/* * MCC subtitle demuxer * Copyright (c) 2020 Paul B Mahol * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "avformat.h" #include "demux.h" #include "internal.h" #include "subtitles.h" #include "libavutil/avstring.h" #include "libavutil/bprint.h" #include "libavutil/intreadwrite.h" typedef struct MCCContext { FFDemuxSubtitlesQueue q; } MCCContext; static int mcc_probe(const AVProbeData *p) { char buf[28]; FFTextReader tr; ff_text_init_buf(&tr, p->buf, p->buf_size); while (ff_text_peek_r8(&tr) == '\r' || ff_text_peek_r8(&tr) == '\n') ff_text_r8(&tr); ff_text_read(&tr, buf, sizeof(buf)); if (!memcmp(buf, "File Format=MacCaption_MCC V", 28)) return AVPROBE_SCORE_MAX; return 0; } static int convert(uint8_t x) { if (x >= 'a') x -= 87; else if (x >= 'A') x -= 55; else x -= '0'; return x; } typedef struct alias { uint8_t key; int len; const char *value; } alias; static const alias aliases[20] = { { .key = 16, .len = 3, .value = "\xFA\x0\x0", }, { .key = 17, .len = 6, .value = "\xFA\x0\x0\xFA\x0\x0", }, { .key = 18, .len = 9, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", }, { .key = 19, .len = 12, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", }, { .key = 20, .len = 15, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", }, { .key = 21, .len = 18, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", }, { .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", }, { .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", }, { .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", }, { .key = 25, .len = 3, .value = "\xFB\x80\x80", }, { .key = 26, .len = 3, .value = "\xFC\x80\x80", }, { .key = 27, .len = 3, .value = "\xFD\x80\x80", }, { .key = 28, .len = 2, .value = "\x96\x69", }, { .key = 29, .len = 2, .value = "\x61\x01", }, { .key = 30, .len = 3, .value = "\xFC\x80\x80", }, { .key = 31, .len = 3, .value = "\xFC\x80\x80", }, { .key = 32, .len = 4, .value = "\xE1\x00\x00\x00", }, { .key = 33, .len = 0, .value = NULL, }, { .key = 34, .len = 0, .value = NULL, }, { .key = 35, .len = 1, .value = "\x0", }, }; static int mcc_read_header(AVFormatContext *s) { MCCContext *mcc = s->priv_data; AVStream *st = avformat_new_stream(s, NULL); AVRational rate = {0}; int64_t ts, pos; uint8_t out[4096]; char line[4096]; FFTextReader tr; int ret = 0; ff_text_init_avio(s, &tr, s->pb); if (!st) return AVERROR(ENOMEM); st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE; st->codecpar->codec_id = AV_CODEC_ID_EIA_608; avpriv_set_pts_info(st, 64, 1, 30); while (!ff_text_eof(&tr)) { int hh, mm, ss, fs, i = 0, j = 0; int start = 12, count = 0; AVPacket *sub; char *lline; ff_subtitles_read_line(&tr, line, sizeof(line)); if (!strncmp(line, "File Format=MacCaption_MCC V", 28)) continue; if (!strncmp(line, "//", 2)) continue; if (!strncmp(line, "Time Code Rate=", 15)) { char *rate_str = line + 15; char *df = NULL; int num = -1, den = -1; if (rate_str[0]) { num = strtol(rate_str, &df, 10); den = 1; if (df && !av_strncasecmp(df, "DF", 2)) { av_reduce(&num, &den, num * 1000LL, 1001, INT_MAX); } } if (num > 0 && den > 0) { rate = av_make_q(num, den); avpriv_set_pts_info(st, 64, rate.den, rate.num); } continue; } if (av_sscanf(line, "%d:%d:%d:%d", &hh, &mm, &ss, &fs) != 4 || rate.den <= 0) continue; ts = av_sat_add64(av_rescale(hh * 3600LL + mm * 60LL + ss, rate.num, rate.den), fs); lline = (char *)&line; lline += 12; pos = ff_text_pos(&tr); while (lline[i]) { uint8_t v = convert(lline[i]); if (v >= 16 && v <= 35) { int idx = v - 16; if (aliases[idx].len) { if (j >= sizeof(out) - 1 - aliases[idx].len) { j = 0; break; } memcpy(out + j, aliases[idx].value, aliases[idx].len); j += aliases[idx].len; } } else { uint8_t vv; if (i + 13 >= sizeof(line) - 1) break; vv = convert(lline[i + 1]); if (j >= sizeof(out) - 1) { j = 0; break; } out[j++] = vv | (v << 4); i++; } i++; } out[j] = 0; if (out[7] & 0x80) start += 4; count = (out[11] & 0x1f) * 3; if (j < start + count + 1) continue; if (!count) continue; sub = ff_subtitles_queue_insert(&mcc->q, out + start, count, 0); if (!sub) return AVERROR(ENOMEM); sub->pos = pos; sub->pts = ts; sub->duration = 1; } ff_subtitles_queue_finalize(s, &mcc->q); return ret; } const FFInputFormat ff_mcc_demuxer = { .p.name = "mcc", .p.long_name = NULL_IF_CONFIG_SMALL("MacCaption"), .p.extensions = "mcc", .priv_data_size = sizeof(MCCContext), .flags_internal = FF_INFMT_FLAG_INIT_CLEANUP, .read_probe = mcc_probe, .read_header = mcc_read_header, .read_packet = ff_subtitles_read_packet, .read_seek2 = ff_subtitles_read_seek, .read_close = ff_subtitles_read_close, };