Lrc歌词文件格式及其C++代码实现

Lrc歌词文件格式说明扩展名为Lrc格式的文件，是MP3播放器唯一能够识别的歌词文件，在MP3数码播放器或千千静听中可以区同步显示歌词。

它是一种包含着“[*:*]”形式的“标签(tag)”的、基于纯文本的歌词专用格式。

最早由郭祥祥先生(Djohan)提出并在其程序中得到应用。

这种歌词文件既可以用来实现卡拉OK 功能（需要专门程序），又能以普通的文字处理软件查看、编辑。

当然，实际操作时通常是用专门的LRC歌词编辑软件进行高效编辑的。

Lrc歌词文本中含有两类标签：一是标识标签，其格式为“[标识名:值]”主要包含以下预定义的标签：[ar:歌手名]、[ti:歌曲名]、[al:专辑名]、[by:编辑者(指lrc歌词的制作人)]、[offset:时间补偿值] （其单位是毫秒，正值表示整体提前，负值相反。

这是用于总体调整显示快慢的，但多数的MP3可能不会支持这种标签）。

二是时间标签，形式为“[mm:ss]”或“[mm:ss.fff]”(分钟数:秒数:毫秒数)，时间标签需位于某行歌词中的句首部分，一行歌词可以包含多个时间标签(比如歌词中的迭句部分)。

当歌曲播放到达某一时间点时，MP3就会寻找对应的时间标签并显示标签后面的歌词文本，这样就完成了“歌词同步”的功能。

■时间标签（Time-tag）形式为"[mm:ss]"或"[mm:ss.fff]"（分钟数:秒数）。

数字须为非负整数，比如"[12:34.5]"是有效的，而"[0x0C:-34.5]"无效。

它可以位于某行歌词中的任意位置。

一行歌词可以包含多个时间标签（比如歌词中的迭句部分）。

根据这些时间标签，用户端程序会按顺序依次高亮显示歌词，从而实现卡拉OK 功能。

另外，标签无须排序。

■标识标签（ID-tags）其格式为"[标识名:值]"。

大小写等价。

以下是预定义的标签。

[ar:艺人名][ti:曲名][al:专辑名][by:编者（指编辑LRC歌词的人）][offset:时间补偿值] 其单位是毫秒，正值表示整体提前，负值相反。

这是用于总体调整显示快慢的。

分钟：秒.毫秒]歌词用记事本按照上述格式写好后,将拓展名改为lrc即可做出该文件.LRC歌词是一种通过编辑器把歌词按歌曲歌词出现的时间编辑成一个文件，在播放歌曲时同步依次显示出来的一种歌词文件。

