| 1 | /* |
| 2 | * MicroDVD subtitle demuxer |
| 3 | * Copyright (c) 2010 Aurelien Jacobs <aurel@gnuage.org> |
| 4 | * Copyright (c) 2012 Clément Bœsch <u pkh me> |
| 5 | * |
| 6 | * This file is part of FFmpeg. |
| 7 | * |
| 8 | * FFmpeg is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU Lesser General Public |
| 10 | * License as published by the Free Software Foundation; either |
| 11 | * version 2.1 of the License, or (at your option) any later version. |
| 12 | * |
| 13 | * FFmpeg is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 16 | * Lesser General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU Lesser General Public |
| 19 | * License along with FFmpeg; if not, write to the Free Software |
| 20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 21 | */ |
| 22 | |
| 23 | #include "avformat.h" |
| 24 | #include "internal.h" |
| 25 | #include "subtitles.h" |
| 26 | #include "libavutil/intreadwrite.h" |
| 27 | #include "libavutil/opt.h" |
| 28 | |
| 29 | #define MAX_LINESIZE 2048 |
| 30 | |
| 31 | |
| 32 | typedef struct { |
| 33 | const AVClass *class; |
| 34 | FFDemuxSubtitlesQueue q; |
| 35 | AVRational frame_rate; |
| 36 | } MicroDVDContext; |
| 37 | |
| 38 | |
| 39 | static int microdvd_probe(AVProbeData *p) |
| 40 | { |
| 41 | unsigned char c; |
| 42 | const uint8_t *ptr = p->buf; |
| 43 | int i; |
| 44 | |
| 45 | if (AV_RB24(ptr) == 0xEFBBBF) |
| 46 | ptr += 3; /* skip UTF-8 BOM */ |
| 47 | |
| 48 | for (i=0; i<3; i++) { |
| 49 | if (sscanf(ptr, "{%*d}{}%c", &c) != 1 && |
| 50 | sscanf(ptr, "{%*d}{%*d}%c", &c) != 1 && |
| 51 | sscanf(ptr, "{DEFAULT}{}%c", &c) != 1) |
| 52 | return 0; |
| 53 | ptr += ff_subtitles_next_line(ptr); |
| 54 | } |
| 55 | return AVPROBE_SCORE_MAX; |
| 56 | } |
| 57 | |
| 58 | static int64_t get_pts(const char *buf) |
| 59 | { |
| 60 | int frame; |
| 61 | char c; |
| 62 | |
| 63 | if (sscanf(buf, "{%d}{%c", &frame, &c) == 2) |
| 64 | return frame; |
| 65 | return AV_NOPTS_VALUE; |
| 66 | } |
| 67 | |
| 68 | static int get_duration(const char *buf) |
| 69 | { |
| 70 | int frame_start, frame_end; |
| 71 | |
| 72 | if (sscanf(buf, "{%d}{%d}", &frame_start, &frame_end) == 2) |
| 73 | return frame_end - frame_start; |
| 74 | return -1; |
| 75 | } |
| 76 | |
| 77 | static const char *bom = "\xEF\xBB\xBF"; |
| 78 | |
| 79 | static int microdvd_read_header(AVFormatContext *s) |
| 80 | { |
| 81 | AVRational pts_info = (AVRational){ 2997, 125 }; /* default: 23.976 fps */ |
| 82 | MicroDVDContext *microdvd = s->priv_data; |
| 83 | AVStream *st = avformat_new_stream(s, NULL); |
| 84 | int i = 0; |
| 85 | char line_buf[MAX_LINESIZE]; |
| 86 | int has_real_fps = 0; |
| 87 | |
| 88 | if (!st) |
| 89 | return AVERROR(ENOMEM); |
| 90 | |
| 91 | while (!avio_feof(s->pb)) { |
| 92 | char *p; |
| 93 | AVPacket *sub; |
| 94 | int64_t pos = avio_tell(s->pb); |
| 95 | int len = ff_get_line(s->pb, line_buf, sizeof(line_buf)); |
| 96 | char *line = line_buf; |
| 97 | |
| 98 | if (!strncmp(line, bom, 3)) |
| 99 | line += 3; |
| 100 | p = line; |
| 101 | |
| 102 | if (!len) |
| 103 | break; |
| 104 | line[strcspn(line, "\r\n")] = 0; |
| 105 | if (i++ < 3) { |
| 106 | int frame; |
| 107 | double fps; |
| 108 | char c; |
| 109 | |
| 110 | if ((sscanf(line, "{%d}{}%6lf", &frame, &fps) == 2 || |
| 111 | sscanf(line, "{%d}{%*d}%6lf", &frame, &fps) == 2) |
| 112 | && frame <= 1 && fps > 3 && fps < 100) { |
