| EXAMINATION OF MPEG 1 LAYER II AUDIO FILE FRAME HEADERS | ||||||||||||||
| Allen Rieland, rieland@wpr.org, Wisconsin Public Radio, January 12, 2006 - for PRSS | ||||||||||||||
| BYTE# | BYTE #1 | BYTE #2 | BYTE #3 | BYTE #4 | ||||||||||
| HEADER HEX | FF | FC (CRC on), FD (CRC off) | C0 (256kbps) or 80 (128kbps) | 00 (Stereo, no options) 50 (J-Stereo, no options) | ||||||||||
| C0 (Mono, no options) 08,58,C8 if Copyright On | ||||||||||||||
| LOCATION | bits 1-8 | bits 1-3 | bits 4-5 | bits 6-7 | bit 8 | bits 1-4 | bits 5-6 | bit 7 | bit 8 | bits 1-2 | bits 3-4 | bit 5 | bit 6 | bits 7-8 |
| BINARY LOC | 7,6,5,4,3,2,1,0 | 7,6,5 | 4,3 | 2,1 | 0 | 7,6,5,4 | 3,2 | 1 | 0 | 7,6 | 5,4 | 3 | 2 | 1,0 |
| PREFERRED | 11111111 | 111 | 11 | 10 | 0 | 1100/1000 | 00 | 0 | 0 | 00/01/11 | 00/01 | 0/1 | 0 | 00 |
| DESCRIPTION | Frame Sync | Frame Hdr | MPEG-V | Layer | CRC | BitRate | Sample | Padding | Priv | Mode | J-Mode | Copyright | Original | Emphasis |
| COMMENTS | First 8 bits of 13 bit Frame Sync marker. If not FF, unwanted additional ID or Summary information has been added | Part of Frame Sync Header | MPEG 1 Version 1 (10 is V2) | Layer II | CRC On (0) or Off (1) | 1100 = 256kbps, 1000 = 128kbps All Layer II, Version 1 | 00 = 44,100Hz | 0 = off | Special use or private bit, usually 0 | 00 = Stereo 01 = JStereo 11 = Mono | 00 = Typical for Intensity stereo subbands 04-31 | 0 = Not copyrighted 1 = Copyrighted | 0 = original media | 00 = None |
| BYTE #4 COMMON OPTIONS | ||||||||||||||
| ALL BELOW ARE: MPEG 1, Version 1, Layer II, 44.1KHz, Padding Off, Original, Emphasis Off | 00 | 00 | 00 | 0 | 0 | 00 | ||||||||
| COMMONLY ACCEPTABLE HEADERS | 08 | 00 | 00 | 1 | 0 | 00 | ||||||||
| FFFCC000 | CRC On, 256kbps, Stereo, Copyright Off | 40 | 01 | 00 | 0 | 0 | 00 | |||||||
| FFFCC008 | CRC On, 256kbps, Stereo, Copyright On | 48 | 01 | 00 | 1 | 0 | 00 | |||||||
| FFFCC040 | CRC On, 256kbps, Joint Intensity Stereo, Copyright Off | C0 | 11 | 00 | 0 | 0 | 00 | |||||||
| FFFCC048 | CRC On, 256kbps, Joint Intensity Stereo, Copyright On | C8 | 11 | 00 | 1 | 0 | 00 | |||||||
| FFFC80C0 | CRC On, 128kbps, Mono, Copyright Off | |||||||||||||
| FFFC80C8 | CRC On, 128kbps, Mono, Copyright On | |||||||||||||
| FFFDC000 | CRC Off, 256kbps, Stereo, Copyright Off | |||||||||||||
| FFFDC008 | CRC Off, 256kbps, Stereo, Copyright On | More Information on MPEG Headers is available at: | ||||||||||||
| FFFDC040 | CRC Off, 256kbps, Joint Intensity Stereo, Copyright Off | http://mpgedit.org/mpgedit/mpeg_format/mpeghdr.htm#MPEG%20HEADER | ||||||||||||
| FFFDC048 | CRC Off, 256kbps, Joint Intensity Stereo, Copyright On | http://www.codeproject.com/audio/mpegaudioinfo.asp? | ||||||||||||
| FFFD80C0 | CRC Off, 128kbps, Mono, Copyright Off | |||||||||||||
| FFFD80C8 | CRC Off, 128kbps, Mono, Copyright On | |||||||||||||