1/* 2 * MCC subtitle demuxer 3 * Copyright (c) 2020 Paul B Mahol 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 "avformat.h" 23#include "internal.h" 24#include "subtitles.h" 25#include "libavutil/avstring.h" 26#include "libavutil/bprint.h" 27#include "libavutil/intreadwrite.h" 28 29typedef struct MCCContext { 30 FFDemuxSubtitlesQueue q; 31} MCCContext; 32 33static int mcc_probe(const AVProbeData *p) 34{ 35 char buf[28]; 36 FFTextReader tr; 37 38 ff_text_init_buf(&tr, p->buf, p->buf_size); 39 40 while (ff_text_peek_r8(&tr) == '\r' || ff_text_peek_r8(&tr) == '\n') 41 ff_text_r8(&tr); 42 43 ff_text_read(&tr, buf, sizeof(buf)); 44 45 if (!memcmp(buf, "File Format=MacCaption_MCC V", 28)) 46 return AVPROBE_SCORE_MAX; 47 48 return 0; 49} 50 51static int convert(uint8_t x) 52{ 53 if (x >= 'a') 54 x -= 87; 55 else if (x >= 'A') 56 x -= 55; 57 else 58 x -= '0'; 59 return x; 60} 61 62typedef struct alias { 63 uint8_t key; 64 int len; 65 const char *value; 66} alias; 67 68static const alias aliases[20] = { 69 { .key = 16, .len = 3, .value = "\xFA\x0\x0", }, 70 { .key = 17, .len = 6, .value = "\xFA\x0\x0\xFA\x0\x0", }, 71 { .key = 18, .len = 9, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", }, 72 { .key = 19, .len = 12, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", }, 73 { .key = 20, .len = 15, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", }, 74 { .key = 21, .len = 18, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", }, 75 { .key = 22, .len = 21, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", }, 76 { .key = 23, .len = 24, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", }, 77 { .key = 24, .len = 27, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", }, 78 { .key = 25, .len = 3, .value = "\xFB\x80\x80", }, 79 { .key = 26, .len = 3, .value = "\xFC\x80\x80", }, 80 { .key = 27, .len = 3, .value = "\xFD\x80\x80", }, 81 { .key = 28, .len = 2, .value = "\x96\x69", }, 82 { .key = 29, .len = 2, .value = "\x61\x01", }, 83 { .key = 30, .len = 3, .value = "\xFC\x80\x80", }, 84 { .key = 31, .len = 3, .value = "\xFC\x80\x80", }, 85 { .key = 32, .len = 4, .value = "\xE1\x00\x00\x00", }, 86 { .key = 33, .len = 0, .value = NULL, }, 87 { .key = 34, .len = 0, .value = NULL, }, 88 { .key = 35, .len = 1, .value = "\x0", }, 89}; 90 91static int mcc_read_header(AVFormatContext *s) 92{ 93 MCCContext *mcc = s->priv_data; 94 AVStream *st = avformat_new_stream(s, NULL); 95 AVRational rate; 96 int64_t ts, pos; 97 uint8_t out[4096]; 98 char line[4096]; 99 FFTextReader tr; 100 int ret = 0; 101 102 ff_text_init_avio(s, &tr, s->pb); 103 104 if (!st) 105 return AVERROR(ENOMEM); 106 st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE; 107 st->codecpar->codec_id = AV_CODEC_ID_EIA_608; 108 avpriv_set_pts_info(st, 64, 1, 30); 109 110 while (!ff_text_eof(&tr)) { 111 int hh, mm, ss, fs, i = 0, j = 0; 112 int start = 12, count = 0; 113 AVPacket *sub; 114 char *lline; 115 116 ff_subtitles_read_line(&tr, line, sizeof(line)); 117 if (!strncmp(line, "File Format=MacCaption_MCC V", 28)) 118 continue; 119 if (!strncmp(line, "//", 2)) 120 continue; 121 if (!strncmp(line, "Time Code Rate=", 15)) { 122 char *rate_str = line + 15; 123 char *df = NULL; 124 int num = -1, den = -1; 125 126 if (rate_str[0]) { 127 num = strtol(rate_str, &df, 10); 128 den = 1; 129 if (df && !av_strncasecmp(df, "DF", 2)) { 130 av_reduce(&num, &den, num * 1000LL, 1001, INT_MAX); 131 } 132 } 133 134 if (num > 0 && den > 0) { 135 rate = av_make_q(num, den); 136 avpriv_set_pts_info(st, 64, rate.den, rate.num); 137 } 138 continue; 139 } 140 141 if (av_sscanf(line, "%d:%d:%d:%d", &hh, &mm, &ss, &fs) != 4) 142 continue; 143 144 ts = av_sat_add64(av_rescale(hh * 3600LL + mm * 60LL + ss, rate.num, rate.den), fs); 145 146 lline = (char *)&line; 147 lline += 12; 148 pos = ff_text_pos(&tr); 149 150 while (lline[i]) { 151 uint8_t v = convert(lline[i]); 152 153 if (v >= 16 && v <= 35) { 154 int idx = v - 16; 155 if (aliases[idx].len) { 156 if (j >= sizeof(out) - 1 - aliases[idx].len) { 157 j = 0; 158 break; 159 } 160 memcpy(out + j, aliases[idx].value, aliases[idx].len); 161 j += aliases[idx].len; 162 } 163 } else { 164 uint8_t vv; 165 166 if (i + 13 >= sizeof(line) - 1) 167 break; 168 vv = convert(lline[i + 1]); 169 if (j >= sizeof(out) - 1) { 170 j = 0; 171 break; 172 } 173 out[j++] = vv | (v << 4); 174 i++; 175 } 176 177 i++; 178 } 179 out[j] = 0; 180 181 if (out[7] & 0x80) 182 start += 4; 183 count = (out[11] & 0x1f) * 3; 184 if (j < start + count + 1) 185 continue; 186 187 if (!count) 188 continue; 189 sub = ff_subtitles_queue_insert(&mcc->q, out + start, count, 0); 190 if (!sub) 191 return AVERROR(ENOMEM); 192 193 sub->pos = pos; 194 sub->pts = ts; 195 sub->duration = 1; 196 } 197 198 ff_subtitles_queue_finalize(s, &mcc->q); 199 200 return ret; 201} 202 203const AVInputFormat ff_mcc_demuxer = { 204 .name = "mcc", 205 .long_name = NULL_IF_CONFIG_SMALL("MacCaption"), 206 .priv_data_size = sizeof(MCCContext), 207 .flags_internal = FF_FMT_INIT_CLEANUP, 208 .read_probe = mcc_probe, 209 .read_header = mcc_read_header, 210 .extensions = "mcc", 211 .read_packet = ff_subtitles_read_packet, 212 .read_seek2 = ff_subtitles_read_seek, 213 .read_close = ff_subtitles_read_close, 214}; 215