mpeg.txt

MPEG文件格式定义清单

From: Wilson Woo <[e-mail]>
To: [e-mail]
Subject: MPEG Video

THIS TEXT CONTAINS ONLY MPEG VIDEO HEADER INFO - BY WILSON WOO
It's only what I know. Please feel free to update it.

Below is information got from someone.

/*****************************************************************/

Sequence Header

This contains information related to one or more "group-of-pictures"

Byte#      Data                Details
===================================================================
1-4        Sequence header     In Hex 000001B3
           code
12 bits    Horizontal size     In pixels
12 bits    Vertical size       In pixels
 4 bits    Pel aspect ratio    See below
18 bits    Picture rate        See below
 1 bit     Marker bit          Always 1
10 bits    VBV buffer size     Minimum buffer needed to decode this
                               sequence of pictures; in 16KB units
 1 bit     Constrained
           parameter flag
 1 bit     Load intra          0: false; 1: true (matrix follows)
           quantizer matrix
64 bytes   Intra quantizer     Optional
           matrix
 1 bit     Load nonintra       0: false; 1: true (matrix follows)
           quantizer matrix
64 bytes   Nonintra quantizer  Optional
           matrix
 -         Squence extension   Optional
           Data
 -         User data           Optional application-dependent data
===================================================================

Aspect raios are defined by a code which represents the height and
width of the Video image.
Picture rates are also defined by a code that represents the number
of pictures that may be displayed each second.

Each group of pictures has a header that contains one "I picture"
and zero or more B and P pictures. The header is concerned with
the time synchronisation for the first picture in this group, and
the closeness of the previous group to this one.

/*****************************************************************/

For picture rate:
1 = 23.976 frames/sec
2 = 24
3 = 25
4 = 29.97
5 = 30
6 = 50
7 = 59.94
8 = 60

Here gives an example. Below is Hex dump of first 256 bytes of
the first Video frame of TEST.MPG from XingMPEG.

00 00 01 B3 16 00 F0 C4 02 A3 20 A5 10 12 12 14
14 14 16 16 16 16 18 18 19 18 18 1A 1B 1B 1B 1B
1A 1C 1D 1E 1E 1E 1D 1C 1E 1F 20 21 21 20 1F 1E
21 23 23 24 23 23 21 25 26 27 27 26 25 29 2A 2A
2A 29 2D 2D 2D 2D 30 31 30 34 34 38 16 00 F0 C4
00 00 01 B8 00 08 00 00 00 00 01 00 00 0A 72 00
00 00 01 01 13 F9 50 02 BC B2 B8 BE 68 8B A4 9F
C5 B5 CA 00 56 76 39 65 F2 30 8B A6 9D 50 69 E7
DA FE 13 CF B7 FF 8F F4 CE 7B FA 0E F0 66 AE 1C
5D E7 00 C8 0A 92 B9 29 3C 21 23 F1 D6 40 13 06
F0 10 10 C6 27 80 A0 34 E1 C8 E4 0F 74 91 DA C4
03 A0 DC 03 12 60 18 49 27 1D D4 BC 67 0E 54 8C
96 FC 5D C0 06 E0 1A 72 11 7C 9A 8D C9 45 89 6D
CD C4 0B 63 DC 90 18 24 00 EC 84 90 18 10 C9 3B
1E A7 60 3C 9D 74 80 76 05 0B 02 81 A9 29 39 68
53 8F 59 F1 BF 93 FB A0 04 01 BC B0 CE 18 E1 25

Sequence header  = (Hex) 00 00 01 B3
Horizontal size  = 0x160 = 352
Vertical size    = 0x0F0 = 240
Pel aspect ratio = [I don't know]
Picture rate     = 4 = 29.97 frames/sec
Marker bit       = 1