[FFmpeg-devel] [PATCH v2 1/3] avfilter: add v360 filter

[Paul B Mahol]

On Wed, Aug 14, 2019 at 11:56 AM Thilo Borgmann <thilo.borgmann at mail.de>
wrote:

> [...]
>
> >>> +static int config_output(AVFilterLink *outlink)
> >>> +{
> >>> +    AVFilterContext *ctx = outlink->src;
> >>> +    AVFilterLink *inlink = ctx->inputs[0];
> >>> +    V360Context *s = ctx->priv;
> >>> +    const AVPixFmtDescriptor *desc =
> >>> av_pix_fmt_desc_get(inlink->format);
> >>> +    const int depth = desc->comp[0].depth;
> >>> +    float remap_data_size = 0.f;
> >>> +    int sizeof_remap;
> >>> +    int err;
> >>> +    int p, h, w;
> >>> +    float hf, wf;
> >>> +    float mirror_modifier[3];
> >>> +    void (*in_transform)(const V360Context *s,
> >>> +                         const float *vec, int width, int height,
> >>> +                         uint16_t us[4][4], uint16_t vs[4][4], float
> >>> *du, float *dv);
> >>> +    void (*out_transform)(const V360Context *s,
> >>> +                          int i, int j, int width, int height,
> >>> +                          float *vec);
> >>> +    void (*calculate_kernel)(float du, float dv, int shift, const
> >> XYRemap4
> >>> *r_tmp, void *r);
> >>> +    float rot_mat[3][3];
> >>> +
> >>> +    switch (s->interp) {
> >>> +    case NEAREST:
> >>> +        calculate_kernel = nearest_kernel;
> >>> +        s->remap_slice = depth <= 8 ? remap1_8bit_slice :
> >>> remap1_16bit_slice;
> >>> +        sizeof_remap = sizeof(XYRemap1);
> >>> +        break;
> >>> +    case BILINEAR:
> >>> +        calculate_kernel = bilinear_kernel;
> >>> +        s->remap_slice = depth <= 8 ? remap2_8bit_slice :
> >>> remap2_16bit_slice;
> >>> +        sizeof_remap = sizeof(XYRemap2);
> >>> +        break;
> >>> +    case BICUBIC:
> >>> +        calculate_kernel = bicubic_kernel;
> >>> +        s->remap_slice = depth <= 8 ? remap4_8bit_slice :
> >>> remap4_16bit_slice;
> >>> +        sizeof_remap = sizeof(XYRemap4);
> >>> +        break;
> >>> +    case LANCZOS:
> >>> +        calculate_kernel = lanczos_kernel;
> >>> +        s->remap_slice = depth <= 8 ? remap4_8bit_slice :
> >>> remap4_16bit_slice;
> >>> +        sizeof_remap = sizeof(XYRemap4);
> >>> +        break;
> >>> +    }
> >>> +
> >>> +    switch (s->in) {
> >>> +    case EQUIRECTANGULAR:
> >>> +        in_transform = xyz_to_equirect;
> >>> +        err = 0;
> >>> +        wf = inlink->w;
> >>> +        hf = inlink->h;
> >>> +        break;
> >>> +    case CUBEMAP_3_2:
> >>> +        in_transform = xyz_to_cube3x2;
> >>> +        err = prepare_cube_in(ctx);
> >>> +        wf = inlink->w / 3.f * 4.f;
> >>> +        hf = inlink->h;
> >>> +        break;
> >>> +    case CUBEMAP_6_1:
> >>> +        in_transform = xyz_to_cube6x1;
> >>> +        err = prepare_cube_in(ctx);
> >>> +        wf = inlink->w / 3.f * 2.f;
> >>> +        hf = inlink->h * 2.f;
> >>> +        break;
> >>> +    case EQUIANGULAR:
> >>> +        in_transform = xyz_to_eac;
> >>> +        err = prepare_eac_in(ctx);
> >>> +        wf = inlink->w;
> >>> +        hf = inlink->h / 9.f * 8.f;
> >>> +        break;
> >>> +    case FLAT:
> >>> +        av_log(ctx, AV_LOG_ERROR, "Flat format is not accepted as
> >>> input.\n");
> >>> +        return AVERROR(EINVAL);
> >>> +    }
> >>> +
> >>> +    if (err != 0) {
> >>> +        return err;
> >>> +    }
> >>> +
> >>> +    switch (s->out) {
> >>> +    case EQUIRECTANGULAR:
> >>> +        out_transform = equirect_to_xyz;
> >>> +        err = 0;
> >>> +        w = roundf(wf);
> >>> +        h = roundf(hf);
> >>> +        break;
> >>> +    case CUBEMAP_3_2:
> >>> +        out_transform = cube3x2_to_xyz;
> >>> +        err = prepare_cube_out(ctx);
> >>> +        w = roundf(wf / 4.f * 3.f);
> >>> +        h = roundf(hf);
> >>> +        break;
> >>> +    case CUBEMAP_6_1:
> >>> +        out_transform = cube6x1_to_xyz;
> >>> +        err = prepare_cube_out(ctx);
> >>> +        w = roundf(wf / 2.f * 3.f);
> >>> +        h = roundf(hf / 2.f);
> >>> +        break;
> >>> +    case EQUIANGULAR:
> >>> +        out_transform = eac_to_xyz;
> >>> +        err = prepare_eac_out(ctx);
> >>> +        w = roundf(wf);
> >>> +        h = roundf(hf / 8.f * 9.f);
> >>> +        break;
> >>> +    case FLAT:
> >>> +        out_transform = flat_to_xyz;
> >>> +        err = prepare_flat_out(ctx);
> >>> +        w = roundf(wf * s->flat_range[0] / s->flat_range[1] / 2.f);
> >>> +        h = roundf(hf);
> >>> +        break;
> >>> +    }
> >>> +
> >>> +    if (err != 0) {
> >>> +        return err;
> >>> +    }
> >>> +
> >>> +    if (s->width > 0 && s->height > 0) {
> >>> +        w = s->width;
> >>> +        h = s->height;
> >>> +    }
> >>
> >> If s->width/height are checked, should handle the case of no ture,
> >> Else w/h may be used but not initialized.
> >>
> >
> > Please try more hard to write english. I do not understand what is typed
> > above.
>
> If w and h don't have initial values at declaration. So they might never
> get set if that last if statement evaluates to false.
>
> So he suggests to add an else case like
>
> if (s->width > 0 && s->height > 0) {
>  w = s->width;
>  h = s->height;
> } else {
>  w = 0;
>  h = 0;
> }
>
> or whatever values might make sense.
>

else case should have assert or return AVERROR_BUG.


>
> Thilo
>
>
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