aacsbr: Cleanup the newly merged read_sbr_grid, eliminating several context

and some duplicate local variables.

Originally committed as revision 22384 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 48 insertions, 61 deletions

diff --git a/libavcodec/aacsbr.c b/libavcodec/aacsbr.c
index a7ad13a2d5..390d72493a 100644
--- a/libavcodec/aacsbr.c
+++ b/libavcodec/aacsbr.c
@@ -617,6 +617,12 @@ static int read_sbr_grid(AACContext *ac, SpectralBandReplication *sbr,
                          GetBitContext *gb, SBRData *ch_data)
 {
     int i;
+    unsigned bs_pointer;
+    int abs_bord_lead = 0;
+    // frameLengthFlag ? 15 : 16; 960 sample length frames unsupported; this value is numTimeSlots
+    int abs_bord_trail = 16;
+    int num_rel_lead, num_rel_trail;
+    uint8_t bs_rel_bord[2][3];
 
     ch_data->bs_freq_res[0] = ch_data->bs_freq_res[ch_data->bs_num_env[1]];
     ch_data->bs_num_env[0] = ch_data->bs_num_env[1];
@@ -625,6 +631,7 @@ static int read_sbr_grid(AACContext *ac, SpectralBandReplication *sbr,
     switch (ch_data->bs_frame_class = get_bits(gb, 2)) {
     case FIXFIX:
         ch_data->bs_num_env[1] = 1 << get_bits(gb, 2);
+        num_rel_lead           = ch_data->bs_num_env[1] - 1;
         if (ch_data->bs_num_env[1] == 1)
             ch_data->bs_amp_res = 0;
 
@@ -635,43 +642,44 @@ static int read_sbr_grid(AACContext *ac, SpectralBandReplication *sbr,
             return -1;
         }
 
-        ch_data->bs_pointer = 0;
+        bs_pointer = 0;
 
         ch_data->bs_freq_res[1] = get_bits1(gb);
         for (i = 1; i < ch_data->bs_num_env[1]; i++)
             ch_data->bs_freq_res[i + 1] = ch_data->bs_freq_res[1];
         break;
     case FIXVAR:
-        ch_data->bs_var_bord[1] = get_bits(gb, 2);
-        ch_data->bs_num_rel[1]  = get_bits(gb, 2);
-        ch_data->bs_num_env[1]  = ch_data->bs_num_rel[1] + 1;
+        abs_bord_trail         += get_bits(gb, 2);
+        num_rel_trail           = get_bits(gb, 2);
+        num_rel_lead            = 0;
+        ch_data->bs_num_env[1]  = num_rel_trail + 1;
 
-        for (i = 0; i < ch_data->bs_num_rel[1]; i++)
-            ch_data->bs_rel_bord[1][i] = 2 * get_bits(gb, 2) + 2;
+        for (i = 0; i < num_rel_trail; i++)
+            bs_rel_bord[1][i] = 2 * get_bits(gb, 2) + 2;
 
-        ch_data->bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env[1]]);
+        bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env[1]]);
 
         for (i = 0; i < ch_data->bs_num_env[1]; i++)
             ch_data->bs_freq_res[ch_data->bs_num_env[1] - i] = get_bits1(gb);
         break;
     case VARFIX:
-        ch_data->bs_var_bord[0] = get_bits(gb, 2);
-        ch_data->bs_num_rel[0]  = get_bits(gb, 2);
-        ch_data->bs_num_env[1]  = ch_data->bs_num_rel[0] + 1;
+        abs_bord_lead           = get_bits(gb, 2);
+        num_rel_lead            = get_bits(gb, 2);
+        ch_data->bs_num_env[1]  = num_rel_lead + 1;
 
-        for (i = 0; i < ch_data->bs_num_rel[0]; i++)
-            ch_data->bs_rel_bord[0][i] = 2 * get_bits(gb, 2) + 2;
+        for (i = 0; i < num_rel_lead; i++)
+            bs_rel_bord[0][i] = 2 * get_bits(gb, 2) + 2;
 
-        ch_data->bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env[1]]);
+        bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env[1]]);
 
         get_bits1_vector(gb, ch_data->bs_freq_res + 1, ch_data->bs_num_env[1]);
         break;
     case VARVAR:
-        ch_data->bs_var_bord[0] = get_bits(gb, 2);
-        ch_data->bs_var_bord[1] = get_bits(gb, 2);
-        ch_data->bs_num_rel[0]  = get_bits(gb, 2);
-        ch_data->bs_num_rel[1]  = get_bits(gb, 2);
-        ch_data->bs_num_env[1]  = ch_data->bs_num_rel[0] + ch_data->bs_num_rel[1] + 1;
+        abs_bord_lead           = get_bits(gb, 2);
+        abs_bord_trail         += get_bits(gb, 2);
+        num_rel_lead            = get_bits(gb, 2);
+        num_rel_trail           = get_bits(gb, 2);
+        ch_data->bs_num_env[1]  = num_rel_lead + num_rel_trail + 1;
 
         if (ch_data->bs_num_env[1] > 5) {
             av_log(ac->avccontext, AV_LOG_ERROR,
@@ -680,38 +688,21 @@ static int read_sbr_grid(AACContext *ac, SpectralBandReplication *sbr,
             return -1;
         }
 
