mirror of
https://git.videolan.org/git/ffmpeg.git
synced 2024-08-30 21:26:13 +02:00
250 lines
7.3 KiB
C
250 lines
7.3 KiB
C
/*
|
|
* LRC lyrics file format decoder
|
|
* Copyright (c) 2014 StarBrilliant <m13253@hotmail.com>
|
|
*
|
|
* 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 <inttypes.h>
|
|
#include <stdint.h>
|
|
#include <string.h>
|
|
|
|
#include "avformat.h"
|
|
#include "internal.h"
|
|
#include "lrc.h"
|
|
#include "metadata.h"
|
|
#include "subtitles.h"
|
|
#include "libavutil/bprint.h"
|
|
#include "libavutil/dict.h"
|
|
|
|
typedef struct LRCContext {
|
|
FFDemuxSubtitlesQueue q;
|
|
int64_t ts_offset; // offset metadata item
|
|
} LRCContext;
|
|
|
|
static int64_t find_header(const char *p)
|
|
{
|
|
int64_t offset = 0;
|
|
while(p[offset] == ' ' || p[offset] == '\t') {
|
|
offset++;
|
|
}
|
|
if(p[offset] == '[' && p[offset + 1] >= 'a' && p[offset + 1] <= 'z') {
|
|
return offset;
|
|
} else {
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
static int64_t count_ts(const char *p)
|
|
{
|
|
int64_t offset = 0;
|
|
int in_brackets = 0;
|
|
|
|
for(;;) {
|
|
if(p[offset] == ' ' || p[offset] == '\t') {
|
|
offset++;
|
|
} else if(p[offset] == '[') {
|
|
offset++;
|
|
in_brackets++;
|
|
} else if (p[offset] == ']' && in_brackets) {
|
|
offset++;
|
|
in_brackets--;
|
|
} else if(in_brackets &&
|
|
(p[offset] == ':' || p[offset] == '.' || p[offset] == '-' ||
|
|
(p[offset] >= '0' && p[offset] <= '9'))) {
|
|
offset++;
|
|
} else {
|
|
break;
|
|
}
|
|
}
|
|
return offset;
|
|
}
|
|
|
|
static int64_t read_ts(const char *p, int64_t *start)
|
|
{
|
|
int64_t offset = 0;
|
|
uint64_t mm, ss, cs;
|
|
|
|
while(p[offset] == ' ' || p[offset] == '\t') {
|
|
offset++;
|
|
}
|
|
if(p[offset] != '[') {
|
|
return 0;
|
|
}
|
|
if(sscanf(p, "[-%"SCNu64":%"SCNu64".%"SCNu64"]", &mm, &ss, &cs) == 3) {
|
|
/* Just in case negative pts, players may drop it but we won't. */
|
|
*start = -(int64_t) (mm*60000 + ss*1000 + cs*10);
|
|
} else if(sscanf(p, "[%"SCNu64":%"SCNu64".%"SCNu64"]", &mm, &ss, &cs) == 3) {
|
|
*start = mm*60000 + ss*1000 + cs*10;
|
|
} else {
|
|
return 0;
|
|
}
|
|
do {
|
|
offset++;
|
|
} while(p[offset] && p[offset-1] != ']');
|
|
return offset;
|
|
}
|
|
|
|
static int64_t read_line(AVBPrint *buf, AVIOContext *pb)
|
|
{
|
|
int64_t pos = avio_tell(pb);
|
|
|
|
av_bprint_clear(buf);
|
|
while(!avio_feof(pb)) {
|
|
int c = avio_r8(pb);
|
|
if(c != '\r') {
|
|
av_bprint_chars(buf, c, 1);
|
|
}
|
|
if(c == '\n') {
|
|
break;
|
|
}
|
|
}
|
|
return pos;
|
|
}
|
|
|
|
static int lrc_probe(AVProbeData *p)
|
|
{
|
|
int64_t offset = 0;
|
|
int64_t mm;
|
|
uint64_t ss, cs;
|
|
const AVMetadataConv *metadata_item;
|
|
|
|
if(!memcmp(p->buf, "\xef\xbb\xbf", 3)) { // Skip UTF-8 BOM header
|
|
offset += 3;
|
|
}
|
|
while(p->buf[offset] == '\n' || p->buf[offset] == '\r') {
|
|
offset++;
|
|
}
|
|
if(p->buf[offset] != '[') {
|
|
return 0;
|
|
}
|
|
offset++;
|
|
// Common metadata item but not exist in ff_lrc_metadata_conv
|
|
if(!memcmp(p->buf + offset, "offset:", 7)) {
|
|
return 40;
|
|
}
|
|
if(sscanf(p->buf + offset, "%"SCNd64":%"SCNu64".%"SCNu64"]",
|
|
&mm, &ss, &cs) == 3) {
|
|
return 50;
|
|
}
|
|
