From 47ee8352c5bdec86e3a73fdca9cf69ba3e5c24ff Mon Sep 17 00:00:00 2001 From: jstebbins Date: Sun, 30 May 2010 17:26:03 +0000 Subject: [PATCH] Improve left/right dplii surround separation This analysis and measurement shows that a difference of 4.8db between Ls and Rs in Lt and Rt provides better separation than 3db http://forum.doom9.org/showthread.php?t=57988 git-svn-id: svn://localhost/HandBrake/trunk@3336 b64f7644-9d1e-0410-96f1-a4d463321fa5 --- libhb/downmix.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) diff --git a/libhb/downmix.c b/libhb/downmix.c index b713f9bc..2a441e9f 100644 --- a/libhb/downmix.c +++ b/libhb/downmix.c @@ -16,8 +16,8 @@ #define LVL_45DB 0.5946035575013605 #define LVL_6DB 0.5 -#define LVL_SQRT_1_3 0.577350269 -#define LVL_SQRT_2_3 0.816496581 +#define LVL_SQRT_1_4 0.5 +#define LVL_SQRT_3_4 0.866025404 #define HB_CH_FRONT_LEFT 0x00000001 #define HB_CH_FRONT_RIGHT 0x00000002 @@ -605,8 +605,8 @@ hb_sample_t downmix_matrix[DOWNMIX_NUM_MODES][DOWNMIX_NUM_MODES][8][8] = // DPLII out { { 1, 0, 0, 0, 0, 0, 0, 0 }, { 0, 1, 0, 0, 0, 0, 0, 0 }, - { LVL_SQRT_2_3, -LVL_SQRT_1_3, 0, 0, 0, 0, 0, 0 }, - { -LVL_SQRT_1_3, LVL_SQRT_2_3, 0, 0, 0, 0, 0, 0 }, + { -LVL_SQRT_3_4, LVL_SQRT_1_4, 0, 0, 0, 0, 0, 0 }, + { -LVL_SQRT_1_4, LVL_SQRT_3_4, 0, 0, 0, 0, 0, 0 }, { 0, 0, 1, 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0, 0, 0, 0 }, @@ -699,8 +699,8 @@ hb_sample_t downmix_matrix[DOWNMIX_NUM_MODES][DOWNMIX_NUM_MODES][8][8] = { { LVL_3DB, LVL_3DB, 0, 0, 0, 0, 0, 0 }, { 1, 0, 0, 0, 0, 0, 0, 0 }, { 0, 1, 0, 0, 0, 0, 0, 0 }, - { LVL_SQRT_2_3, -LVL_SQRT_1_3, 0, 0, 0, 0, 0, 0 }, - { -LVL_SQRT_1_3, LVL_SQRT_2_3, 0, 0, 0, 0, 0, 0 }, + { -LVL_SQRT_3_4, LVL_SQRT_1_4, 0, 0, 0, 0, 0, 0 }, + { -LVL_SQRT_1_4, LVL_SQRT_3_4, 0, 0, 0, 0, 0, 0 }, { 0, 0, 1, 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0, 0, 0, 0 } }, @@ -792,10 +792,10 @@ hb_sample_t downmix_matrix[DOWNMIX_NUM_MODES][DOWNMIX_NUM_MODES][8][8] = { { LVL_3DB, LVL_3DB, 0, 0, 0, 0, 0, 0 }, { 1, 0, 0, 0, 0, 0, 0, 0 }, { 0, 1, 0, 0, 0, 0, 0, 0 }, - { LVL_SQRT_2_3*LVL_3DB, -LVL_SQRT_1_3*LVL_3DB, 0, 0, 0, 0, 0, 0 }, - { -LVL_SQRT_1_3*LVL_3DB, LVL_SQRT_2_3*LVL_3DB, 0, 0, 0, 0, 0, 0 }, - { LVL_SQRT_2_3*LVL_3DB, -LVL_SQRT_1_3*LVL_3DB, 0, 0, 0, 0, 0, 0 }, - { -LVL_SQRT_1_3*LVL_3DB, LVL_SQRT_2_3*LVL_3DB, 0, 0, 0, 0, 0, 0 }, + { -LVL_SQRT_3_4*LVL_3DB, LVL_SQRT_1_4*LVL_3DB, 0, 0, 0, 0, 0, 0 }, + { -LVL_SQRT_1_4*LVL_3DB, LVL_SQRT_3_4*LVL_3DB, 0, 0, 0, 0, 0, 0 }, + { -LVL_SQRT_3_4*LVL_3DB, LVL_SQRT_1_4*LVL_3DB, 0, 0, 0, 0, 0, 0 }, + { -LVL_SQRT_1_4*LVL_3DB, LVL_SQRT_3_4*LVL_3DB, 0, 0, 0, 0, 0, 0 }, { 0, 0, 1, 0, 0, 0, 0, 0 } } }, }; @@ -1349,7 +1349,7 @@ void hb_downmix_adjust_level( hb_downmix_t * downmix ) break; case MIXMODE(DOWNMIX_2F2R, DOWNMIX_DPLII): - level /= 1 + LVL_SQRT_1_3 + LVL_SQRT_2_3; + level /= 1 + LVL_SQRT_1_4 + LVL_SQRT_3_4; break; case MIXMODE(DOWNMIX_3F2R, DOWNMIX_MONO): @@ -1366,7 +1366,7 @@ void hb_downmix_adjust_level( hb_downmix_t * downmix ) break; case MIXMODE(DOWNMIX_3F2R, DOWNMIX_DPLII): - level /= 1 + LVL_3DB + LVL_SQRT_1_3 + LVL_SQRT_2_3; + level /= 1 + LVL_3DB + LVL_SQRT_1_4 + LVL_SQRT_3_4; break; case MIXMODE(DOWNMIX_3F4R, DOWNMIX_STEREO): @@ -1382,7 +1382,7 @@ void hb_downmix_adjust_level( hb_downmix_t * downmix ) break; case MIXMODE(DOWNMIX_3F4R, DOWNMIX_DPLII): - level /= 1 + LVL_3DB + 2 * LVL_SQRT_1_3 + 2 * LVL_SQRT_2_3; + level /= 1 + LVL_3DB + 2 * LVL_SQRT_1_4 + 2 * LVL_SQRT_3_4; } downmix->level = level; -- 2.11.0