1/* 2 * DVD subtitle decoding for ffmpeg 3 * Copyright (c) 2005 Fabrice Bellard 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22#include "libavutil/intreadwrite.h" 23#include "avcodec.h" 24 25/* parser definition */ 26typedef struct DVDSubParseContext { 27 uint8_t *packet; 28 int packet_len; 29 int packet_index; 30} DVDSubParseContext; 31 32static av_cold int dvdsub_parse_init(AVCodecParserContext *s) 33{ 34 return 0; 35} 36 37static int dvdsub_parse(AVCodecParserContext *s, 38 AVCodecContext *avctx, 39 const uint8_t **poutbuf, int *poutbuf_size, 40 const uint8_t *buf, int buf_size) 41{ 42 DVDSubParseContext *pc = s->priv_data; 43 44 if (pc->packet_index == 0) { 45 if (buf_size < 2) 46 return 0; 47 pc->packet_len = AV_RB16(buf); 48 if (pc->packet_len == 0) /* HD-DVD subpicture packet */ 49 pc->packet_len = AV_RB32(buf+2); 50 av_freep(&pc->packet); 51 pc->packet = av_malloc(pc->packet_len); 52 } 53 if (pc->packet) { 54 if (pc->packet_index + buf_size <= pc->packet_len) { 55 memcpy(pc->packet + pc->packet_index, buf, buf_size); 56 pc->packet_index += buf_size; 57 if (pc->packet_index >= pc->packet_len) { 58 *poutbuf = pc->packet; 59 *poutbuf_size = pc->packet_len; 60 pc->packet_index = 0; 61 return buf_size; 62 } 63 } else { 64 /* erroneous size */ 65 pc->packet_index = 0; 66 } 67 } 68 *poutbuf = NULL; 69 *poutbuf_size = 0; 70 return buf_size; 71} 72 73static av_cold void dvdsub_parse_close(AVCodecParserContext *s) 74{ 75 DVDSubParseContext *pc = s->priv_data; 76 av_freep(&pc->packet); 77} 78 79AVCodecParser dvdsub_parser = { 80 { CODEC_ID_DVD_SUBTITLE }, 81 sizeof(DVDSubParseContext), 82 dvdsub_parse_init, 83 dvdsub_parse, 84 dvdsub_parse_close, 85}; 86