Before configuring video playback, determine the model and
chipset of the video card. While
Xorg supports a wide variety of
video cards, not all provide good playback performance. To
obtain a list of extensions supported by the
Xorg server using the card, run
xdpyinfo
while
Xorg is running.
It is a good idea to have a short MPEG test file for
evaluating various players and options. Since some
DVD applications look for
DVD media in /dev/dvd
by
default, or have this device name hardcoded in them, it might be
useful to make a symbolic link to the proper device:
#
ln -sf /dev/cd0 /dev/dvd
Due to the nature of devfs(5), manually created links
will not persist after a system reboot. In order to recreate
the symbolic link automatically when the system boots, add the
following line to /etc/devfs.conf
:
link cd0 dvd
DVD decryption invokes certain functions that require write permission to the DVD device.
To enhance the shared memory Xorg interface, it is recommended to increase the values of these sysctl(8) variables:
kern.ipc.shmmax=67108864 kern.ipc.shmall=32768
There are several possible ways to display video under Xorg and what works is largely hardware dependent. Each method described below will have varying quality across different hardware.
Common video interfaces include:
Xorg: normal output using shared memory.
XVideo: an extension to the Xorg interface which allows video to be directly displayed in drawable objects through a special acceleration. This extension provides good quality playback even on low-end machines. The next section describes how to determine if this extension is running.
SDL: the Simple Directmedia Layer is a porting layer for many operating systems, allowing cross-platform applications to be developed which make efficient use of sound and graphics. SDL provides a low-level abstraction to the hardware which can sometimes be more efficient than the Xorg interface. On FreeBSD, SDL can be installed using the devel/sdl20 package or port.
DGA: the Direct Graphics Access is
an Xorg extension which
allows a program to bypass the
Xorg server and directly
alter the framebuffer. Because it relies on a low level
memory mapping, programs using it must be run as
root
. The
DGA extension can be tested and
benchmarked using dga(1). When
dga
is running, it changes the colors
of the display whenever a key is pressed. To quit, press
q.
SVGAlib: a low level console graphics layer.
To check whether this extension is running, use
xvinfo
:
%
xvinfo
XVideo is supported for the card if the result is similar to:
X-Video Extension version 2.2 screen #0 Adaptor #0: "Savage Streams Engine" number of ports: 1 port base: 43 operations supported: PutImage supported visuals: depth 16, visualID 0x22 depth 16, visualID 0x23 number of attributes: 5 "XV_COLORKEY" (range 0 to 16777215) client settable attribute client gettable attribute (current value is 2110) "XV_BRIGHTNESS" (range -128 to 127) client settable attribute client gettable attribute (current value is 0) "XV_CONTRAST" (range 0 to 255) client settable attribute client gettable attribute (current value is 128) "XV_SATURATION" (range 0 to 255) client settable attribute client gettable attribute (current value is 128) "XV_HUE" (range -180 to 180) client settable attribute client gettable attribute (current value is 0) maximum XvImage size: 1024 x 1024 Number of image formats: 7 id: 0x32595559 (YUY2) guid: 59555932-0000-0010-8000-00aa00389b71 bits per pixel: 16 number of planes: 1 type: YUV (packed) id: 0x32315659 (YV12) guid: 59563132-0000-0010-8000-00aa00389b71 bits per pixel: 12 number of planes: 3 type: YUV (planar) id: 0x30323449 (I420) guid: 49343230-0000-0010-8000-00aa00389b71 bits per pixel: 12 number of planes: 3 type: YUV (planar) id: 0x36315652 (RV16) guid: 52563135-0000-0000-0000-000000000000 bits per pixel: 16 number of planes: 1 type: RGB (packed) depth: 0 red, green, blue masks: 0x1f, 0x3e0, 0x7c00 id: 0x35315652 (RV15) guid: 52563136-0000-0000-0000-000000000000 bits per pixel: 16 number of planes: 1 type: RGB (packed) depth: 0 red, green, blue masks: 0x1f, 0x7e0, 0xf800 id: 0x31313259 (Y211) guid: 59323131-0000-0010-8000-00aa00389b71 bits per pixel: 6 number of planes: 3 type: YUV (packed) id: 0x0 guid: 00000000-0000-0000-0000-000000000000 bits per pixel: 0 number of planes: 0 type: RGB (packed) depth: 1 red, green, blue masks: 0x0, 0x0, 0x0
The formats listed, such as YUV2 and YUV12, are not present with every implementation of XVideo and their absence may hinder some players.
If the result instead looks like:
X-Video Extension version 2.2 screen #0 no adaptors present
XVideo is probably not supported for the card. This means that it will be more difficult for the display to meet the computational demands of rendering video, depending on the video card and processor.
This section introduces some of the software available from the FreeBSD Ports Collection which can be used for video playback.
MPlayer is a command-line video player with an optional graphical interface which aims to provide speed and flexibility. Other graphical front-ends to MPlayer are available from the FreeBSD Ports Collection.
MPlayer can be installed using the multimedia/mplayer package or port. Several compile options are available and a variety of hardware checks occur during the build process. For these reasons, some users prefer to build the port rather than install the package.
When compiling the port, the menu options should be reviewed to determine the type of support to compile into the port. If an option is not selected, MPlayer will not be able to display that type of video format. Use the arrow keys and spacebar to select the required formats. When finished, press Enter to continue the port compile and installation.
