[FFmpeg-devel] [PATCH] avfilter/showcqt: add fontcolor option

Clément Bœsch u at pkh.me
Tue Aug 19 07:38:33 CEST 2014


On Mon, Aug 18, 2014 at 06:54:55AM +0700, Muhammad Faiz wrote:
> This fontcolor option uses arithmetic expression, not color value,
> so color names aren't available.
> Thank's

> 
> ---
>  doc/filters.texi          | 20 +++++++++++
>  libavfilter/avf_showcqt.c | 84 ++++++++++++++++++++++++++++++++++-------------
>  2 files changed, 81 insertions(+), 23 deletions(-)
> 
> diff --git a/doc/filters.texi b/doc/filters.texi
> index 0ca1d6f..958b48e 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -10610,6 +10610,26 @@ Default value is @code{3.0}.
>  @item fontfile
>  Specify font file for use with freetype. If not specified, use embedded font.
>  
> + at item fontcolor
> +Specify font color expression. This is arithmetic expression that should return
> +integer value 0xRRGGBB. The expression can contain variables:
> + at table @option
> + at item frequency, freq, f
> +the frequency where transform is evaluated
> + at item timeclamp, tc
> +value of timeclamp option
> + at end table
> +and functions:
> + at table @option
> + at item midi(f)
> +midi number of frequency f
> + at item r(x), g(x), b(x)
> +red, green, and blue value of intensity x
> + at end table
> +Default value is @code{st(0, (midi(f)-59.5)/12);
> +st(1, if(between(ld(0),0,1), 0.5-0.5*cos(2*PI*ld(0)), 0));
> +r(1-ld(1)) + b(ld(1)}
> +

Can you suggest an alternative in the examples? (maybe with some green?)

>  @item fullhd
>  If set to 1 (the default), the video size is 1920x1080 (full HD),
>  if set to 0, the video size is 960x540. Use this option to make CPU usage lower.
> diff --git a/libavfilter/avf_showcqt.c b/libavfilter/avf_showcqt.c
> index 012362b..d349c3d 100644
> --- a/libavfilter/avf_showcqt.c
> +++ b/libavfilter/avf_showcqt.c
> @@ -54,6 +54,9 @@
>  #define TLENGTH_DEFAULT "384/f*tc/(384/f+tc)"
>  #define VOLUME_MIN 1e-10
>  #define VOLUME_MAX 100.0
> +#define FONTCOLOR_DEFAULT "st(0, (midi(f)-59.5)/12);" \
> +    "st(1, if(between(ld(0),0,1), 0.5-0.5*cos(2*PI*ld(0)), 0));" \
> +    "r(1-ld(1)) + b(ld(1))"
>  
>  typedef struct {
>      FFTSample value;
> @@ -73,7 +76,7 @@ typedef struct {
>      uint8_t *font_alpha;
>      char *fontfile;     /* using freetype */
>      int coeffs_len[VIDEO_WIDTH];
> -    uint8_t font_color[VIDEO_WIDTH];
> +    uint8_t fontcolor_value[VIDEO_WIDTH*3];  /* result of fontcolor option */
>      int64_t frame_count;
>      int spectogram_count;
>      int spectogram_index;
> @@ -82,6 +85,7 @@ typedef struct {
>      int remaining_fill;
>      char *tlength;
>      char *volume;
> +    char *fontcolor;
>      double timeclamp;   /* lower timeclamp, time-accurate, higher timeclamp, freq-accurate (at low freq)*/
>      float coeffclamp;   /* lower coeffclamp, more precise, higher coeffclamp, faster */
>      int fullhd;         /* if true, output video is at full HD resolution, otherwise it will be halved */
> @@ -103,6 +107,7 @@ static const AVOption showcqt_options[] = {
>      { "fps", "set video fps", OFFSET(fps), AV_OPT_TYPE_INT, { .i64 = 25 }, 10, 100, FLAGS },
>      { "count", "set number of transform per frame", OFFSET(count), AV_OPT_TYPE_INT, { .i64 = 6 }, 1, 30, FLAGS },
>      { "fontfile", "set font file", OFFSET(fontfile), AV_OPT_TYPE_STRING, { .str = NULL }, CHAR_MIN, CHAR_MAX, FLAGS },
> +    { "fontcolor", "set font color", OFFSET(fontcolor), AV_OPT_TYPE_STRING, { .str = FONTCOLOR_DEFAULT }, CHAR_MIN, CHAR_MAX, FLAGS },
>      { NULL }
>  };
>  
> @@ -275,6 +280,29 @@ static double c_weighting(void *p, double f)
>      return ret;
>  }
>  
> +static double midi(void *p, double f)
> +{
> +    return log2(f/440.0) * 12.0 + 69.0;
> +}
> +
> +static double r_func(void *p, double x)
> +{
> +    x = FFMAX(0.0, FFMIN(1.0, x));

