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FFmpeg/libavcodec/libzvbi-teletextdec.c
Andreas Rheinhardt a247ac640d avcodec: Constify AVCodecs 
Given that the AVCodec.next pointer has now been removed, most of the
AVCodecs are not modified at all any more and can therefore be made
const (as this patch does); the only exceptions are the very few codecs
for external libraries that have a init_static_data callback.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>
2021-04-27 10:43:15 -03:00

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/*
* Teletext decoding for ffmpeg
* Copyright (c) 2005-2010, 2012 Wolfram Gloger
* Copyright (c) 2013 Marton Balint
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "avcodec.h"
#include "libavcodec/ass.h"
#include "libavcodec/dvbtxt.h"
#include "libavutil/opt.h"
#include "libavutil/bprint.h"
#include "libavutil/internal.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/log.h"
#include "libavutil/common.h"
#include <libzvbi.h>
#define TEXT_MAXSZ (25 * (56 + 1) * 4 + 2)
#define VBI_NB_COLORS 40
#define VBI_TRANSPARENT_BLACK 8
#define RGBA(r,g,b,a) (((a) << 24) | ((r) << 16) | ((g) << 8) | (b))
#define VBI_R(rgba) (((rgba) >> 0) & 0xFF)
#define VBI_G(rgba) (((rgba) >> 8) & 0xFF)
#define VBI_B(rgba) (((rgba) >> 16) & 0xFF)
#define VBI_A(rgba) (((rgba) >> 24) & 0xFF)
#define MAX_BUFFERED_PAGES 25
#define BITMAP_CHAR_WIDTH 12
#define BITMAP_CHAR_HEIGHT 10
#define MAX_SLICES 64
typedef struct TeletextPage
{
AVSubtitleRect *sub_rect;
int pgno;
int subno;
int64_t pts;
} TeletextPage;
typedef struct TeletextContext
{
AVClass *class;
char *pgno;
int default_region;
int x_offset;
int y_offset;
int format_id; /* 0 = bitmap, 1 = text/ass, 2 = ass */
int chop_top;
int sub_duration; /* in msec */
int transparent_bg;
int opacity;
int chop_spaces;
int lines_processed;
TeletextPage *pages;
int nb_pages;
int64_t pts;
int handler_ret;
vbi_decoder * vbi;
vbi_sliced sliced[MAX_SLICES];
int readorder;
uint8_t subtitle_map[2048];
int last_pgno;
int last_p5;
int last_ass_alignment;
} TeletextContext;
static int my_ass_subtitle_header(AVCodecContext *avctx)
{
int ret = ff_ass_subtitle_header_default(avctx);
char *new_header;
uint8_t *event_pos;
if (ret < 0)
return ret;
event_pos = strstr(avctx->subtitle_header, "\r\n[Events]\r\n");
if (!event_pos)
return AVERROR_BUG;
new_header = av_asprintf("%.*s%s%s",
(int)(event_pos - avctx->subtitle_header), avctx->subtitle_header,
"Style: "
"Teletext," /* Name */
"Monospace,11," /* Font{name,size} */
"&Hffffff,&Hffffff,&H0,&H0," /* {Primary,Secondary,Outline,Back}Colour */
"0,0,0,0," /* Bold, Italic, Underline, StrikeOut */
"160,100," /* Scale{X,Y} */
"0,0," /* Spacing, Angle */
"3,0.1,0," /* BorderStyle, Outline, Shadow */
"5,1,1,1," /* Alignment, Margin[LRV] */
"0\r\n" /* Encoding */
"Style: "
"Subtitle," /* Name */
"Monospace,16," /* Font{name,size} */
"&Hffffff,&Hffffff,&H0,&H0," /* {Primary,Secondary,Outline,Back}Colour */
"0,0,0,0," /* Bold, Italic, Underline, StrikeOut */
"100,100," /* Scale{X,Y} */
"0,0," /* Spacing, Angle */
"1,1,1," /* BorderStyle, Outline, Shadow */
"8,48,48,20," /* Alignment, Margin[LRV] */
"0\r\n" /* Encoding */
, event_pos);
if (!new_header)
return AVERROR(ENOMEM);
av_free(avctx->subtitle_header);
avctx->subtitle_header = new_header;
avctx->subtitle_header_size = strlen(new_header);
return 0;
}
static int chop_spaces_utf8(const unsigned char* t, int len)
{
t += len;
while (len > 0) {
if (*--t != ' ' || (len-1 > 0 && *(t-1) & 0x80))
break;
--len;
}
return len;
}
static void subtitle_rect_free(AVSubtitleRect **sub_rect)
{
av_freep(&(*sub_rect)->data[0]);
