Use 15-bit LPC precision by default. This generally gives better compression

results. Also update Ogg regression test.

Originally committed as revision 12630 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/flacenc.c

@@ -367,16 +367,8 @@ static av_cold int flac_encode_init(AVCodecContext *avctx)
         }
         s->options.lpc_coeff_precision = avctx->lpc_coeff_precision;
     } else {
-        /* select LPC precision based on block size */
-        if(     s->blocksize <=   192) s->options.lpc_coeff_precision =  7;
-        else if(s->blocksize <=   384) s->options.lpc_coeff_precision =  8;
-        else if(s->blocksize <=   576) s->options.lpc_coeff_precision =  9;
-        else if(s->blocksize <=  1152) s->options.lpc_coeff_precision = 10;
-        else if(s->blocksize <=  2304) s->options.lpc_coeff_precision = 11;
-        else if(s->blocksize <=  4608) s->options.lpc_coeff_precision = 12;
-        else if(s->blocksize <=  8192) s->options.lpc_coeff_precision = 13;
-        else if(s->blocksize <= 16384) s->options.lpc_coeff_precision = 14;
-        else                           s->options.lpc_coeff_precision = 15;
+        /* default LPC precision */
+        s->options.lpc_coeff_precision = 15;
     }
     av_log(avctx, AV_LOG_DEBUG, " lpc precision: %d\n",
            s->options.lpc_coeff_precision);

tests/libav.regression.ref

@@ -84,9 +84,9 @@ ae3a23a7ea13c92a2909445ca8144dcd *./tests/data/b-libav.aif
 8d117c49d6b210abe783d1b0b897cec7 *./tests/data/b-libav.voc
   32768 ./tests/data/b-libav.voc
 ./tests/data/b-libav.voc CRC=0x49972c8c
-8ac1fa6e0ee5d47ea98aea17b67d5908 *./tests/data/b-libav.ogg
-23596 ./tests/data/b-libav.ogg
-./tests/data/b-libav.ogg CRC=0x93baa056
+9268c90bd2623a5ab3c2a1a751826f69 *./tests/data/b-libav.ogg
+  14210 ./tests/data/b-libav.ogg
+./tests/data/b-libav.ogg CRC=0x6bcbb966
 ce356ce2708cb6033ab5d762da93cfd4 *./tests/data/b-libav-yuv420p.yuv
  304128 ./tests/data/b-libav-yuv420p.yuv
 ce356ce2708cb6033ab5d762da93cfd4 *./tests/data/b-libav-yuv422p.yuv