[FFmpeg-devel] Fwd: [PATCH] added expr evaluation to drawtext - fontsize
Michael Niedermayer
michael at niedermayer.cc
Tue Apr 18 03:48:16 EEST 2017
On Sun, Apr 16, 2017 at 10:01:01PM -0700, Brett Harrison wrote:
> Any comments on this patch?
>
> ---------- Forwarded message ----------
> From: Brett Harrison <brett.harrison at zyamusic.com>
> Date: Tue, Apr 11, 2017 at 1:37 PM
> Subject: Re: [FFmpeg-devel] [PATCH] added expr evaluation to drawtext -
> fontsize
> To: FFmpeg development discussions and patches <ffmpeg-devel at ffmpeg.org>
>
>
> Pinging for comments / review...
>
> On Tue, Apr 4, 2017 at 3:45 PM, Brett Harrison <brett.harrison at zyamusic.com>
> wrote:
>
> > Resurrecting this patch.
> >
> > On Thu, Sep 15, 2016 at 3:20 AM, Michael Niedermayer <
> > michael at niedermayer.cc> wrote:
> >
> >> On Fri, Sep 09, 2016 at 05:26:03PM -0700, Brett Harrison wrote:
> >> > Here are the changes requested
> >> [...]
> >> > +static av_cold int parse_fontsize(AVFilterContext *ctx)
> >> > +{
> >> > + DrawTextContext *s = ctx->priv;
> >> > + int err;
> >> > +
> >> > + if (s->fontsize_expr == NULL)
> >> > + return AVERROR(EINVAL);
> >> > +
> >> > + av_expr_free(s->fontsize_pexpr);
> >> > + s->fontsize_pexpr = NULL;
> >> > +
> >> > + if ((err = av_expr_parse(&s->fontsize_pexpr, s->fontsize_expr,
> >> var_names,
> >> > + NULL, NULL, fun2_names, fun2, 0, ctx)) <
> >> 0)
> >> > + return err;
> >> > +
> >> > + return 0;
> >> > +}
> >>
> >> why is av_expr_parse() not executed where the other av_expr_parse()
> >> are ?
> >>
> >
> > I needed to perform av_expr_parse() during init() to resolve the default
> > fontsize. init() is called before config_input() where the other
> > av_expr_parse() calls are.
> >
> >
> vf_drawtext.c | 125 ++++++++++++++++++++++++++++++++++++++++++++++++++--------
> 1 file changed, 108 insertions(+), 17 deletions(-)
> 085506596906b7f89f46edf6d21d34374e92d994 0001-added-expr-evaluation-to-drawtext-fontsize.patch
> From 8647e01f8ac2cd622e0ff5c1257773cfffa01ed9 Mon Sep 17 00:00:00 2001
> From: Brett Harrison <brett.harrison at musicmastermind.com>
> Date: Tue, 4 Apr 2017 15:39:06 -0700
> Subject: [PATCH] added expr evaluation to drawtext - fontsize
>
> ---
> libavfilter/vf_drawtext.c | 125 +++++++++++++++++++++++++++++++++++++++-------
> 1 file changed, 108 insertions(+), 17 deletions(-)
>
> diff --git a/libavfilter/vf_drawtext.c b/libavfilter/vf_drawtext.c
> index 8b24f50..77209f3 100644
> --- a/libavfilter/vf_drawtext.c
> +++ b/libavfilter/vf_drawtext.c
> @@ -156,7 +156,10 @@ typedef struct DrawTextContext {
> int max_glyph_h; ///< max glyph height
> int shadowx, shadowy;
> int borderw; ///< border width
> + char *fontsize_expr; ///< expression for fontsize
> + AVExpr *fontsize_pexpr; ///< parsed expressions for fontsize
> unsigned int fontsize; ///< font size to use
> + unsigned int default_fontsize; ///< default font size to use
>
> int line_spacing; ///< lines spacing in pixels
> short int draw_box; ///< draw box around text - true or false
> @@ -211,7 +214,7 @@ static const AVOption drawtext_options[]= {
> {"box", "set box", OFFSET(draw_box), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1 , FLAGS},
> {"boxborderw", "set box border width", OFFSET(boxborderw), AV_OPT_TYPE_INT, {.i64=0}, INT_MIN, INT_MAX , FLAGS},