av_freep(&(*sub_rect)->data[1]);
av_freep(&(*sub_rect)->ass);
av_freep(sub_rect);
}
static char *create_ass_text(TeletextContext *ctx, const char *text)
{
char *dialog;
AVBPrint buf;
av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
ff_ass_bprint_text_event(&buf, text, strlen(text), "", 0);
if (!av_bprint_is_complete(&buf)) {
av_bprint_finalize(&buf, NULL);
return NULL;
}
dialog = ff_ass_get_dialog(ctx->readorder++, 0, NULL, NULL, buf.str);
av_bprint_finalize(&buf, NULL);
return dialog;
}
/* Draw a page as text */
static int gen_sub_text(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page, int chop_top)
{
const char *in;
AVBPrint buf;
char *vbi_text = av_malloc(TEXT_MAXSZ);
int sz;
if (!vbi_text)
return AVERROR(ENOMEM);
sz = vbi_print_page_region(page, vbi_text, TEXT_MAXSZ-1, "UTF-8",
/*table mode*/ TRUE, FALSE,
0, chop_top,
page->columns, page->rows-chop_top);
if (sz <= 0) {
av_log(ctx, AV_LOG_ERROR, "vbi_print error\n");
av_free(vbi_text);
return AVERROR_EXTERNAL;
}
vbi_text[sz] = '\0';
in = vbi_text;
av_bprint_init(&buf, 0, TEXT_MAXSZ);
if (ctx->chop_spaces) {
for (;;) {
int nl, sz;
// skip leading spaces and newlines
in += strspn(in, " \n");
// compute end of row
for (nl = 0; in[nl]; ++nl)
if (in[nl] == '\n' && (nl==0 || !(in[nl-1] & 0x80)))
break;
if (!in[nl])
break;
// skip trailing spaces
sz = chop_spaces_utf8(in, nl);
av_bprint_append_data(&buf, in, sz);
av_bprintf(&buf, "\n");
in += nl;
}
} else {
av_bprintf(&buf, "%s\n", vbi_text);
}
av_free(vbi_text);
if (!av_bprint_is_complete(&buf)) {
av_bprint_finalize(&buf, NULL);
return AVERROR(ENOMEM);
}
if (buf.len) {
sub_rect->type = SUBTITLE_ASS;
sub_rect->ass = create_ass_text(ctx, buf.str);
if (!sub_rect->ass) {
av_bprint_finalize(&buf, NULL);
return AVERROR(ENOMEM);
}
av_log(ctx, AV_LOG_DEBUG, "subtext:%s:txetbus\n", sub_rect->ass);
} else {
sub_rect->type = SUBTITLE_NONE;
}
av_bprint_finalize(&buf, NULL);
return 0;
}
static void bprint_color(const char *type, AVBPrint *buf, vbi_page *page, unsigned ci)
{
int r = VBI_R(page->color_map[ci]);
int g = VBI_G(page->color_map[ci]);
int b = VBI_B(page->color_map[ci]);
av_bprintf(buf, "{\\%s&H%02X%02X%02X&}", type, b, g, r);
}
#define IS_TXT_SPACE(ch) ((ch).unicode < 0x0020 || (ch).unicode >= 0xe000 || (ch).unicode == 0x00a0 ||\
(ch).size > VBI_DOUBLE_SIZE || (ch).opacity == VBI_TRANSPARENT_SPACE)
static void get_trim_info(vbi_page *page, vbi_char *row, int *leading, int *trailing, int *olen)
{
int i, len = 0;
int char_seen = 0;
*leading = 0;
for (i = 0; i < page->columns; i++) {
uint16_t out = IS_TXT_SPACE(row[i]) ? 32 : row[i].unicode;
if (out == 32 && !char_seen)
(*leading)++;
else if (out != 32)
char_seen = 1, len = i - (*leading) + 1;
}
*olen = len;
*trailing = len > 0 ? page->columns - *leading - len : page->columns;
}
static void decode_string(vbi_page *page, vbi_char *row, AVBPrint *buf,
int start, int end, vbi_color *cur_color, vbi_color *cur_back_color)
{
int i;
for (i = start; i < end; i++) {
uint16_t out = IS_TXT_SPACE(row[i]) ? 32 : row[i].unicode;
if (*cur_color != row[i].foreground) {
bprint_color("c", buf, page, row[i].foreground);
*cur_color = row[i].foreground;
}
if (*cur_back_color != row[i].background) {
bprint_color("3c", buf, page, row[i].background);
*cur_back_color = row[i].background;
}
if (out == 32) {
av_bprintf(buf, "\\h");
} else if (out == '\\' || out == '{' || out == '}') {
av_bprintf(buf, "\\%c", (char)out);
} else {
char tmp;
/* convert to utf-8 */
PUT_UTF8(out, tmp, av_bprint_chars(buf, tmp, 1););
}
}
}
/* Draw a page as ass formatted text */
