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Diffstat (limited to 'README.md')
| -rw-r--r-- | README.md | 29 |
1 files changed, 26 insertions, 3 deletions
@@ -76,9 +76,32 @@ the audio is captured from the soundcard, and encoded into HE-AACv2. High occurrence of these will lead to audible artifacts. - Scenario 2 ---------- + +Play some local audio source from a file, with ZMQ output for ODR-DabMux. The problem with +playing a file is that dabplus-enc-file-zmq cannot directly be used, because ODR-DabMux +does not back-pressure the encoder, which will therefore encode much faster than realtime. + +While this issue is sorted out, the following trick is a very flexible solution: use the +alsa virtual loop soundcard *snd-aloop* in the following way: + + modprobe snd-aloop + +This creates a new audio card (usually 'hw:1' but have a look at /proc/asound/card to be sure) that +can then be used for the alsa encoder: + + ./dabplus-enc-alsa-zmq -d hw:1 -c 2 -r 32000 -b 64 -o + +Then, you can use any media player that has an alsa output to play whatever source it supports: + + cd your/preferred/music + mplayer -ao alsa:device=hw=1.1 -srate 32000 -shuffle * + +Important: you must specify the correct sample rate on both "sides" of the virtual sound card. + +Scenario 3 +---------- Live Stream encoding and preparing for DAB muxer, with ZMQ output, at 32kHz, using sox. This illustrates the fifo input of *dabplus-enc-file-zmq*. @@ -91,7 +114,7 @@ The -p 53 sets the padlen, compatible with the default mot-encoder setting. mot- to be given the same value for this option. -Scenario 3 +Scenario 4 ---------- Live Stream encoding and preparing for DAB muxer, with FIFO to odr-dabmux, 48kHz, using arecord. @@ -102,7 +125,7 @@ arecord. Here we are also using the ALSA plughw feature. -Scenario 4 +Scenario 5 ---------- Wave file encoding, for non-realtime processing |