[FFmpeg-devel] [PATCH v2 3/5] avfilter/scale: separate exprs parse and eval
Gyan Doshi
ffmpeg at gyani.pro
Tue Dec 31 21:42:21 EET 2019
Retains parsed expressions which allows for better
error-checking and adding animation support.
---
First version was rebased incorrectly in scale_eval_dimensions
libavfilter/scale_eval.c | 69 +---------
libavfilter/vf_scale.c | 264 +++++++++++++++++++++++++++++++++++----
2 files changed, 246 insertions(+), 87 deletions(-)
diff --git a/libavfilter/scale_eval.c b/libavfilter/scale_eval.c
index 6c526a97af..dfec081e15 100644
--- a/libavfilter/scale_eval.c
+++ b/libavfilter/scale_eval.c
@@ -54,46 +54,6 @@ enum var_name {
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
-};
-
int ff_scale_eval_dimensions(void *log_ctx,
const char *w_expr, const char *h_expr,
AVFilterLink *inlink, AVFilterLink *outlink,
@@ -104,16 +64,7 @@ int ff_scale_eval_dimensions(void *log_ctx,
const char *expr;
int eval_w, eval_h;
int ret;
- const char scale2ref = outlink->src->nb_inputs == 2 && outlink->src->inputs[1] == inlink;
- double var_values[VARS_NB + VARS_S2R_NB], res;
- const AVPixFmtDescriptor *main_desc;
- const AVFilterLink *main_link;
- const char *const *names = scale2ref ? var_names_scale2ref : var_names;
-
- if (scale2ref) {
- main_link = outlink->src->inputs[0];
- main_desc = av_pix_fmt_desc_get(main_link->format);
- }
+ double var_values[VARS_NB], res;
var_values[VAR_IN_W] = var_values[VAR_IW] = inlink->w;
var_values[VAR_IN_H] = var_values[VAR_IH] = inlink->h;
@@ -128,32 +79,20 @@ int ff_scale_eval_dimensions(void *log_ctx,
var_values[VAR_OHSUB] = 1 << out_desc->log2_chroma_w;
var_values[VAR_OVSUB] = 1 << out_desc->log2_chroma_h;
- if (scale2ref) {
- var_values[VARS_NB + VAR_S2R_MAIN_W] = main_link->w;
- var_values[VARS_NB + VAR_S2R_MAIN_H] = main_link->h;
- var_values[VARS_NB + VAR_S2R_MAIN_A] = (double) main_link->w / main_link->h;
- 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;
- var_values[VARS_NB + VAR_S2R_MAIN_DAR] = var_values[VARS_NB + VAR_S2R_MDAR] =
- var_values[VARS_NB + VAR_S2R_MAIN_A] * var_values[VARS_NB + VAR_S2R_MAIN_SAR];
- var_values[VARS_NB + VAR_S2R_MAIN_HSUB] = 1 << main_desc->log2_chroma_w;
- var_values[VARS_NB + VAR_S2R_MAIN_VSUB] = 1 << main_desc->log2_chroma_h;
- }
-
/* evaluate width and height */
av_expr_parse_and_eval(&res, (expr = w_expr),
- names, var_values,
+ var_names, var_values,
NULL, NULL, NULL, NULL, NULL, 0, log_ctx);
eval_w = var_values[VAR_OUT_W] = var_values[VAR_OW] = (int) res == 0 ? inlink->w : (int) res;
if ((ret = av_expr_parse_and_eval(&res, (expr = h_expr),
- names, var_values,
+ var_names, var_values,
NULL, NULL, NULL, NULL, NULL, 0, log_ctx)) < 0)
goto fail;
eval_h = var_values[VAR_OUT_H] = var_values[VAR_OH] = (int) res == 0 ? inlink->h : (int) res;
/* evaluate again the width, as it may depend on the output height */
if ((ret = av_expr_parse_and_eval(&res, (expr = w_expr),
- names, var_values,
+ var_names, var_values,
NULL, NULL, NULL, NULL, NULL, 0, log_ctx)) < 0)
goto fail;
eval_w = (int) res == 0 ? inlink->w : (int) res;
diff --git a/libavfilter/vf_scale.c b/libavfilter/vf_scale.c
index 5a375fac5d..582b34ce09 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;
}
--
2.24.1
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