static int gen_sub_ass(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page, int chop_top)
{
int i;
int leading, trailing, len;
int last_trailing = -1, last_leading = -1;
int min_trailing = page->columns, min_leading = page->columns;
int alignment = 2;
int vertical_align = -1;
int can_align_left = 1, can_align_right = 1, can_align_center = 1;
int is_subtitle_page = ctx->subtitle_map[page->pgno & 0x7ff];
int empty_lines = 0;
vbi_color cur_color = VBI_WHITE;
vbi_color cur_back_color = VBI_BLACK;
AVBPrint buf;
av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
for (i = chop_top; i < page->rows; i++) {
vbi_char *row = page->text + i * page->columns;
get_trim_info(page, row, &leading, &trailing, &len);
if (len) {
if (last_leading != -1 && last_leading != leading || leading > 5)
can_align_left = 0;
if (last_trailing != -1 && last_trailing != trailing || trailing > 2)
can_align_right = 0;
if (last_trailing != -1 && (FFABS((trailing - leading) - (last_trailing - last_leading)) > 1) || trailing - leading > 4)
can_align_center = 0;
last_leading = leading;
last_trailing = trailing;
min_leading = FFMIN(leading, min_leading);
min_trailing = FFMIN(trailing, min_trailing);
}
}
if (!can_align_right && can_align_left && !can_align_center) {
ctx->last_ass_alignment = alignment = 1;
} else if (!can_align_right && !can_align_left && can_align_center) {
ctx->last_ass_alignment = alignment = 2;
} else if (can_align_right && !can_align_left && !can_align_center) {
ctx->last_ass_alignment = alignment = 3;
} else {
if (ctx->last_ass_alignment == 1 && can_align_left ||
ctx->last_ass_alignment == 2 && can_align_center ||
ctx->last_ass_alignment == 3 && can_align_right)
alignment = ctx->last_ass_alignment;
}
for (i = chop_top; i < page->rows; i++) {
int j;
vbi_char *row = page->text + i * page->columns;
int is_transparent_line;
for (j = 0; j < page->columns; j++)
if (row[j].opacity != VBI_TRANSPARENT_SPACE)
break;
is_transparent_line = (j == page->columns);
len = is_transparent_line ? 0 : page->columns;
leading = trailing = is_transparent_line ? page->columns : 0;
if (is_subtitle_page) {
if (!is_transparent_line)
get_trim_info(page, row, &leading, &trailing, &len);
if (vertical_align == -1 && len) {
vertical_align = (2 - (av_clip(i + 1, 0, 23) / 8));
av_bprintf(&buf, "{\\an%d}", alignment + vertical_align * 3);
if (vertical_align != 2)
empty_lines = 0;
}
if (len && empty_lines > 1)
for (empty_lines /= 2; empty_lines > 0; empty_lines--)
av_bprintf(&buf, " \\N");
if (alignment == 1 || alignment == 2 && !can_align_center)
leading = min_leading;
if (alignment == 3 || alignment == 2 && !can_align_center)
trailing = min_trailing;
}
if (len || !is_subtitle_page) {
decode_string(page, row, &buf, leading, page->columns - trailing, &cur_color, &cur_back_color);
av_bprintf(&buf, " \\N");
empty_lines = 0;
} else {
empty_lines++;
}
}
if (vertical_align == 0)
for (empty_lines = (empty_lines - 1) / 2; empty_lines > 0; empty_lines--)
av_bprintf(&buf, " \\N");
if (!av_bprint_is_complete(&buf)) {
av_bprint_finalize(&buf, NULL);
return AVERROR(ENOMEM);
}
if (buf.len) {
sub_rect->type = SUBTITLE_ASS;
sub_rect->ass = ff_ass_get_dialog(ctx->readorder++, 0, is_subtitle_page ? "Subtitle" : "Teletext", NULL, buf.str);
if (!sub_rect->ass) {
av_bprint_finalize(&buf, NULL);
return AVERROR(ENOMEM);
}
av_log(ctx, AV_LOG_DEBUG, "subtext:%s:txetbus\n", sub_rect->ass);
} else {
sub_rect->type = SUBTITLE_NONE;
}
av_bprint_finalize(&buf, NULL);
return 0;
}
static void fix_transparency(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page,
int chop_top, int resx, int resy)
{
int iy;
// Hack for transparency, inspired by VLC code...
