Multimedia

GStreamer

GStreamer is a powerful pipeline-based multimedia framework. It allows programmers to create a variety of media-handling components, including simple audio playback, audio and video playback, recording, streaming and editing. This is not a GStreamer reference manual but an overview for using it on NeuralPlex. This release uses the gstreamer-imx set of GStreamer 1.0 plugins for NXP’s i.MX platform, which make use of the i.MX multimedia capabilities.

There are two major commands: gst-inspect - allows you to to get documentation on available elements and detailed information on a specific element. gst-launch - allows you to create and execute GStreamer pipelines.

root@neuralplex:~# gst-inspect-1.0 | grep sink
pulseaudio:  pulsesink: PulseAudio Audio Sink
hls:  hlssink2: HTTP Live Streaming sink
hls:  hlssink: HTTP Live Streaming sink
bluez:  avdtpsink: Bluetooth AVDTP sink
bluez:  a2dpsink: Bluetooth A2DP sink
coreelements:  filesink: File Sink
coreelements:  fdsink: Filedescriptor Sink
coreelements:  fakesink: Fake Sink
alsa:  alsasink: Audio sink (ALSA)
gdkpixbuf:  gdkpixbufsink: GdkPixbuf sink
...

Detailed hlep on specific element:

root@neuralplex:~# gst-inspect-1.0 <name of the element>

Here are a couple examples of playing video and audio files:

# Play Video
gst-launch-1.0 filesrc location=big_buck_bunny_1080p_h264.mov ! decodebin \
  ! imxvideoconvert_g2d ! waylandsink

# Play Audio
gst-launch-1.0 filesrc location=Sultans_Of_Swing.mp3 ! decodebin ! alsasink

ALSA

# Speaker Test (Play 440Hz sin wave)
speaker-test -c8 -t sin -f440 -P9 -s7

# Speaker Test (Play wav file on specific speaker output)
speaker-test -c8 -t wav -w ~/Welcome_to_the_Jungle.wav -P9 -s7

# Speaker Mapping:
s1 = OUT1
s2 = OUT5
s3 = OUT2
s4 = AMP_L
s5 = OUT4
s6 = OUT3
s7 = AMP_R
s8 = OUT6

# Record Audio
arecord -D plughw:0,1 -r 48000 -f S32_LE sample.wav -c4

# Play Audio
aplay Sultans_Of_Swing.wav