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| author | Stefano Sabatini <stefasab@gmail.com> | 2013-01-31 12:53:50 +0100 |
|---|---|---|
| committer | Stefano Sabatini <stefasab@gmail.com> | 2013-01-31 15:29:53 +0100 |
| commit | a842dc632ecaee437bac10e37c9d9d234089517d (patch) | |
| tree | ab6f24602179d6c24ba4d4f7983e24a2d1dfc18e /doc | |
| parent | 514216d8a928cf80980ca8dc5daea46e9d41cad9 (diff) | |
| download | ffmpeg-a842dc632ecaee437bac10e37c9d9d234089517d.tar.gz | |
doc/indevs: apply misc fixes to the v4l2 documentation
Reviewed-by: Giorgio Vazzana <mywing81@gmail.com>
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/indevs.texi | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/doc/indevs.texi b/doc/indevs.texi index 82d500dff8..39204d80c0 100644 --- a/doc/indevs.texi +++ b/doc/indevs.texi @@ -583,10 +583,16 @@ command: ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav @end example -@section video4linux2 +@section video4linux2, v4l2 Video4Linux2 input video device. +"v4l2" can be used as alias for "video4linux2". + +If FFmpeg is built with v4l-utils support (by using the +@code{--enable-libv4l2} configure option), the device will always rely +on libv4l2. + 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 into the system, and has a name of the @@ -599,8 +605,6 @@ supported using @command{-list_formats all} for Video4Linux2 devices. Some devices, like TV cards, support one or more standards. It is possible to list all the supported standards using @command{-list_standards all}. -Some usage examples of the video4linux2 devices with ffmpeg and ffplay: - The time base for the timestamps is 1 microsecond. Depending on the kernel version and configuration, the timestamps may be derived from the real time clock (origin at the Unix Epoch) or the monotonic clock (origin usually at @@ -608,8 +612,8 @@ boot time, unaffected by NTP or manual changes to the clock). The @option{-timestamps abs} or @option{-ts abs} option can be used to force conversion into the real time clock. -Note that if FFmpeg is build with v4l-utils support ("--enable-libv4l2" -option), it will always be used. +Some usage examples of the video4linux2 devices with @command{ffmpeg} +and @command{ffplay}: @example # Grab and show the input of a video4linux2 device. ffplay -f video4linux2 -framerate 30 -video_size hd720 /dev/video0 @@ -619,8 +623,7 @@ framerate and size as previously set. ffmpeg -f video4linux2 -input_format mjpeg -i /dev/video0 out.mpeg @end example -"v4l" and "v4l2" can be used as aliases for the respective "video4linux" and -"video4linux2". +For more information about Video4Linux, check @url{http://linuxtv.org/}. @section vfwcap |