for (iy = 0; iy < resy; iy++) {
uint8_t *pixel = sub_rect->data[0] + iy * sub_rect->linesize[0];
vbi_char *vc = page->text + (iy / BITMAP_CHAR_HEIGHT + chop_top) * page->columns;
vbi_char *vcnext = vc + page->columns;
for (; vc < vcnext; vc++) {
uint8_t *pixelnext = pixel + BITMAP_CHAR_WIDTH;
switch (vc->opacity) {
case VBI_TRANSPARENT_SPACE:
memset(pixel, VBI_TRANSPARENT_BLACK, BITMAP_CHAR_WIDTH);
break;
case VBI_OPAQUE:
if (!ctx->transparent_bg)
break;
case VBI_SEMI_TRANSPARENT:
if (ctx->opacity > 0) {
if (ctx->opacity < 255)
for(; pixel < pixelnext; pixel++)
if (*pixel == vc->background)
*pixel += VBI_NB_COLORS;
break;
}
case VBI_TRANSPARENT_FULL:
for(; pixel < pixelnext; pixel++)
if (*pixel == vc->background)
*pixel = VBI_TRANSPARENT_BLACK;
break;
}
pixel = pixelnext;
}
}
}
/* Draw a page as bitmap */
static int gen_sub_bitmap(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page, int chop_top)
{
int resx = page->columns * BITMAP_CHAR_WIDTH;
int resy = (page->rows - chop_top) * BITMAP_CHAR_HEIGHT;
uint8_t ci;
vbi_char *vc = page->text + (chop_top * page->columns);
vbi_char *vcend = page->text + (page->rows * page->columns);
for (; vc < vcend; vc++) {
if (vc->opacity != VBI_TRANSPARENT_SPACE)
break;
}
if (vc >= vcend) {
av_log(ctx, AV_LOG_DEBUG, "dropping empty page %3x\n", page->pgno);
sub_rect->type = SUBTITLE_NONE;
return 0;
}
sub_rect->data[0] = av_mallocz(resx * resy);
sub_rect->linesize[0] = resx;
if (!sub_rect->data[0])
return AVERROR(ENOMEM);
vbi_draw_vt_page_region(page, VBI_PIXFMT_PAL8,
sub_rect->data[0], sub_rect->linesize[0],
0, chop_top, page->columns, page->rows - chop_top,
/*reveal*/ 1, /*flash*/ 1);
fix_transparency(ctx, sub_rect, page, chop_top, resx, resy);
sub_rect->x = ctx->x_offset;
sub_rect->y = ctx->y_offset + chop_top * BITMAP_CHAR_HEIGHT;
sub_rect->w = resx;
sub_rect->h = resy;
sub_rect->nb_colors = ctx->opacity > 0 && ctx->opacity < 255 ? 2 * VBI_NB_COLORS : VBI_NB_COLORS;
sub_rect->data[1] = av_mallocz(AVPALETTE_SIZE);
if (!sub_rect->data[1]) {
av_freep(&sub_rect->data[0]);
return AVERROR(ENOMEM);
}
for (ci = 0; ci < VBI_NB_COLORS; ci++) {
int r, g, b, a;
r = VBI_R(page->color_map[ci]);
g = VBI_G(page->color_map[ci]);
b = VBI_B(page->color_map[ci]);
a = VBI_A(page->color_map[ci]);
