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MPEG(1) USER COMMANDS MPEG(1)
NAME
mpeg - MPEG compression and decompression
SYNOPSIS
mpeg [-d] [-NTSC] [-CIF] [-QCIF] [-PF] [-NPS] [-MBPS mbps]
[-UTC]
[-a StartNumber] [-b EndNumber]
[-h HorizontalSize] [-v VerticalSize]
[-f FrameInterval] [-g GroupInterval]
[-4] [-c] [-i MCSearchLimit] [-o] [-p PictureRate]
[-q Quantization] [-r Target Rate]
[-s StreamFile] [-x Target Filesize] [-y]
[-z ComponentFileSuffix i]
ComponentFilePrefix1 [ComponentFilePrefix2 Com-
ponentFilePrefix3]
DESCRIPTION
mpeg is a multimedia image sequence
compression/decompression program that performs MPEG encod-
ing and decoding.
OPTIONS
-NTSC
indicates that the source frame size for the Luminance
component is 352x240 and for the Chrominance components
is 176x120. This is the default size.
-CIF indicates that the source frame size for the Luminance
component is 352x288 and for the Chrominance components
is 176x144.
-QCIF
indicates that the source frame size for the Luminance
component is 176x144 and for the Chrominance components
is 88x72.
-PF indicates that the component sizes specified by -h and
-v are not multiples of 16 and furthermore that the
input files (or output files) should be exactly that
specified by the component size -h and -v (or as read
from the compressed stream). Otherwise the input and
output files will be the component size rounded up to a
multiple of 16 in each dimension.
-NPS The NPS option allows the encoder to encode without
having the restriction that the last macroblock in a
slice cannot be skipped. For coding purposes, the
first macroblock in a slice must be coded, although the
decoder will probably handle that case as well.
-MBPS
This specifies the macroblocks per slice. If left
AT&T Bell Laboratories Last change: 24 February 1993 1
MPEG(1) USER COMMANDS MPEG(1)
unspecified then the number of macroblocks per slice is
the number of macroblocks on one row of the image.
-UTC Forces the frame number of the image to match the
Group-of-Pictures time code. Only useful for the
decoder.
-a denotes the following value to be the start of the
filename index [inclusive]. Defaults to 0.
-b denotes the following value to be the end of the
filename index [inclusive]. Defaults to 0.
-d enables the decoder. The only options useful for the
decoder are the filename specifications and the -NPS,
-UTC commmands; the rest of the command-line informa-
tion is used for encoding.
-h is the horizontal size of the picture in terms of the
luminance component, used for a non -NTSC, -CIF, -QCIF
filesize. See the preceding note about -PF about the
dimensions of the file relative to that of the com-
ponent.
-v is the vertical size of the picture in terms of the
luminance component, used for a non -NTSC, -CIF, -QCIF
filesize. See the preceding note about -PF about the
dimensions of the file relative to that of the com-
ponent.
-f is the number of interpolated frames between each
intra/predicted frame. FrameInterval-1 is the number
of interpolated frames within each frame interval.
-g is the number of frame intervals per group-of-pictures.
With a group interval of 1 then there are no predicted
frames. The value GroupInterval-1 is the number of
predicted frames in each group of pictures.
-4 is used to DC Intraframe mode where only the DC com-
ponents of each picture block is coded.
-i is the diameter of the motion estimation search. The
diameter must be inclusively between 1 and 15, desig-
nating a region from interframe only (0,0) search, to
full search (+- 7.5, +- 7.5). The motion estimation is
telescopic for frame distances greater than 1 (thus
having a greater effective range).
-o signals that the program interpreter will read the con-
trol algorithms from the standard input.
AT&T Bell Laboratories Last change: 24 February 1993 2
MPEG(1) USER COMMANDS MPEG(1)
-p specifies the picture rate by a code directly placed
into the stream. It must be a number between 0 and 8.
(default 5=30Hz).
-q gives a value for the quantization not in the presence
of rate control (rate control automatically changes the
quantization values). If rate control is specified,
this parameter gives a value for the initial quantiza-
tion of the first frame (which the program usually
takes an educated guess at).
-r specified a rate for the coded stream. If this is
enabled, a buffer model is used to limit the size of
the coding stream. Note this is given in bits per
second.
-s specifies the filename to store the coded image. If
unspecified it defaults to ComponentFilePrefix0.mpg.
-v designates that quantization decisions are to be writ-
ten to standard output. This is the verbose mode.
-x gives a target filesize for the compressed stream. This
overrides the rate option -r, if specified. This is
specified in bits. The actual implementation of this
technique is through calculating the equivalent bit-
rate. Since the buffer usually has some contents at the
end of coding, the final filesize is larger than actu-
ally designated.
-y enables the double-precision floating point Reference
DCT. The default is the Chen DCT.
-z denotes the component file suffixes in sequential
order. For example
-z .y.clr -z .u.clr -z .v.clr indicates that the lumi-
nance and the two chrominance files end with a suffix
of .y.clr, .u.clr, and .v.clr, in that order. If
unspecified, the suffixes default to .Y, U, and .V.
ComponentFilePrefixn
must be specified. In general, the other component
files share the same prefix and will default to Com-
ponentFilePrefix1 if not explicitly specified. However,
in some cases the prefix is what changes in the file
and we can specify this individually.
EXAMPLES
To encode a set of raw raster scan YUV files with dimension
352x240 Y, 176x120 U,V, with labels, hello0.Y hello0.U
hello0.V, hello1.Y hello1.U hello1.V, ..., hello12.Y
hello12.U hello12.V through the mpeg encoder, type
AT&T Bell Laboratories Last change: 24 February 1993 3
MPEG(1) USER COMMANDS MPEG(1)
mpeg -a 0 -b 12 hello -s hello.mpg
This creates the output file hello.mpg. In order to decode
such a file into a sequence of image files with prefix good-
bye, type
mpeg -d -s hello.mpg goodbye
The output will be placed in the files goodbye0.Y goodbye0.U
goodbye0.V, goodbye1.Y goodbye1.U goodbye1.V, ...,
goodbye12.Y goodbye12.U goodbye12.V. These image sequences
can be displayed by the cv program available by anonymous
ftp from havefun.stanford.edu:pub/cv/CVv1.1.tar.Z. There are
more options within an internal program interpreter. Please
see the accompanying documentation in doc.ps for more
details.
FTP
mpeg is available by anonymous ftp from
havefun.stanford.edu:pub/mpeg/MPEGv1.1.tar.Z.
BUGS
Somewhat slower than many commercial implementations.
Please inform the author at achung@cs.stanford.edu if any
bugs are found.
AUTHOR
Andy Hung
AT&T Bell Laboratories Last change: 24 February 1993 4