[FFmpeg-devel] [PATCH 1/2] avfilter/dnn: do not manually parse anchors filter option

[Guo, Yejun]

> -----Original Message-----
> From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of Chen,
> Wenbin
> Sent: Thursday, February 27, 2025 10:39 AM
> To: FFmpeg development discussions and patches <ffmpeg-
> devel at ffmpeg.org>
> Subject: Re: [FFmpeg-devel] [PATCH 1/2] avfilter/dnn: do not manually parse
> anchors filter option
> 
> > Instead, rely on AV_OPT_TYPE_FLAG_ARRAY, which will automatically
> > perform the parsing.
> >
> > Signed-off-by: Leandro Santiago <leandrosansilva at gmail.com>
> > ---
> >  libavfilter/vf_dnn_detect.c | 43
> > ++++---------------------------------
> >  1 file changed, 4 insertions(+), 39 deletions(-)
> >
> > diff --git a/libavfilter/vf_dnn_detect.c b/libavfilter/vf_dnn_detect.c
> > index 590e4e256d..cd70c64e98 100644
> > --- a/libavfilter/vf_dnn_detect.c
> > +++ b/libavfilter/vf_dnn_detect.c
> > @@ -31,6 +31,7 @@
> >  #include "libavutil/avstring.h"
> >  #include "libavutil/detection_bbox.h"
> >  #include "libavutil/fifo.h"
> > +#include <float.h>
> >
> >  typedef enum {
> >      DDMT_SSD,
> > @@ -53,11 +54,12 @@ typedef struct DnnDetectContext {
> >      AVFifo *bboxes_fifo;
> >      int scale_width;
> >      int scale_height;
> > -    char *anchors_str;
> >      float *anchors;
> >      int nb_anchor;
> >  } DnnDetectContext;
> >
> > +static const AVOptionArrayDef anchor_array_def = { .sep = '&' };
> > +
> >  #define OFFSET(x) offsetof(DnnDetectContext, dnnctx.x)  #define
> > OFFSET2(x) offsetof(DnnDetectContext, x)  #define FLAGS
> > AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_VIDEO_PARAM @@ -
> 79,7 +81,7
> > @@ static const AVOption dnn_detect_options[] = {
> >      { "cell_w",      "cell width",                 OFFSET2(cell_w),
> > AV_OPT_TYPE_INT,       { .i64 = 0 },    0, INTMAX_MAX, FLAGS },
> >      { "cell_h",      "cell height",                OFFSET2(cell_h),
> > AV_OPT_TYPE_INT,       { .i64 = 0 },    0, INTMAX_MAX, FLAGS },
> >      { "nb_classes",  "The number of class",        OFFSET2(nb_classes),
> > AV_OPT_TYPE_INT,       { .i64 = 0 },    0, INTMAX_MAX, FLAGS },
> > -    { "anchors",     "anchors, splited by '&'",    OFFSET2(anchors_str),
> > AV_OPT_TYPE_STRING,    { .str = NULL }, 0, 0, FLAGS },
> > +    { "anchors",     "anchors, splited by '&'",    OFFSET2(anchors),
> > AV_OPT_TYPE_FLOAT | AV_OPT_TYPE_FLAG_ARRAY,    { .arr =
> > &anchor_array_def }, FLT_MIN, FLT_MAX, FLAGS },
> >      { NULL }
> >  };
> >
> > @@ -106,34 +108,6 @@ static int dnn_detect_get_label_id(int
> > nb_classes, int cell_size, float *label_d
> >      return label_id;
> >  }
> >
> > -static int dnn_detect_parse_anchors(char *anchors_str, float
> > **anchors) -{
> > -    char *saveptr = NULL, *token;
> > -    float *anchors_buf;
> > -    int nb_anchor = 0, i = 0;
> > -    while(anchors_str[i] != '\0') {
> > -        if(anchors_str[i] == '&')
> > -            nb_anchor++;
> > -        i++;
> > -    }
> > -    nb_anchor++;
> > -    anchors_buf = av_mallocz(nb_anchor * sizeof(**anchors));
> > -    if (!anchors_buf) {
> > -        return 0;
> > -    }
> > -    for (int i = 0; i < nb_anchor; i++) {
> > -        token = av_strtok(anchors_str, "&", &saveptr);
> > -        if (!token) {
> > -            av_freep(&anchors_buf);
> > -            return 0;
> > -        }
> > -        anchors_buf[i] = strtof(token, NULL);
> > -        anchors_str = NULL;
> > -    }
> > -    *anchors = anchors_buf;
> > -    return nb_anchor;
> > -}
> > -
> >  /* Calculate Intersection Over Union */  static float
> > dnn_detect_IOU(AVDetectionBBox *bbox1, AVDetectionBBox
> > *bbox2)
> >  {
> > @@ -701,15 +675,6 @@ static av_cold int
> > dnn_detect_init(AVFilterContext
> > *context)
> >          }
> >      }
> >
> > -    if (ctx->anchors_str) {
> > -        ret = dnn_detect_parse_anchors(ctx->anchors_str, &ctx->anchors);
> > -        if (!ctx->anchors) {
> > -            av_log(context, AV_LOG_ERROR, "failed to parse anchors_str\n");
> > -            return AVERROR(EINVAL);
> > -        }
> > -        ctx->nb_anchor = ret;
> > -    }
> > -
> >      return 0;
> >  }
> >
> > --
> > 2.48.1
> >
> 
> LGTM. Thanks
> 
> Wenbin

Will push soon, thanks.