470 lines
16 KiB
C
470 lines
16 KiB
C
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/*
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* Teletext decoding for ffmpeg
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* Copyright (c) 2005-2010, 2012 Wolfram Gloger
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* Copyright (c) 2013 Marton Balint
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include "avcodec.h"
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#include "libavutil/opt.h"
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#include "libavutil/intreadwrite.h"
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#include <libzvbi.h>
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#define TEXT_MAXSZ (25 * (56 + 1) * 4 + 2)
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#define VBI_NB_COLORS 40
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#define RGBA(r,g,b,a) (((a) << 24) | ((r) << 16) | ((g) << 8) | (b))
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#define VBI_R(rgba) (((rgba) >> 0) & 0xFF)
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#define VBI_G(rgba) (((rgba) >> 8) & 0xFF)
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#define VBI_B(rgba) (((rgba) >> 16) & 0xFF)
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#define VBI_A(rgba) (((rgba) >> 24) & 0xFF)
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/* main data structure */
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typedef struct TeletextContext
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{
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AVClass *class;
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char *pgno;
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int x_offset;
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int y_offset;
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char *format;
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int format_id; /* 0 = bitmap, 1 = text */
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int chop_top;
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int sub_duration; /* in msec */
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int transparent_bg;
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int chop_spaces;
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int lines_processed;
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AVSubtitleRect *sub_rect;
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vbi_decoder * vbi;
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vbi_dvb_demux * dx;
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#ifdef DEBUG
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vbi_export * ex;
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#endif
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/* Don't even _think_ about making sliced stack-local! */
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vbi_sliced sliced[64];
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} TeletextContext;
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/************************************************************************/
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static int
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chop_spaces_utf8(const unsigned char* t, int len)
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{
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t += len;
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while (len > 0) {
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if (*--t != ' ' || (len-1 > 0 && *(t-1) & 0x80))
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break;
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--len;
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}
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return len;
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}
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// draw a page as text
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static int
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gen_sub_text(TeletextContext *ctx, vbi_page *page, int chop_top)
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{
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AVSubtitleRect *sub_rect = ctx->sub_rect;
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char *text;
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const char *in;
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char *out;
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char *vbi_text = av_malloc(TEXT_MAXSZ);
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int sz;
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if (!vbi_text)
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return AVERROR(ENOMEM);
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sz = vbi_print_page_region(page, vbi_text, TEXT_MAXSZ-1, "UTF-8",
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/*table mode*/ TRUE, FALSE,
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0, chop_top,
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page->columns, page->rows-chop_top);
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if (sz <= 0) {
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av_log(ctx, AV_LOG_ERROR, "vbi_print error\n");
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av_free(vbi_text);
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return AVERROR_EXTERNAL;
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}
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vbi_text[sz] = '\0';
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in = vbi_text;
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out = text = av_malloc(TEXT_MAXSZ);
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if (!text) {
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av_free(vbi_text);
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return AVERROR(ENOMEM);
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}
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if (ctx->chop_spaces) {
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for (;;) {
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int nl, sz;
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// skip leading spaces and newlines
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in += strspn(in, " \n");
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// compute end of row
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for (nl = 0; in[nl]; ++nl)
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if (in[nl] == '\n' && (nl==0 || !(in[nl-1] & 0x80)))
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break;
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if (!in[nl])
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break;
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// skip trailing spaces
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sz = chop_spaces_utf8(in, nl);
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memcpy(out, in, sz);
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out += sz;
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*out++ = '\n';
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in += nl;
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}
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} else {
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strcpy(text, vbi_text);
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out += sz;
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*out++ = '\n';
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}
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av_free(vbi_text);
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*out = '\0';
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if (out > text) {
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sub_rect->type = SUBTITLE_TEXT;
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sub_rect->text = text;
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av_log(ctx, AV_LOG_DEBUG, "subtext:%s:txetbus\n", text);
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} else {
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sub_rect->type = SUBTITLE_NONE;
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av_free(text);
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}
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return 0;
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}
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static void
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fix_transparency(TeletextContext *ctx, vbi_page *page, int chop_top, uint8_t transparent_color, int resx, int resy)
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{
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AVSubtitleRect *sub_rect = ctx->sub_rect;
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int iy;
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// Hack for transparency, inspired by VLC code...