| 113 | pts_info = av_d2q(fps, 100000); |
| 114 | has_real_fps = 1; |
| 115 | } |
| 116 | if (!st->codec->extradata && sscanf(line, "{DEFAULT}{}%c", &c) == 1) { |
| 117 | st->codec->extradata = av_strdup(line + 11); |
| 118 | if (!st->codec->extradata) |
| 119 | return AVERROR(ENOMEM); |
| 120 | st->codec->extradata_size = strlen(st->codec->extradata) + 1; |
| 121 | continue; |
| 122 | } |
| 123 | } |
| 124 | #define SKIP_FRAME_ID \ |
| 125 | p = strchr(p, '}'); \ |
| 126 | if (!p) { \ |
| 127 | av_log(s, AV_LOG_WARNING, "Invalid event \"%s\"" \ |
| 128 | " at line %d\n", line, i); \ |
| 129 | continue; \ |
| 130 | } \ |
| 131 | p++ |
| 132 | SKIP_FRAME_ID; |
| 133 | SKIP_FRAME_ID; |
| 134 | if (!*p) |
| 135 | continue; |
| 136 | sub = ff_subtitles_queue_insert(µdvd->q, p, strlen(p), 0); |
| 137 | if (!sub) |
| 138 | return AVERROR(ENOMEM); |
| 139 | sub->pos = pos; |
| 140 | sub->pts = get_pts(line); |
| 141 | sub->duration = get_duration(line); |
| 142 | } |
| 143 | ff_subtitles_queue_finalize(µdvd->q); |
| 144 | if (has_real_fps) { |
| 145 | /* export the FPS info only if set in the file */ |
| 146 | microdvd->frame_rate = pts_info; |
| 147 | } else if (microdvd->frame_rate.num) { |
| 148 | /* fallback on user specified frame rate */ |
| 149 | pts_info = microdvd->frame_rate; |
| 150 | } |
| 151 | avpriv_set_pts_info(st, 64, pts_info.den, pts_info.num); |
| 152 | st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE; |
| 153 | st->codec->codec_id = AV_CODEC_ID_MICRODVD; |
| 154 | return 0; |
| 155 | } |
| 156 | |
| 157 | static int microdvd_read_packet(AVFormatContext *s, AVPacket *pkt) |
| 158 | { |
| 159 | MicroDVDContext *microdvd = s->priv_data; |
| 160 | return ff_subtitles_queue_read_packet(µdvd->q, pkt); |
| 161 | } |
| 162 | |
| 163 | static int microdvd_read_seek(AVFormatContext *s, int stream_index, |
| 164 | int64_t min_ts, int64_t ts, int64_t max_ts, int flags) |
| 165 | { |
| 166 | MicroDVDContext *microdvd = s->priv_data; |
| 167 | return ff_subtitles_queue_seek(µdvd->q, s, stream_index, |
| 168 | min_ts, ts, max_ts, flags); |
| 169 | } |
| 170 | |
| 171 | static int microdvd_read_close(AVFormatContext *s) |
| 172 | { |
| 173 | MicroDVDContext *microdvd = s->priv_data; |
| 174 | ff_subtitles_queue_clean(µdvd->q); |
| 175 | return 0; |
| 176 | } |
| 177 | |
| 178 | |
| 179 | #define OFFSET(x) offsetof(MicroDVDContext, x) |
| 180 | #define SD AV_OPT_FLAG_SUBTITLE_PARAM|AV_OPT_FLAG_DECODING_PARAM |
| 181 | static const AVOption microdvd_options[] = { |
| 182 | { "subfps", "set the movie frame rate fallback", OFFSET(frame_rate), AV_OPT_TYPE_RATIONAL, {.dbl=0}, 0, INT_MAX, SD }, |
| 183 | { NULL } |
| 184 | }; |
| 185 | |
| 186 | static const AVClass microdvd_class = { |
| 187 | .class_name = "microdvddec", |
| 188 | .item_name = av_default_item_name, |
| 189 | .option = microdvd_options, |
| 190 | .version = LIBAVUTIL_VERSION_INT, |
| 191 | }; |
| 192 | |
| 193 | AVInputFormat ff_microdvd_demuxer = { |
| 194 | .name = "microdvd", |
| 195 | .long_name = NULL_IF_CONFIG_SMALL("MicroDVD subtitle format"), |
| 196 | .priv_data_size = sizeof(MicroDVDContext), |
| 197 | .read_probe = microdvd_probe, |
| 198 | .read_header = microdvd_read_header, |
| 199 | .read_packet = microdvd_read_packet, |
| 200 | .read_seek2 = microdvd_read_seek, |
| 201 | .read_close = microdvd_read_close, |
| 202 | .priv_class = µdvd_class, |
| 203 | }; |