diff options
| -rw-r--r-- | doc/indevs.texi | 61 | ||||
| -rw-r--r-- | doc/outdevs.texi | 4 |
2 files changed, 32 insertions, 33 deletions
diff --git a/doc/indevs.texi b/doc/indevs.texi index cf29c4c306..b77d9d2084 100644 --- a/doc/indevs.texi +++ b/doc/indevs.texi @@ -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. When you configure your FFmpeg build, all the supported input devices -are enabled by default. You can list them using the configure option -"--list-indevs". +are enabled by default. You can list all available ones using the +configure option "--list-indevs". You can disable all the input devices using the configure option "--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 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. 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 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: @example ffmpeg -f alsa -i hw:0 alsaout.wav @@ -65,38 +65,38 @@ Linux DV 1394 input device. @section jack -Jack input device. +JACK input device. To enable this input device during configuration you need libjack 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 @var{client_name} is the name provided by the application, and @var{N} is a number which identifies the channel. Each writable client will send the acquired data to the FFmpeg input device. -Once you have created one or more jack readable clients, you need to -connect them to one or more jack writable clients. +Once you have created one or more JACK readable clients, you need to +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 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}. -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}. @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 -# start the sample jack_metro readable client +# Start the sample jack_metro readable client. $ jack_metro -b 120 -d 0.2 -f 4000 -# list the current jack clients +# List the current JACK clients. $ jack_lsp -c system:capture_1 system:capture_2 @@ -105,7 +105,7 @@ system:playback_2 ffmpeg:input_1 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 @end example @@ -122,9 +122,9 @@ Open Sound System input device. The filename to provide to the input device is the device node 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: @example 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 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 the device. Video4Linux and Video4Linux2 devices only support a limited set of @var{width}x@var{height} sizes and framerates. You can check which are -supported for example using the command @file{dov4l} for Video4Linux -devices, and the command @file{v4l-info} for Video4Linux2 devices. +supported for example with the command @file{dov4l} for Video4Linux +devices and the command @file{v4l-info} for Video4Linux2 devices. If the size for the device is set to 0x0, the input device will 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* tools. @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 -# 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 -# 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 @end example @section vfwcap -VFW (Video For Window) catpure input device. +VFW (Video For Windows) capture input device. @section x11grab @@ -177,31 +177,30 @@ X11 video input device. 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 [@var{hostname}]:@var{display_number}.@var{screen_number}[+@var{x_offset},@var{y_offset}] @end example @var{hostname}:@var{display_number}.@var{screen_number} specifies the -X11 display name of the screen to grab from. @var{hostname} can be not -specified, and defaults to "localhost". The environment variable +X11 display name of the screen to grab from. @var{hostname} can be +ommitted, and defaults to "localhost". The environment variable @env{DISPLAY} contains the default display name. @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. Check the X11 documentation (e.g. man X) for more detailed information. Use the @file{dpyinfo} program for getting basic information about the -properties of your X11 display screen (e.g. grep for "name" or -"dimensions"). +properties of your X11 display (e.g. grep for "name" or "dimensions"). For example to grab from @file{:0.0} using @file{ffmpeg}: @example 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 @end example diff --git a/doc/outdevs.texi b/doc/outdevs.texi index 6aedfa7079..ef277b797f 100644 --- a/doc/outdevs.texi +++ b/doc/outdevs.texi @@ -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. When you configure your FFmpeg build, all the supported output devices -are enabled by default. You can list them using the configure option -"--list-outdevs". +are enabled by default. You can list all available ones using the +configure option "--list-outdevs". You can disable all the output devices using the configure option "--disable-outdevs", and selectively enable an output device using the |