把歌曲和LRC歌词命为相同的文件名放在同一目录下，用带显示歌词功能的播放器播放歌曲时歌词就可以同步显示显示，方便查看和学歌。

(供程序员阅读参考)以下列出了开发支持LRC格式的软件时应遵守的一些标准。

无论是否在行首，行内凡具有“[*:*]”形式的都应认为是标签。

（注意：其中的冒号并非全角字符“：”）凡是标签都不应显示。

凡是标签，且被冒号分隔的两部分都为非负数，则应认为是时间标签。

因此，对于非标准形式（非“[mm:ss]”）的时间标签也应能识别（如“[0:0]”）。

凡是标签，且非时间标签的，应认为是标识标签。

标识名中大小写等价。

·为了向后兼容，应对未定义的新标签作忽略处理。

另应对注释标签（[:]）后的同一行内容作忽略处理。

应允许一行中存在多个标签，并能正确处理。

应能正确处理未排序的标签。

以下附上C++实现代码，支持ANSI和Unicode格式，超强纠错。

-----------------------------------------------------Lyric.h----------------------------------------------------- typedef struct{DWORD dwStartTime; // The unit is millisecondCString csLyric;} LineLyric, *PLineLyric;class CLyric{public:CLyric();~CLyric();CString m_csArtist;CString m_csTitle;CString m_csAlbum;CString m_csBy;LONG m_lOffset; // Lead time of the lyricCString m_csKey;public:BOOL Load(LPCWSTR szFileName, LONG lUserOffset = 0); // If lUserOffset > 0: ahead; if < 0: put offvoid UnLoad();BOOL GetItemByID(DWORD dwItemID, LineLyric &lyric); // Get the lyric data by dwItemIDDWORD GetTimeByID(DWORD dwItemID); // Get the lyric's start time by dwItemIDLONG GetItemIDByTime(DWORD dwTime, DWORD dwStartLineID = 0);// Search the line index by time(in milliseconds) begin at nStartLineIDDWORD GetTotalNum() { return m_dwLineNum; }BOOL IsValid() { return m_bValid; }private:BOOL m_bValid;CArray<LineLyric> m_LyricList;DWORD m_dwLineNum;BOOL m_bAnalyseTag;LONG m_lUserOffset;__forceinline BOOL ReadALine(FILE *fp, CHAR *buff, INT bufflen, INT &readlen);__forceinline void AnalyseLine(CHAR *szLine, INT nLength);__forceinline BOOL CheckTag(CHAR *szText);__forceinline LONG GetStartTime(CHAR *szTime);__forceinline BOOL ReadALineW(FILE *fp, WCHAR *buff, INT bufflen, INT&readlen);__forceinline void AnalyseLineW(WCHAR *szLine, INT nLength);__forceinline BOOL CheckTagW(WCHAR *szText);__forceinline LONG GetStartTimeW(WCHAR *szTime);__forceinline DWORD Find(DWORD dwTime); // return the line ID matched the time};-----------------------------------------------------Lyric.cpp----------------------------------------------------- #include"Lyric.h"#define MAX_LYRIC_LINE_LEN512#define MAX_LYRIC_LEN128#define MAX_LYRIC_LINE_NUM5000#define MAX_LYRIC_TIME_LEN30CLyric::CLyric(){m_bValid = FALSE;m_lUserOffset = 0;}CLyric::~CLyric(){}BOOL CLyric::Load(LPCWSTR szFileName, LONG lUserOffset){UnLoad();FILE*fp;INT readlen;m_lUserOffset = lUserOffset;fp = _tfopen(szFileName, _T("r"));if (fp == NULL){return FALSE;}WORD wUnicode_tag = 0;DWORD dwReadLen = 0;try{dwReadLen = fread((void *)&wUnicode_tag, sizeof(WCHAR), 1, fp);}catch (...){printf("CLyric::Load: fread Exception: %s!\r\n", szFileName);fclose(fp);return FALSE;}if (dwReadLen != 1){printf("CLyric::Load: read file %s failed!\r\n", szFileName);fclose(fp);return FALSE;}if (wUnicode_tag == 0xfeff) // unicode file{fclose(fp);fp = _tfopen(szFileName, _T("rb"));if (fp == NULL){return FALSE;}fseek(fp, sizeof(WCHAR), SEEK_SET);WCHAR wstr[MAX_LYRIC_LINE_LEN];do{if (!ReadALineW(fp, wstr, MAX_LYRIC_LINE_LEN, readlen)) break;if (readlen <= 0)continue;AnalyseLineW(wstr, readlen);}while (m_dwLineNum < MAX_LYRIC_LINE_NUM);}else{fseek(fp, 0L, SEEK_SET);CHAR str[MAX_LYRIC_LINE_LEN];do{if (!ReadALine(fp, str, MAX_LYRIC_LINE_LEN, readlen)) break;if (readlen <= 0)continue;AnalyseLine(str, readlen);}while (m_dwLineNum < MAX_LYRIC_LINE_NUM);}fclose(fp);m_bValid = TRUE;return TRUE;}void CLyric::UnLoad(){m_bValid = FALSE;m_csArtist.Empty();m_csTitle.Empty();m_csAlbum.Empty();m_csBy.Empty();m_lOffset = 0;m_csKey.Empty();m_LyricList.RemoveAll();m_dwLineNum = 0;m_bAnalyseTag = TRUE;m_lUserOffset = 0;}BOOL CLyric::GetItemByID(DWORD dwItemID, LineLyric &lyric) {if (dwItemID < (DWORD)m_LyricList.GetSize()){lyric = m_LyricList[dwItemID];return TRUE;}else{return FALSE;}}DWORD CLyric::GetTimeByID(DWORD dwItemID){DWORD dwTotalItem = (DWORD)m_LyricList.GetSize();if (dwTotalItem == 0)return 0;if (dwItemID < dwTotalItem){return m_LyricList[dwItemID].dwStartTime;}else{return m_LyricList[dwTotalItem-1].dwStartTime;}}LONG CLyric::GetItemIDByTime(DWORD dwTime, DWORD dwStartLineID){DWORD dwLineNum = m_LyricList.GetSize();if (dwTime <= 0 || dwLineNum == 0)return -1;for (DWORD i = dwStartLineID; i < dwLineNum; i++){if (m_LyricList[i].dwStartTime > dwTime){return i-1;}}return dwLineNum-1;}__forceinline BOOL CLyric::ReadALine(FILE *fp, CHAR *buff, INT bufflen, INT &readlen) {readlen = 0;if (feof(fp)) /* End or file, return -1 */return FALSE;int ch;do{ch = fgetc(fp);if (ch == '\r' || ch == '\n' || ch == EOF)break;if (readlen >= bufflen-1)continue; // Use continue for ignoring the remanent character of the line*buff = ch;buff++;readlen++;} while (!feof(fp));if (readlen > 0 && *(buff-1) == '\r')*(buff-1) = 0;else*buff = 0;return TRUE;}__forceinline void CLyric::AnalyseLine(CHAR *szLine, INT nLength){WCHAR szLyric[MAX_LYRIC_LEN];CHAR szTime[MAX_LYRIC_TIME_LEN];CHAR *szTimeBegin = NULL; // Begin at the next char of '['CHAR *szTimeEnd = NULL; // End at ']'CHAR *szNextTimeBegin = strchr(szLine, '[');if (szNextTimeBegin == NULL)return;szNextTimeBegin++;CHAR *szNextTimeEnd = strchr(szNextTimeBegin, ']');if (szNextTimeEnd == NULL)return;LineLyric lyric;LONG lStartTime;while (szNextTimeBegin != NULL && szNextTimeEnd != NULL)// Support multi time/tag in one line{szTimeBegin = szNextTimeBegin;szTimeEnd = szNextTimeEnd;szNextTimeBegin = strchr(szTimeEnd, '[');if (szNextTimeBegin != NULL){szNextTimeEnd = strchr(szNextTimeBegin, ']');if (szNextTimeEnd != NULL){// Find a next Time in the same line*szNextTimeBegin = 0; // Set '[' as the end flag of the stringszNextTimeBegin++;}}if (szTimeEnd > szTimeBegin+1){INT nTimeLen = min(MAX_LYRIC_TIME_LEN-1,szTimeEnd-szTimeBegin);strncpy(szTime, szTimeBegin, nTimeLen);szTime[nTimeLen] = 0;if (m_bAnalyseTag){if (CheckTag(szTime))continue;}lStartTime = GetStartTime(szTime);if (lStartTime < 0)continue;lyric.dwStartTime = max((lStartTime - m_lOffset - m_lUserOffset), 0);MultiByteToWideChar(Core_GetDefCodePage(), 0, szTimeEnd+1, -1, szLyric, MAX_LYRIC_LEN-1);lyric.csLyric = szLyric;if (lyric.csLyric.IsEmpty() && szTimeEnd+2 != 0){// To get MultiTimeLyricCHAR *szMultiTimeLyric = szTimeEnd+2;szMultiTimeLyric = strchr(szMultiTimeLyric, ']');if (szMultiTimeLyric != NULL){CHAR *szMultiTimeLyricBegin = szMultiTimeLyric+1;while (1){szMultiTimeLyric = strchr(szMultiTimeLyricBegin, '[');if (szMultiTimeLyric == NULL) // Find MultiTimeLyric, it's at the end of the line{MultiByteToWideChar(Core_GetDefCodePage(), 0, szMultiTimeLyricBegin, -1, szLyric, MAX_LYRIC_LEN-1);lyric.csLyric = szLyric;break;}else if (szMultiTimeLyric-szMultiTimeLyricBegin > 0) // Find MultiTimeLyric, it's at the middle of the line{MultiByteToWideChar(Core_GetDefCodePage(), 0, szMultiTimeLyricBegin, -1, szLyric, MAX_LYRIC_LEN-1);lyric.csLyric = szLyric;lyric.csLyric = lyric.csLyric.Mid(0,szMultiTimeLyric-szMultiTimeLyricBegin);break;}szMultiTimeLyric = strchr(szMultiTimeLyric+1, ']');if (szMultiTimeLyric == NULL) // Invalid