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