2 * LRC lyrics file format decoder
3 * Copyright (c) 2014 StarBrilliant <m13253@hotmail.com>
5 * This file is part of FFmpeg.
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.
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.
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
30 #include "subtitles.h"
31 #include "libavutil/bprint.h"
32 #include "libavutil/dict.h"
34 typedef struct LRCContext
{
35 FFDemuxSubtitlesQueue q
;
36 int64_t ts_offset
; // offset metadata item
39 static int64_t find_header(const char *p
)
42 while(p
[offset
] == ' ' || p
[offset
] == '\t') {
45 if(p
[offset
] == '[' && p
[offset
+ 1] >= 'a' && p
[offset
+ 1] <= 'z') {
52 static int64_t count_ts(const char *p
)
58 if(p
[offset
] == ' ' || p
[offset
] == '\t') {
60 } else if(p
[offset
] == '[') {
63 } else if (p
[offset
] == ']' && in_brackets
) {
66 } else if(in_brackets
&&
67 (p
[offset
] == ':' || p
[offset
] == '.' || p
[offset
] == '-' ||
68 (p
[offset
] >= '0' && p
[offset
] <= '9'))) {
77 static int64_t read_ts(const char *p
, int64_t *start
)
82 while(p
[offset
] == ' ' || p
[offset
] == '\t') {
85 if(p
[offset
] != '[') {
88 if(sscanf(p
, "[-%"SCNu64
":%"SCNu64
".%"SCNu64
"]", &mm
, &ss
, &cs
) == 3) {
89 /* Just in case negative pts, players may drop it but we won't. */
90 *start
= -(int64_t) (mm
*60000 + ss
*1000 + cs
*10);
91 } else if(sscanf(p
, "[%"SCNu64
":%"SCNu64
".%"SCNu64
"]", &mm
, &ss
, &cs
) == 3) {
92 *start
= mm
*60000 + ss
*1000 + cs
*10;
98 } while(p
[offset
] && p
[offset
-1] != ']');
102 static int64_t read_line(AVBPrint
*buf
, AVIOContext
*pb
)
104 int64_t pos
= avio_tell(pb
);
106 av_bprint_clear(buf
);
107 while(!avio_feof(pb
)) {
110 av_bprint_chars(buf
, c
, 1);
119 static int lrc_probe(AVProbeData
*p
)
124 const AVMetadataConv
*metadata_item
;
126 if(!memcmp(p
->buf
, "\xef\xbb\xbf", 3)) { // Skip UTF-8 BOM header
129 while(p
->buf
[offset
] == '\n' || p
->buf
[offset
] == '\r') {
132 if(p
->buf
[offset
] != '[') {
136 // Common metadata item but not exist in ff_lrc_metadata_conv
137 if(!memcmp(p
->buf
+ offset
, "offset:", 7)) {
140 if(sscanf(p
->buf
+ offset
, "%"SCNd64
":%"SCNu64
".%"SCNu64
"]",
141 &mm
, &ss
, &cs
) == 3) {
144 // Metadata items exist in ff_lrc_metadata_conv
145 for(metadata_item
= ff_lrc_metadata_conv
;
146 metadata_item
->native
; metadata_item
++) {
147 size_t metadata_item_len
= strlen(metadata_item
->native
);
148 if(p
->buf
[offset
+ metadata_item_len
] == ':' &&
149 !memcmp(p
->buf
+ offset
, metadata_item
->native
, metadata_item_len
)) {
153 return 5; // Give it 5 scores since it starts with a bracket
156 static int lrc_read_header(AVFormatContext
*s
)
158 LRCContext
*lrc
= s
->priv_data
;
162 st
= avformat_new_stream(s
, NULL
);
164 return AVERROR(ENOMEM
);
166 avpriv_set_pts_info(st
, 64, 1, 1000);
168 st
->codec
->codec_type
= AVMEDIA_TYPE_SUBTITLE
;
169 st
->codec
->codec_id
= AV_CODEC_ID_TEXT
;
170 av_bprint_init(&line
, 0, AV_BPRINT_SIZE_UNLIMITED
);
172 while(!avio_feof(s
->pb
)) {
173 int64_t pos
= read_line(&line
, s
->pb
);
174 int64_t header_offset
= find_header(line
.str
);
175 if(header_offset
>= 0) {
176 char *comma_offset
= strchr(line
.str
, ':');
178 char *right_bracket_offset
= strchr(line
.str
, ']');
179 if(!right_bracket_offset
) {
183 *right_bracket_offset
= *comma_offset
= '\0';
184 if(strcmp(line
.str
+ 1, "offset") ||
185 sscanf(comma_offset
+ 1, "%"SCNd64
, &lrc
->ts_offset
) != 1) {
186 av_dict_set(&s
->metadata
, line
.str
+ 1, comma_offset
+ 1, 0);
189 *right_bracket_offset
= ']';
194 int64_t ts_start
= AV_NOPTS_VALUE
;
195 int64_t ts_stroffset
= 0;
196 int64_t ts_stroffset_incr
= 0;
197 int64_t ts_strlength
= count_ts(line
.str
);
199 while((ts_stroffset_incr
= read_ts(line
.str
+ ts_stroffset
,
201 ts_stroffset
+= ts_stroffset_incr
;
202 sub
= ff_subtitles_queue_insert(&lrc
->q
, line
.str
+ ts_strlength
,
203 line
.len
- ts_strlength
, 0);
205 return AVERROR(ENOMEM
);
208 sub
->pts
= ts_start
- lrc
->ts_offset
;
213 ff_subtitles_queue_finalize(&lrc
->q
);
214 ff_metadata_conv_ctx(s
, NULL
, ff_lrc_metadata_conv
);
218 static int lrc_read_packet(AVFormatContext
*s
, AVPacket
*pkt
)
220 LRCContext
*lrc
= s
->priv_data
;
221 return ff_subtitles_queue_read_packet(&lrc
->q
, pkt
);
224 static int lrc_read_seek(AVFormatContext
*s
, int stream_index
,
225 int64_t min_ts
, int64_t ts
, int64_t max_ts
, int flags
)
227 LRCContext
*lrc
= s
->priv_data
;
228 return ff_subtitles_queue_seek(&lrc
->q
, s
, stream_index
,
229 min_ts
, ts
, max_ts
, flags
);
232 static int lrc_read_close(AVFormatContext
*s
)
234 LRCContext
*lrc
= s
->priv_data
;
235 ff_subtitles_queue_clean(&lrc
->q
);
239 AVInputFormat ff_lrc_demuxer
= {
241 .long_name
= NULL_IF_CONFIG_SMALL("LRC lyrics"),
242 .priv_data_size
= sizeof (LRCContext
),
243 .read_probe
= lrc_probe
,
244 .read_header
= lrc_read_header
,
245 .read_packet
= lrc_read_packet
,
246 .read_close
= lrc_read_close
,
247 .read_seek2
= lrc_read_seek