MPEG Headers Quick Reference
This is a quick reference to the various headers and streams found in MPEG/DVD. For a complete description you should get a copy of ISO/IEC 13818.
This is an incomplete work-in-progress
The header
Every stream or table begins with a 32-bit start code, codes 00 through B8 are video stream start codes (fully defined in 13818-2), and codes B9-FF are stream-id's
| byte 0 |
byte 1 |
byte 2 |
byte 3 |
0000 0000 0000 0000 0000 0001
Start code prefix |
Start Code
-or- Stream ID |
| Start Code |
used for |
| 0x00 |
Picture |
| 0x01 - 0xAF |
slice |
| 0xB0 |
reserved |
| 0xB1 |
reserved |
| 0xB2 |
user data |
| 0xB3 |
Sequence header |
| 0xB4 |
sequence error |
| 0xB5 |
extension |
| 0xB6 |
reserved |
| 0xB7 |
sequence end |
| 0xB8 |
Group of Pictures |
|
| Stream ID |
used for |
| 0xB9 |
Program end (terminates a program stream) |
| 0xBA |
Pack header |
| 0xBB |
System Header |
| 0xBC |
Program Stream Map |
| 0xBD |
Private stream 1 |
| 0xBE |
Padding stream |
| 0xBF |
Private stream 2 |
| 0xC0 - 0xDF |
MPEG-1 or MPEG-2 audio stream |
| 0xE0 - 0xEF |
MPEG-1 or MPEG-2 video stream |
| 0xF0 |
ECM Stream |
| 0xF1 |
EMM Stream |
| 0xF2 |
ITU-T Rec. H.222.0 | ISO/IEC 13818-1 Annex A or ISO/IEC 13818-6_DSMCC_stream |
| 0xF3 |
ISO/IEC_13522_stream |
| 0xF4 |
ITU-T Rec. H.222.1 type A |
| 0xF5 |
ITU-T Rec. H.222.1 type B |
| 0xF6 |
ITU-T Rec. H.222.1 type C |
| 0xF7 |
ITU-T Rec. H.222.1 type D |
| 0xF8 |
ITU-T Rec. H.222.1 type E |
| 0xF9 |
ancillary_stream |
| 0xFA - 0xFE |
reserved |
| 0xFF |
Program Stream Directory |
|
Picture header (0100)
Variable length.
| byte 4 |
byte 5 |
byte 6 |
byte 7 |
| 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 |
| temporal sequence number |
frame type
1=I, 2=P
3=B, 4=D |
VBV delay |
--- |
additional fields appended beginning at byte 7 bit 2:
If frame type = 2 (P) or 3 (B) the following 4 bits are appended to the header:
| 3 |
2 |
1 |
0 |
| full_pel_forward_vector |
forward_f_code |
This field is used by MPEG-1 only, for MPEG-2 it should be set to 0 1 1 1
If frame type = 3 (B) the following 4 bits are appended to the header:
| 3 |
2 |
1 |
0 |
| full_pel_backward_vector |
backward_f_code |
This field is used by MPEG-1 only, for MPEG-2 it should be set to 0 1 1 1
additionally if the next bit is "1" (extra_bit_picture) it is followed by 8 bits of "extra" data (discarded by decoders). This continues until a "0" bit is encountered.
Sequence header (01B3)
Variable length.
| byte 4 |
byte 5 |
byte 6 |
byte 7 |
| 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 |
| horizontal size |
vertical size |
aspect ratio |
frame rate |
| byte 8 |
byte 9 |
byte 10 |
byte 11 |
| 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 |
| bit rate |
1 |
VBV buffer size |
constrained parameters flag |
load intra quantiser matrix |
(load non-intra quantiser matrix) |
If either load quantiser matrix flag is =1, it is immediately followed by the 64 byte table (moving the "load non-intra quantiser matrix" flag, in the case of "load intra quantiser matrix")
| Code |
MPEG-1 Aspect Ratio (PAR) |
MPEG-2 Aspect Ratio (DAR) |
Frame Rate |
| 0 |
forbidden |
forbidden |
forbidden |
| 1 |
1.0000 |
1:1 |
24000/1001 (23.976) |
| 2 |
0.6735 |
4:3 |
24 |
| 3 |
0.7031 PAL 16:9 |
16:9 |
25 |
| 4 |
0.7615 |
2.21:1 |
30000/1001 (29.97) |
| 5 |
0.8055 |
reserved |
30 |
| 6 |
0.8437 NTSC 16:9 |
reserved |
50 |
| 7 |
0.8935 |
reserved |
60000/1001 (59.94) |
| 8 |
0.9375 PAL 4:3 |
reserved |
60 |
| 9 |
0.9815 |
reserved |
reserved |
| 10 |
1.0255 |
reserved |
reserved |
| 11 |
1.0695 |
reserved |
reserved |
| 12 |
1.1250 NTSC 4:3 |
reserved |
reserved |
| 13 |
1.1575 |
reserved |
reserved |
| 14 |
1.2015 |
reserved |
reserved |
| 15 |
reserved |
reserved |
reserved |
extension header (01B5)
There are a variety of extensions, denoted by the first 4 bits.
