GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/htmlsubtitles.c Lines: 152 165 92.1 %
Date: 2019-11-22 03:34:36 Branches: 136 166 81.9 %

Line Branch Exec Source
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/*
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 * Copyright (c) 2010  Aurelien Jacobs <aurel@gnuage.org>
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 * Copyright (c) 2017  Clément Bœsch <u@pkh.me>
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg 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 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg 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 FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#include "libavutil/avassert.h"
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#include "libavutil/avstring.h"
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#include "libavutil/common.h"
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#include "libavutil/parseutils.h"
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#include "htmlsubtitles.h"
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#include <ctype.h>
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29
57
static int html_color_parse(void *log_ctx, const char *str)
30
{
31
    uint8_t rgba[4];
32
57
    int nb_sharps = 0;
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79
    while (str[nb_sharps] == '#')
34
22
        nb_sharps++;
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57
    str += FFMAX(0, nb_sharps - 1);
36
57
    if (av_parse_color(rgba, str, strcspn(str, "\" >"), log_ctx) < 0)
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        return -1;
38
57
    return rgba[0] | rgba[1] << 8 | rgba[2] << 16;
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}
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41
429
static void rstrip_spaces_buf(AVBPrint *buf)
42
{
43
429
    if (av_bprint_is_complete(buf))
44

546
        while (buf->len > 0 && buf->str[buf->len - 1] == ' ')
45
117
            buf->str[--buf->len] = 0;
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429
}
47
48
/*
49
 * Fast code for scanning text enclosed in braces. Functionally
50
 * equivalent to this sscanf call:
51
 *
52
 * sscanf(in, "{\\an%*1u}%n", &len) >= 0 && len > 0
53
 */
54
48
static int scanbraces(const char* in) {
55
48
    if (strncmp(in, "{\\an", 4) != 0) {
56
9
        return 0;
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    }
58
39
    if (!av_isdigit(in[4])) {
59
        return 0;
60
    }
61
39
    if (in[5] != '}') {
62
        return 0;
63
    }
64
39
    return 1;
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}
66
67
/* skip all {\xxx} substrings except for {\an%d}
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   and all microdvd like styles such as {Y:xxx} */
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48
static void handle_open_brace(AVBPrint *dst, const char **inp, int *an, int *closing_brace_missing)
70
{
71
48
    const char *in = *inp;
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73
48
    *an += scanbraces(in);
74
75
48
    if (!*closing_brace_missing) {
76

48
        if (   (*an != 1 && in[1] == '\\')
77

42
            || (in[1] && strchr("CcFfoPSsYy", in[1]) && in[2] == ':')) {
78
9
            char *bracep = strchr(in+2, '}');
79
9
            if (bracep) {
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9
                *inp = bracep;
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9
                return;
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            } else
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                *closing_brace_missing = 1;
84
        }
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    }
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87
39
    av_bprint_chars(dst, *in, 1);
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}
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90
struct font_tag {
91
    char face[128];
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    int size;
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    uint32_t color;
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};
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/*
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 * Fast code for scanning the rest of a tag. Functionally equivalent to
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 * this sscanf call:
99
 *
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 * sscanf(in, "%127[^<>]>%n", buffer, lenp) == 2
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 */
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422
static int scantag(const char* in, char* buffer, int* lenp) {
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    int len;
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105
3409
    for (len = 0; len < 128; len++) {
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3409
        const char c = *in++;
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3409
        switch (c) {
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6
        case '\0':
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6
            return 0;
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8
        case '<':
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8
            return 0;
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408
        case '>':
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408
            buffer[len] = '\0';
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408
            *lenp = len+1;
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            return 1;
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2987
        default:
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2987
            break;
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        }
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2987
        buffer[len] = c;
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    }
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    return 0;
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}
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/*
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 * The general politic of the convert is to mask unsupported tags or formatting
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 * errors (but still alert the user/subtitles writer with an error/warning)
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 * without dropping any actual text content for the final user.
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 */
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226
int ff_htmlmarkup_to_ass(void *log_ctx, AVBPrint *dst, const char *in)
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{
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    char *param, buffer[128];
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    int len, tag_close, sptr = 0, line_start = 1, an = 0, end = 0;
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    int closing_brace_missing = 0;
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    int i, likely_a_tag;
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    /*
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     * state stack is only present for fonts since they are the only tags where
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     * the state is not binary. Here is a typical use case:
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     *
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     *   <font color="red" size=10>
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     *     red 10
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     *     <font size=50> RED AND BIG </font>
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     *     red 10 again
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     *   </font>
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     *
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     * On the other hand, using the state system for all the tags should be
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     * avoided because it breaks wrongly nested tags such as:
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     *
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     *   <b> foo <i> bar </b> bla </i>
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     *
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     * We don't want to break here; instead, we will treat all these tags as
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     * binary state markers. Basically, "<b>" will activate bold, and "</b>"
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     * will deactivate it, whatever the current state.
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     *
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     * This will also prevents cases where we have a random closing tag
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     * remaining after the opening one was dropped. Yes, this happens and we
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     * still don't want to print a "</b>" at the end of the dialog event.
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     */
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    struct font_tag stack[16];
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    memset(&stack[0], 0, sizeof(stack[0]));
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163

