[FFmpeg-devel] [PATCH] New p2p mode for showwaves filter

[Paul B Mahol]

On Mon, Aug 4, 2014 at 9:24 AM, mrskman <mrskman at gmail.com> wrote:

> New patch attached.
>
> Thank you.
>
> ---
>  doc/filters.texi            |    3 +++
>  libavfilter/avf_showwaves.c |   33 ++++++++++++++++++++++++++++++++-
>  2 files changed, 35 insertions(+), 1 deletions(-)
>
> diff --git a/doc/filters.texi b/doc/filters.texi
> index a7919a3..145acbf 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -10698,6 +10698,9 @@ Draw a point for each sample.
>
>  @item line
>  Draw a vertical line for each sample.
> +
> + at item p2p
> +Draw a point for each sample and a line between them.
>  @end table
>
>  Default value is @code{point}.
> diff --git a/libavfilter/avf_showwaves.c b/libavfilter/avf_showwaves.c
> index 0b45bd0..e6158b2 100644
> --- a/libavfilter/avf_showwaves.c
> +++ b/libavfilter/avf_showwaves.c
> @@ -35,6 +35,7 @@
>  enum ShowWavesMode {
>      MODE_POINT,
>      MODE_LINE,
> +    MODE_P2P,
>      MODE_NB,
>  };
>
> @@ -43,6 +44,7 @@ typedef struct {
>      int w, h;
>      AVRational rate;
>      int buf_idx;
> +    int *buf_idy;    /* y coordinate of previous sample for each channel
> */
>      AVFrame *outpicref;
>      int req_fullfilled;
>      int n;
> @@ -59,6 +61,7 @@ static const AVOption showwaves_options[] = {
>      { "mode", "select display mode", OFFSET(mode), AV_OPT_TYPE_INT,
> {.i64=MODE_POINT}, 0, MODE_NB-1, FLAGS, "mode"},
>          { "point", "draw a point for each sample", 0, AV_OPT_TYPE_CONST,
> {.i64=MODE_POINT}, .flags=FLAGS, .unit="mode"},
>          { "line",  "draw a line for each sample",  0, AV_OPT_TYPE_CONST,
> {.i64=MODE_LINE},  .flags=FLAGS, .unit="mode"},
> +        { "p2p", "draw a line between samples", 0, AV_OPT_TYPE_CONST,
> {.i64=MODE_P2P}, .flags=FLAGS, .unit="mode"},
>      { "n",    "set how many samples to show in the same point",
> OFFSET(n), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, FLAGS },
>      { "rate", "set video rate", OFFSET(rate), AV_OPT_TYPE_VIDEO_RATE,
> {.str = "25"}, 0, 0, FLAGS },
>      { "r",    "set video rate", OFFSET(rate), AV_OPT_TYPE_VIDEO_RATE,
> {.str = "25"}, 0, 0, FLAGS },
> @@ -72,6 +75,8 @@ static av_cold void uninit(AVFilterContext *ctx)
>      ShowWavesContext *showwaves = ctx->priv;
>
>      av_frame_free(&showwaves->outpicref);
> +    if (showwaves->buf_idy)
> +        av_freep(showwaves->buf_idy);
>  }
>
>  static int query_formats(AVFilterContext *ctx)
> @@ -110,14 +115,22 @@ static int query_formats(AVFilterContext *ctx)
>
>  static int config_output(AVFilterLink *outlink)
>  {
> +    int i;
>
Could you put this one down where nb_channels is.


>      AVFilterContext *ctx = outlink->src;
>      AVFilterLink *inlink = ctx->inputs[0];
>      ShowWavesContext *showwaves = ctx->priv;
> +    int nb_channels = inlink->channels;
>
>      if (!showwaves->n)
>          showwaves->n = FFMAX(1, ((double)inlink->sample_rate /
> (showwaves->w * av_q2d(showwaves->rate))) + 0.5);
>
>      showwaves->buf_idx = 0;
> +    if (!(showwaves->buf_idy = av_malloc_array(nb_channels, 1))) {
>

Use calloc, or av_mallocz_array.


> +        av_log(NULL, AV_LOG_ERROR, "Could not allocate showwaves
> buffer\n");
>

This can use ctx : av_log(ctx,..


>  +        return AVERROR(ENOMEM);
> +    }
> +    for (i = 0; i <= nb_channels; i++)
> +        showwaves->buf_idy[i] = 0;
>

Not needed to manually do this if you use one of above mentioned functions.


>       outlink->w = showwaves->w;
>      outlink->h = showwaves->h;
>      outlink->sample_aspect_ratio = (AVRational){1,1};
> @@ -132,13 +145,18 @@ static int config_output(AVFilterLink *outlink)
>
>  inline static int push_frame(AVFilterLink *outlink)
>  {
> +    AVFilterContext *ctx = outlink->src;
> +    AVFilterLink *inlink = ctx->inputs[0];
>      ShowWavesContext *showwaves = outlink->src->priv;
> -    int ret;
> +    int nb_channels = inlink->channels;
> +    int ret, i;
>
>      if ((ret = ff_filter_frame(outlink, showwaves->outpicref)) >= 0)
>          showwaves->req_fullfilled = 1;
>      showwaves->outpicref = NULL;
>      showwaves->buf_idx = 0;
> +    for (i = 0; i <= nb_channels; i++)
> +        showwaves->buf_idy[i] = 0;
>      return ret;
>  }
>
> @@ -207,7 +225,20 @@ static int filter_frame(AVFilterLink *inlink, AVFrame
> *insamples)
>                      *(outpicref->data[0] + showwaves->buf_idx + k *
> linesize) += x;
>                  break;
>              }
> +            case MODE_P2P:
> +                if (h >= 0 && h < outlink->h) {
> +                    *(outpicref->data[0] + showwaves->buf_idx + h *
> linesize) += x;
> +                    if (showwaves->buf_idy[j] && h !=
> showwaves->buf_idy[j]) {
> +                        int start = showwaves->buf_idy[j], end =
> av_clip(h, 0, outlink->h-1);
> +                        if (start > end) FFSWAP(int16_t, start, end);
>
FFSWAP.. should be on its own line

+                        for (k = start + 1; k < end; k++)
> +                            *(outpicref->data[0] + showwaves->buf_idx + k
> * linesize) += x;
> +                    }
> +                }
> +                break;
>              }
> +            /* store current y coordinate for this channel */
> +            showwaves->buf_idy[j] = h;
>          }
>
>          showwaves->sample_count_mod++;
> --
> 1.7.1
>
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