av_clipd()?

> +    return (int)(x*255.0+0.5) << 16;
> +}
> +
> +static double g_func(void *p, double x)
> +{
> +    x = FFMAX(0.0, FFMIN(1.0, x));
> +    return (int)(x*255.0+0.5) << 8;
> +}
> +
> +static double b_func(void *p, double x)
> +{
> +    x = FFMAX(0.0, FFMIN(1.0, x));
> +    return (int)(x*255.0+0.5);
> +}
> +
>  static inline int qsort_sparsecoeff(const SparseCoeff *a, const SparseCoeff *b)
>  {
>      if (fabsf(a->value) >= fabsf(b->value))
> @@ -288,10 +316,13 @@ static int config_output(AVFilterLink *outlink)
>      AVFilterContext *ctx = outlink->src;
>      AVFilterLink *inlink = ctx->inputs[0];
>      ShowCQTContext *s = ctx->priv;
> -    AVExpr *tlength_expr, *volume_expr;
> +    AVExpr *tlength_expr, *volume_expr, *fontcolor_expr;
> +    uint8_t *fontcolor_value = s->fontcolor_value;
>      static const char * const expr_vars[] = { "timeclamp", "tc", "frequency", "freq", "f", NULL };
>      static const char * const expr_func_names[] = { "a_weighting", "b_weighting", "c_weighting", NULL };
> +    static const char * const expr_fontcolor_func_names[] = { "midi", "r", "g", "b", NULL };
>      static double (* const expr_funcs[])(void *, double) = { a_weighting, b_weighting, c_weighting, NULL };
> +    static double (* const expr_fontcolor_funcs[])(void *, double) = { midi, r_func, g_func, b_func, NULL };
>      int fft_len, k, x, y, ret;
>      int num_coeffs = 0;
>      int rate = inlink->sample_rate;
> @@ -319,17 +350,6 @@ static int config_output(AVFilterLink *outlink)
>      if (!s->fft_data || !s->coeff_sort || !s->fft_result_left || !s->fft_result_right || !s->fft_context)
>          return AVERROR(ENOMEM);
>  
> -    /* initializing font */
> -    for (x = 0; x < video_width; x++) {
> -        if (x >= (12*3+8)*8*video_scale && x < (12*4+8)*8*video_scale) {
> -            float fx = (x-(12*3+8)*8*video_scale) * (2.0f/(192.0f*video_scale));
> -            float sv = sinf(M_PI*fx);
> -            s->font_color[x] = sv*sv*255.0f + 0.5f;
> -        } else {
> -            s->font_color[x] = 0;
> -        }
> -    }
> -
>  #if CONFIG_LIBFREETYPE
>      load_freetype_font(ctx);
>  #else
> @@ -349,6 +369,13 @@ static int config_output(AVFilterLink *outlink)
>          av_expr_free(tlength_expr);
>          return ret;
>      }
> +    ret = av_expr_parse(&fontcolor_expr, s->fontcolor, expr_vars, expr_fontcolor_func_names,
> +                        expr_fontcolor_funcs, NULL, NULL, 0, ctx);
> +    if (ret < 0) {
> +        av_expr_free(volume_expr);
> +        av_expr_free(tlength_expr);
> +        return ret;
> +    }

It would probably be better to consider a goto end to cleanup these
instead of adding the av_expr_free() in every fail path (Non-blocking
request).

[...]

LGTM otherwise

-- 
Clément B.
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