By default, the package or port will build the
mplayer
command line utility and the
gmplayer
graphical utility. To encode
videos, compile the multimedia/mencoder
port. Due to licensing restrictions, a package is not
available for MEncoder.
The first time MPlayer is
run, it will create ~/.mplayer
in the
user's home directory. This subdirectory contains default
versions of the user-specific configuration files.
This section describes only a few common uses. Refer to mplayer(1) for a complete description of its numerous options.
To play the file
,
specify the video interfaces with testfile.avi
-vo
, as
seen in the following examples:
%
mplayer -vo xv
testfile.avi
%
mplayer -vo sdl
testfile.avi
%
mplayer -vo x11
testfile.avi
#
mplayer -vo dga
testfile.avi
#
mplayer -vo 'sdl:dga'
testfile.avi
It is worth trying all of these options, as their relative performance depends on many factors and will vary significantly with hardware.
To play a DVD, replace
with testfile.avi
dvd://
, where
N
-dvd-device
DEVICE
N
is the title number to play and
DEVICE
is the device node for the
DVD. For example, to play title 3 from
/dev/dvd
:
#
mplayer -vo xv dvd://3 -dvd-device /dev/dvd
The default DVD device can be
defined during the build of the
MPlayer port by including the
WITH_DVD_DEVICE=/path/to/desired/device
option. By default, the device is
/dev/cd0
. More details can be found
in the port's
Makefile.options
.
To stop, pause, advance, and so on, use a keybinding.
To see the list of keybindings, run mplayer
-h
or read mplayer(1).
Additional playback options include -fs
-zoom
, which engages fullscreen mode, and
-framedrop
, which helps performance.
Each user can add commonly used options to their
~/.mplayer/config
like so:
vo=xv fs=yes zoom=yes
mplayer
can be used to rip a
DVD title to a .vob
.
To dump the second title from a
DVD:
#
mplayer -dumpstream -dumpfile out.vob dvd://2 -dvd-device /dev/dvd
The output file, out.vob
, will be
in MPEG format.
Anyone wishing to obtain a high level of expertise with UNIX® video should consult mplayerhq.hu/DOCS as it is technically informative. This documentation should be considered as required reading before submitting any bug reports.
Before using mencoder
, it is a good
idea to become familiar with the options described at mplayerhq.hu/DOCS/HTML/en/mencoder.html.
There are innumerable ways to improve quality, lower
bitrate, and change formats, and some of these options may
make the difference between good or bad performance.
Improper combinations of command line options can yield
output files that are unplayable even by
mplayer
.
Here is an example of a simple copy:
%
mencoder
input.avi
-oac copy -ovc copy -ooutput.avi
To rip to a file, use -dumpfile
with
mplayer
.
To convert
to
the MPEG4 codec with MPEG3 audio encoding, first install the
audio/lame port. Due to licensing
restrictions, a package is not available. Once installed,
type:input.avi
%
mencoder
input.avi
-oac mp3lame -lameopts br=192 \ -ovc lavc -lavcopts vcodec=mpeg4:vhq -ooutput.avi
This will produce output playable by applications such
as mplayer
and
xine
.
can be replaced with input.avi
dvd://1 -dvd-device
/dev/dvd
and run as root
to re-encode a
DVD title directly. Since it may take a
few tries to get the desired result, it is recommended to
instead dump the title to a file and to work on the
file.
xine is a video player with a reusable base library and a modular executable which can be extended with plugins. It can be installed using the multimedia/xine package or port.
In practice, xine requires either a fast CPU with a fast video card, or support for the XVideo extension. The xine video player performs best on XVideo interfaces.
By default, the xine player starts a graphical user interface. The menus can then be used to open a specific file.
Alternatively, xine may be invoked from the command line by specifying the name of the file to play:
%
xine -g -p
mymovie.avi
Refer to xine-project.org/faq for more information and troubleshooting tips.
Transcode provides a suite of tools for re-encoding video and audio files. Transcode can be used to merge video files or repair broken files using command line tools with stdin/stdout stream interfaces.
In FreeBSD, Transcode can be installed using the multimedia/transcode package or port. Many users prefer to compile the port as it provides a menu of compile options for specifying the support and codecs to compile in. If an option is not selected, Transcode will not be able to encode that format. Use the arrow keys and spacebar to select the required formats. When finished, press Enter to continue the port compile and installation.
This example demonstrates how to convert a DivX file into a PAL MPEG-1 file (PAL VCD):
%
transcode -i
input.avi
-V --export_prof vcd-pal -o output_vcd%
mplex -f 1 -o
output_vcd.mpg output_vcd.m1v output_vcd.mpa
The resulting MPEG file,
,
is ready to be played with
MPlayer. The file can be burned
on a CD media to create a video
CD using a utility such as
multimedia/vcdimager or
sysutils/cdrdao.output_vcd.mpg
In addition to the manual page for
transcode
, refer to transcoding.org/cgi-bin/transcode
for further information and examples.
All FreeBSD documents are available for download at http://ftp.FreeBSD.org/pub/FreeBSD/doc/
Questions that are not answered by the
documentation may be
sent to <[email protected]>.
Send questions about this document to <[email protected]>.