| 1 | /* |
| 2 | * DVD subtitle decoding |
| 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 <string.h> |
| 23 | |
| 24 | #include "libavutil/intreadwrite.h" |
| 25 | #include "libavutil/mem.h" |
| 26 | #include "avcodec.h" |
| 27 | |
| 28 | /* parser definition */ |
| 29 | typedef struct DVDSubParseContext { |
| 30 | uint8_t *packet; |
| 31 | int packet_len; |
| 32 | int packet_index; |
| 33 | } DVDSubParseContext; |
| 34 | |
| 35 | static av_cold int dvdsub_parse_init(AVCodecParserContext *s) |
| 36 | { |
| 37 | return 0; |
| 38 | } |
| 39 | |
| 40 | static int dvdsub_parse(AVCodecParserContext *s, |
| 41 | AVCodecContext *avctx, |
| 42 | const uint8_t **poutbuf, int *poutbuf_size, |
| 43 | const uint8_t *buf, int buf_size) |
| 44 | { |
| 45 | DVDSubParseContext *pc = s->priv_data; |
| 46 | |
| 47 | if (pc->packet_index == 0) { |
| 48 | if (buf_size < 2 || AV_RB16(buf) && buf_size < 6) { |
| 49 | if (buf_size) |
| 50 | av_log(avctx, AV_LOG_DEBUG, "Parser input %d too small\n", buf_size); |
| 51 | return buf_size; |
| 52 | } |
| 53 | pc->packet_len = AV_RB16(buf); |
| 54 | if (pc->packet_len == 0) /* HD-DVD subpicture packet */ |
| 55 | pc->packet_len = AV_RB32(buf+2); |
| 56 | av_freep(&pc->packet); |
| 57 | pc->packet = av_malloc(pc->packet_len); |
| 58 | } |
| 59 | if (pc->packet) { |
| 60 | if (pc->packet_index + buf_size <= pc->packet_len) { |
| 61 | memcpy(pc->packet + pc->packet_index, buf, buf_size); |
| 62 | pc->packet_index += buf_size; |
| 63 | if (pc->packet_index >= pc->packet_len) { |
| 64 | *poutbuf = pc->packet; |
| 65 | *poutbuf_size = pc->packet_len; |
| 66 | pc->packet_index = 0; |
| 67 | return buf_size; |
| 68 | } |
| 69 | } else { |
| 70 | /* erroneous size */ |
| 71 | pc->packet_index = 0; |
| 72 | } |
| 73 | } |
| 74 | *poutbuf = NULL; |
| 75 | *poutbuf_size = 0; |
| 76 | return buf_size; |
| 77 | } |
| 78 | |
| 79 | static av_cold void dvdsub_parse_close(AVCodecParserContext *s) |
| 80 | { |
| 81 | DVDSubParseContext *pc = s->priv_data; |
| 82 | av_freep(&pc->packet); |
| 83 | } |
| 84 | |
| 85 | AVCodecParser ff_dvdsub_parser = { |
| 86 | .codec_ids = { AV_CODEC_ID_DVD_SUBTITLE }, |
| 87 | .priv_data_size = sizeof(DVDSubParseContext), |
| 88 | .parser_init = dvdsub_parse_init, |
| 89 | .parser_parse = dvdsub_parse, |
| 90 | .parser_close = dvdsub_parse_close, |
| 91 | }; |