yading@10: /*
yading@10:  * DVD subtitle decoding
yading@10:  * Copyright (c) 2005 Fabrice Bellard
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: #include <string.h>
yading@10: 
yading@10: #include "libavutil/intreadwrite.h"
yading@10: #include "libavutil/mem.h"
yading@10: #include "avcodec.h"
yading@10: 
yading@10: /* parser definition */
yading@10: typedef struct DVDSubParseContext {
yading@10:     uint8_t *packet;
yading@10:     int packet_len;
yading@10:     int packet_index;
yading@10: } DVDSubParseContext;
yading@10: 
yading@10: static av_cold int dvdsub_parse_init(AVCodecParserContext *s)
yading@10: {
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int dvdsub_parse(AVCodecParserContext *s,
yading@10:                         AVCodecContext *avctx,
yading@10:                         const uint8_t **poutbuf, int *poutbuf_size,
yading@10:                         const uint8_t *buf, int buf_size)
yading@10: {
yading@10:     DVDSubParseContext *pc = s->priv_data;
yading@10: 
yading@10:     if (pc->packet_index == 0) {
yading@10:         if (buf_size < 2)
yading@10:             return 0;
yading@10:         pc->packet_len = AV_RB16(buf);
yading@10:         if (pc->packet_len == 0) /* HD-DVD subpicture packet */
yading@10:             pc->packet_len = AV_RB32(buf+2);
yading@10:         av_freep(&pc->packet);
yading@10:         pc->packet = av_malloc(pc->packet_len);
yading@10:     }
yading@10:     if (pc->packet) {
yading@10:         if (pc->packet_index + buf_size <= pc->packet_len) {
yading@10:             memcpy(pc->packet + pc->packet_index, buf, buf_size);
yading@10:             pc->packet_index += buf_size;
yading@10:             if (pc->packet_index >= pc->packet_len) {
yading@10:                 *poutbuf = pc->packet;
yading@10:                 *poutbuf_size = pc->packet_len;
yading@10:                 pc->packet_index = 0;
yading@10:                 return buf_size;
yading@10:             }
yading@10:         } else {
yading@10:             /* erroneous size */
yading@10:             pc->packet_index = 0;
yading@10:         }
yading@10:     }
yading@10:     *poutbuf = NULL;
yading@10:     *poutbuf_size = 0;
yading@10:     return buf_size;
yading@10: }
yading@10: 
yading@10: static av_cold void dvdsub_parse_close(AVCodecParserContext *s)
yading@10: {
yading@10:     DVDSubParseContext *pc = s->priv_data;
yading@10:     av_freep(&pc->packet);
yading@10: }
yading@10: 
yading@10: AVCodecParser ff_dvdsub_parser = {
yading@10:     .codec_ids      = { AV_CODEC_ID_DVD_SUBTITLE },
yading@10:     .priv_data_size = sizeof(DVDSubParseContext),
yading@10:     .parser_init    = dvdsub_parse_init,
yading@10:     .parser_parse   = dvdsub_parse,
yading@10:     .parser_close   = dvdsub_parse_close,
yading@10: };