yuv2lav.1

Motion JPEG编解码器源代码

.TH "yuv2lav" "1" "2 June 2001" "MJPEG Linux Square" "MJPEG tools manual"

.SH "NAME"
yuv2lav \- encodes lavtool's raw YUV frame streams into MJPEG files

.SH "SYNOPSIS"
.B yuv2lav
.RB [ -f \| \ a | A | q | m ]
.RB [ -q
.IR num ]
.RB [ -b
.IR num ]
.RB [ -I
.IR num ]
.RB [ -m
.IR num ]
.RB [ -v
.IR num ]
.B -o
.I output-file

.SH "DESCRIPTION"
yuv2lav is a simple MJPEG encoder for raw YUV frame
streams as they are emitted by
.BR lav2yuv "(1) or " lavpipe "(1),"
for example. It reads its input from stdin and is capable of
writing AVI and Quicktime.

.SH "OPTIONS"
The command line options allow to specify the output file
name, JPEG encoding quality and the amount of memory that
will be allocated for JPEG compressed data.

.TP
.BI -o \ output-file
This (compulsorary) option sets the name of the file that
yuv2lav will write its output to. If the output file contains
a % (e.g. file%02d.avi), the output will be written to multiple
files in case this is necessary (file00.avi, file01.avi and so
on).

.TP
.BR -f \| \ a | A | q | m
This sets the output file format, which has to be one of
.br
.B \ a
- for AVI file output,
.br
.B \ A
- for AVI with reversed fields,
.br
.B \ q
- for Quicktime output or
.br
AVI with reversed field of course only makes sense if yuv2lav's
feed is an interlaced video source and should only be needed if
you experience frame reversal problems in your output.

.TP
.BI -q \ num
This option specifies the JPEG encoding quality as passed through
to libjpeg. The default value is 80,
.I num
must lie within 24...100 inclusive
(think of it as percentage values, although with a lossy compression
algorithm like JPEG, keeping 100% of the original quality is of
course not really possible).

.TP
.BI -b \ num
This option specifies the size of the buffer (in kBytes) that yuv2lav
allocates in order to store the compressed JPEG data in it. The default
value (256k) is perfectly enough for 100% quality full sized PAL/NTSC,
but if you want to compress Super-Mega-HDTV or if you are low on memory,
you can use this option to suit your needs.

.TP
.BI -m \ num
This is the maximum size (in MB) per file. Normally this depends on
the output file type.

.TP
.BI -I \ num
Force a specific interlacing type. 0 means no interlacing, 1 means
top-field-first, 2 means bottom-field-first.

.TP
.BI -v \ num
Verbosity level. 0 means only print error messages, 2 prints full
debug output.

.TP
.B -?
Display a synopsis of the command syntax.

.SH "EXAMPLES"

.TP
lav2yuv movie.avi | yuv2lav -fq -q 30 lowbitrate.qt
would recompress movie.avi as a low bit rate Quicktime file.
.TP
lavpipe input.pli | yuv2lav -q80 output.avi
would save the movie assembled by lavpipe as a single AVI file.

.SH "BUGS"
If you experience any problems with this tool, please feel
free to contact the developers (see below).

.SH AUTHOR
This man page was written by pHilipp Zabel.
.br
If you have questions, remarks, problems or you just want to contact
the developers, the main mailing list for the MJPEG\-tools is:
.br
    \fImjpeg\[e-mail]\fP
.br
.br
For more info, see our website at
.br
    \fIhttp://mjpeg.sourceforge.net/\fP

.SH "SEE ALSO"
.BR lav2yuv "(1), " lavpipe "(1), " lavplay "(1),"
.BR lavrec "(1), " mpeg2enc "(1), " yuvscaler "(1)"