((uint32_t *)sub_rect->data[1])[ci] = RGBA(r, g, b, a);
((uint32_t *)sub_rect->data[1])[ci + VBI_NB_COLORS] = RGBA(r, g, b, ctx->opacity);
ff_dlog(ctx, "palette %0x\n", ((uint32_t *)sub_rect->data[1])[ci]);
}
((uint32_t *)sub_rect->data[1])[VBI_TRANSPARENT_BLACK] = RGBA(0, 0, 0, 0);
((uint32_t *)sub_rect->data[1])[VBI_TRANSPARENT_BLACK + VBI_NB_COLORS] = RGBA(0, 0, 0, 0);
sub_rect->type = SUBTITLE_BITMAP;
return 0;
}
static void handler(vbi_event *ev, void *user_data)
{
TeletextContext *ctx = user_data;
TeletextPage *new_pages;
vbi_page page;
int res;
char pgno_str[12];
int chop_top;
int is_subtitle_page = ctx->subtitle_map[ev->ev.ttx_page.pgno & 0x7ff];
snprintf(pgno_str, sizeof pgno_str, "%03x", ev->ev.ttx_page.pgno);
av_log(ctx, AV_LOG_DEBUG, "decoded page %s.%02x\n",
pgno_str, ev->ev.ttx_page.subno & 0xFF);
if (strcmp(ctx->pgno, "*") && (strcmp(ctx->pgno, "subtitle") || !is_subtitle_page) && !strstr(ctx->pgno, pgno_str))
return;
if (ctx->handler_ret < 0)
return;
res = vbi_fetch_vt_page(ctx->vbi, &page,
ev->ev.ttx_page.pgno,
ev->ev.ttx_page.subno,
VBI_WST_LEVEL_3p5, 25, TRUE);
if (!res)
return;
chop_top = ctx->chop_top || ((page.rows > 1) && is_subtitle_page);
av_log(ctx, AV_LOG_DEBUG, "%d x %d page chop:%d\n",
page.columns, page.rows, chop_top);
if (ctx->nb_pages < MAX_BUFFERED_PAGES) {
if ((new_pages = av_realloc_array(ctx->pages, ctx->nb_pages + 1, sizeof(TeletextPage)))) {
TeletextPage *cur_page = new_pages + ctx->nb_pages;
ctx->pages = new_pages;
cur_page->sub_rect = av_mallocz(sizeof(*cur_page->sub_rect));
cur_page->pts = ctx->pts;
cur_page->pgno = ev->ev.ttx_page.pgno;
cur_page->subno = ev->ev.ttx_page.subno;
if (cur_page->sub_rect) {
switch (ctx->format_id) {
case 0:
res = gen_sub_bitmap(ctx, cur_page->sub_rect, &page, chop_top);
break;
case 1:
res = gen_sub_text(ctx, cur_page->sub_rect, &page, chop_top);
break;
case 2:
res = gen_sub_ass(ctx, cur_page->sub_rect, &page, chop_top);
break;
default:
res = AVERROR_BUG;
break;
}
if (res < 0) {
av_freep(&cur_page->sub_rect);
ctx->handler_ret = res;
} else {
ctx->pages[ctx->nb_pages++] = *cur_page;
}
} else {
ctx->handler_ret = AVERROR(ENOMEM);
}
} else {
ctx->handler_ret = AVERROR(ENOMEM);
}
} else {
//TODO: If multiple packets contain more than one page, pages may got queued up, and this may happen...
