fate: add ADX encoding/decoding test

tests/codec-regression.sh

@@ -311,6 +311,11 @@ do_audio_encoding g726.wav "-b 32k -ac 1 -ar 8000 -acodec g726"
 do_audio_decoding
 fi
 
+if [ -n "$do_adpcm_adx" ] ; then
+do_audio_encoding adpcm_adx.adx "-acodec adpcm_adx"
+do_audio_decoding
+fi
+
 if [ -n "$do_adpcm_ima_wav" ] ; then
 do_audio_encoding adpcm_ima.wav "-acodec adpcm_ima_wav"
 do_audio_decoding

tests/ref/acodec/adpcm_adx

+0a30509d9296b857e134b762b76dbc31 *./tests/data/acodec/adpcm_adx.adx
+297720 ./tests/data/acodec/adpcm_adx.adx
+2dbc601ed5259f4d74dc48ccd8da7eaf *./tests/data/adpcm_adx.acodec.out.wav
+stddev: 6989.46 PSNR: 19.44 MAXDIFF:65398 bytes:  1058432/  1058400