[FFmpeg-devel] [PATCH v2 3/5] avfilter/scale: separate exprs parse and eval
Gyan
ffmpeg at gyani.pro
Mon Jan 6 08:14:07 EET 2020
Ping for the remainder of patchset. Expression parsing and backup has
been factorized so code duplication is minimized.
On 01-01-2020 01:12 am, Gyan Doshi wrote:
> 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;
> }
>
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