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libavcodec/dvdsub_parser.c

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00001 /*
00002  * DVD subtitle decoding for ffmpeg
00003  * Copyright (c) 2005 Fabrice Bellard
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include "libavutil/intreadwrite.h"
00023 #include "avcodec.h"
00024 
00025 /* parser definition */
00026 typedef struct DVDSubParseContext {
00027     uint8_t *packet;
00028     int packet_len;
00029     int packet_index;
00030 } DVDSubParseContext;
00031 
00032 static av_cold int dvdsub_parse_init(AVCodecParserContext *s)
00033 {
00034     return 0;
00035 }
00036 
00037 static int dvdsub_parse(AVCodecParserContext *s,
00038                         AVCodecContext *avctx,
00039                         const uint8_t **poutbuf, int *poutbuf_size,
00040                         const uint8_t *buf, int buf_size)
00041 {
00042     DVDSubParseContext *pc = s->priv_data;
00043 
00044     if (pc->packet_index == 0) {
00045         if (buf_size < 2)
00046             return 0;
00047         pc->packet_len = AV_RB16(buf);
00048         if (pc->packet_len == 0) /* HD-DVD subpicture packet */
00049             pc->packet_len = AV_RB32(buf+2);
00050         av_freep(&pc->packet);
00051         pc->packet = av_malloc(pc->packet_len);
00052     }
00053     if (pc->packet) {
00054         if (pc->packet_index + buf_size <= pc->packet_len) {
00055             memcpy(pc->packet + pc->packet_index, buf, buf_size);
00056             pc->packet_index += buf_size;
00057             if (pc->packet_index >= pc->packet_len) {
00058                 *poutbuf = pc->packet;
00059                 *poutbuf_size = pc->packet_len;
00060                 pc->packet_index = 0;
00061                 return buf_size;
00062             }
00063         } else {
00064             /* erroneous size */
00065             pc->packet_index = 0;
00066         }
00067     }
00068     *poutbuf = NULL;
00069     *poutbuf_size = 0;
00070     return buf_size;
00071 }
00072 
00073 static av_cold void dvdsub_parse_close(AVCodecParserContext *s)
00074 {
00075     DVDSubParseContext *pc = s->priv_data;
00076     av_freep(&pc->packet);
00077 }
00078 
00079 AVCodecParser dvdsub_parser = {
00080     { CODEC_ID_DVD_SUBTITLE },
00081     sizeof(DVDSubParseContext),
00082     dvdsub_parse_init,
00083     dvdsub_parse,
00084     dvdsub_parse_close,
00085 };

Generated on Fri Sep 16 2011 17:17:35 for FFmpeg by  doxygen 1.7.1