16613
    for (; !end && *in; in++) {
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16387
        switch (*in) {
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        case '\r':
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            break;
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203
        case '\n':
168
203
            if (line_start) {
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                end = 1;
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                break;
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            }
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            rstrip_spaces_buf(dst);
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            av_bprintf(dst, "\\N");
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            line_start = 1;
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            break;
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2243
        case ' ':
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2243
            if (!line_start)
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2213
                av_bprint_chars(dst, *in, 1);
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2243
            break;
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48
        case '{':
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            handle_open_brace(dst, &in, &an, &closing_brace_missing);
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48
            break;
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422
        case '<':
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            /*
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             * "<<" are likely latin guillemets in ASCII or some kind of random
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             * style effect; see sub/badsyntax.srt in the FATE samples
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             * directory for real test cases.
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             */
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422
            likely_a_tag = 1;
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449
            for (i = 0; in[1] == '<'; i++) {
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27
                av_bprint_chars(dst, '<', 1);
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                likely_a_tag = 0;
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27
                in++;
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            }
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422
            tag_close = in[1] == '/';
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422
            if (tag_close)
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192
                likely_a_tag = 1;
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201
422
            av_assert0(in[0] == '<');
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422
            len = 0;
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205

830
            if (scantag(in+tag_close+1, buffer, &len) && len > 0) {
206
408
                const int skip = len + tag_close;
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408
                const char *tagname = buffer;
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413
                while (*tagname == ' ') {
209
5
                    likely_a_tag = 0;
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5
                    tagname++;
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                }
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408
                if ((param = strchr(tagname, ' ')))
213
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                    *param++ = 0;
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                /* Check if this is likely a tag */
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#define LIKELY_A_TAG_CHAR(x) (((x) >= '0' && (x) <= '9') || \
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                              ((x) >= 'a' && (x) <= 'z') || \
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                              ((x) >= 'A' && (x) <= 'Z') || \
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                               (x) == '_' || (x) == '/')
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1877
                for (i = 0; tagname[i]; i++) {
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1475
                    if (!LIKELY_A_TAG_CHAR(tagname[i])) {
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6
                        likely_a_tag = 0;
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6
                        break;
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                    }
225
                }
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227
408
                if (!av_strcasecmp(tagname, "font")) {
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270
                    if (tag_close && sptr > 0) {
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90
                        struct font_tag *cur_tag  = &stack[sptr--];
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                        struct font_tag *last_tag = &stack[sptr];
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                        if (cur_tag->size) {
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48
                            if (!last_tag->size)
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                                av_bprintf(dst, "{\\fs}");
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6
                            else if (last_tag->size != cur_tag->size)
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3
                                av_bprintf(dst, "{\\fs%d}", last_tag->size);
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                        }
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239
90
                        if (cur_tag->color & 0xff000000) {
240
76
                            if (!(last_tag->color & 0xff000000))
241
53
                                av_bprintf(dst, "{\\c}");
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                            else if (last_tag->color != cur_tag->color)
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4
                                av_bprintf(dst, "{\\c&H%"PRIX32"&}", last_tag->color & 0xffffff);
244
                        }
245
246
90
                        if (cur_tag->face[0]) {
247
3
                            if (!last_tag->face[0])
248
3
                                av_bprintf(dst, "{\\fn}");
249
                            else if (strcmp(last_tag->face, cur_tag->face))
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                                av_bprintf(dst, "{\\fn%s}", last_tag->face);
251
                        }
252