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for (iy = 0; iy < resy; iy++) {
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uint8_t *pixel = sub_rect->pict.data[0] + iy * sub_rect->pict.linesize[0];
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vbi_char *vc = page->text + (iy / 10 + chop_top) * page->columns;
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vbi_char *vcnext = vc + page->columns;
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for (; vc < vcnext; vc++) {
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uint8_t *pixelnext = pixel + 12;
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switch (vc->opacity) {
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case VBI_TRANSPARENT_SPACE:
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memset(pixel, transparent_color, 12);
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break;
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case VBI_OPAQUE:
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case VBI_SEMI_TRANSPARENT:
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if (!ctx->transparent_bg)
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break;
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case VBI_TRANSPARENT_FULL:
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for(; pixel < pixelnext; pixel++)
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if (*pixel == vc->background)
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*pixel = transparent_color;
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break;
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}
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pixel = pixelnext;
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}
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}
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}
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// draw a page as bitmap
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static int
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gen_sub_bitmap(TeletextContext *ctx, vbi_page *page, int chop_top)
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{
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AVSubtitleRect *sub_rect = ctx->sub_rect;
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int resx = page->columns * 12;
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int resy = (page->rows - chop_top) * 10;
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uint8_t ci, cmax = 0;
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int ret;
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vbi_char *vc = page->text + (chop_top * page->columns);
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vbi_char *vcend = page->text + (page->rows * page->columns);
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for (; vc < vcend; vc++) {
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if (vc->opacity != VBI_TRANSPARENT_SPACE) {
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cmax = VBI_NB_COLORS;
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break;
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}
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}
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if (cmax == 0) {
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av_log(ctx, AV_LOG_DEBUG, "dropping empty page %3x\n", page->pgno);
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sub_rect->type = SUBTITLE_NONE;
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return 0;
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}
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if ((ret = avpicture_alloc(&sub_rect->pict, AV_PIX_FMT_PAL8, resx, resy)) < 0)
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return ret;
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// Yes, we want to allocate the palette on our own because AVSubtitle works this way
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sub_rect->pict.data[1] = NULL;
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vbi_draw_vt_page_region(page, VBI_PIXFMT_PAL8,
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sub_rect->pict.data[0], sub_rect->pict.linesize[0],
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0, chop_top, page->columns, page->rows - chop_top,
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/*reveal*/ 1, /*flash*/ 1);
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fix_transparency(ctx, page, chop_top, cmax, resx, resy);
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sub_rect->x = ctx->x_offset;
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sub_rect->y = ctx->y_offset;
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sub_rect->w = resx;
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sub_rect->h = resy;
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sub_rect->nb_colors = (int)cmax + 1;
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sub_rect->pict.data[1] = av_mallocz(AVPALETTE_SIZE);
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if (!sub_rect->pict.data[1]) {
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av_freep(&sub_rect->pict.data[0]);
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return AVERROR(ENOMEM);
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}
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for (ci = 0; ci < cmax; ci++) {
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int r, g, b, a;
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r = VBI_R(page->color_map[ci]);
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g = VBI_G(page->color_map[ci]);
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b = VBI_B(page->color_map[ci]);
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a = VBI_A(page->color_map[ci]);
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((uint32_t *)sub_rect->pict.data[1])[ci] = RGBA(r, g, b, a);
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#ifdef DEBUG
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av_log(ctx, AV_LOG_DEBUG, "palette %0x\n",
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((uint32_t *)sub_rect->pict.data[1])[ci]);
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#endif
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}
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((uint32_t *)sub_rect->pict.data[1])[cmax] = RGBA(0, 0, 0, 0);
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sub_rect->type = SUBTITLE_BITMAP;
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return 0;
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}
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static void
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handler(vbi_event *ev, void *user_data)
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{
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TeletextContext *ctx = user_data;
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vbi_page page;
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int res;
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char pgno_str[12];
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vbi_subno subno;
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vbi_page_type vpt;
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int chop_top;
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char *lang;
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snprintf(pgno_str, sizeof pgno_str, "%03x", ev->ev.ttx_page.pgno);
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av_log(ctx, AV_LOG_DEBUG, "decoded page %s.%02x\n",
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pgno_str, ev->ev.ttx_page.subno & 0xFF);
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if (strcmp(ctx->pgno, "*") && !strstr(ctx->pgno, pgno_str))
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return;
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/* Fetch the page. */
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res = vbi_fetch_vt_page(ctx->vbi, &page,
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ev->ev.ttx_page.pgno,
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ev->ev.ttx_page.subno,
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VBI_WST_LEVEL_3p5, 25, TRUE);
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if (!res)
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return;
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#ifdef DEBUG
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fprintf(stderr, "\nSaving res=%d dy0=%d dy1=%d...\n",
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res, page.dirty.y0, page.dirty.y1);
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fflush(stderr);
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if (!vbi_export_stdio(ctx->ex, stderr, &page))
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fprintf(stderr, "failed: %s\n", vbi_export_errstr(ctx->ex));
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#endif
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vpt = vbi_classify_page(ctx->vbi, ev->ev.ttx_page.pgno, &subno, &lang);
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chop_top = ctx->chop_top ||
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((page.rows > 1) && (vpt == VBI_SUBTITLE_PAGE));
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av_log(ctx, AV_LOG_DEBUG, "%d x %d page chop:%d\n",
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page.columns, page.rows, chop_top);
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if (!ctx->sub_rect) {
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ctx->sub_rect = av_mallocz(sizeof(*ctx->sub_rect));
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if (ctx->sub_rect) {
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res = (ctx->format_id == 0) ?
