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Apply misc fixes spotted by Diego to indevs.texi and outdevs.texi.

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Originally committed as revision 24724 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Stefano Sabatini 2010-08-06 23:15:27 +00:00
parent c32ccf7c43
commit 2f6bc4e76e
2 changed files with 32 additions and 33 deletions
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61
doc/indevs.texi
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@ -5,8 +5,8 @@ Input devices are configured elements in FFmpeg which allow to access
the data coming from a multimedia device attached to your system. the data coming from a multimedia device attached to your system.
When you configure your FFmpeg build, all the supported input devices When you configure your FFmpeg build, all the supported input devices
are enabled by default. You can list them using the configure option are enabled by default. You can list all available ones using the
"--list-indevs". configure option "--list-indevs".
You can disable all the input devices using the configure option You can disable all the input devices using the configure option
"--disable-indevs", and selectively enable an input device using the "--disable-indevs", and selectively enable an input device using the
@ -25,7 +25,7 @@ ALSA (Advanced Linux Sound Architecture) input device.
To enable this input device during configuration you need libasound To enable this input device during configuration you need libasound
installed on your system. installed on your system.
This device allows to capture from an ALSA device. The name of the This device allows capturing from an ALSA device. The name of the
device to capture has to be an ALSA card identifier. device to capture has to be an ALSA card identifier.
An ALSA identifier has the syntax: An ALSA identifier has the syntax:
@ -42,7 +42,7 @@ specify card number or identifier, device number and subdevice number
To see the list of cards currently recognized by your system check the To see the list of cards currently recognized by your system check the
files @file{/proc/asound/cards} and @file{/proc/asound/devices}. files @file{/proc/asound/cards} and @file{/proc/asound/devices}.
For example to capture with @file{ffmpeg} from an alsa device with For example to capture with @file{ffmpeg} from an ALSA device with
card id 0, you may run the command: card id 0, you may run the command:
@example @example
ffmpeg -f alsa -i hw:0 alsaout.wav ffmpeg -f alsa -i hw:0 alsaout.wav
@ -65,38 +65,38 @@ Linux DV 1394 input device.
@section jack @section jack
Jack input device. JACK input device.
To enable this input device during configuration you need libjack To enable this input device during configuration you need libjack
installed on your system. installed on your system.
A jack input device creates one or more jack writable clients, one for A JACK input device creates one or more JACK writable clients, one for
each audio channel, with name @var{client_name}:input_@var{N}, where each audio channel, with name @var{client_name}:input_@var{N}, where
@var{client_name} is the name provided by the application, and @var{N} @var{client_name} is the name provided by the application, and @var{N}
is a number which identifies the channel. is a number which identifies the channel.
Each writable client will send the acquired data to the FFmpeg input Each writable client will send the acquired data to the FFmpeg input
device. device.
Once you have created one or more jack readable clients, you need to Once you have created one or more JACK readable clients, you need to
connect them to one or more jack writable clients. connect them to one or more JACK writable clients.
To connect or disconnect jack clients you can use the To connect or disconnect JACK clients you can use the
@file{jack_connect} and @file{jack_disconnect} programs, or do it @file{jack_connect} and @file{jack_disconnect} programs, or do it
through a graphical interface, for example with @file{qjackctl}. through a graphical interface, for example with @file{qjackctl}.
To list the jack clients and their properties you can invoke the command To list the JACK clients and their properties you can invoke the command
@file{jack_lsp}. @file{jack_lsp}.
Follows an example which shows how to capture a jack readable client Follows an example which shows how to capture a JACK readable client
with @file{ffmpeg}. with @file{ffmpeg}.
@example @example
# create a jack writable client with name "ffmpeg" # Create a JACK writable client with name "ffmpeg".
$ ffmpeg -f jack -i ffmpeg -y out.wav $ ffmpeg -f jack -i ffmpeg -y out.wav
# start the sample jack_metro readable client # Start the sample jack_metro readable client.
$ jack_metro -b 120 -d 0.2 -f 4000 $ jack_metro -b 120 -d 0.2 -f 4000
# list the current jack clients # List the current JACK clients.
$ jack_lsp -c $ jack_lsp -c
system:capture_1 system:capture_1
system:capture_2 system:capture_2
@ -105,7 +105,7 @@ system:playback_2
ffmpeg:input_1 ffmpeg:input_1
metro:120_bpm metro:120_bpm
# connect metro to the ffmpeg writable client # Connect metro to the ffmpeg writable client.
$ jack_connect metro:120_bpm ffmpeg:input_1 $ jack_connect metro:120_bpm ffmpeg:input_1
@end example @end example
@ -122,9 +122,9 @@ Open Sound System input device.
The filename to provide to the input device is the device node The filename to provide to the input device is the device node
representing the OSS input device, and is usually set to representing the OSS input device, and is usually set to
@file{/dev/dsp/}. @file{/dev/dsp}.
For example to grab from @file{/dev/dsp/} using @file{ffmpeg} use the For example to grab from @file{/dev/dsp} using @file{ffmpeg} use the
command: command:
@example @example
ffmpeg -f oss -i /dev/dsp /tmp/oss.wav ffmpeg -f oss -i /dev/dsp /tmp/oss.wav
@ -139,14 +139,14 @@ Video4Linux and Video4Linux2 input video devices.
