[M4IF Technotes] Decoder specific info for visual atoms

[Herbert Thoma]

Stage NexVision schrieb:
> Does any of you can explain me if these 'crazy' 32 bytes contains any
> informations about the movie size ?

These crazy bytes are the headers of the video elementary stream,
see ISO/IEC 14496-2. And yes, the VOL width and VOL height are
encoded in these bits.
> Decoder specific info
> \/
> 05 80808020 00 00 01 B0 01 00 00 01 B5 0E E0 40 40 AF
> 00 00 01 00 00 00 01 20 00 84 5D 4C 28 50 20 F0 A3 1F

The following is what our Fraunhofer IIS MPEG-4 Video Decoder
says to your 32 bytes:
----------------------------------------------------------
Visual Sequence Header (VS ID = 0):
Start Code Prefix: "000000000000000000000001", Start Code: "10110000" = 0xB0
Profile and Level Indication: "00000001" = 1
----------------------------------------------------------
Visual Object Header (VO ID = 0, VS ID = 0):
Start Code Prefix: "000000000000000000000001", Start Code: "10110101" = 0xB5
Is Visual Object Identifier: "0" = 0
Visual Object Type: "0001" = 1
Video Signal Type: "1" = 1
  Video Format: "101" = 5
  Video Range: "1" = 1
  Colour Description: "1" = 1
    Colour Primaries: "00000010" = 2
    Transfer Characteristics: "00000010" = 2
    Matrix Coefficients: "00000101" = 5
Align Bits: "01111" = 5 bit(s)
----------------------------------------------------------
Video Object Header (VO ID = 0, VS ID = 0):
Start Code Prefix: "000000000000000000000001", Start Code: "00000000" = 0x00
----------------------------------------------------------
Video Object Layer Header (VOL ID = 0, VO ID = 0, VS ID = 0):
Start Code Prefix: "000000000000000000000001", Start Code: "00100000" = 0x20
Random Accessible VOL: "0" = 0
Video Object Type Indication: "00000001" = 1
Is Visual Object Layer Identifier: "0" = 0
Aspect Ratio Info: "0001" = 1
VOL Control Parameters: "0" = 0
Video Object Layer Shape: "00" = 0
Marker Bit: "1"
VOP Timeincrement Resolution: "0111010100110000" = 30000
Marker Bit: "1"
Fixed VOP Rate: "0" = 0
Marker Bit: "1"
VOL Width: "0000101000000" = 320
Marker Bit: "1"
VOL Height: "0000011110000" = 240
Marker Bit: "1"
Interlaced: "0" = 0
OBMC Disable: "1" = 1
Sprite Enable: "0" = 0
Not 8 Bit: "0" = 0
Quant Type: "0" = 0
Complexity Estimation Disable: "1" = 1
Resync Marker Disable: "1" = 1
Data Partitioned: "0" = 0
Scalability: "0" = 0
Align Bits: "011111" = 6 bit(s)
 Herbert.
-- 
Herbert Thoma
FhG-IIS A, Studio Department
Am Wolfsmantel 33, 91058 Erlangen, Germany
Phone: +49-9131-776-323
Fax:   +49-9131-776-399
email: tma   iis.fhg.de
www: http://www.iis.fhg.de/