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gen_sub_bitmap(ctx, &page, chop_top) :
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gen_sub_text (ctx, &page, chop_top);
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if (res)
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av_freep(&ctx->sub_rect);
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}
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} else {
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// FIXME: Multiple teletext pages in a single packet, some kind of buffering should be done instead of dropping the page...
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av_log(ctx, AV_LOG_WARNING, "Missed page %s.%02x.\n", pgno_str, ev->ev.ttx_page.subno & 0xFF);
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}
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vbi_unref_page(&page);
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}
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static int
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teletext_decode_frame(AVCodecContext *avctx,
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void *data, int *data_size,
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AVPacket *pkt)
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{
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TeletextContext *ctx = avctx->priv_data;
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AVSubtitle *sub = data;
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const uint8_t *buf = pkt->data;
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unsigned int left = pkt->size;
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uint8_t pesheader[45] = {0x00, 0x00, 0x01, 0xbd, 0x00, 0x00, 0x85, 0x80, 0x24, 0x21, 0x00, 0x01, 0x00, 0x01};
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int pesheader_size = sizeof(pesheader);
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const uint8_t *pesheader_buf = pesheader;
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if (!ctx->vbi) {
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if (!(ctx->vbi = vbi_decoder_new()))
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return AVERROR(ENOMEM);
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if (!vbi_event_handler_add(ctx->vbi, VBI_EVENT_TTX_PAGE, handler, ctx)) {
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vbi_decoder_delete(ctx->vbi);
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ctx->vbi = NULL;
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return AVERROR(ENOMEM);
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}
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}
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if (!ctx->dx && (!(ctx->dx = vbi_dvb_pes_demux_new (/* callback */ NULL, NULL))))
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return AVERROR(ENOMEM);
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// We allow unreasonably big packets, even if the standard only allows a max size of 1472
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if ((pesheader_size + left) < 184 || (pesheader_size + left) > 65504 || (pesheader_size + left) % 184 != 0)
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return AVERROR_INVALIDDATA;
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memset(pesheader + 14, 0xff, pesheader_size - 14);
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AV_WB16(pesheader + 4, left + pesheader_size - 6);
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/* PTS is deliberately left as 0 in the PES header, otherwise libzvbi uses
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* it to detect dropped frames. Unforunatey the guessed packet PTS values
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* (see mpegts demuxer) are not accurate enough to pass that test. */
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vbi_dvb_demux_cor(ctx->dx, ctx->sliced, 64, NULL, &pesheader_buf, &pesheader_size);
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while (left > 0) {
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int64_t pts = 0;
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unsigned int lines = vbi_dvb_demux_cor(ctx->dx, ctx->sliced, 64, &pts, &buf, &left);
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#ifdef DEBUG
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av_log(avctx, AV_LOG_DEBUG,
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"ctx=%p buf_size=%d left=%u lines=%u pts=%f pkt_pts=%f\n",
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ctx, pkt->size, left, lines, (double)pts/90000.0, (double)pkt->pts/90000.0);
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#endif
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if (lines > 0) {
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#ifdef DEBUGx
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int i;
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for(i=0; i<lines; ++i)
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av_log(avctx, AV_LOG_DEBUG,
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"lines=%d id=%x\n", i, ctx->sliced[i].id);
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#endif
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vbi_decode(ctx->vbi, ctx->sliced, lines, (double)pts/90000.0);
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ctx->lines_processed += lines;
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}
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}
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// is there a subtitle to pass?
