Rasta

From Sphinx

This page is dedicated to the using of RASTA feature set in sphinxtrain. Here is a little step-by-step howto:

• Download RASTA C code http://www.icsi.berkeley.edu/~dpwe/projects/sprach/sprachcore.html
• Unpack and go to the rasta subfolder
• In rasta.c add the following lines after the comment about main analysis loop:

     /* main analysis loop */                                                  
     {                                                                         
       int fcount = runparam.nframes * 13;                                     
       int swap_count = bswap_32(fcount);                                      
       fwrite (&swap_count, 1, 4, outfp);                                      
     }

• Build rasta executable
• Download and unpack and setup an4, run the script to extract RASTA features:

 for f in `cat etc/an4_train.fileids`; do 
    ./rasta -T -m 12 -S 16000 -i ./wav/$f.raw -o ./feat/$f.mfc;
 done
 for f in `cat etc/an4_test.fileids`; do 
    ./rasta -T -m 12 -S 16000 -i ./wav/$f.raw -o ./feat/$f.mfc;     
 done 

• Run ./scripts/RunAll.pl as usual
• Run ./scripts/decode.pl and get the following result:

With RASTA:

 SENTENCE ERROR: 74.6% (96/130)   WORD ERROR RATE: 36.0% (278/773)

You can try without RASTA as described in tutorial:

 SENTENCE ERROR: 79.2% (102/130)   WORD ERROR RATE: 37.0% (286/773)