Until now, subtitle renderers could export SUBBITMAP_INDEXED, which is a
8 bit per pixel with palette format. sd_lavc.c was the only renderer
doing this, and the result was converted to RGBA in every use-case
(except maybe when the subtitles were hidden.)
Change it so that sd_lavc.c converts to RGBA on its own. This simplifies
everything a bit, and the palette handling can be removed from the
common code.
This is also preparation for making subtitle images refcounted. The
"caching" in img_convert.c is a PITA in this respect, and needs to be
redone. So getting rid of some img_convert.c code is a positive side-
effect. Also related to refcounted subtitles is packing them into a
single mp_image. Fewer objects to refcount is easier, and for the libass
format the same will be done. The plan is to remove manual packing from
the VOs which need single images entirely.
This reverts commit 689a25003f, with some
adjustments to code that was added after that commit.
I just messed up big time. We don't need this, and in fact the commit
confused straight and premultiplied alpha at one point (just a simple
inverted condition due to an oversight), which is why it looked like
it was working.
In commit 2827295 I wrote:
Also, libva can't decide whether it accepts straight or premultiplied
alpha for OSD sub-pictures [...]
That was just me messing up and being severely confused by my own bugs.
VA API uses premultiplied alpha, which by the way is nice and
thoughtful of the VA API devs.
Well, this was stupid. But in the end, I'm glad that I could actually
reduce codesize by a good amount again.
This is for VAAPI support. VAAPI does not support premultiplied alpha
for OSD. (Normally, we prefer premultiplied, because it has better
behavior on scaling.)
I'm not sure whether blending in the ASS->RGBA part is correct and I
didn't test it extensively.
MPlayer/mplayer2 still show DVD subtitles in gray. Depending on who you
ask, this can be considered a bug or a feature. Include rendering in
gray as explicit feature, so the user can decide what is better.
This affects all indexed sub bitmaps entering the OSD rendering path.
Currently, this means all image subs are affected by this option, but
nothing else.
Apparently the -spugauss option was popular. The code originally
implementing this is gone (scaler stuff in spudec.c). Reimplement it
using libswscale to scale and blur image subtitles if the --sub-gauss
option is set.
The code does some rather lazy padding to allow the blur to spread
pixels past the original image bounding box. (This problem exists with
normal bilinear scaling too, but is barely noticable.)
Technically, this doesn't just blur subtitles, but anything RGBA (or
indexed) that enters the OSD rendering path. But only image subtitles
produce these OSD formats currently, so no explicit check is done to
prevent blurring in other cases.
To ease changing all the VOs to the new OSD rendering, fallbacks,
conversions, support code etc. was left all over the code. Now that
all VOs have been changed, all that code is inactive. Remove it.
Strip down spudec.c. We don't need the old grayscale and scaling stuff
anymore. (Not removing spudec itself yet - I'm not confident that the
libavcodec DVD sub decoder is sufficient, and it would also require
some hacks to get DVD palette and resolution information from libdvdread
to libavcodec.)
The option --spuaa, --spualign, --spugauss were used with the old sub
scaling code, and don't do anything anymore.
Instead, sd_lavc.c and spudec.c (the two image sub decoders) always
output indexed/paletted images. For this purpose, add SUBBITMAP_INDEXED,
and convert the subs to RGBA in img_convert.c instead. If a VO is used
that supports the old OSD format only, the indexed bitmaps are converted
to the old OSD format by abusing spudec.c in a similar way sd_lavc.c
used to do.
The main reason why spudec.c is used is because the images must not only
be converted to the old format, but also properly scaled, cropped, and
aligned (the asm code in libvo/osd.c requires this alignment).
Remove support for the old format (packed variant) from the OpenGL VOs.
(The packed formats were how the actual OSD format was handled in some
GPU-driven VOs for a while.)
Remove all conversions from old to new formats. Now all subtitle
decoders and OSD renderers produce the new formats only.
Add an evil hack to convert the new format (scaled+indexed bitmaps) to
the old format. It creates a new spudec instance to convert images to
grayscale and to scale them. This is temporary for VOs which don't
support new OSD formats yet (vo_xv, vo_x11, vo_lavc).
The mplayer DVD sub decoder is the only remaining OSD image producer
that still requires the old mplayer OSD format (SUBBITMAP_OLD_PLANAR).
To make supporting this format optional in VOs, add a step that allows
converting these images to RGBA in case the VO doesn't have direct
support for it.
Note: the mplayer DVD sub decoder uses the old mplayer OSD format
(SUBBITMAP_OLD_PLANAR), which is assumed to use premultiplied alpha.
However, it seems DVDs allow only binary transparency, so the rendered
result will be the same.
Before this commit, the OSD was drawn using libass, but the resulting
bitmaps were converted to the internal mplayer OSD format. We want to
get rid of the old OSD format, because it's monochrome, and can't even
be rendered directly using modern video output methods (like with
OpenGL/Direct3D/VDPAU).
Change it so that VOs can get the ASS images directly, without
additional conversions. (This also has the consequence that the OSD can
render colors now.) Currently, this is vo_gl3 only. The other VOs still
use the old method. Also, the old OSD format is still used for all VOs
with DVD subtitles (spudec).
Rewrite sub.c. Remove all the awkward flags and bounding boxes and
change detection things. It turns out that much of that isn't needed.
Move code related to converting subtitle images to img_convert.c. (It
has to be noted that all of these conversions were already done before
in some places, and that the new code actually makes less use of them.)