format, has '[', but no ']'{MultiByteToWideChar(Core_GetDefCodePage(), 0, szMultiTimeLyricBegin, -1, szLyric, MAX_LYRIC_LEN-1);lyric.csLyric = szLyric;break;}szMultiTimeLyricBegin = szMultiTimeLyric+1;}}}if (m_dwLineNum > 0 || !lyric.csLyric.IsEmpty()) // First line must no be empty{if (m_dwLineNum > 0 && lyric.dwStartTime >=m_LyricList.GetAt(m_dwLineNum-1).dwStartTime)m_LyricList.Add(lyric);elsem_LyricList.InsertAt(Find(lyric.dwStartTime), lyric); // Auto sort by timem_dwLineNum++;}m_bAnalyseTag = FALSE; // Consider Tag info is at the beginning of the file}}}BOOL CLyric::CheckTag(CHAR *szText){if (_strnicmp(szText, "ar", 2) == 0){m_csArtist = szText+3;return TRUE;}if (_strnicmp(szText, "ti", 2) == 0){m_csTitle = szText+3;return TRUE;}if (_strnicmp(szText, "al", 2) == 0){m_csAlbum = szText+3;return TRUE;}if (_strnicmp(szText, "by", 2) == 0){m_csBy = szText+3;return TRUE;}if (_strnicmp(szText, "offset", 6) == 0){m_lOffset = atol(szText+7);return TRUE;}if (_strnicmp(szText, "key", 3) == 0){m_csKey = szText+4;return TRUE;}return FALSE;}__forceinline LONG CLyric::GetStartTime(CHAR *szTime){INT nMinute = 0;INT nSecond = 0;INT nMilliSecond = 0;CHAR *szMinuteEnd = strrchr(szTime, ':');if (szMinuteEnd == NULL){nMinute = 0;szMinuteEnd = szTime;}else{CHAR szMinute[10];INT nMinuteLen = min(9, szMinuteEnd-szTime);strncpy(szMinute, szTime, nMinuteLen);if (nMinuteLen > 0 && (szMinute[0] < '0' || szMinute[0] > '9')) return -1;nMinute = atoi(szMinute);if (nMinute < 0)nMinute = 0;szMinuteEnd++;}CHAR *szSecondEnd = strrchr(szMinuteEnd, '.');if (szSecondEnd == NULL){nSecond = atoi(szMinuteEnd);if (nSecond < 0)nSecond = 0;}else{CHAR szSecond[10];INT nSecondLen = min(9, szSecondEnd-szMinuteEnd);strncpy(szSecond, szMinuteEnd, nSecondLen);if (nSecondLen > 0 && (szSecond[0] < '0' || szSecond[0] > '9'))return -1;nSecond = atoi(szSecond);if (nSecond < 0)nSecond = 0;szSecondEnd++;INT nMilliSecondLen = strlen(szSecondEnd);if (nMilliSecondLen == 1)nMilliSecond = atoi(szSecondEnd) * 100;else if (nMilliSecondLen == 2)nMilliSecond = atoi(szSecondEnd) * 10;else if (nMilliSecondLen == 3)nMilliSecond = atoi(szSecondEnd);if (nMilliSecond < 0)nMilliSecond = 0;}return nMinute*60000+nSecond*1000+nMilliSecond;}__forceinline BOOL CLyric::ReadALineW(FILE *fp, WCHAR *buff, INT bufflen, INT &readlen){WCHAR *pReturn = fgetws(buff, bufflen, fp);if (pReturn == NULL)return FALSE;readlen = lstrlen(buff);if (readlen > 0 && buff[readlen-1] == _T('\n')){buff[readlen-1] = 0;readlen--;}if (readlen > 0 && buff[readlen-1] == _T('\r')){buff[readlen-1] = 0;readlen--;}return TRUE;}__forceinline void CLyric::AnalyseLineW(WCHAR *szLine, INT nLength){WCHAR szTime[MAX_LYRIC_TIME_LEN];WCHAR *szTimeBegin = NULL; // Begin at the next char of '['WCHAR *szTimeEnd = NULL; // End at ']'WCHAR *szNextTimeBegin = wcschr(szLine, _T('['));if (szNextTimeBegin == NULL)return;szNextTimeBegin++;WCHAR *szNextTimeEnd = wcschr(szNextTimeBegin, _T(']'));if (szNextTimeEnd == NULL)return;LineLyric lyric;LONG lStartTime;while (szNextTimeBegin != NULL && szNextTimeEnd != NULL)// Support multi time/tag in one line{szTimeBegin = szNextTimeBegin;szTimeEnd = szNextTimeEnd;szNextTimeBegin = wcschr(szTimeEnd, _T('['));if (szNextTimeBegin != NULL){szNextTimeEnd = wcschr(szNextTimeBegin, _T(']'));if (szNextTimeEnd != NULL){// Find a next Time in the same line*szNextTimeBegin = 0; // Set '[' as the end flag of the stringszNextTimeBegin++;}}if (szTimeEnd > szTimeBegin+1){INT