Libav 0.7.1
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00001 /* 00002 * Metadata demuxer 00003 * Copyright (c) 2010 Anton Khirnov 00004 * 00005 * This file is part of Libav. 00006 * 00007 * Libav is free software; you can redistribute it and/or 00008 * modify it under the terms of the GNU Lesser General Public 00009 * License as published by the Free Software Foundation; either 00010 * version 2.1 of the License, or (at your option) any later version. 00011 * 00012 * Libav is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00015 * Lesser General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU Lesser General Public 00018 * License along with Libav; if not, write to the Free Software 00019 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00020 */ 00021 00022 #include "avformat.h" 00023 #include "ffmeta.h" 00024 #include "internal.h" 00025 #include "libavutil/dict.h" 00026 00027 static int probe(AVProbeData *p) 00028 { 00029 if(!memcmp(p->buf, ID_STRING, strlen(ID_STRING))) 00030 return AVPROBE_SCORE_MAX; 00031 return 0; 00032 } 00033 00034 static void get_line(AVIOContext *s, uint8_t *buf, int size) 00035 { 00036 do { 00037 uint8_t c; 00038 int i = 0; 00039 00040 while ((c = avio_r8(s))) { 00041 if (c == '\\') { 00042 if (i < size - 1) 00043 buf[i++] = c; 00044 c = avio_r8(s); 00045 } else if (c == '\n') 00046 break; 00047 00048 if (i < size - 1) 00049 buf[i++] = c; 00050 } 00051 buf[i] = 0; 00052 } while (!s->eof_reached && (buf[0] == ';' || buf[0] == '#' || buf[0] == 0)); 00053 } 00054 00055 static AVChapter *read_chapter(AVFormatContext *s) 00056 { 00057 uint8_t line[256]; 00058 int64_t start, end; 00059 AVRational tb = {1, 1e9}; 00060 00061 get_line(s->pb, line, sizeof(line)); 00062 00063 if (sscanf(line, "TIMEBASE=%d/%d", &tb.num, &tb.den)) 00064 get_line(s->pb, line, sizeof(line)); 00065 if (!sscanf(line, "START=%"SCNd64, &start)) { 00066 av_log(s, AV_LOG_ERROR, "Expected chapter start timestamp, found %s.\n", line); 00067 start = (s->nb_chapters && s->chapters[s->nb_chapters - 1]->end != AV_NOPTS_VALUE) ? 00068 s->chapters[s->nb_chapters - 1]->end : 0; 00069 } else 00070 get_line(s->pb, line, sizeof(line)); 00071 00072 if (!sscanf(line, "END=%"SCNd64, &end)) { 00073 av_log(s, AV_LOG_ERROR, "Expected chapter end timestamp, found %s.\n", line); 00074 end = AV_NOPTS_VALUE; 00075 } 00076 00077 return ff_new_chapter(s, s->nb_chapters, tb, start, end, NULL); 00078 } 00079 00080 static uint8_t *unescape(uint8_t *buf, int size) 00081 { 00082 uint8_t *ret = av_malloc(size + 1); 00083 uint8_t *p1 = ret, *p2 = buf; 00084 00085 if (!ret) 00086 return NULL; 00087 00088 while (p2 < buf + size) { 00089 if (*p2 == '\\') 00090 p2++; 00091 *p1++ = *p2++; 00092 } 00093 *p1 = 0; 00094 return ret; 00095 } 00096 00097 static int read_tag(uint8_t *line, AVDictionary **m) 00098 { 00099 uint8_t *key, *value, *p = line; 00100 00101 /* find first not escaped '=' */ 00102 while (1) { 00103 if (*p == '=') 00104 break; 00105 else if (*p == '\\') 00106 p++; 00107 00108 if (*p++) 00109 continue; 00110 00111 return 0; 00112 } 00113 00114 if (!(key = unescape(line, p - line))) 00115 return AVERROR(ENOMEM); 00116 if (!(value = unescape(p + 1, strlen(p + 1)))) { 00117 av_free(key); 00118 return AVERROR(ENOMEM); 00119 } 00120 00121 av_dict_set(m, key, value, AV_DICT_DONT_STRDUP_KEY | AV_DICT_DONT_STRDUP_VAL); 00122 return 0; 00123 } 00124 00125 static int read_header(AVFormatContext *s, AVFormatParameters *ap) 00126 { 00127 AVDictionary **m = &s->metadata; 00128 uint8_t line[1024]; 00129 00130 while(!s->pb->eof_reached) { 00131 get_line(s->pb, line, sizeof(line)); 00132 00133 if (!memcmp(line, ID_STREAM, strlen(ID_STREAM))) { 00134 AVStream *st = av_new_stream(s, 0); 00135 00136 if (!st) 00137 return -1; 00138 00139 st->codec->codec_type = AVMEDIA_TYPE_DATA; 00140 st->codec->codec_id = CODEC_ID_FFMETADATA; 00141 00142 m = &st->metadata; 00143 } else if (!memcmp(line, ID_CHAPTER, strlen(ID_CHAPTER))) { 00144 AVChapter *ch = read_chapter(s); 00145 00146 if (!ch) 00147 return -1; 00148 00149 m = &ch->metadata; 00150 } else 00151 read_tag(line, m); 00152 } 00153 00154 s->start_time = 0; 00155 if (s->nb_chapters) 00156 s->duration = av_rescale_q(s->chapters[s->nb_chapters - 1]->end, 00157 s->chapters[s->nb_chapters - 1]->time_base, 00158 AV_TIME_BASE_Q); 00159 00160 return 0; 00161 } 00162 00163 static int read_packet(AVFormatContext *s, AVPacket *pkt) 00164 { 00165 return AVERROR_EOF; 00166 } 00167 00168 AVInputFormat ff_ffmetadata_demuxer = { 00169 .name = "ffmetadata", 00170 .long_name = NULL_IF_CONFIG_SMALL("FFmpeg metadata in text format"), 00171 .read_probe = probe, 00172 .read_header = read_header, 00173 .read_packet = read_packet, 00174 };