[vlc-devel] [PATCH] cleanup fine grain control of playback rate

[Rov Juvano]

- Reverts rate-{slower,faster} to previous 2x behavior
- Adds rate-{slower,faster}-step (inc/dec by musical semi-tone ~1.05x)
- Adds rate-normal
---
 src/input/input.c          |   60 +++++++++++--------------------------------
 src/input/input_internal.h |    2 +
 2 files changed, 18 insertions(+), 44 deletions(-)

diff --git a/src/input/input.c b/src/input/input.c
index 90ce56a..ac203d4 100644
--- a/src/input/input.c
+++ b/src/input/input.c
@@ -34,6 +34,7 @@
 #include <ctype.h>
 #include <limits.h>
 #include <assert.h>
+#include <math.h>
 
 #include "input_internal.h"
 
@@ -98,7 +99,7 @@ static void AppendAttachment( int *pi_attachment, input_attachment_t ***ppp_atta
  * Variables for _public_ use:
  * * Get and Set:
  *  - state
- *  - rate,rate-slower, rate-faster
+ *  - rate, rate-slower, rate-faster, rate-slower-step, rate-faster-step
  *  - position, position-offset
  *  - time, time-offset
  *  - title,title-next,title-prev
@@ -1599,54 +1600,25 @@ static bool Control( input_thread_t *p_input, int i_type,
         case INPUT_CONTROL_SET_RATE:
         case INPUT_CONTROL_SET_RATE_SLOWER:
         case INPUT_CONTROL_SET_RATE_FASTER:
+        case INPUT_CONTROL_SET_RATE_SLOWER_STEP:
+        case INPUT_CONTROL_SET_RATE_FASTER_STEP:
         {
             int i_rate;
 
             if( i_type == INPUT_CONTROL_SET_RATE )
-            {
                 i_rate = val.i_int;
-            }
-            else
-            {
-                static const int ppi_factor[][2] = {
-                    {1,64}, {1,32}, {1,16}, {1,8}, {1,4}, {1,3}, {1,2}, {2,3},
-                    {1,1},
-                    {3,2}, {2,1}, {3,1}, {4,1}, {8,1}, {16,1}, {32,1}, {64,1},
-                    {0,0}
-                };
-                int i_error;
-                int i_idx;
-                int i;
-
-                i_error = INT_MAX;
-                i_idx = -1;
-                for( i = 0; ppi_factor[i][0] != 0; i++ )
-                {
-                    const int i_test_r = INPUT_RATE_DEFAULT * ppi_factor[i][0] / ppi_factor[i][1];
-                    const int i_test_e = abs(p_input->p->i_rate - i_test_r);
-                    if( i_test_e < i_error )
-                    {
-                        i_idx = i;
-                        i_error = i_test_e;
-                    }
-                }
-                assert( i_idx >= 0 && ppi_factor[i_idx][0] != 0 );
-
-                if( i_type == INPUT_CONTROL_SET_RATE_SLOWER )
-                {
-                    if( ppi_factor[i_idx+1][0] > 0 )
-                        i_rate = INPUT_RATE_DEFAULT * ppi_factor[i_idx+1][0] / ppi_factor[i_idx+1][1];
-                    else
-                        i_rate = INPUT_RATE_MAX+1;
-                }
-                else
-                {
-                    assert( i_type == INPUT_CONTROL_SET_RATE_FASTER );
-                    if( i_idx > 0 )
-                        i_rate = INPUT_RATE_DEFAULT * ppi_factor[i_idx-1][0] / ppi_factor[i_idx-1][1];
-                    else
-                        i_rate = INPUT_RATE_MIN-1;
-                }
+            else if( i_type == INPUT_CONTROL_SET_RATE_FASTER )
+                i_rate = p_input->p->i_rate / 2;
+            else if( i_type == INPUT_CONTROL_SET_RATE_SLOWER )
+                i_rate = p_input->p->i_rate * 2;
+            else {  /* STEP */
+              double d_exp = 12 * log( (double)INPUT_RATE_DEFAULT / p_input->p->i_rate ) / log( 2 );
+              int i_exp = (int) ( ( d_exp > 0 ) ? d_exp + .5 : d_exp - .5 );
+              if( i_type == INPUT_CONTROL_SET_RATE_SLOWER_STEP )
+                  i_exp--;
+              else
+                  i_exp++;
+              i_rate = INPUT_RATE_DEFAULT / pow( 2, (double)i_exp / 12 );
             }
 
             if( i_rate < INPUT_RATE_MIN )
diff --git a/src/input/input_internal.h b/src/input/input_internal.h
index 580b4fd..01075ad 100644
--- a/src/input/input_internal.h
+++ b/src/input/input_internal.h
@@ -166,6 +166,8 @@ enum input_control_e
     INPUT_CONTROL_SET_RATE,
     INPUT_CONTROL_SET_RATE_SLOWER,
     INPUT_CONTROL_SET_RATE_FASTER,
+    INPUT_CONTROL_SET_RATE_SLOWER_STEP,
+    INPUT_CONTROL_SET_RATE_FASTER_STEP,
 
     INPUT_CONTROL_SET_POSITION,
     INPUT_CONTROL_SET_POSITION_OFFSET,
-- 
1.5.4.3