90
                    } else if (!tag_close && sptr < FF_ARRAY_ELEMS(stack) - 1) {
253
90
                        struct font_tag *new_tag = &stack[sptr + 1];
254
255
90
                        *new_tag = stack[sptr++];
256
257
196
                        while (param) {
258
106
                            if (!av_strncasecmp(param, "size=", 5)) {
259
45
                                param += 5 + (param[5] == '"');
260
45
                                if (sscanf(param, "%u", &new_tag->size) == 1)
261
45
                                    av_bprintf(dst, "{\\fs%u}", new_tag->size);
262
61
                            } else if (!av_strncasecmp(param, "color=", 6)) {
263
                                int color;
264
57
                                param += 6 + (param[6] == '"');
265
57
                                color = html_color_parse(log_ctx, param);
266
57
                                if (color >= 0) {
267
57
                                    new_tag->color = 0xff000000 | color;
268
57
                                    av_bprintf(dst, "{\\c&H%"PRIX32"&}", new_tag->color & 0xffffff);
269
                                }
270
4
                            } else if (!av_strncasecmp(param, "face=", 5)) {
271
3
                                param += 5 + (param[5] == '"');
272
3
                                len = strcspn(param,
273
3
                                              param[-1] == '"' ? "\"" :" ");
274
3
                                av_strlcpy(new_tag->face, param,
275
3
                                           FFMIN(sizeof(new_tag->face), len+1));
276
3
                                param += len;
277
3
                                av_bprintf(dst, "{\\fn%s}", new_tag->face);
278
                            }
279
106
                            if ((param = strchr(param, ' ')))
280
16
                                param++;
281
                        }
282
                    }
283
180
                    in += skip;
284

228
                } else if (tagname[0] && !tagname[1] && strchr("bisu", av_tolower(tagname[0]))) {
285
116
                    av_bprintf(dst, "{\\%c%d}", (char)av_tolower(tagname[0]), !tag_close);
286
116
                    in += skip;
287
112
                } else if (!av_strncasecmp(tagname, "br", 2) &&
288

6
                           (!tagname[2] || (tagname[2] == '/' && !tagname[3]))) {
289
4
                    av_bprintf(dst, "\\N");
290
4
                    in += skip;
291
108
                } else if (likely_a_tag) {
292
96
                    if (!tag_close) // warn only once
293
51
                        av_log(log_ctx, AV_LOG_WARNING, "Unrecognized tag %s\n", tagname);
294
96
                    in += skip;
295
                } else {
296
12
                    av_bprint_chars(dst, '<', 1);
297
                }
298
            } else {
299
14
                av_bprint_chars(dst, *in, 1);
300
            }
301
422
            break;
302
13471
        default:
303
13471
            av_bprint_chars(dst, *in, 1);
304
13471
            break;
305
        }
306

16387
        if (*in != ' ' && *in != '\r' && *in != '\n')
307
13941
            line_start = 0;
308
    }
309
310
226
    if (!av_bprint_is_complete(dst))
311
        return AVERROR(ENOMEM);
312
313

226
    while (dst->len >= 2 && !strncmp(&dst->str[dst->len - 2], "\\N", 2))
314
        dst->len -= 2;
315
226
    dst->str[dst->len] = 0;
316
226
    rstrip_spaces_buf(dst);
317
318
226
    return 0;
319
}