To merge or break down the MP3 file (that is, MPEG-1 Layer 3 file), you must first understand the format of the MP3 file. Simply put, the MP3 file is composed of smaller parts-frame (frame), each frame including its own frame head and audio information. According to the MP3 specification, the duration of one frame is 26 ms (milliseconds), which is equivalent to 38fps (38 frames per second). If the bit rate of the file is, the larger the size of the frame, the size of the frame is more small. Frames and frames are relatively independent, each frame has its own frame head and audio information. The first 11 bits of the frame head are set to binary 1, so quickly find a frame is to find hexadecimal FF in the file. If the next byte is higher than E0, then ff is this frame. beginning. The MP3 file itself has no file header, but the appearance of ID3 extensions has changed this. ID3 extension defines two tags (TAGs) to store songs, author, copyright, etc., using Winamp's friends, the song name of the playlist, can be seen, selecting file information. The ID3V1 label is at the end of the MP3 file. The length is 128 bytes starting with the "tag" flag. The ID3V2 label is at the beginning of the MP3 file, the length of 2002 bytes starting with the "ID3" flag. Tell this, everyone should understand. If you want to cut your MP3 file yourself, you can use UltraEdit to support the binary / hexadecimal editing tool to open the file, find the beginning of the frame, and save it. If it is further, it is necessary to split according to time, the position of the cutting can be calculated according to the method introduced in this article. If it is a merge, you should pay attention to whether there is an ID3v1, ID3v2 tag, if necessary, delete or move to the end of the new file. However, there is still a matter of particular attention, it is to merge the bit rate (bitrate, such as 128kbit) and sampling rate (SampleRate, such as 44100Hz), must be the same (what? What? Still uses WINAMP to see file information). Otherwise, playback may be incorrect. Ok, it is limited to the space, there are still many details. If you have any questions, email I will.
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Note: This article was originally read "Computer News" No. 12 B9 (17 edition), the "easy combined audio and video document", will be angry after "easy to combine audio and video files" on March 31, 2003.