// Metadata items exist in ff_lrc_metadata_conv
|
|
for(metadata_item = ff_lrc_metadata_conv;
|
|
metadata_item->native; metadata_item++) {
|
|
size_t metadata_item_len = strlen(metadata_item->native);
|
|
if(p->buf[offset + metadata_item_len] == ':' &&
|
|
!memcmp(p->buf + offset, metadata_item->native, metadata_item_len)) {
|
|
return 40;
|
|
}
|
|
}
|
|
return 5; // Give it 5 scores since it starts with a bracket
|
|
}
|
|
|
|
static int lrc_read_header(AVFormatContext *s)
|
|
{
|
|
LRCContext *lrc = s->priv_data;
|
|
AVBPrint line;
|
|
AVStream *st;
|
|
|
|
st = avformat_new_stream(s, NULL);
|
|
if(!st) {
|
|
return AVERROR(ENOMEM);
|
|
}
|
|
avpriv_set_pts_info(st, 64, 1, 1000);
|
|
lrc->ts_offset = 0;
|
|
st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
|
|
st->codecpar->codec_id = AV_CODEC_ID_TEXT;
|
|
av_bprint_init(&line, 0, AV_BPRINT_SIZE_UNLIMITED);
|
|
|
|
while(!avio_feof(s->pb)) {
|
|
int64_t pos = read_line(&line, s->pb);
|
|
int64_t header_offset = find_header(line.str);
|
|
if(header_offset >= 0) {
|
|
char *comma_offset = strchr(line.str, ':');
|
|
if(comma_offset) {
|
|
char *right_bracket_offset = strchr(line.str, ']');
|
|
if(!right_bracket_offset) {
|
|
continue;
|
|
}
|
|
|
|
*right_bracket_offset = *comma_offset = '\0';
|
|
if(strcmp(line.str + 1, "offset") ||
|
|
sscanf(comma_offset + 1, "%"SCNd64, &lrc->ts_offset) != 1) {
|
|
av_dict_set(&s->metadata, line.str + 1, comma_offset + 1, 0);
|
|
}
|
|
*comma_offset = ':';
|
|
*right_bracket_offset = ']';
|
|
}
|
|
|
|
} else {
|
|
AVPacket *sub;
|
|
int64_t ts_start = AV_NOPTS_VALUE;
|
|
int64_t ts_stroffset = 0;
|
|
int64_t ts_stroffset_incr = 0;
|
|
int64_t ts_strlength = count_ts(line.str);
|
|
|
|
while((ts_stroffset_incr = read_ts(line.str + ts_stroffset,
|
|
&ts_start)) != 0) {
|
|
ts_stroffset += ts_stroffset_incr;
|
|
sub = ff_subtitles_queue_insert(&lrc->q, line.str + ts_strlength,
|
|
line.len - ts_strlength, 0);
|
|
if(!sub) {
|
|
return AVERROR(ENOMEM);
|
|
}
|
|
sub->pos = pos;
|
|
sub->pts = ts_start - lrc->ts_offset;
|
|
sub->duration = -1;
|
|
}
|
|
}
|
|
}
|
|
ff_subtitles_queue_finalize(s, &lrc->q);
|
|
ff_metadata_conv_ctx(s, NULL, ff_lrc_metadata_conv);
|
|
av_bprint_finalize(&line, NULL);
|
|
return 0;
|
|
}
|
|
|
|
static int lrc_read_packet(AVFormatContext *s, AVPacket *pkt)
|
|
{
|
|
LRCContext *lrc = s->priv_data;
|
|
return ff_subtitles_queue_read_packet(&lrc->q, pkt);
|
|
}
|
|
|
|
static int lrc_read_seek(AVFormatContext *s, int stream_index,
|
|
int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
|
|
{
|
|
LRCContext *lrc = s->priv_data;
|
|
return ff_subtitles_queue_seek(&lrc->q, s, stream_index,
|
|
min_ts, ts, max_ts, flags);
|
|
}
|
|
|
|
static int lrc_read_close(AVFormatContext *s)
|
|
{
|
|
LRCContext *lrc = s->priv_data;
|
|
ff_subtitles_queue_clean(&lrc->q);
|
|
return 0;
|
|
}
|
|
|
|
AVInputFormat ff_lrc_demuxer = {
|
|
.name = "lrc",
|
|
.long_name = NULL_IF_CONFIG_SMALL("LRC lyrics"),
|
|
.priv_data_size = sizeof (LRCContext),
|
|
.read_probe = lrc_probe,
|
|
.read_header = lrc_read_header,
|
|
.read_packet = lrc_read_packet,
|
|
.read_close = lrc_read_close,
|
|
.read_seek2 = lrc_read_seek
|
|
};
|