https://sound.bai-hua.org/index.php?action=history&feed=atom&title=MP3_Encoding_and_File_Format 2026-11-10T22:30:14Z Revision history for this page on the wiki MediaWiki 1.29.0 https://sound.bai-hua.org/index.php?title=MP3_Encoding_and_File_Format&diff=277&oldid=prev 2011-05-17T10:08:00Z

<p></p> <table class="diff diff-contentalign-left" data-mw="interface"> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr style='vertical-align: top;' lang='en'> <td colspan='2' style="background-color: white; color:black; text-align: center;">← Older revision</td> <td colspan='2' style="background-color: white; color:black; text-align: center;">Revision as of 10:08, 17 May 2011</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l1" >Line 1:</td> <td colspan="2" class="diff-lineno">Line 1:</td></tr> <tr><td class='diff-marker'>−</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>What is MP3? MP3 is a short name for MPEG-1 Audio Layer 3, which is a very popular encoding format for audio recording. MP3 was invented by a team of European engineers at Philips, CCETT, IRT and Fraunhofer Society in 1991.</div></td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">&lt;pre&gt;</ins>What is MP3? MP3 is a short name for MPEG-1 Audio Layer 3, which is a very popular encoding format for audio recording. MP3 was invented by a team of European engineers at Philips, CCETT, IRT and Fraunhofer Society in 1991.</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>MP3 supports several bit rates: 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256 and 320 kbit/s. But 128 kbit/s is most commonly used since it typically offers very good audio quality in a relatively small space. By contrast, uncompressed audio as stored on an audio CD (Compact Disc Digital Audio or CD-DA) has a bit rate of 1,411.2 kbit/s (16 bits/sample * 44100 samples/second * 2 channels / 1000 bits/kilobit).</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>MP3 supports several bit rates: 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256 and 320 kbit/s. But 128 kbit/s is most commonly used since it typically offers very good audio quality in a relatively small space. By contrast, uncompressed audio as stored on an audio CD (Compact Disc Digital Audio or CD-DA) has a bit rate of 1,411.2 kbit/s (16 bits/sample * 44100 samples/second * 2 channels / 1000 bits/kilobit).</div></td></tr> <tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l36" >Line 36:</td> <td colspan="2" class="diff-lineno">Line 36:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>In 1998, ID3v2 was created to add tags at the start of MP3 files. ID3V2 tags uses frames to store pieces of metadata.</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>In 1998, ID3v2 was created to add tags at the start of MP3 files. ID3V2 tags uses frames to store pieces of metadata.</div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color:black; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">&lt;/pre&gt;</ins></div></td></tr> </table>

Admin https://sound.bai-hua.org/index.php?title=MP3_Encoding_and_File_Format&diff=276&oldid=prev 2011-05-17T10:07:14Z

<p>Created page with &quot;What is MP3? MP3 is a short name for MPEG-1 Audio Layer 3, which is a very popular encoding format for audio recording. MP3 was invented by a team of European engineers at Philip...&quot;</p> <p><b>New page</b></p><div>What is MP3? MP3 is a short name for MPEG-1 Audio Layer 3, which is a very popular encoding format for audio recording. MP3 was invented by a team of European engineers at Philips, CCETT, IRT and Fraunhofer Society in 1991.<br /> <br /> MP3 supports several bit rates: 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256 and 320 kbit/s. But 128 kbit/s is most commonly used since it typically offers very good audio quality in a relatively small space. By contrast, uncompressed audio as stored on an audio CD (Compact Disc Digital Audio or CD-DA) has a bit rate of 1,411.2 kbit/s (16 bits/sample * 44100 samples/second * 2 channels / 1000 bits/kilobit).<br /> <br /> A MP3 file name has the file extension of .mp3.<br /> <br /> A MP3 file contains many MP3 frames with a MP3 header and a MP3 data in each frame:<br /> <br /> MP3 Header | MP3 Frame<br /> MP3 Data |<br /> MP3 Header | MP3 Frame<br /> MP3 Data |<br /> MP3 Header | MP3 Frame<br /> MP3 Data |<br /> ...<br /> <br /> A MP3 header has the following structure:<br /> <br /> Bits Meaning Value Note<br /> <br /> 1-12 Sync word 111111111111 <br /> 13 Version 1 1 = MPEG-1<br /> 14-15 Layer 01 01 = Layer 3<br /> 16 Error protection 1 1 = No<br /> 17-20 Bit rate 1000 1000 = 128 kbps<br /> 21-22 Frequency 00 00 = 44100 Hz<br /> 23 Pad bit 0 0 = Frame is no padded<br /> 24 Priv. bit 0 Unkown<br /> 25-26 Mode 01 Joint stereo<br /> 27-28 Mode extension 00 00 = Intensity and MS off<br /> 29 Copyright 0 0 = Not copyrighted<br /> 30 Original 0 0 = Not original<br /> 31-32 Emphasis 00 00 = None<br /> <br /> The original MP3 file format does not allow any places to store information about the MP3 file. So a new standard called ID3v1 was developed in 1996. ID3v1 adds a 128-byte tag space to the end of a MP3 file. The tag space starts with the string TAG, and contains information about the MP3 file like, title, artist, album, comment, etc.<br /> <br /> In 1998, ID3v2 was created to add tags at the start of MP3 files. ID3V2 tags uses frames to store pieces of metadata.</div>

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