blob: 89d21b9c1fb25a1cc8be842a2d3d41a53c22abf1
| 1 | /* |
| 2 | * SCC subtitle demuxer |
| 3 | * Copyright (c) 2017 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/bprint.h" |
| 26 | #include "libavutil/intreadwrite.h" |
| 27 | |
| 28 | typedef struct SCCContext { |
| 29 | FFDemuxSubtitlesQueue q; |
| 30 | } SCCContext; |
| 31 | |
| 32 | static int scc_probe(AVProbeData *p) |
| 33 | { |
| 34 | char buf[18]; |
| 35 | FFTextReader tr; |
| 36 | |
| 37 | ff_text_init_buf(&tr, p->buf, p->buf_size); |
| 38 | |
| 39 | while (ff_text_peek_r8(&tr) == '\r' || ff_text_peek_r8(&tr) == '\n') |
| 40 | ff_text_r8(&tr); |
| 41 | |
| 42 | ff_text_read(&tr, buf, sizeof(buf)); |
| 43 | |
| 44 | if (!memcmp(buf, "Scenarist_SCC V1.0", 18)) |
| 45 | return AVPROBE_SCORE_MAX; |
| 46 | |
| 47 | return 0; |
| 48 | } |
| 49 | |
| 50 | static int convert(uint8_t x) |
| 51 | { |
| 52 | if (x >= 'a') |
| 53 | x -= 87; |
| 54 | else if (x >= 'A') |
| 55 | x -= 55; |
| 56 | else |
| 57 | x -= '0'; |
| 58 | return x; |
| 59 | } |
| 60 | |
| 61 | static int scc_read_header(AVFormatContext *s) |
| 62 | { |
| 63 | SCCContext *scc = s->priv_data; |
| 64 | AVStream *st = avformat_new_stream(s, NULL); |
| 65 | char line[4096], line2[4096]; |
| 66 | int count = 0, ret = 0; |
| 67 | ptrdiff_t len2, len; |
| 68 | uint8_t out[4096]; |
| 69 | FFTextReader tr; |
| 70 | |
| 71 | ff_text_init_avio(s, &tr, s->pb); |
| 72 | |
| 73 | if (!st) |
| 74 | return AVERROR(ENOMEM); |
| 75 | avpriv_set_pts_info(st, 64, 1, 1000); |
| 76 | st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE; |
| 77 | st->codecpar->codec_id = AV_CODEC_ID_EIA_608; |
| 78 | |
| 79 | while (!ff_text_eof(&tr)) { |
| 80 | const int64_t pos = ff_text_pos(&tr); |
| 81 | char *saveptr = NULL, *lline; |
| 82 | int hh1, mm1, ss1, fs1, i; |
| 83 | int hh2, mm2, ss2, fs2; |
| 84 | int64_t ts_start, ts_end; |
| 85 | AVPacket *sub; |
| 86 | |
| 87 | if (count == 0) { |
| 88 | while (!ff_text_eof(&tr)) { |
| 89 | len = ff_subtitles_read_line(&tr, line, sizeof(line)); |
| 90 | if (len > 13) |
| 91 | break; |
| 92 | } |
| 93 | } |
| 94 | |
| 95 | if (!strncmp(line, "Scenarist_SCC V1.0", 18)) |
| 96 | continue; |
| 97 | if (sscanf(line, "%d:%d:%d%*[:;]%d", &hh1, &mm1, &ss1, &fs1) != 4) |
| 98 | continue; |
| 99 | |
| 100 | ts_start = (hh1 * 3600LL + mm1 * 60LL + ss1) * 1000LL + fs1 * 33; |
| 101 | |
| 102 | while (!ff_text_eof(&tr)) { |
| 103 | len2 = ff_subtitles_read_line(&tr, line2, sizeof(line2)); |
| 104 | if (len2 > 13) |
| 105 | break; |
| 106 | } |
| 107 | if (sscanf(line2, "%d:%d:%d%*[:;]%d", &hh2, &mm2, &ss2, &fs2) != 4) |
| 108 | continue; |
| 109 | |
| 110 | ts_end = (hh2 * 3600LL + mm2 * 60LL + ss2) * 1000LL + fs2 * 33; |
| 111 | count++; |
| 112 | |
| 113 | lline = (char *)&line; |
| 114 | lline += 12; |
| 115 | |
| 116 | for (i = 0; i < 4095; i += 3) { |
| 117 | char *ptr = av_strtok(lline, " ", &saveptr); |
| 118 | char c1, c2, c3, c4; |
| 119 | |
| 120 | if (!ptr) |
| 121 | break; |
| 122 | |
| 123 | if (sscanf(ptr, "%c%c%c%c", &c1, &c2, &c3, &c4) != 4) |
| 124 | break; |
| 125 | |
| 126 | lline = NULL; |
| 127 | out[i+0] = 0xfc; |
| 128 | out[i+1] = convert(c2) | (convert(c1) << 4); |
| 129 | out[i+2] = convert(c4) | (convert(c3) << 4); |
| 130 | } |
| 131 | out[i] = 0; |
| 132 | |
| 133 | sub = ff_subtitles_queue_insert(&scc->q, out, i, 0); |
| 134 | if (!sub) |
| 135 | return AVERROR(ENOMEM); |
| 136 | |
| 137 | sub->pos = pos; |
| 138 | sub->pts = ts_start; |
| 139 | sub->duration = FFMAX(1200, ts_end - ts_start); |
| 140 | memmove(line, line2, sizeof(line)); |
| 141 | FFSWAP(ptrdiff_t, len, len2); |
| 142 | } |
| 143 | |
| 144 | ff_subtitles_queue_finalize(s, &scc->q); |
| 145 | |
| 146 | return ret; |
| 147 | } |
| 148 | |
| 149 | static int scc_read_packet(AVFormatContext *s, AVPacket *pkt) |
| 150 | { |
| 151 | SCCContext *scc = s->priv_data; |
| 152 | return ff_subtitles_queue_read_packet(&scc->q, pkt); |
| 153 | } |
| 154 | |
| 155 | static int scc_read_seek(AVFormatContext *s, int stream_index, |
| 156 | int64_t min_ts, int64_t ts, int64_t max_ts, int flags) |
| 157 | { |
| 158 | SCCContext *scc = s->priv_data; |
| 159 | return ff_subtitles_queue_seek(&scc->q, s, stream_index, |
| 160 | min_ts, ts, max_ts, flags); |
| 161 | } |
| 162 | |
| 163 | static int scc_read_close(AVFormatContext *s) |
| 164 | { |
| 165 | SCCContext *scc = s->priv_data; |
| 166 | ff_subtitles_queue_clean(&scc->q); |
| 167 | return 0; |
| 168 | } |
| 169 | |
| 170 | AVInputFormat ff_scc_demuxer = { |
| 171 | .name = "scc", |
| 172 | .long_name = NULL_IF_CONFIG_SMALL("Scenarist Closed Captions"), |
| 173 | .priv_data_size = sizeof(SCCContext), |
| 174 | .read_probe = scc_probe, |
| 175 | .read_header = scc_read_header, |
| 176 | .read_packet = scc_read_packet, |
| 177 | .read_seek2 = scc_read_seek, |
| 178 | .read_close = scc_read_close, |
| 179 | .extensions = "scc", |
| 180 | }; |
| 181 |