W] ||
+ vars_w[VAR_S2R_MAIN_H] || vars_h[VAR_S2R_MAIN_H] ||
+ vars_w[VAR_S2R_MAIN_A] || vars_h[VAR_S2R_MAIN_A] ||
+ vars_w[VAR_S2R_MAIN_SAR] || vars_h[VAR_S2R_MAIN_SAR] ||
+ vars_w[VAR_S2R_MAIN_DAR] || vars_h[VAR_S2R_MAIN_DAR] ||
+ vars_w[VAR_S2R_MDAR] || vars_h[VAR_S2R_MDAR] ||
+ vars_w[VAR_S2R_MAIN_HSUB] || vars_h[VAR_S2R_MAIN_HSUB] ||
+ vars_w[VAR_S2R_MAIN_VSUB] || vars_h[VAR_S2R_MAIN_VSUB]) ) {
+ av_log(ctx, AV_LOG_ERROR, "Expressions with scale2ref variables are not valid in scale filter.\n");
+ return AVERROR(EINVAL);
+ }
+
+ return 0;
+}
+
static av_cold int init_dict(AVFilterContext *ctx, AVDictionary **opts)
{
ScaleContext *scale = ctx->priv;
int ret;
- const char scale2ref = ctx->filter == &ff_vf_scale2ref;
- const char *const *names = scale2ref ? var_names_scale2ref : var_names;
if (scale->size_str && (scale->w_expr || scale->h_expr)) {
av_log(ctx, AV_LOG_ERROR,
@@ -205,7 +220,7 @@ static av_cold int init_dict(AVFilterContext *ctx, AVDictionary **opts)
av_opt_set(scale, "h", "ih", 0);
ret = av_expr_parse(&scale->w_pexpr, scale->w_expr,
- names,
+ var_names,
NULL, NULL, NULL, NULL, 0, ctx);
if (ret < 0) {
av_log(ctx, AV_LOG_ERROR, "Cannot parse width expression: '%s'\n", scale->w_expr);
@@ -213,13 +228,17 @@ static av_cold int init_dict(AVFilterContext *ctx, AVDictionary **opts)
}
ret = av_expr_parse(&scale->h_pexpr, scale->h_expr,
- names,
+ var_names,
NULL, NULL, NULL, NULL, 0, ctx);
if (ret < 0) {
av_log(ctx, AV_LOG_ERROR, "Cannot parse height expression: '%s'\n", scale->h_expr);
return ret;
}
+ ret = check_exprs(ctx);
+ 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);
@@ -348,15 +367,15 @@ static int scale_eval_dimensions(AVFilterContext *ctx)
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 ?
+ scale->var_values[VAR_S2R_MAIN_W] = main_link->w;
+ scale->var_values[VAR_S2R_MAIN_H] = main_link->h;
+ scale->var_values[VAR_S2R_MAIN_A] = (double) main_link->w / main_link->h;
+ scale->var_values[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;
+ scale->var_values[VAR_S2R_MAIN_DAR] = scale->var_values[VAR_S2R_MDAR] =
+ scale->var_values[VAR_S2R_MAIN_A] * scale->var_values[VAR_S2R_MAIN_SAR];
+ scale->var_values[VAR_S2R_MAIN_HSUB] = 1 << main_desc->log2_chroma_w;
+ scale->var_values[VAR_S2R_MAIN_VSUB] = 1 << main_desc->log2_chroma_h;
}
res = av_expr_eval(scale->w_pexpr, scale->var_values, NULL);
@@ -796,7 +815,8 @@ static int process_command(AVFilterContext *ctx, const char *cmd, const char *ar
}
}
- if ((ret = config_props(outlink)) < 0) {
+ if ((ret = check_exprs(ctx)) < 0 ||
+ (ret = config_props(outlink)) < 0) {
av_log(ctx, AV_LOG_ERROR, "Command failed. Continuing with existing parameters.\n");
goto revert;
}
--
2.24.1
More information about the ffmpeg-devel
mailing list