Before reading trying to use video inputs, you should read and understand how
themes work in general (see :doc:`theme`). Video inputs are available from
-Nageru 1.6.0 onwards. There is currently no support for audio from video inputs;
-all videos are silent. (This may change in the future.) If a file contains
-multiple video streams, like different angles or resolutions, only the first
-will be used.
+Nageru 1.6.0 onwards, and from Nageru 1.7.2, you can get audio from video inputs
+like any other input. (Be advised, though, that making a general video player
+that can maintain A/V sync on all kinds of video files is a hard problem,
+so there may still be bugs in this support.)
+
+If a file contains multiple video streams, like different
+angles or resolutions, only the first will be used. Similarly, only the first
+audio stream is used, and it's always converted to 48 kHz stereo.
Basic video inputs
video:change_rate(2.0)
This will make it play at twice its usual speed. Your rate should not be
-negative nor exactly zero. Be aware that once you've set a rate, the player
-will wait for the next frame before considering any other commands,
-so if you set your rate to e.g. 0.001 to nearly stop it, you will indeed
-need to wait 16.67 seconds (assuming 60 fps video) before you can speed it
-up again. This restriction may be lifted in the future.
+negative nor exactly zero. You can set a rate to e.g. 1e-6 if you want to
+in practice stop the video; once you change it back to normal speed,
+the next frame will resume playing. Be aware that changing the rate may
+make the audio behave unpredictably; there are no attempts to do time
+stretching or change the pitch accordingly.
+
+Finally, if you want to forcibly abort the playing of a video,
+even one that is blocking on I/O, you can use (since Nageru 1.7.2)::
+
+ video:disconnect()
+
+This is particularly useful when dealing with network streams, as FFmpeg does not
+always properly detect if the connection has been lost. See :ref:`menus`
+for a way to expose such functionality to the operator.
+
+.. _subtitle-ingest:
+
+Ingesting subtitles
+-------------------
+
+Video streams can contain separate subtitle tracks. Since Nageru 1.8.1,
+you can read these streams. This is particularly useful when using Nageru
+and Futatabi together (see :ref:`talkback`).
+
+To get the last subtitle given before the current video frame, call
+“signals:get_last_subtitle(n)” from get_chain, where n is the signal number
+of your video signal. It will either contain nil, if there hasn't been
+a subtitle, or else the raw subtitle. Note that if the video frame and
+the subtitle occur on the exact same timestamp, and the video frame
+is muxed before the subtitle packet, the subtitle will not make it in time.
+(Futatabi puts the subtitle slightly ahead of the video frame to avoid this.)
Integration with CasparCG
-------------------------
-TODO
+This section has been removed, as since 1.7.0, Nageru has :doc:`native support for HTML5 inputs <html>`,
+obsoleting CasparCG integration.
projects / nageru-docs / blobdiff