Aegisub/subprojects/csri/backends/libass/libass_csri.c
Oneric 85ce9663a6 Pass storage size to libass to fix rendering
Since ASS rendering depends on the storage size of the video libass
needs to know about it to render the subtitles correctly. If it isn't
told about the storage size libass uses the value from PlayRes{X,Y} as
a guess, but this isn't always correct.
With Aegisub currently always rendering at storage resolution
this ends up the same as the frame size.
2022-06-08 01:10:11 -07:00

260 lines
6.5 KiB
C

/*****************************************************************************
* csri: common subtitle renderer interface
*****************************************************************************
* Copyright (C) 2007 David Lamparter
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
****************************************************************************/
/** libass csri wrapper.
* Indirectly based on code from aegisub,
* (c) 2006-2007, Rodrigo Braz Monteiro, Evgeniy Stepanov
*/
#ifdef HAVE_CONFIG_H
#include "acconf.h"
#endif
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <ass/ass.h>
#ifdef _WIN32
# define CSRIAPI __declspec(dllexport)
#else
# ifdef HAVE_GCC_VISIBILITY
# define CSRIAPI __attribute__((visibility ("default")))
# else
# define CSRIAPI
# endif
#endif
#define CSRI_OWN_HANDLES
typedef struct csri_libass_rend {
ass_library_t* ass_library;
} csri_rend;
typedef struct csri_asa_inst {
ass_renderer_t* ass_renderer;
ass_track_t* ass_track;
} csri_inst;
#include <csri/csri.h>
#include <csri/stream.h>
#include <subhelp.h>
static struct csri_libass_rend csri_libass = { NULL };
csri_inst *csri_open_file(csri_rend *renderer,
const char *filename, struct csri_openflag *flags)
{
return subhelp_open_file(renderer, csri_open_mem, filename, flags);
}
csri_inst *csri_open_mem(csri_rend *renderer,
const void *data, size_t length, struct csri_openflag *flags)
{
csri_inst *rv;
if (renderer != &csri_libass)
return NULL;
rv = (csri_inst *)malloc(sizeof(csri_inst));
if (!rv)
return NULL;
rv->ass_renderer = ass_renderer_init(renderer->ass_library);
if (!rv->ass_renderer) {
free(rv);
return NULL;
}
ass_set_font_scale(rv->ass_renderer, 1.);
ass_set_fonts(rv->ass_renderer, NULL, "Sans");
rv->ass_track = ass_read_memory(csri_libass.ass_library,
(void *)data, length, "UTF-8");
if (!rv->ass_track) {
ass_renderer_done(rv->ass_renderer);
free(rv);
return NULL;
}
return rv;
}
void csri_close(csri_inst *inst)
{
ass_free_track(inst->ass_track);
ass_renderer_done(inst->ass_renderer);
free(inst);
}
int csri_request_fmt(csri_inst *inst, const struct csri_fmt *fmt)
{
if (!csri_is_rgb(fmt->pixfmt) || csri_has_alpha(fmt->pixfmt))
return -1;
ass_set_frame_size(inst->ass_renderer, fmt->width, fmt->height);
// Note: this relies on CSRI always rendering at video storage res
ass_set_storage_size(inst->ass_renderer, fmt->width, fmt->height);
return 0;
}
void csri_render(csri_inst *inst, struct csri_frame *frame, double time)
{
ass_image_t *img = ass_render_frame(inst->ass_renderer,
inst->ass_track, (int)(time * 1000), NULL);
while (img) {
unsigned bpp, alpha = 256 - (img->color && 0xFF);
int src_d, dst_d;
unsigned char *src, *dst, *endy, *endx;
unsigned char c[3] = {
(img->color >> 8) & 0xFF, /* B */
(img->color >> 16) & 0xFF, /* G */
img->color >> 24 /* R */
};
if ((frame->pixfmt | 1) == CSRI_F__RGB
|| frame->pixfmt == CSRI_F_RGB) {
unsigned char tmp = c[2];
c[2] = c[0];
c[0] = tmp;
}
bpp = frame->pixfmt >= 0x200 ? 3 : 4;
dst = frame->planes[0]
+ img->dst_y * frame->strides[0]
+ img->dst_x * bpp;
if (frame->pixfmt & 1)
dst++;
src = img->bitmap;
src_d = img->stride - img->w;
dst_d = frame->strides[0] - img->w * bpp;
endy = src + img->h * img->stride;
while (src != endy) {
endx = src + img->w;
while (src != endx) {
/* src[x]: 0..255, alpha: 1..256 (see above)
* -> src[x]*alpha: 0<<8..255<<8
* -> need 1..256 for mult => +1
*/
unsigned s = ((*src++ * alpha) >> 8) + 1;
unsigned d = 257 - s;
/* c[0]: 0.255, s/d: 1..256 */
dst[0] = (s*c[0] + d*dst[0]) >> 8;
dst[1] = (s*c[1] + d*dst[1]) >> 8;
dst[2] = (s*c[2] + d*dst[2]) >> 8;
dst += bpp;
}
dst += dst_d;
src += src_d;
}
img = img->next;
}
}
static csri_inst *libass_init_stream(csri_rend *renderer,
const void *header, size_t headerlen,
struct csri_openflag *flags)
{
csri_inst *rv;
if (renderer != &csri_libass)
return NULL;
rv = (csri_inst *)malloc(sizeof(csri_inst));
if (!rv)
return NULL;
rv->ass_renderer = ass_renderer_init(renderer->ass_library);
if (!rv->ass_renderer) {
free(rv);
return NULL;
}
ass_set_font_scale(rv->ass_renderer, 1.);
ass_set_fonts(rv->ass_renderer, NULL, "Sans");
rv->ass_track = ass_new_track(csri_libass.ass_library);
if (!rv->ass_track) {
ass_renderer_done(rv->ass_renderer);
free(rv);
return NULL;
}
ass_process_codec_private(rv->ass_track, (void *)header, headerlen);
return rv;
}
static void libass_push_packet(csri_inst *inst,
const void *packet, size_t packetlen,
double pts_start, double pts_end)
{
ass_process_chunk(inst->ass_track, (void *)packet, packetlen,
(int)(pts_start * 1000), (int)((pts_end - pts_start) * 1000));
}
static struct csri_stream_ext streamext = {
libass_init_stream,
libass_push_packet,
NULL
};
void *csri_query_ext(csri_rend *rend, csri_ext_id extname)
{
if (!rend)
return NULL;
if (!strcmp(extname, CSRI_EXT_STREAM_ASS))
return &streamext;
return NULL;
}
static struct csri_info csri_libass_info = {
"libass",
"0.9.x",
"libass (the MPlayer SSA/ASS renderer, 0.9.x API)",
"Evgeniy Stepanov",
"Copyright (c) 2006, 2007 by Evgeniy Stepanov"
};
struct csri_info *csri_renderer_info(csri_rend *rend)
{
return &csri_libass_info;
}
csri_rend *csri_renderer_byname(const char *name,
const char *specific)
{
if (strcmp(name, csri_libass_info.name))
return NULL;
if (specific && strcmp(specific, csri_libass_info.specific))
return NULL;
return &csri_libass;
}
csri_rend *csri_renderer_default()
{
csri_libass.ass_library = ass_library_init();
if (!csri_libass.ass_library)
return NULL;
ass_set_fonts_dir(csri_libass.ass_library, "");
ass_set_extract_fonts(csri_libass.ass_library, 0);
ass_set_style_overrides(csri_libass.ass_library, NULL);
return &csri_libass;
}
csri_rend *csri_renderer_next(csri_rend *prev)
{
return NULL;
}