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 36static 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 85static 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 129const 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