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diff --git a/doc/a52.txt b/doc/a52.txt new file mode 100644 index 0000000..236e64a --- /dev/null +++ b/doc/a52.txt @@ -0,0 +1,48 @@ +A52 OUTPUT PLUGIN +================= + +This plugin converts S16 linear format to A52 compressed stream and +send to an SPDIF output. It requires libavcodec for encoding the +audio stream. + +A PCM using this plugin can be defined like below: + + pcm.myout { + type a52 + } + +In addition, the following options are available: + +- The "card" option specifies the card ID or number of the SPDIF. + The output PCM becomes "iec958:{CARD=$CARD}" with extra AESx + settings. When omitted, the default card is used. + +- The "rate" option specifies the input/output sample rate in HZ. + The accepted rate is either 44100 or 48000. + When omitted, 48000 is used. + +- The "channels" option specifies the number of _input_ channels. + It must be either 2, 4 or 6. The default value is 6. + +- The "bitrate" option specifies the bit-rate of the compressed + stream in kbps. Too small or too big value may not be accepted by + the encoder. When omitted, 448 is used. + +- The "format" option specifies the output format type. It's either + S16_LE or S16_BE. As default, S16_LE is used. + +An example using the secondary card, 44.1kHz, 4 channels, output +bitrate 256kbps and output format S16_BE looks like below: + + pcm.myout { + type a52 + card 1 + rate 44100 + channels 4 + bitrate 256 + format S16_BE + } + + +The plugin reads always S16 format (i.e. native-endian) as input, so +you'd need plug layer appropriately to covert it. |