1 /*
2 * LRC lyrics file format decoder
3 * Copyright (c) 2014 StarBrilliant <m13253@hotmail.com>
4 *
5 * This file is part of FFmpeg.
6 *
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.
11 *
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.
16 *
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
20 */
21
22 #include <inttypes.h>
23 #include <stdint.h>
24 #include <string.h>
25
26 #include "avformat.h"
27 #include "internal.h"
28 #include "lrc.h"
29 #include "metadata.h"
30 #include "mux.h"
31 #include "version.h"
32 #include "libavutil/dict.h"
33 #include "libavutil/log.h"
34 #include "libavutil/macros.h"
35
lrc_write_header(AVFormatContext * s)36 static int lrc_write_header(AVFormatContext *s)
37 {
38 const AVDictionaryEntry *metadata_item;
39
40 if(s->nb_streams != 1 ||
41 s->streams[0]->codecpar->codec_type != AVMEDIA_TYPE_SUBTITLE) {
42 av_log(s, AV_LOG_ERROR,
43 "LRC supports only a single subtitle stream.\n");
44 return AVERROR(EINVAL);
45 }
46 if(s->streams[0]->codecpar->codec_id != AV_CODEC_ID_SUBRIP &&
47 s->streams[0]->codecpar->codec_id != AV_CODEC_ID_TEXT) {
48 av_log(s, AV_LOG_ERROR, "Unsupported subtitle codec: %s\n",
49 avcodec_get_name(s->streams[0]->codecpar->codec_id));
50 return AVERROR(EINVAL);
51 }
52 avpriv_set_pts_info(s->streams[0], 64, 1, 100);
53
54 ff_standardize_creation_time(s);
55 ff_metadata_conv_ctx(s, ff_lrc_metadata_conv, NULL);
56 if(!(s->flags & AVFMT_FLAG_BITEXACT)) { // avoid breaking regression tests
57 /* LRC provides a metadata slot for specifying encoder version
58 * in addition to encoder name. We will store LIBAVFORMAT_VERSION
59 * to it.
60 */
61 av_dict_set(&s->metadata, "ve", AV_STRINGIFY(LIBAVFORMAT_VERSION), 0);
62 } else {
63 av_dict_set(&s->metadata, "ve", NULL, 0);
64 }
65 for(metadata_item = NULL;
66 (metadata_item = av_dict_get(s->metadata, "", metadata_item,
67 AV_DICT_IGNORE_SUFFIX));) {
68 char *delim;
69 if(!metadata_item->value[0]) {
70 continue;
71 }
72 while((delim = strchr(metadata_item->value, '\n'))) {
73 *delim = ' ';
74 }
75 while((delim = strchr(metadata_item->value, '\r'))) {
76 *delim = ' ';
77 }
78 avio_printf(s->pb, "[%s:%s]\n",
79 metadata_item->key, metadata_item->value);
80 }
81 avio_w8(s->pb, '\n');
82 return 0;
83 }
84
lrc_write_packet(AVFormatContext * s,AVPacket * pkt)85 static int lrc_write_packet(AVFormatContext *s, AVPacket *pkt)
86 {
87 if(pkt->pts != AV_NOPTS_VALUE) {
88 const uint8_t *line = pkt->data;
89 const uint8_t *end = pkt->data + pkt->size;
90
91 while (end > line && (end[-1] == '\n' || end[-1] == '\r'))
92 end--;
93 if (line != end) {
94 while (line[0] == '\n' || line[0] == '\r')
95 line++; // Skip first empty lines
96 }
97
98 while(line) {
99 const uint8_t *next_line = memchr(line, '\n', end - line);
100 size_t size = end - line;
101
102 if (next_line) {
103 size = next_line - line;
104 if (next_line > line && next_line[-1] == '\r')
105 size--;
106 next_line++;
107 }
108 if(line[0] == '[') {
109 av_log(s, AV_LOG_WARNING,
110 "Subtitle starts with '[', may cause problems with LRC format.\n");
111 }
112
113 /* Offset feature of LRC can easily make pts negative,
114 * we just output it directly and let the player drop it. */
115 avio_write(s->pb, "[-", 1 + (pkt->pts < 0));
116 avio_printf(s->pb, "%02"PRIu64":%02"PRIu64".%02"PRIu64"]",
117 (FFABS64U(pkt->pts) / 6000),
118 ((FFABS64U(pkt->pts) / 100) % 60),
119 (FFABS64U(pkt->pts) % 100));
120
121 avio_write(s->pb, line, size);
122 avio_w8(s->pb, '\n');
123 line = next_line;
124 }
125 }
126 return 0;
127 }
128
129 const AVOutputFormat ff_lrc_muxer = {
130 .name = "lrc",
131 .long_name = NULL_IF_CONFIG_SMALL("LRC lyrics"),
132 .extensions = "lrc",
133 .priv_data_size = 0,
134 .write_header = lrc_write_header,
135 .write_packet = lrc_write_packet,
136 .flags = AVFMT_VARIABLE_FPS | AVFMT_GLOBALHEADER |
137 AVFMT_TS_NEGATIVE | AVFMT_TS_NONSTRICT,
138 .subtitle_codec = AV_CODEC_ID_SUBRIP
139 };
140