av_log(ctx, AV_LOG_ERROR, "Buffered too many pages, dropping page %s.\n", pgno_str);
ctx->handler_ret = AVERROR(ENOSYS);
}
vbi_unref_page(&page);
}
static int slice_to_vbi_lines(TeletextContext *ctx, uint8_t* buf, int size)
{
int lines = 0;
while (size >= 2 && lines < MAX_SLICES) {
int data_unit_id = buf[0];
int data_unit_length = buf[1];
if (data_unit_length + 2 > size)
return AVERROR_INVALIDDATA;
if (ff_data_unit_id_is_teletext(data_unit_id)) {
if (data_unit_length != 0x2c)
return AVERROR_INVALIDDATA;
else {
int line_offset = buf[2] & 0x1f;
int field_parity = buf[2] & 0x20;
uint8_t *p = ctx->sliced[lines].data;
int i, pmag;
ctx->sliced[lines].id = VBI_SLICED_TELETEXT_B;
ctx->sliced[lines].line = (line_offset > 0 ? (line_offset + (field_parity ? 0 : 313)) : 0);
for (i = 0; i < 42; i++)
p[i] = vbi_rev8(buf[4 + i]);
/* Unfortunately libzvbi does not expose page flags, and
* vbi_classify_page only checks MIP, so we have to manually
* decode the page flags and store the results. */
pmag = vbi_unham16p(p);
if (pmag >= 0 && pmag >> 3 == 0) { // We found a row 0 header
int page = vbi_unham16p(p + 2);
int flags1 = vbi_unham16p(p + 6);
int flags2 = vbi_unham16p(p + 8);
if (page >= 0 && flags1 >= 0 && flags2 >= 0) {
int pgno = ((pmag & 7) << 8) + page;
// Check for disabled NEWSFLASH flag and enabled SUBTITLE and SUPRESS_HEADER flags
ctx->subtitle_map[pgno] = (!(flags1 & 0x40) && flags1 & 0x80 && flags2 & 0x01);
// Propagate ERASE_PAGE flag for repeated page headers to work around a libzvbi bug
if (ctx->subtitle_map[pgno] && pgno == ctx->last_pgno) {
int last_byte9 = vbi_unham8(ctx->last_p5);
if (last_byte9 >= 0 && last_byte9 & 0x8) {
int byte9 = vbi_unham8(p[5]);
if (byte9 >= 0)
p[5] = vbi_ham8(byte9 | 0x8);
}
}
ctx->last_pgno = pgno;
ctx->last_p5 = p[5];
}
}
lines++;
}
}
size -= data_unit_length + 2;
buf += data_unit_length + 2;
}
if (size)
av_log(ctx, AV_LOG_WARNING, "%d bytes remained after slicing data\n", size);
return lines;
}
static int teletext_decode_frame(AVCodecContext *avctx, void *data, int *got_sub_ptr, AVPacket *pkt)
{
TeletextContext *ctx = avctx->priv_data;
AVSubtitle *sub = data;
int ret = 0;
if (!ctx->vbi) {
if (!(ctx->vbi = vbi_decoder_new()))
return AVERROR(ENOMEM);
if (ctx->default_region != -1) {
av_log(avctx, AV_LOG_INFO, "Setting default zvbi region to %i\n", ctx->default_region);
vbi_teletext_set_default_region(ctx->vbi, ctx->default_region);
}
if (!vbi_event_handler_register(ctx->vbi, VBI_EVENT_TTX_PAGE, handler, ctx)) {
vbi_decoder_delete(ctx->vbi);
ctx->vbi = NULL;
return AVERROR(ENOMEM);
}
}
if (avctx->pkt_timebase.num && pkt->pts != AV_NOPTS_VALUE)
ctx->pts = av_rescale_q(pkt->pts, avctx->pkt_timebase, AV_TIME_BASE_Q);
if (pkt->size) {
int lines;
const int full_pes_size = pkt->size + 45; /* PES header is 45 bytes */
// We allow unreasonably big packets, even if the standard only allows a max size of 1472
if (full_pes_size < 184 || full_pes_size > 65504 || full_pes_size % 184 != 0)
return AVERROR_INVALIDDATA;
ctx->handler_ret = pkt->size;
if (ff_data_identifier_is_teletext(*pkt->data)) {
if ((lines = slice_to_vbi_lines(ctx, pkt->data + 1, pkt->size - 1)) < 0)
return lines;
ff_dlog(avctx, "ctx=%p buf_size=%d lines=%u pkt_pts=%7.3f\n",
ctx, pkt->size, lines, (double)pkt->pts/90000.0);
if (lines > 0) {
vbi_decode(ctx->vbi, ctx->sliced, lines, 0.0);
ctx->lines_processed += lines;
}
}
ctx->pts = AV_NOPTS_VALUE;
ret = ctx->handler_ret;
}
if (ret < 0)
return ret;
// is there a subtitle to pass?
