User`s manual

Alcorn McBride Digital Video Machine DVM-7400 User’s Manual Rev 1.5
68
MPEG-2 Formats
The MPEG-2 Program Stream
The DVM only
supports files up to
2GB in size. See File
System Limitations
section for more
information.
The DVM only plays MPEG-2 Program Streams. This stream is a Variable or
Constant bitrate stream containing both audio and video information. In order to
achieve playback of video only, you must encode an elementary stream of silent
audio that will be combined with your elementary video stream to create a program
stream. A program stream is not the same as a DVD VOB file. The DVM does not
play VOB files.
What is a Variable Bitrate?
Unlike MPEG-1, which uses a constant bitrate, MPEG-2 supports variable bitrate
program streams. This means that the encoding process scales the bitrate up and
down depending on quality needs. A scene with a tremendous amount of movement
requires more bits than a much more still scene.
Program Stream:
Multiplexed Bit Rate: 15.0 Mbits/s max
The stream should be authored according to ISO 13818-1 Format
MPEG-2 Video:
SIF-NTSC: 240 lines by 352
pixels
SIF-PAL: 288 lines by 352
pixels
HalfD1-NTSC: 480 lines by
352 pixels
HalfD1-PAL: 576 lines by 352
pixels
CCIR-NTSC: 480 lines by
704(or 720) pixels
Picture Format
CCIR-PAL: 576 lines by 704(or
720) pixels
Chroma
Format
4:2:0
MPEG-1 Audio (Layer I or II):
Sample Rate: 44.1 KHz or 48KHz
Emphasis: Off
Mode: Stereo