NGL tools

The ngl-tools is a set of small C programs making use of libnopegl.

ngl-player

ngl-player is a basic real time video player. If you are looking into testing or diagnose video playback and seeking issues, this tool is likely a good start.

Usage: ngl-player [options] <media>

The detail of available options can be obtained with ngl-player -h.

Source: ngl-tools/ngl-player.c

ngl-render

ngl-render is a rendering test tool. It takes a serialized scene as input (input.ngl or stdin if not specified) and render the specified time ranges (by default, in a hidden window).

Usage: ngl-render [-o out.raw] [-s WxH] [-w] [-d] [-z swapinterval] -t start:duration:freq [-t start:duration:freq ...] [-i input.ngl]

Option	Description
-o <out.raw>	specify the raw output file, “-” can be used for stdout output
-s <WxH>	specify the output dimensions in WxH format
-w	if specified, the rendering window will be shown
-d	enable debugging (of the tool)
-z <swapinterval>	specify the OpenGL swapping interval (useful in combination with -w); 0 (the default) means non capped while 1 corresponds to the vsync
-t <start:duration:freq>	specify a time range to render in start:duration:freq format. All three values are floats. start is the start time of the range (in seconds), duration is the duration of the range (also in seconds), and freq is the refresh frame rate.

Example: ngl-serialize pynopegl_utils.examples.misc fibo - | ngl-render -t 0:60:60 -s 640x480 -o - | ffplay -f rawvideo -framerate 60 -video_size 640x480 -pixel_format rgba -

Source: ngl-tools/ngl-render.c

ngl-python

ngl-python is a nope.gl Python scene loader. It uses the C API of Python to execute a demo script (in order to get the scene) and render it using the libnopegl C API.

Note: it is only available if the Python headers are present on the system at build time.

Usage: ngl-python [options] <module|script.py> <scene_func>

The detail of available options can be obtained with ngl-python -h.

Example: ngl-python pynopegl_utils.examples.misc fibo

Source: ngl-tools/ngl-python.c

ngl-serialize

ngl-serialize serializes a nope.gl Python scene into the ngl format. Similarly to ngl-python, it relies on the C API of Python to execute the specified entry point.

Note: it is only available if the Python headers are present on the system at build time.

Usage: ngl-serialize <module> <scene_func> <output.ngl>

Example: ngl-serialize pynopegl_utils.examples.misc fibo -

Source: ngl-tools/ngl-serialize.c

ngl-desktop

ngl-desktop is a player waiting for user commands from a socket connection. It is meant to be used with ngl-ipc for communicating commands.

By default, ngl-desktop listen for connections on localhost on port 1234.

The detail of available options can be obtained with ngl-desktop -h.

Example: ngl-desktop -x 0.0.0.0 -p 2000 --backend opengles -c 223344FF

ngl-ipc

ngl-ipc is the tool used to make queries to ngl-desktop instances.

The detail of available options can be obtained with ngl-ipc -h.

Example: ngl-serialize pynopegl_utils.examples.misc fibo - | ngl-ipc -p 2000 -f -

ngl-probe

ngl-probe is a backend capabilities probing tool.

By default, ngl-probe prints the capabilities of every available backends, following a YAML output layout. If the --cap option is specified, it will query the specified backend if set (-b/--backend) or query the default one.

The detail of available options can be obtained with ngl-probe -h.

Player keyboard controls

ngl-player, ngl-python and ngl-desktop are scene players supporting the following keyboard controls:

Key	Action
ESC or q	quit the application
SPACE	toggle the pause/playback
LEFT	seek by -10 seconds
RIGHT	seek by +10 seconds
f	toggle windowed/fullscreen
s	take a screenshot
k	kill the current scene
h	toggle the HUD