Document unsynchronized HDMI/SDI output.

[nageru-docs] / hdmisdi.rst

diff --git a/hdmisdi.rst b/hdmisdi.rst
index 91f6c9f0f6fa26b4ba1406f25649e6060788276e..a04c62ba3d09336680d80acb5d6936a2f75e90a8 100644 (file)
--- a/hdmisdi.rst
+++ b/hdmisdi.rst
@@ -15,7 +15,7 @@ output, turning it into a simple, reasonably low-latency audio/video switcher.
 Setting up HDMI/SDI output
 --------------------------
 
-Turning on HDMI/SDI output is simple; just right-click on the live view and
+To turn on HDMI/SDI output, right-click on the live view and
 select the output card. (Equivalently, you can access the same functionality
 from the *Video* menu in the regular menu bar, or you can give the
 *--output-card=* parameter on the command line.) Currently, this is supported
@@ -26,11 +26,23 @@ keep running just as before.
 A video mode will automatically be picked for you, favoring 59.94 fps if possible,
 but you can change the mode on-the-fly to something else if you'd like,
 as long as the resolution matches with what you've set up at program start.
-Note that whenever HDMI/SDI output is active, the output card will be the
+
+
+Unsynchronized HDMI/SDI output
+------------------------------
+
+By default, whenever HDMI/SDI output is active, the output card will be the
 master clock; you cannot change it to any of the input cards. This also means
 that the frame rate you choose here will determine the frame rate for the
 stream.
 
+In Nageru 2.1.0 or newer, you can use the flag --output-card-unsynchronized
+to counteract this (there is currently no way to do it from the GUI).
+This is for if you want just a monitor output without synchronizing
+your entire stream chain to the output card (ie., you want to keep
+some other camera as the master). Sound support is untested, and is
+probably going to crackle a fair bit.
+
 
 A note on latency
 -----------------
@@ -171,7 +183,7 @@ Measuring latency
 
 In order to optimize latency, it can be useful to measure it, but for most
 people, it's hard to measure delays precisely enough to distinguish reliably
-between e.g. 70 and 80 milliseconds by eye alone. Nageru gives you some simple
+between e.g. 70 and 80 milliseconds by eye alone. Nageru gives you some
 tools that will help.
 
 The most direct is the flag *--print-video-latency*. This samples, for every