4.2. Stream a file with VLS
% vls -vv -d udp:192.168.0.42 file:video1.xyz --ttl 12
|
where
:
video1.xyz
is the file you want to stream
,
192.168.0.42
is either
:
the IP address of the machine you want to unicast
to
;
or the DNS name the machine you want to unicast
to
;
or a multicast IP address
.
12
is the value of the TTL (Time To
Live) of your IP packets (which means that the stream will be
able to cross 11 routers)
.
When you want to stop VLS, use the key combination
Ctrl-c.
If you want to stream the file continuously, add the
--loop option
.
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VLS can stream MPEG files that meet two critera
:
the file must be MPEG PS
(Program Stream) or MPEG TS (Transport Stream),
that contain video and audio multiplexed. VLS cannot stream MPEG
ES (Elementary Stream), i.e. a file with only audio
or video
.
In order to know if an MPEG file is MPEG
PS, MPEG TS or MPEG
ES, read the file with VLC and look at the messages
(select in the menu View / Messages, or use the
command line vlc -vvv)
.
If you see a line
:
[00000107] main module debug: using demux module "ts_dvbpsi"
|
it means the file is MPEG TS
.
If you see a line
:
[00000109] main module debug: using demux module "ps"
|
it means the file is MPEG PS
.
If you see a line
:
[00000109] main module debug: using demux module "es"
|
it means the file is MPEG ES, VLS can't stream it.
.
the sequence header of the video must repeat itself
regularly, which is often the case with MPEG-2, but very rare with
MPEG-1. There is no easy way to know if the sequence header is repeated
regularly. Files with a .vob extension are
normally MPEG-2 files and files with .mpg or
.mpeg extension or usually MPEG-1 files
.
You can download this
streamable MPEG-2 PS file for your tests : presentation_short.vob
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