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ffmpeg / libavcodec / dvdsub_parser.c @ 2912e87a

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/*
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 * DVD subtitle decoding for ffmpeg
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 * Copyright (c) 2005 Fabrice Bellard
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 *
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 * This file is part of Libav.
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 *
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 * Libav 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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 * Libav 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 Libav; 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/intreadwrite.h"
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#include "avcodec.h"
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/* parser definition */
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typedef struct DVDSubParseContext {
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    uint8_t *packet;
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    int packet_len;
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    int packet_index;
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} DVDSubParseContext;
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static av_cold int dvdsub_parse_init(AVCodecParserContext *s)
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{
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    return 0;
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}
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static int dvdsub_parse(AVCodecParserContext *s,
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                        AVCodecContext *avctx,
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                        const uint8_t **poutbuf, int *poutbuf_size,
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                        const uint8_t *buf, int buf_size)
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{
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    DVDSubParseContext *pc = s->priv_data;
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    if (pc->packet_index == 0) {
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        if (buf_size < 2)
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            return 0;
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        pc->packet_len = AV_RB16(buf);
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        if (pc->packet_len == 0) /* HD-DVD subpicture packet */
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            pc->packet_len = AV_RB32(buf+2);
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        av_freep(&pc->packet);
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        pc->packet = av_malloc(pc->packet_len);
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    }
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    if (pc->packet) {
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        if (pc->packet_index + buf_size <= pc->packet_len) {
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            memcpy(pc->packet + pc->packet_index, buf, buf_size);
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            pc->packet_index += buf_size;
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            if (pc->packet_index >= pc->packet_len) {
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                *poutbuf = pc->packet;
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                *poutbuf_size = pc->packet_len;
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                pc->packet_index = 0;
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                return buf_size;
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            }
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        } else {
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            /* erroneous size */
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            pc->packet_index = 0;
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        }
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    }
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    *poutbuf = NULL;
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    *poutbuf_size = 0;
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    return buf_size;
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}
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static av_cold void dvdsub_parse_close(AVCodecParserContext *s)
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{
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    DVDSubParseContext *pc = s->priv_data;
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    av_freep(&pc->packet);
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}
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AVCodecParser ff_dvdsub_parser = {
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    { CODEC_ID_DVD_SUBTITLE },
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    sizeof(DVDSubParseContext),
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    dvdsub_parse_init,
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    dvdsub_parse,
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    dvdsub_parse_close,
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};