The name of the device to grab is a file device node, usually Linux The name of the device to grab is a file device node, usually Linux
systems tend to automatically create such nodes when the device systems tend to automatically create such nodes when the device
(e.g. an USB webcam) is plugged to the system, and has a name of the (e.g. an USB webcam) is plugged into the system, and has a name of the
kind @file{/dev/video@var{N}}, where @var{N} is a number associated to kind @file{/dev/video@var{N}}, where @var{N} is a number associated to
the device. the device.
Video4Linux and Video4Linux2 devices only support a limited set of Video4Linux and Video4Linux2 devices only support a limited set of
@var{width}x@var{height} sizes and framerates. You can check which are @var{width}x@var{height} sizes and framerates. You can check which are
supported for example using the command @file{dov4l} for Video4Linux supported for example with the command @file{dov4l} for Video4Linux
devices, and the command @file{v4l-info} for Video4Linux2 devices. devices and the command @file{v4l-info} for Video4Linux2 devices.
If the size for the device is set to 0x0, the input device will If the size for the device is set to 0x0, the input device will
try to autodetect the size to use. try to autodetect the size to use.
@ -157,19 +157,19 @@ dropped in later versions.
Follow some usage examples of the video4linux devices with the ff* Follow some usage examples of the video4linux devices with the ff*
tools. tools.
@example @example
# grab and show the input of a video4linux device # Grab and show the input of a video4linux device.
ffplay -s 320x240 -f video4linux /dev/video0 ffplay -s 320x240 -f video4linux /dev/video0
# grab and show the input of a video4linux2 device, autoadjust size # Grab and show the input of a video4linux2 device, autoadjust size.
ffplay -f video4linux2 /dev/video0 ffplay -f video4linux2 /dev/video0
# grab and record the input of a video4linux2 device, autoadjust size # Grab and record the input of a video4linux2 device, autoadjust size.
ffmpeg -f video4linux2 -i /dev/video0 out.mpeg ffmpeg -f video4linux2 -i /dev/video0 out.mpeg
@end example @end example
@section vfwcap @section vfwcap
VFW (Video For Window) catpure input device. VFW (Video For Windows) capture input device.
@section x11grab @section x11grab
@ -177,31 +177,30 @@ X11 video input device.
This device allows to capture a region of an X11 display. This device allows to capture a region of an X11 display.
The filename passed in input has the syntax: The filename passed as input has the syntax:
@example @example
[@var{hostname}]:@var{display_number}.@var{screen_number}[+@var{x_offset},@var{y_offset}] [@var{hostname}]:@var{display_number}.@var{screen_number}[+@var{x_offset},@var{y_offset}]
@end example @end example
@var{hostname}:@var{display_number}.@var{screen_number} specifies the @var{hostname}:@var{display_number}.@var{screen_number} specifies the
X11 display name of the screen to grab from. @var{hostname} can be not X11 display name of the screen to grab from. @var{hostname} can be
specified, and defaults to "localhost". The environment variable ommitted, and defaults to "localhost". The environment variable
@env{DISPLAY} contains the default display name. @env{DISPLAY} contains the default display name.
@var{x_offset} and @var{y_offset} specify the offsets of the grabbed @var{x_offset} and @var{y_offset} specify the offsets of the grabbed
area with respect to the top/left border of the X11 screen image. They area with respect to the top-left border of the X11 screen. They
default to 0. default to 0.
Check the X11 documentation (e.g. man X) for more detailed information. Check the X11 documentation (e.g. man X) for more detailed information.
Use the @file{dpyinfo} program for getting basic information about the Use the @file{dpyinfo} program for getting basic information about the
properties of your X11 display screen (e.g. grep for "name" or properties of your X11 display (e.g. grep for "name" or "dimensions").
"dimensions").
For example to grab from @file{:0.0} using @file{ffmpeg}: For example to grab from @file{:0.0} using @file{ffmpeg}:
@example @example
ffmpeg -f x11grab -r 25 -s cif -i :0.0 out.mpg ffmpeg -f x11grab -r 25 -s cif -i :0.0 out.mpg
# grab at position 10,20 # Grab at position 10,20.
ffmpeg -f x11grab -25 -s cif -i :0.0+10,20 out.mpg ffmpeg -f x11grab -25 -s cif -i :0.0+10,20 out.mpg
@end example @end example

4
doc/outdevs.texi
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@ -5,8 +5,8 @@ Output devices are configured elements in FFmpeg which allow to write
multimedia data to an output device attached to your system. multimedia data to an output device attached to your system.
When you configure your FFmpeg build, all the supported output devices When you configure your FFmpeg build, all the supported output devices
are enabled by default. You can list them using the configure option are enabled by default. You can list all available ones using the
"--list-outdevs". configure option "--list-outdevs".
You can disable all the output devices using the configure option You can disable all the output devices using the configure option
"--disable-outdevs", and selectively enable an output device using the "--disable-outdevs", and selectively enable an output device using the