Sequence_Extension
Fixed length.
| byte 4 |
byte 5 |
byte 6 |
byte 7 |
byte 8 |
byte 9 |
| 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 |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| 0001 |
profile and level |
progressive_sequence |
chroma_format |
horizontal size extension |
vertical size extension |
bit rate extension |
1 |
vbv buffer size extension |
low delay |
frame rate extension n |
frame rate extension d |
Sequence_Display_Extension
Variable length.
With no color description information, the last 3 bits of byte 8 are not part of this table.
| byte 4 |
byte 5 |
byte 6 |
byte 7 |
byte 8 |
| 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 |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| 0010 |
video format |
color description flag =0 |
display horizontal size |
1 |
display vertical size |
|
With color description information, the last 3 bits of byte 11 are not part of this table.
| byte 4 |
byte 5 |
byte 6 |
byte 7 |
byte 8 |
byte 9 |
byte 10 |
byte 11 |
| 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 |
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 |
| 0010 |
video format |
color description flag =1 |
color primaries |
transfer characteristics |
matrix coefficients |
display horizontal size |
1 |
display vertical size |
|
Picture_Display_Extension
Variable length, depending on number of offsets encoded (see section 6.3.12 of ISO/IEC 13818-2).
For a single offset (the last 2 bits of byte 8 are not part of this table).
| byte 4 |
byte 5 |
byte 6 |
byte 7 |
byte 8 |
| 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 |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| 0111 |
frame_center_horizontal_offset[1] |
1 |
frame_center_vertical_offset[1] |
1 |
|
For two offsets.
| byte 4 |
byte 5 |
byte 6 |
byte 7 |
byte 8 |
byte 9 |
byte 10 |
byte 11 |
byte 12 |
| 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 |
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 |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| 0111 |
frame_center_horizontal_offset[1] |
1 |
frame_center_vertical_offset[1] |
1 |
frame_center_horizontal_offset[2] |
1 |
frame_center_vertical_offset[2] |
1 |
For three offsets (the maximum, the last 6 bits of byte 17 are not part of this table).
| byte 4 |
byte 5 |
byte 6 |
byte 7 |
byte 8 |
byte 9 |
byte 10 |
byte 11 |
byte 12 |
byte 13 |
byte 14 |
byte 15 |
byte 16 |
byte 17 |
| 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 |
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 |
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 |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| 0111 |
frame_center_horizontal_offset[1] |
1 |
frame_center_vertical_offset[1] |
1 |
frame_center_horizontal_offset[2] |
1 |
frame_center_vertical_offset[2] |
1 |
frame_center_horizontal_offset[3] |
1 |
frame_center_vertical_offset[3] |
1 |
|
Picture_Coding_Extension
Variable length.
| byte 4 |
byte 5 |
byte 6 |
| 7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| 1000 |
f_code[0][0] (forward horizontal) |
f_code[0][1] (forward vertical) |
f_code[1][0] (backward horizontal) |
f_code[1][1] (backward vertical) |
intra_DC_precision |
picture_structure |
| byte 7 |
| 7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| Top_Field_First |
frame_pred_frame_dct |
concealment_motion_vectors |
q_scale_type |
intra_vlc_format |
alternate_scan |
Repeat_First_Field |
chroma_420_type |
| byte 8 |
byte 9 |
byte 10 |
| 7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
| progressive_frame |
composite_display =0 |
0 0 0 0 0 0 |
(not present) |
| =1 |
v_axis |
field_sequence |
sub_carrier |
burst_amplitude |
sub_carrier_phase |
0 0 |
Group Of Pictures (GOP) (01B8)
Fixed length, contains 3 flags and the time stamp for the first frame.
| byte 4 |
byte 5 |
byte 6 |
byte 7 |
| 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 |
| drop frame flag |
hour (0-23) |
minute (0-59) |
1 |
second (0-59) |
frame (0-59) |
closed GOP |
broken GOP |
0 0 0 0 0 |
