yading@11: /*
yading@11:  * Metadata demuxer
yading@11:  * Copyright (c) 2010 Anton Khirnov
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include "libavutil/mathematics.h"
yading@11: #include "avformat.h"
yading@11: #include "ffmeta.h"
yading@11: #include "internal.h"
yading@11: #include "libavutil/dict.h"
yading@11: 
yading@11: static int probe(AVProbeData *p)
yading@11: {
yading@11:     if(!memcmp(p->buf, ID_STRING, strlen(ID_STRING)))
yading@11:         return AVPROBE_SCORE_MAX;
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static void get_line(AVIOContext *s, uint8_t *buf, int size)
yading@11: {
yading@11:     do {
yading@11:         uint8_t c;
yading@11:         int i = 0;
yading@11: 
yading@11:         while ((c = avio_r8(s))) {
yading@11:             if (c == '\\') {
yading@11:                 if (i < size - 1)
yading@11:                     buf[i++] = c;
yading@11:                 c = avio_r8(s);
yading@11:             } else if (c == '\n')
yading@11:                 break;
yading@11: 
yading@11:             if (i < size - 1)
yading@11:                 buf[i++] = c;
yading@11:         }
yading@11:         buf[i] = 0;
yading@11:     } while (!url_feof(s) && (buf[0] == ';' || buf[0] == '#' || buf[0] == 0));
yading@11: }
yading@11: 
yading@11: static AVChapter *read_chapter(AVFormatContext *s)
yading@11: {
yading@11:     uint8_t line[256];
yading@11:     int64_t start, end;
yading@11:     AVRational tb = {1, 1e9};
yading@11: 
yading@11:     get_line(s->pb, line, sizeof(line));
yading@11: 
yading@11:     if (sscanf(line, "TIMEBASE=%d/%d", &tb.num, &tb.den))
yading@11:         get_line(s->pb, line, sizeof(line));
yading@11:     if (!sscanf(line, "START=%"SCNd64, &start)) {
yading@11:         av_log(s, AV_LOG_ERROR, "Expected chapter start timestamp, found %s.\n", line);
yading@11:         start = (s->nb_chapters && s->chapters[s->nb_chapters - 1]->end != AV_NOPTS_VALUE) ?
yading@11:                  s->chapters[s->nb_chapters - 1]->end : 0;
yading@11:     } else
yading@11:         get_line(s->pb, line, sizeof(line));
yading@11: 
yading@11:     if (!sscanf(line, "END=%"SCNd64, &end)) {
yading@11:         av_log(s, AV_LOG_ERROR, "Expected chapter end timestamp, found %s.\n", line);
yading@11:         end = AV_NOPTS_VALUE;
yading@11:     }
yading@11: 
yading@11:     return avpriv_new_chapter(s, s->nb_chapters, tb, start, end, NULL);
yading@11: }
yading@11: 
yading@11: static uint8_t *unescape(uint8_t *buf, int size)
yading@11: {
yading@11:     uint8_t *ret = av_malloc(size + 1);
yading@11:     uint8_t *p1  = ret, *p2 = buf;
yading@11: 
yading@11:     if (!ret)
yading@11:         return NULL;
yading@11: 
yading@11:     while (p2 < buf + size) {
yading@11:         if (*p2 == '\\')
yading@11:             p2++;
yading@11:         *p1++ = *p2++;
yading@11:     }
yading@11:     *p1 = 0;
yading@11:     return ret;
yading@11: }
yading@11: 
yading@11: static int read_tag(uint8_t *line, AVDictionary **m)
yading@11: {
yading@11:     uint8_t *key, *value, *p = line;
yading@11: 
yading@11:     /* find first not escaped '=' */
yading@11:     while (1) {
yading@11:         if (*p == '=')
yading@11:             break;
yading@11:         else if (*p == '\\')
yading@11:             p++;
yading@11: 
yading@11:         if (*p++)
yading@11:             continue;
yading@11: 
yading@11:         return 0;
yading@11:     }
yading@11: 
yading@11:     if (!(key = unescape(line, p - line)))
yading@11:         return AVERROR(ENOMEM);
yading@11:     if (!(value = unescape(p + 1, strlen(p + 1)))) {
yading@11:         av_free(key);
yading@11:         return AVERROR(ENOMEM);
yading@11:     }
yading@11: 
yading@11:     av_dict_set(m, key, value, AV_DICT_DONT_STRDUP_KEY | AV_DICT_DONT_STRDUP_VAL);
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int read_header(AVFormatContext *s)
yading@11: {
yading@11:     AVDictionary **m = &s->metadata;
yading@11:     uint8_t line[1024];
yading@11: 
yading@11:     while(!url_feof(s->pb)) {
yading@11:         get_line(s->pb, line, sizeof(line));
yading@11: 
yading@11:         if (!memcmp(line, ID_STREAM, strlen(ID_STREAM))) {
yading@11:             AVStream *st = avformat_new_stream(s, NULL);
yading@11: 
yading@11:             if (!st)
yading@11:                 return -1;
yading@11: 
yading@11:             st->codec->codec_type = AVMEDIA_TYPE_DATA;
yading@11:             st->codec->codec_id   = AV_CODEC_ID_FFMETADATA;
yading@11: 
yading@11:             m = &st->metadata;
yading@11:         } else if (!memcmp(line, ID_CHAPTER, strlen(ID_CHAPTER))) {
yading@11:             AVChapter *ch = read_chapter(s);
yading@11: 
yading@11:             if (!ch)
yading@11:                 return -1;
yading@11: 
yading@11:             m = &ch->metadata;
yading@11:         } else
yading@11:             read_tag(line, m);
yading@11:     }
yading@11: 
yading@11:     s->start_time = 0;
yading@11:     if (s->nb_chapters)
yading@11:         s->duration = av_rescale_q(s->chapters[s->nb_chapters - 1]->end,
yading@11:                                    s->chapters[s->nb_chapters - 1]->time_base,
yading@11:                                    AV_TIME_BASE_Q);
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int read_packet(AVFormatContext *s, AVPacket *pkt)
yading@11: {
yading@11:     return AVERROR_EOF;
yading@11: }
yading@11: 
yading@11: AVInputFormat ff_ffmetadata_demuxer = {
yading@11:     .name        = "ffmetadata",
yading@11:     .long_name   = NULL_IF_CONFIG_SMALL("FFmpeg metadata in text"),
yading@11:     .read_probe  = probe,
yading@11:     .read_header = read_header,
yading@11:     .read_packet = read_packet,
yading@11: };