GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/webvttdec.c Lines: 39 40 97.5 %
Date: 2020-10-23 17:01:47 Branches: 25 30 83.3 %

Line Branch Exec Source
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/*
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 * Copyright (c) 2012 Clément Bœsch
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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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/**
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 * @file
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 * WebVTT subtitle decoder
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 * @see http://dev.w3.org/html5/webvtt/
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 * @todo need to support extended markups and cue settings
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 */
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#include "avcodec.h"
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#include "ass.h"
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#include "libavutil/bprint.h"
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static const struct {
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    const char *from;
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    const char *to;
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} webvtt_tag_replace[] = {
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    {"<i>", "{\\i1}"}, {"</i>", "{\\i0}"},
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    {"<b>", "{\\b1}"}, {"</b>", "{\\b0}"},
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    {"<u>", "{\\u1}"}, {"</u>", "{\\u0}"},
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    {"{", "\\{"}, {"}", "\\}"}, // escape to avoid ASS markup conflicts
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    {"&gt;", ">"}, {"&lt;", "<"},
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    {"&lrm;", ""}, {"&rlm;", ""}, // FIXME: properly honor bidi marks
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    {"&amp;", "&"}, {"&nbsp;", "\\h"},
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};
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static int webvtt_event_to_ass(AVBPrint *buf, const char *p)
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{
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    int i, again = 0, skip = 0;
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    while (*p) {
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        for (i = 0; i < FF_ARRAY_ELEMS(webvtt_tag_replace); i++) {
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            const char *from = webvtt_tag_replace[i].from;
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            const size_t len = strlen(from);
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            if (!strncmp(p, from, len)) {
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                av_bprintf(buf, "%s", webvtt_tag_replace[i].to);
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                p += len;
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                again = 1;
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                break;
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            }
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        }
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        if (!*p)
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            break;
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        if (again) {
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            again = 0;
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            skip = 0;
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            continue;
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        }
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        if (*p == '<')
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            skip = 1;
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        else if (*p == '>')
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            skip = 0;
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        else if (p[0] == '\n' && p[1])
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            av_bprintf(buf, "\\N");
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        else if (!skip && *p != '\r')
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            av_bprint_chars(buf, *p, 1);
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        p++;
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    }
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    return 0;
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}
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static int webvtt_decode_frame(AVCodecContext *avctx,
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                               void *data, int *got_sub_ptr, AVPacket *avpkt)
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{
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    int ret = 0;
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    AVSubtitle *sub = data;
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    const char *ptr = avpkt->data;
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    FFASSDecoderContext *s = avctx->priv_data;
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    AVBPrint buf;
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    av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
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    if (ptr && avpkt->size > 0 && !webvtt_event_to_ass(&buf, ptr))
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        ret = ff_ass_add_rect(sub, buf.str, s->readorder++, 0, NULL, NULL);
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    av_bprint_finalize(&buf, NULL);
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    if (ret < 0)
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        return ret;
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    *got_sub_ptr = sub->num_rects > 0;
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    return avpkt->size;
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}
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AVCodec ff_webvtt_decoder = {
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    .name           = "webvtt",
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    .long_name      = NULL_IF_CONFIG_SMALL("WebVTT subtitle"),
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    .type           = AVMEDIA_TYPE_SUBTITLE,
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    .id             = AV_CODEC_ID_WEBVTT,
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    .decode         = webvtt_decode_frame,
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    .init           = ff_ass_subtitle_header_default,
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    .flush          = ff_ass_decoder_flush,
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    .priv_data_size = sizeof(FFASSDecoderContext),
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};