| 1 | /* |
| 2 | * Metadata demuxer |
| 3 | * Copyright (c) 2010 Anton Khirnov |
| 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 "libavutil/mathematics.h" |
| 23 | #include "avformat.h" |
| 24 | #include "ffmeta.h" |
| 25 | #include "internal.h" |
| 26 | #include "libavutil/dict.h" |
| 27 | |
| 28 | static int probe(AVProbeData *p) |
| 29 | { |
| 30 | if(!memcmp(p->buf, ID_STRING, strlen(ID_STRING))) |
| 31 | return AVPROBE_SCORE_MAX; |
| 32 | return 0; |
| 33 | } |
| 34 | |
| 35 | static void get_line(AVIOContext *s, uint8_t *buf, int size) |
| 36 | { |
| 37 | do { |
| 38 | uint8_t c; |
| 39 | int i = 0; |
| 40 | |
| 41 | while ((c = avio_r8(s))) { |
| 42 | if (c == '\\') { |
| 43 | if (i < size - 1) |
| 44 | buf[i++] = c; |
| 45 | c = avio_r8(s); |
| 46 | } else if (c == '\n') |
| 47 | break; |
| 48 | |
| 49 | if (i < size - 1) |
| 50 | buf[i++] = c; |
| 51 | } |
| 52 | buf[i] = 0; |
| 53 | } while (!avio_feof(s) && (buf[0] == ';' || buf[0] == '#' || buf[0] == 0)); |
| 54 | } |
| 55 | |
| 56 | static AVChapter *read_chapter(AVFormatContext *s) |
| 57 | { |
| 58 | uint8_t line[256]; |
| 59 | int64_t start, end; |
| 60 | AVRational tb = {1, 1e9}; |
| 61 | |
| 62 | get_line(s->pb, line, sizeof(line)); |
| 63 | |
| 64 | if (sscanf(line, "TIMEBASE=%d/%d", &tb.num, &tb.den)) |
| 65 | get_line(s->pb, line, sizeof(line)); |
| 66 | if (!sscanf(line, "START=%"SCNd64, &start)) { |
| 67 | av_log(s, AV_LOG_ERROR, "Expected chapter start timestamp, found %s.\n", line); |
| 68 | start = (s->nb_chapters && s->chapters[s->nb_chapters - 1]->end != AV_NOPTS_VALUE) ? |
| 69 | s->chapters[s->nb_chapters - 1]->end : 0; |
| 70 | } else |
| 71 | get_line(s->pb, line, sizeof(line)); |
| 72 | |
| 73 | if (!sscanf(line, "END=%"SCNd64, &end)) { |
| 74 | av_log(s, AV_LOG_ERROR, "Expected chapter end timestamp, found %s.\n", line); |
| 75 | end = AV_NOPTS_VALUE; |
| 76 | } |
| 77 | |
| 78 | return avpriv_new_chapter(s, s->nb_chapters, tb, start, end, NULL); |
| 79 | } |
| 80 | |
| 81 | static uint8_t *unescape(uint8_t *buf, int size) |
| 82 | { |
| 83 | uint8_t *ret = av_malloc(size + 1); |
| 84 | uint8_t *p1 = ret, *p2 = buf; |
| 85 | |
| 86 | if (!ret) |
| 87 | return NULL; |
| 88 | |
| 89 | while (p2 < buf + size) { |
| 90 | if (*p2 == '\\') |
| 91 | p2++; |
| 92 | *p1++ = *p2++; |
| 93 | } |
| 94 | *p1 = 0; |
| 95 | return ret; |
| 96 | } |
| 97 | |
| 98 | static int read_tag(uint8_t *line, AVDictionary **m) |
| 99 | { |
| 100 | uint8_t *key, *value, *p = line; |
| 101 | |
| 102 | /* find first not escaped '=' */ |
| 103 | while (1) { |
| 104 | if (*p == '=') |
| 105 | break; |
| 106 | else if (*p == '\\') |
| 107 | p++; |
| 108 | |
| 109 | if (*p++) |
| 110 | continue; |
| 111 | |
| 112 | return 0; |
| 113 | } |
| 114 | |
| 115 | if (!(key = unescape(line, p - line))) |
| 116 | return AVERROR(ENOMEM); |
| 117 | if (!(value = unescape(p + 1, strlen(p + 1)))) { |
| 118 | av_free(key); |
| 119 | return AVERROR(ENOMEM); |
| 120 | } |
| 121 | |
| 122 | av_dict_set(m, key, value, AV_DICT_DONT_STRDUP_KEY | AV_DICT_DONT_STRDUP_VAL); |
| 123 | return 0; |
| 124 | } |
| 125 | |
| 126 | static int read_header(AVFormatContext *s) |
| 127 | { |
| 128 | AVDictionary **m = &s->metadata; |
| 129 | uint8_t line[1024]; |
| 130 | |
| 131 | while(!avio_feof(s->pb)) { |
| 132 | get_line(s->pb, line, sizeof(line)); |
| 133 | |
| 134 | if (!memcmp(line, ID_STREAM, strlen(ID_STREAM))) { |
| 135 | AVStream *st = avformat_new_stream(s, NULL); |
| 136 | |
| 137 | if (!st) |
| 138 | return AVERROR(ENOMEM); |
| 139 | |
| 140 | st->codec->codec_type = AVMEDIA_TYPE_DATA; |
| 141 | st->codec->codec_id = AV_CODEC_ID_FFMETADATA; |
| 142 | |
| 143 | m = &st->metadata; |
| 144 | } else if (!memcmp(line, ID_CHAPTER, strlen(ID_CHAPTER))) { |
| 145 | AVChapter *ch = read_chapter(s); |
| 146 | |
| 147 | if (!ch) |
| 148 | return AVERROR(ENOMEM); |
| 149 | |
| 150 | m = &ch->metadata; |
| 151 | } else |
| 152 | read_tag(line, m); |
| 153 | } |
| 154 | |
| 155 | s->start_time = 0; |
| 156 | if (s->nb_chapters) |
| 157 | s->duration = av_rescale_q(s->chapters[s->nb_chapters - 1]->end, |
| 158 | s->chapters[s->nb_chapters - 1]->time_base, |
| 159 | AV_TIME_BASE_Q); |
| 160 | |
| 161 | return 0; |
| 162 | } |
| 163 | |
| 164 | static int read_packet(AVFormatContext *s, AVPacket *pkt) |
| 165 | { |
| 166 | return AVERROR_EOF; |
| 167 | } |
| 168 | |
| 169 | AVInputFormat ff_ffmetadata_demuxer = { |
| 170 | .name = "ffmetadata", |
| 171 | .long_name = NULL_IF_CONFIG_SMALL("FFmpeg metadata in text"), |
| 172 | .read_probe = probe, |
| 173 | .read_header = read_header, |
| 174 | .read_packet = read_packet, |
| 175 | }; |