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if (ctx->sub_rect) {
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sub->format = (ctx->sub_rect->type == SUBTITLE_TEXT ? 1: 0);
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sub->start_display_time = 0;
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sub->end_display_time = ctx->sub_duration;
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sub->num_rects = 0;
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if (ctx->sub_rect->type != SUBTITLE_NONE) {
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sub->rects = av_malloc(sizeof(*sub->rects) * 1);
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if (sub->rects) {
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sub->num_rects = 1;
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sub->rects[0] = ctx->sub_rect;
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}
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} else {
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av_log(avctx, AV_LOG_DEBUG, "sending empty sub\n");
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sub->rects = NULL;
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}
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if (!sub->rects) // no rect was passed
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av_free(ctx->sub_rect);
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ctx->sub_rect = NULL;
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*data_size = 1;
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} else
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*data_size = 0;
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return pkt->size;
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}
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static int teletext_init_decoder(AVCodecContext *avctx)
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{
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TeletextContext *ctx = avctx->priv_data;
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unsigned int maj, min, rev;
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vbi_version(&maj, &min, &rev);
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if (!(maj > 0 || min > 2 || min == 2 && rev >= 26)) {
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av_log(avctx, AV_LOG_ERROR, "decoder needs zvbi version >= 0.2.26.\n");
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return AVERROR_EXTERNAL;
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}
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ctx->dx = NULL;
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ctx->vbi = NULL;
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ctx->sub_rect = NULL;
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if (!strcmp(ctx->format, "bitmap")) {
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ctx->format_id = 0;
|
||
|
} else if (!strcmp(ctx->format, "text")) {
|
||
|
ctx->format_id = 1;
|
||
|
} else {
|
||
|
av_log(avctx, AV_LOG_ERROR, "unkown format %s\n", ctx->format);
|
||
|
return AVERROR_OPTION_NOT_FOUND;
|
||
|
}
|
||
|
|
||
|
#ifdef DEBUG
|
||
|
{
|
||
|
char *t;
|
||
|
ctx->ex = vbi_export_new("text", &t);
|
||
|
}
|
||
|
#endif
|
||
|
av_log(avctx, AV_LOG_VERBOSE, "page filter: %s\n", ctx->pgno);
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static int teletext_close_decoder(AVCodecContext *avctx)
|
||
|
{
|
||
|
TeletextContext *ctx = avctx->priv_data;
|
||
|
|
||
|
#ifdef DEBUG
|
||
|
av_log(avctx, AV_LOG_DEBUG, "lines_total=%u\n", ctx->lines_processed);
|
||
|
#endif
|
||
|
|
||
|
vbi_dvb_demux_delete(ctx->dx);
|
||
|
vbi_decoder_delete(ctx->vbi);
|
||
|
ctx->dx = NULL;
|
||
|
ctx->vbi = NULL;
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static void teletext_flush(AVCodecContext *avctx)
|
||
|
{
|
||
|
teletext_close_decoder(avctx);
|
||
|
}
|
||
|
|
||
|
#define OFFSET(x) offsetof(TeletextContext, x)
|
||
|
#define SD AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_DECODING_PARAM
|
||
|
static const AVOption options[] = {
|
||
|
{"txt_page", "list of teletext page numbers to decode, * is all", OFFSET(pgno), AV_OPT_TYPE_STRING, {.str = "*"}, 0, 0, SD},
|
||
|
{"txt_chop_top", "discards the top teletext line", OFFSET(chop_top), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, SD},
|
||
|
{"txt_format", "format of the subtitles (bitmap or text)", OFFSET(format), AV_OPT_TYPE_STRING, {.str = "bitmap"}, 0, 0, SD},
|
||
|
{"txt_left", "x offset of generated bitmaps", OFFSET(x_offset), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 65535, SD},
|
||
|
{"txt_top", "y offset of generated bitmaps", OFFSET(y_offset), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 65535, SD},
|
||
|
{"txt_chop_spaces", "chops leading and trailing spaces from text", OFFSET(chop_spaces), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, SD},
|
||
|
{"txt_duration", "display duration of teletext pages in msecs", OFFSET(sub_duration), AV_OPT_TYPE_INT, {.i64 = 30000}, 0, 86400000, SD},
|
||
|
{"txt_transparent", "force transparent background of the teletext", OFFSET(transparent_bg), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, SD},
|
||
|
{ NULL },
|
||
|
};
|
||
|
|
||
|
static const AVClass teletext_class = {
|
||
|
.class_name = "libzvbi_teletextdec",
|
||
|
.item_name = av_default_item_name,
|
||
|
.option = options,
|
||
|
.version = LIBAVUTIL_VERSION_INT,
|
||
|
};
|
||
|
|
||
|
AVCodec ff_libzvbi_teletext_decoder = {
|
||
|
.name = "libzvbi_teletextdec",
|
||
|
.long_name = NULL_IF_CONFIG_SMALL("Libzvbi DVB teletext decoder"),
|
||
|
.type = AVMEDIA_TYPE_SUBTITLE,
|
||
|
.id = CODEC_ID_DVB_TELETEXT,
|
||
|
.priv_data_size = sizeof(TeletextContext),
|
||
|
.init = teletext_init_decoder,
|
||
|
.close = teletext_close_decoder,
|
||
|
.decode = teletext_decode_frame,
|
||
|
.flush = teletext_flush,
|
||
|
.priv_class= &teletext_class,
|
||
|
};
|