bring AC3 encoder output up to input volume level

patch by Bill O'Shaughnessy % bill P oshaughnessy A gmail.com %
+ reg tests update gruntwork by me
Original thread:
date: Nov 21, 2006 11:36 PM
subject: [Ffmpeg-devel] Simpler Patch to bring AC3 encoder output up to input level

Originally committed as revision 7160 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/ac3enc.c

@@ -1379,7 +1379,7 @@ static int AC3_encode_frame(AVCodecContext *avctx,
             v = 14 - log2_tab(input_samples, N);
             if (v < 0)
                 v = 0;
-            exp_samples[i][ch] = v - 9;
+            exp_samples[i][ch] = v - 10;
             lshift_tab(input_samples, N, v);
 
             /* do the MDCT */

tests/ffmpeg.regression.ref

@@ -158,7 +158,7 @@ stddev: 10.99 PSNR:27.30 bytes:7602176
 83f8df5d5f84480566af548bb037fceb *./data/out.wav
 stddev:9330.70 PSNR:16.92 bytes:1054720
 stddev:4396.13 PSNR:23.46 bytes:1052672
-aefe11ab5067621a1c674859d6413891 *./data/a-ac3.rm
+dd68110cb7e5388392f89d5160d3a825 *./data/a-ac3.rm
 98203 ./data/a-ac3.rm
 9e6e66847a568ef4f1f229b0939d2aae *./data/a-g726.wav
 24268 ./data/a-g726.wav

tests/libav.regression.ref

@@ -5,7 +5,7 @@ ffmpeg regression test
 bac6c5f50f3ca5db6e2ef6eaccf1d4f1 *./data/b-libav.asf
 342967 ./data/b-libav.asf
 ./data/b-libav.asf CRC=0x94d219de
-5275686385346789108ec4fdf06ecef8 *./data/b-libav.rm
+3f63f396a3e9f08cdb5c30b4ef3a2436 *./data/b-libav.rm
 360269 ./data/b-libav.rm
 90784a1b9589095f20fc6bcc0cc23cc4 *./data/b-libav.mpg
 387072 ./data/b-libav.mpg

tests/rotozoom.regression.ref

@@ -158,7 +158,7 @@ stddev:  3.44 PSNR:37.38 bytes:7602176
 83f8df5d5f84480566af548bb037fceb *./data/out.wav
 stddev:9330.70 PSNR:16.92 bytes:1054720
 stddev:4396.13 PSNR:23.46 bytes:1052672
-aefe11ab5067621a1c674859d6413891 *./data/a-ac3.rm
+dd68110cb7e5388392f89d5160d3a825 *./data/a-ac3.rm
 98203 ./data/a-ac3.rm
 9e6e66847a568ef4f1f229b0939d2aae *./data/a-g726.wav
 24268 ./data/a-g726.wav