[FFmpeg-devel] [PATCH] avfilter/vf_stereo3d: implement auto detection by using frame side data

[wm4]

On Wed, 29 Nov 2017 23:15:44 +0100
Paul B Mahol <onemda at gmail.com> wrote:

> Signed-off-by: Paul B Mahol <onemda at gmail.com>
> ---
>  doc/filters.texi          |  4 ++++
>  libavfilter/vf_stereo3d.c | 35 ++++++++++++++++++++++++++++++++---
>  2 files changed, 36 insertions(+), 3 deletions(-)
> 
> diff --git a/doc/filters.texi b/doc/filters.texi
> index 4a4efc70c8..e8da5e21a6 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -14057,6 +14057,10 @@ Set stereoscopic image format of input.
>  
>  Available values for input image formats are:
>  @table @samp
> + at item auto
> +set input format using frame side data
> +If such data is not available filter will return unchanged input.
> +
>  @item sbsl
>  side by side parallel (left eye left, right eye right)
>  
> diff --git a/libavfilter/vf_stereo3d.c b/libavfilter/vf_stereo3d.c
> index 8b22f880ca..a51fbeb75d 100644
> --- a/libavfilter/vf_stereo3d.c
> +++ b/libavfilter/vf_stereo3d.c
> @@ -25,6 +25,7 @@
>  #include "libavutil/opt.h"
>  #include "libavutil/parseutils.h"
>  #include "libavutil/pixdesc.h"
> +#include "libavutil/stereo3d.h"
>  #include "avfilter.h"
>  #include "drawutils.h"
>  #include "formats.h"
> @@ -47,8 +48,8 @@ enum StereoCode {
>      ANAGLYPH_YB_DUBOIS, // anaglyph yellow/blue dubois
>      ANAGLYPH_RB_GRAY,   // anaglyph red/blue gray
>      ANAGLYPH_RG_GRAY,   // anaglyph red/green gray
> -    MONO_L,             // mono output for debugging (left eye only)
> -    MONO_R,             // mono output for debugging (right eye only)
> +    MONO_L,             // mono output (left eye only)
> +    MONO_R,             // mono output (right eye only)
>      INTERLEAVE_ROWS_LR, // row-interleave (left eye has top row)
>      INTERLEAVE_ROWS_RL, // row-interleave (right eye has top row)
>      SIDE_BY_SIDE_LR,    // side by side parallel (left eye left, right eye right)
> @@ -66,7 +67,8 @@ enum StereoCode {
>      INTERLEAVE_COLS_LR, // column-interleave (left eye first, right eye second)
>      INTERLEAVE_COLS_RL, // column-interleave (right eye first, left eye second)
>      HDMI,               // HDMI frame pack (left eye first, right eye second)
> -    STEREO_CODE_COUNT   // TODO: needs autodetection
> +    AUTO,               // guess input format using frame's metadata.
> +    STEREO_CODE_COUNT
>  };
>  
>  typedef struct StereoComponent {
> @@ -173,6 +175,7 @@ static const AVOption stereo3d_options[] = {
>      { "irr",   "interleave rows right first",         0, AV_OPT_TYPE_CONST, {.i64=INTERLEAVE_ROWS_RL}, 0, 0, FLAGS, "in" },
>      { "icl",   "interleave columns left first",       0, AV_OPT_TYPE_CONST, {.i64=INTERLEAVE_COLS_LR}, 0, 0, FLAGS, "in" },
>      { "icr",   "interleave columns right first",      0, AV_OPT_TYPE_CONST, {.i64=INTERLEAVE_COLS_RL}, 0, 0, FLAGS, "in" },
> +    { "auto",  "guess using frame metadata",          0, AV_OPT_TYPE_CONST, {.i64=AUTO},               0, 0, FLAGS, "in" },
>      { "out",   "set output format", OFFSET(out.format),  AV_OPT_TYPE_INT,   {.i64=ANAGLYPH_RC_DUBOIS}, 0, STEREO_CODE_COUNT-1, FLAGS, "out"},
>      { "ab2l",  "above below half height left first",  0, AV_OPT_TYPE_CONST, {.i64=ABOVE_BELOW_2_LR},   0, 0, FLAGS, "out" },
>      { "ab2r",  "above below half height right first", 0, AV_OPT_TYPE_CONST, {.i64=ABOVE_BELOW_2_RL},   0, 0, FLAGS, "out" },
> @@ -366,6 +369,9 @@ static int config_output(AVFilterLink *outlink)
>      int ret;
>      s->aspect = inlink->sample_aspect_ratio;
>  
> +    if (s->in.format == AUTO || (s->in.format == s->out.format))
> +        return 0;
> +
>      switch (s->in.format) {
>      case INTERLEAVE_COLS_LR:
>      case INTERLEAVE_COLS_RL:
> @@ -670,6 +676,29 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *inpicref)
>      int out_off_left[4], out_off_right[4];
>      int i, ret;
>  
> +    if (s->in.format == AUTO) {
> +        AVFrameSideData *sd = av_frame_get_side_data(inpicref, AV_FRAME_DATA_STEREO3D);
> +
> +        if (sd) {
> +            AVStereo3D *s3d = (AVStereo3D *)sd->data;
> +
> +            switch (s3d->type) {
> +            case AV_STEREO3D_SIDEBYSIDE:          s->in.format = SIDE_BY_SIDE_LR;    break;
> +            case AV_STEREO3D_SIDEBYSIDE_QUINCUNX: s->in.format = SIDE_BY_SIDE_LR;    break;
> +            case AV_STEREO3D_TOPBOTTOM:           s->in.format = ABOVE_BELOW_LR;     break;
> +            case AV_STEREO3D_CHECKERBOARD:        s->in.format = CHECKERBOARD_LR;    break;
> +            case AV_STEREO3D_FRAMESEQUENCE:       s->in.format = ALTERNATING_LR;     break;
> +            case AV_STEREO3D_LINES:               s->in.format = INTERLEAVE_ROWS_LR; break;
> +            case AV_STEREO3D_COLUMNS:             s->in.format = INTERLEAVE_COLS_LR; break;
> +            default:                              s->in.format = s->out.format = MONO_L;
> +            };
> +        } else {
> +            s->in.format = s->out.format = MONO_L;
> +        }
> +        if ((ret = config_output(outlink)) < 0)
> +            return ret;

Attempting midstream parameter changes is an API violation.

> +    }
> +
>      if (s->in.format == s->out.format)
>          return ff_filter_frame(outlink, inpicref);
>