> {"line_spacing", "set line spacing in pixels", OFFSET(line_spacing), AV_OPT_TYPE_INT, {.i64=0}, INT_MIN, INT_MAX,FLAGS},
> - {"fontsize", "set font size", OFFSET(fontsize), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX , FLAGS},
> + {"fontsize", "set font size", OFFSET(fontsize_expr), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX , FLAGS},
> {"x", "set x expression", OFFSET(x_expr), AV_OPT_TYPE_STRING, {.str="0"}, CHAR_MIN, CHAR_MAX, FLAGS},
> {"y", "set y expression", OFFSET(y_expr), AV_OPT_TYPE_STRING, {.str="0"}, CHAR_MIN, CHAR_MAX, FLAGS},
> {"shadowx", "set shadow x offset", OFFSET(shadowx), AV_OPT_TYPE_INT, {.i64=0}, INT_MIN, INT_MAX , FLAGS},
> @@ -281,6 +284,7 @@ typedef struct Glyph {
> FT_Glyph glyph;
> FT_Glyph border_glyph;
> uint32_t code;
> + unsigned int fontsize;
> FT_Bitmap bitmap; ///< array holding bitmaps of font
> FT_Bitmap border_bitmap; ///< array holding bitmaps of font border
> FT_BBox bbox;
> @@ -293,7 +297,11 @@ static int glyph_cmp(const void *key, const void *b)
> {
> const Glyph *a = key, *bb = b;
> int64_t diff = (int64_t)a->code - (int64_t)bb->code;
> - return diff > 0 ? 1 : diff < 0 ? -1 : 0;
> +
> + if (diff != 0)
> + return diff > 0 ? 1 : -1;
> + else
> + return FFDIFFSIGN((int64_t)a->fontsize, (int64_t)bb->fontsize);
> }
>
> /**
> @@ -317,6 +325,7 @@ static int load_glyph(AVFilterContext *ctx, Glyph **glyph_ptr, uint32_t code)
> goto error;
> }
> glyph->code = code;
> + glyph->fontsize = s->fontsize;
>
> if (FT_Get_Glyph(s->face->glyph, &glyph->glyph)) {
> ret = AVERROR(EINVAL);
> @@ -366,6 +375,68 @@ error:
> return ret;
> }
>
> +static av_cold int set_fontsize(AVFilterContext *ctx)
> +{
> + int err;
> + DrawTextContext *s = ctx->priv;
> +
> + if ((err = FT_Set_Pixel_Sizes(s->face, 0, s->fontsize))) {
> + av_log(ctx, AV_LOG_ERROR, "Could not set font size to %d pixels: %s\n",
> + s->fontsize, FT_ERRMSG(err));
> + return AVERROR(EINVAL);
> + }
> +
> + return 0;
> +}
> +
> +static av_cold int parse_fontsize(AVFilterContext *ctx)
> +{
> + DrawTextContext *s = ctx->priv;
> + int err;
> +
> + if (s->fontsize_pexpr)
> + return 0;
indention is inconsistent
> +
> + if (s->fontsize_expr == NULL)
> + return AVERROR(EINVAL);
> +
> + if ((err = av_expr_parse(&s->fontsize_pexpr, s->fontsize_expr, var_names,
> + NULL, NULL, fun2_names, fun2, 0, ctx)) < 0)
> + return err;
> +
> + return 0;
> +}
> +
> +static av_cold int update_fontsize(AVFilterContext *ctx)
> +{
> + DrawTextContext *s = ctx->priv;
> + unsigned int fontsize = s->default_fontsize;
> + int err;
> + double size;
> +
> + // if no fontsize specified use the default
> + if (s->fontsize_expr != NULL) {
> + if ((err = parse_fontsize(ctx)) < 0)
> + return err;
> +
> + size = av_expr_eval(s->fontsize_pexpr, s->var_values, &s->prng);
> +
> + if (!isnan(size))
> + fontsize = round(size);
round() returns a double
fontsize is unsigend int.
the cast can overflow
> + }
> +
> + if (fontsize == 0)
> + fontsize = 1;
> +
> + // no change
> + if (fontsize == s->fontsize)
> + return 0;
> +
> + s->fontsize = fontsize;
> +
> + return set_fontsize(ctx);
set_fontsize(ctx, fontsize);
seems cleaner to me
[...]
thx
--
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
Everything should be made as simple as possible, but not simpler.
-- Albert Einstein
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