nTimeLen = min(MAX_LYRIC_TIME_LEN-1,szTimeEnd-szTimeBegin);wcsncpy(szTime, szTimeBegin, nTimeLen);szTime[nTimeLen] = 0;if (m_bAnalyseTag){if (CheckTagW(szTime))continue;}lStartTime = GetStartTimeW(szTime);if (lStartTime < 0)continue;lyric.dwStartTime = max((lStartTime - m_lOffset - m_lUserOffset), 0);lyric.csLyric = szTimeEnd+1;if (lyric.csLyric.IsEmpty() && szTimeEnd+2 != 0){// To get MultiTimeLyricWCHAR *szMultiTimeLyric = szTimeEnd+2;szMultiTimeLyric = wcschr(szMultiTimeLyric, _T(']'));if (szMultiTimeLyric != NULL){WCHAR *szMultiTimeLyricBegin = szMultiTimeLyric+1;while (1){szMultiTimeLyric = wcschr(szMultiTimeLyricBegin, _T('['));if (szMultiTimeLyric == NULL) // Find MultiTimeLyric, it's at the end of the line{lyric.csLyric = szMultiTimeLyricBegin;break;}else if (szMultiTimeLyric-szMultiTimeLyricBegin > 0) // Find MultiTimeLyric, it's at the middle of the line{lyric.csLyric = szMultiTimeLyricBegin;lyric.csLyric = lyric.csLyric.Mid(0,szMultiTimeLyric-szMultiTimeLyricBegin);break;}szMultiTimeLyric = wcschr(szMultiTimeLyric+1, _T(']'));if (szMultiTimeLyric == NULL) // Invalid format, has '[', but no ']'{lyric.csLyric = szMultiTimeLyricBegin;break;}szMultiTimeLyricBegin = szMultiTimeLyric+1;}}}if (m_dwLineNum > 0 || !lyric.csLyric.IsEmpty()) // First line must no be empty{if (m_dwLineNum > 0 && lyric.dwStartTime >=m_LyricList.GetAt(m_dwLineNum-1).dwStartTime)m_LyricList.Add(lyric);elsem_LyricList.InsertAt(Find(lyric.dwStartTime), lyric); // Auto sort by timem_dwLineNum++;}m_bAnalyseTag = FALSE; // Consider Tag info is at the beginning of the file}}}BOOL CLyric::CheckTagW(WCHAR *szText){if (_wcsnicmp(szText, _T("ar"), 2) == 0){m_csArtist = szText+3;return TRUE;}if (_wcsnicmp(szText, _T("ti"), 2) == 0){m_csTitle = szText+3;return TRUE;}if (_wcsnicmp(szText, _T("al"), 2) == 0){m_csAlbum = szText+3;return TRUE;}if (_wcsnicmp(szText, _T("by"), 2) == 0){m_csBy = szText+3;return TRUE;}if (_wcsnicmp(szText, _T("offset"), 6) == 0){m_lOffset = _wtol(szText+7);return TRUE;}if (_wcsnicmp(szText, _T("key"), 3) == 0){m_csKey = szText+4;return TRUE;}return FALSE;}__forceinline LONG CLyric::GetStartTimeW(WCHAR *szTime){INT nMinute = 0;INT nSecond = 0;INT nMilliSecond = 0;WCHAR *szMinuteEnd = wcsrchr(szTime, ':');if (szMinuteEnd == NULL){nMinute = 0;szMinuteEnd = szTime;}else{WCHAR szMinute[10];INT nMinuteLen = min(9, szMinuteEnd-szTime);wcsncpy(szMinute, szTime, nMinuteLen);if (nMinuteLen > 0 && (szMinute[0] < _T('0') || szMinute[0] > _T('9'))) return -1;nMinute = _wtoi(szMinute);if (nMinute < 0)nMinute = 0;szMinuteEnd++;}WCHAR *szSecondEnd = wcsrchr(szMinuteEnd, _T('.'));if (szSecondEnd == NULL){nSecond = _wtoi(szMinuteEnd);if (nSecond < 0)nSecond = 0;}else{WCHAR szSecond[10];INT nSecondLen = min(9, szSecondEnd-szMinuteEnd);wcsncpy(szSecond, szMinuteEnd, nSecondLen);if (nSecondLen > 0 && (szSecond[0] < _T('0') || szSecond[0] > _T('9'))) return -1;nSecond = _wtoi(szSecond);if (nSecond < 0)nSecond = 0;szSecondEnd++;INT nMilliSecondLen = lstrlen(szSecondEnd);if (nMilliSecondLen == 1)nMilliSecond = _wtoi(szSecondEnd) * 100;else if (nMilliSecondLen == 2)nMilliSecond = _wtoi(szSecondEnd) * 10;else if (nMilliSecondLen == 3)nMilliSecond = _wtoi(szSecondEnd);if (nMilliSecond < 0)nMilliSecond = 0;}return nMinute*60000+nSecond*1000+nMilliSecond;}__forceinline DWORD CLyric::Find(DWORD dwTime){DWORD i = 0;for (i = 0; i < (DWORD)m_LyricList.GetSize(); i++){if (m_LyricList[i].dwStartTime > dwTime){break;}}return i; }。