if (ctx->nb_pages) {
int i;
sub->format = !!ctx->format_id;
sub->start_display_time = 0;
sub->end_display_time = ctx->sub_duration;
sub->num_rects = 0;
sub->pts = ctx->pages->pts;
if (ctx->pages->sub_rect->type != SUBTITLE_NONE) {
sub->rects = av_malloc(sizeof(*sub->rects));
if (sub->rects) {
sub->num_rects = 1;
sub->rects[0] = ctx->pages->sub_rect;
} else {
ret = AVERROR(ENOMEM);
}
} else {
av_log(avctx, AV_LOG_DEBUG, "sending empty sub\n");
sub->rects = NULL;
}
if (!sub->rects) // no rect was passed
subtitle_rect_free(&ctx->pages->sub_rect);
for (i = 0; i < ctx->nb_pages - 1; i++)
ctx->pages[i] = ctx->pages[i + 1];
ctx->nb_pages--;
if (ret >= 0)
*got_sub_ptr = 1;
} else
*got_sub_ptr = 0;
return ret;
}
static int teletext_init_decoder(AVCodecContext *avctx)
{
TeletextContext *ctx = avctx->priv_data;
unsigned int maj, min, rev;
vbi_version(&maj, &min, &rev);
if (!(maj > 0 || min > 2 || min == 2 && rev >= 26)) {
av_log(avctx, AV_LOG_ERROR, "decoder needs zvbi version >= 0.2.26.\n");
return AVERROR_EXTERNAL;
}
if (ctx->format_id == 0) {
avctx->width = 41 * BITMAP_CHAR_WIDTH;
avctx->height = 25 * BITMAP_CHAR_HEIGHT;
}
ctx->vbi = NULL;
ctx->pts = AV_NOPTS_VALUE;
ctx->last_pgno = -1;
ctx->last_ass_alignment = 2;
if (ctx->opacity == -1)
ctx->opacity = ctx->transparent_bg ? 0 : 255;
av_log(avctx, AV_LOG_VERBOSE, "page filter: %s\n", ctx->pgno);
switch (ctx->format_id) {
case 0:
return 0;
case 1:
return ff_ass_subtitle_header_default(avctx);
case 2:
return my_ass_subtitle_header(avctx);
}
return AVERROR_BUG;
}
static int teletext_close_decoder(AVCodecContext *avctx)
{
TeletextContext *ctx = avctx->priv_data;
ff_dlog(avctx, "lines_total=%u\n", ctx->lines_processed);
while (ctx->nb_pages)
subtitle_rect_free(&ctx->pages[--ctx->nb_pages].sub_rect);
av_freep(&ctx->pages);
vbi_decoder_delete(ctx->vbi);
ctx->vbi = NULL;
ctx->pts = AV_NOPTS_VALUE;
ctx->last_pgno = -1;
ctx->last_ass_alignment = 2;
memset(ctx->subtitle_map, 0, sizeof(ctx->subtitle_map));
if (!(avctx->flags2 & AV_CODEC_FLAG2_RO_FLUSH_NOOP))
ctx->readorder = 0;
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", "page numbers to decode, subtitle for subtitles, * for all", OFFSET(pgno), AV_OPT_TYPE_STRING, {.str = "*"}, 0, 0, SD},
{"txt_default_region", "default G0 character set used for decoding", OFFSET(default_region), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 87, 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 or ass)", OFFSET(format_id), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 2, SD, "txt_format"},
{"bitmap", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 0}, 0, 0, SD, "txt_format"},
{"text", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 1}, 0, 0, SD, "txt_format"},
{"ass", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 2}, 0, 0, SD, "txt_format"},
{"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 = -1}, -1, 86400000, SD},
{"txt_transparent", "force transparent background of the teletext", OFFSET(transparent_bg), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, SD},
{"txt_opacity", "set opacity of the transparent background", OFFSET(opacity), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 255, SD},
{ NULL },
};
static const AVClass teletext_class = {
.class_name = "libzvbi_teletextdec",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
const AVCodec ff_libzvbi_teletext_decoder = {
.name = "libzvbi_teletextdec",
.long_name = NULL_IF_CONFIG_SMALL("Libzvbi DVB teletext decoder"),
.type = AVMEDIA_TYPE_SUBTITLE,
.id = AV_CODEC_ID_DVB_TELETEXT,
.priv_data_size = sizeof(TeletextContext),
.init = teletext_init_decoder,
.close = teletext_close_decoder,
.decode = teletext_decode_frame,
.capabilities = AV_CODEC_CAP_DELAY,
.flush = teletext_flush,
.priv_class= &teletext_class,
.wrapper_name = "libzvbi",
};
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