| 1 | /* |
| 2 | * DVB subtitle parser for FFmpeg |
| 3 | * Copyright (c) 2005 Ian Caulfield |
| 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 | #include "avcodec.h" |
| 22 | #include "get_bits.h" |
| 23 | |
| 24 | /* Parser (mostly) copied from dvdsub.c */ |
| 25 | |
| 26 | #define PARSE_BUF_SIZE (65536) |
| 27 | |
| 28 | |
| 29 | /* parser definition */ |
| 30 | typedef struct DVBSubParseContext { |
| 31 | uint8_t *packet_buf; |
| 32 | int packet_start; |
| 33 | int packet_index; |
| 34 | int in_packet; |
| 35 | } DVBSubParseContext; |
| 36 | |
| 37 | static av_cold int dvbsub_parse_init(AVCodecParserContext *s) |
| 38 | { |
| 39 | DVBSubParseContext *pc = s->priv_data; |
| 40 | pc->packet_buf = av_malloc(PARSE_BUF_SIZE); |
| 41 | |
| 42 | return 0; |
| 43 | } |
| 44 | |
| 45 | static int dvbsub_parse(AVCodecParserContext *s, |
| 46 | AVCodecContext *avctx, |
| 47 | const uint8_t **poutbuf, int *poutbuf_size, |
| 48 | const uint8_t *buf, int buf_size) |
| 49 | { |
| 50 | DVBSubParseContext *pc = s->priv_data; |
| 51 | uint8_t *p, *p_end; |
| 52 | int i, len, buf_pos = 0; |
| 53 | |
| 54 | av_dlog(avctx, "DVB parse packet pts=%"PRIx64", lpts=%"PRIx64", cpts=%"PRIx64":\n", |
| 55 | s->pts, s->last_pts, s->cur_frame_pts[s->cur_frame_start_index]); |
| 56 | |
| 57 | for (i=0; i < buf_size; i++) |
| 58 | { |
| 59 | av_dlog(avctx, "%02x ", buf[i]); |
| 60 | if (i % 16 == 15) |
| 61 | av_dlog(avctx, "\n"); |
| 62 | } |
| 63 | |
| 64 | if (i % 16 != 0) |
| 65 | av_dlog(avctx, "\n"); |
| 66 | |
| 67 | *poutbuf = NULL; |
| 68 | *poutbuf_size = 0; |
| 69 | |
| 70 | s->fetch_timestamp = 1; |
| 71 | |
| 72 | if (s->last_pts != s->pts && s->pts != AV_NOPTS_VALUE) /* Start of a new packet */ |
| 73 | { |
| 74 | if (pc->packet_index != pc->packet_start) |
| 75 | { |
| 76 | av_dlog(avctx, "Discarding %d bytes\n", |
| 77 | pc->packet_index - pc->packet_start); |
| 78 | } |
| 79 | |
| 80 | pc->packet_start = 0; |
| 81 | pc->packet_index = 0; |
| 82 | |
| 83 | if (buf_size < 2 || buf[0] != 0x20 || buf[1] != 0x00) { |
| 84 | av_dlog(avctx, "Bad packet header\n"); |
| 85 | return -1; |
| 86 | } |
| 87 | |
| 88 | buf_pos = 2; |
| 89 | |
| 90 | pc->in_packet = 1; |
| 91 | } else { |
| 92 | if (pc->packet_start != 0) |
| 93 | { |
| 94 | if (pc->packet_index != pc->packet_start) |
| 95 | { |
| 96 | memmove(pc->packet_buf, pc->packet_buf + pc->packet_start, |
| 97 | pc->packet_index - pc->packet_start); |
| 98 | |
| 99 | pc->packet_index -= pc->packet_start; |
| 100 | pc->packet_start = 0; |
| 101 | } else { |
| 102 | pc->packet_start = 0; |
| 103 | pc->packet_index = 0; |
| 104 | } |
| 105 | } |
| 106 | } |
| 107 | |
| 108 | if (buf_size - buf_pos + pc->packet_index > PARSE_BUF_SIZE) |
| 109 | return -1; |
| 110 | |
| 111 | /* if not currently in a packet, discard data */ |
| 112 | if (pc->in_packet == 0) |
| 113 | return buf_size; |
| 114 | |
| 115 | memcpy(pc->packet_buf + pc->packet_index, buf + buf_pos, buf_size - buf_pos); |
| 116 | pc->packet_index += buf_size - buf_pos; |
| 117 | |
| 118 | p = pc->packet_buf; |
| 119 | p_end = pc->packet_buf + pc->packet_index; |
| 120 | |
| 121 | while (p < p_end) |
| 122 | { |
| 123 | if (*p == 0x0f) |
| 124 | { |
| 125 | if (p + 6 <= p_end) |
| 126 | { |
| 127 | len = AV_RB16(p + 4); |
| 128 | |
| 129 | if (p + len + 6 <= p_end) |
| 130 | { |
| 131 | *poutbuf_size += len + 6; |
| 132 | |
| 133 | p += len + 6; |
| 134 | } else |
| 135 | break; |
| 136 | } else |
| 137 | break; |
| 138 | } else if (*p == 0xff) { |
| 139 | if (p + 1 < p_end) |
| 140 | { |
| 141 | av_dlog(avctx, "Junk at end of packet\n"); |
| 142 | } |
| 143 | pc->packet_index = p - pc->packet_buf; |
| 144 | pc->in_packet = 0; |
| 145 | break; |
| 146 | } else { |
| 147 | av_log(avctx, AV_LOG_ERROR, "Junk in packet\n"); |
| 148 | |
| 149 | pc->packet_index = p - pc->packet_buf; |
| 150 | pc->in_packet = 0; |
| 151 | break; |
| 152 | } |
| 153 | } |
| 154 | |
| 155 | if (*poutbuf_size > 0) |
| 156 | { |
| 157 | *poutbuf = pc->packet_buf; |
| 158 | pc->packet_start = *poutbuf_size; |
| 159 | } |
| 160 | |
| 161 | if (s->pts == AV_NOPTS_VALUE) |
| 162 | s->pts = s->last_pts; |
| 163 | |
| 164 | return buf_size; |
| 165 | } |
| 166 | |
| 167 | static av_cold void dvbsub_parse_close(AVCodecParserContext *s) |
| 168 | { |
| 169 | DVBSubParseContext *pc = s->priv_data; |
| 170 | av_freep(&pc->packet_buf); |
| 171 | } |
| 172 | |
| 173 | AVCodecParser ff_dvbsub_parser = { |
| 174 | .codec_ids = { AV_CODEC_ID_DVB_SUBTITLE }, |
| 175 | .priv_data_size = sizeof(DVBSubParseContext), |
| 176 | .parser_init = dvbsub_parse_init, |
| 177 | .parser_parse = dvbsub_parse, |
| 178 | .parser_close = dvbsub_parse_close, |
| 179 | }; |