On Mon, Mar 22, 2021 at 5:09 AM Daniel Playfair Cal < daniel.playfair....@gmail.com> wrote:
> I've tried that filtergraph and a few other similar ones and I'm not sure > what you mean - what exactly is the regression? > > I tried it on this image with an equirectangular projection: > https://wiki.panotools.org/images/0/01/Big_ben_equirectangular.jpg > > The only difference I can see is that there are less unmapped areas in the > output with the patches, because the final mapping from the output > equirectangular image to the intermediate fisheye image no longer fails to > map some areas which are present in the fisheye image. I would describe > this as an improvement? > I disagree, if I use 180 hfov and 180 vfov it should not have extra areas but only half of previous input. > > On Mon, Mar 22, 2021 at 3:30 AM Paul B Mahol <one...@gmail.com> wrote: > >> Sorry, but I cannot apply this set as is, It makes at least one serious >> regression. >> >> For example try this filtergraph: >> >> >> v360=input=e:output=fisheye:h_fov=180:v_fov=180,v360=input=fisheye:output=e:ih_fov=180:iv_fov=180 >> >> On Sun, Mar 21, 2021 at 1:45 PM Daniel Playfair Cal < >> daniel.playfair....@gmail.com> wrote: >> >>> This changes the iflat_range and flat_range values for the fisheye >>> projection to match their meaning for the flat/rectilinear projection. >>> That is, the range is between the two x or two y coordinates of the >>> outermost points above/below or left/right of the center, in the >>> flat/rectilinear projection. >>> >>> Signed-off-by: Daniel Playfair Cal <daniel.playfair....@gmail.com> >>> --- >>> libavfilter/vf_v360.c | 19 +++++++++---------- >>> 1 file changed, 9 insertions(+), 10 deletions(-) >>> >>> diff --git a/libavfilter/vf_v360.c b/libavfilter/vf_v360.c >>> index 68bb2f7b0f..3158451963 100644 >>> --- a/libavfilter/vf_v360.c >>> +++ b/libavfilter/vf_v360.c >>> @@ -2807,9 +2807,8 @@ static int prepare_fisheye_out(AVFilterContext >>> *ctx) >>> { >>> V360Context *s = ctx->priv; >>> >>> - s->flat_range[0] = s->h_fov / 180.f; >>> - s->flat_range[1] = s->v_fov / 180.f; >>> - >>> + s->flat_range[0] = 0.5f * s->h_fov * M_PI / 180.f; >>> + s->flat_range[1] = 0.5f * s->v_fov * M_PI / 180.f; >>> return 0; >>> } >>> >>> @@ -2827,8 +2826,8 @@ static int fisheye_to_xyz(const V360Context *s, >>> int i, int j, int width, int height, >>> float *vec) >>> { >>> - const float uf = s->flat_range[0] * ((2.f * i) / width - 1.f); >>> - const float vf = s->flat_range[1] * ((2.f * j + 1.f) / height - >>> 1.f); >>> + const float uf = 2.f * s->flat_range[0] / M_PI * ((2.f * i) / >>> width - 1.f); >>> + const float vf = 2.f * s->flat_range[1] / M_PI * ((2.f * j + 1.f) / >>> height - 1.f); >>> >>> const float phi = atan2f(vf, uf); >>> const float theta = M_PI_2 * (1.f - hypotf(uf, vf)); >>> @@ -2858,8 +2857,8 @@ static int prepare_fisheye_in(AVFilterContext *ctx) >>> { >>> V360Context *s = ctx->priv; >>> >>> - s->iflat_range[0] = s->ih_fov / 180.f; >>> - s->iflat_range[1] = s->iv_fov / 180.f; >>> + s->iflat_range[0] = 0.5f * s->ih_fov * M_PI / 180.f; >>> + s->iflat_range[1] = 0.5f * s->iv_fov * M_PI / 180.f; >>> >>> return 0; >>> } >>> @@ -2882,10 +2881,10 @@ static int xyz_to_fisheye(const V360Context *s, >>> { >>> const float h = hypotf(vec[0], vec[1]); >>> const float lh = h > 0.f ? h : 1.f; >>> - const float phi = atan2f(h, vec[2]) / M_PI; >>> + const float phi = atan2f(h, vec[2]); >>> >>> - float uf = vec[0] / lh * phi / s->iflat_range[0]; >>> - float vf = vec[1] / lh * phi / s->iflat_range[1]; >>> + float uf = 0.5f * vec[0] / lh * phi / s->iflat_range[0]; >>> + float vf = 0.5f * vec[1] / lh * phi / s->iflat_range[1]; >>> >>> const int visible = -0.5f < uf && uf < 0.5f && -0.5f < vf && vf < >>> 0.5f; >>> int ui, vi; >>> -- >>> 2.31.0 >>> >>> _______________________________________________ >>> ffmpeg-devel mailing list >>> ffmpeg-devel@ffmpeg.org >>> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel >>> >>> To unsubscribe, visit link above, or email >>> ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". >> >> _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