-        for (i = 0; i < ch_data->bs_num_rel[0]; i++)
-            ch_data->bs_rel_bord[0][i] = 2 * get_bits(gb, 2) + 2;
-        for (i = 0; i < ch_data->bs_num_rel[1]; i++)
-            ch_data->bs_rel_bord[1][i] = 2 * get_bits(gb, 2) + 2;
+        for (i = 0; i < num_rel_lead; i++)
+            bs_rel_bord[0][i] = 2 * get_bits(gb, 2) + 2;
+        for (i = 0; i < num_rel_trail; i++)
+            bs_rel_bord[1][i] = 2 * get_bits(gb, 2) + 2;
 
-        ch_data->bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env[1]]);
+        bs_pointer = get_bits(gb, ceil_log2[ch_data->bs_num_env[1]]);
 
         get_bits1_vector(gb, ch_data->bs_freq_res + 1, ch_data->bs_num_env[1]);
         break;
     }
 
-    if (ch_data->bs_pointer > ch_data->bs_num_env[1] + 1) {
+    if (bs_pointer > ch_data->bs_num_env[1] + 1) {
         av_log(ac->avccontext, AV_LOG_ERROR,
                "Invalid bitstream, bs_pointer points to a middle noise border outside the time borders table: %d\n",
-               ch_data->bs_pointer);
-        return -1;
-    }
-
-    int abs_bord_lead  =  ch_data->bs_frame_class >= 2 ? ch_data->bs_var_bord[0] : 0;
-    // frameLengthFlag ? 15 : 16; 960 sample length frames unsupported; this value is numTimeSlots
-    int abs_bord_trail = (ch_data->bs_frame_class & 1 ? ch_data->bs_var_bord[1] : 0) + 16;
-    int n_rel_lead;
-
-    if (ch_data->bs_frame_class == FIXFIX) {
-        n_rel_lead = ch_data->bs_num_env[1] - 1;
-    } else if (ch_data->bs_frame_class == FIXVAR) {
-        n_rel_lead = 0;
-    } else if (ch_data->bs_frame_class < 4) { // VARFIX or VARVAR
-        n_rel_lead = ch_data->bs_num_rel[0];
-    } else {
-        av_log(ac->avccontext, AV_LOG_ERROR,
-               "Invalid bs_frame_class for SBR: %d\n", ch_data->bs_frame_class);
+               bs_pointer);
         return -1;
     }
 
@@ -722,22 +713,22 @@ static int read_sbr_grid(AACContext *ac, SpectralBandReplication *sbr,
     if (ch_data->bs_frame_class == FIXFIX) {
         int temp = (abs_bord_trail + (ch_data->bs_num_env[1] >> 1)) /
                    ch_data->bs_num_env[1];
-        for (i = 0; i < n_rel_lead; i++)
+        for (i = 0; i < num_rel_lead; i++)
             ch_data->t_env[i + 1] = ch_data->t_env[i] + temp;
     } else if (ch_data->bs_frame_class > 1) { // VARFIX or VARVAR
-        for (i = 0; i < n_rel_lead; i++)
-            ch_data->t_env[i + 1] = ch_data->t_env[i] + ch_data->bs_rel_bord[0][i];
+        for (i = 0; i < num_rel_lead; i++)
+            ch_data->t_env[i + 1] = ch_data->t_env[i] + bs_rel_bord[0][i];
     } else { // FIXVAR
-        for (i = 0; i < n_rel_lead; i++)
+        for (i = 0; i < num_rel_lead; i++)
             ch_data->t_env[i + 1] = abs_bord_lead;
     }
 
     if (ch_data->bs_frame_class & 1) { // FIXVAR or VARVAR
-        for (i = ch_data->bs_num_env[1] - 1; i > n_rel_lead; i--)
+        for (i = ch_data->bs_num_env[1] - 1; i > num_rel_lead; i--)
             ch_data->t_env[i] = ch_data->t_env[i + 1] -
-                                ch_data->bs_rel_bord[1][ch_data->bs_num_env[1] - 1 - i];
+                                bs_rel_bord[1][ch_data->bs_num_env[1] - 1 - i];
     } else { // FIXFIX or VARFIX
-        for (i = n_rel_lead; i < ch_data->bs_num_env[1]; i++)
+        for (i = num_rel_lead; i < ch_data->bs_num_env[1]; i++)
             ch_data->t_env[i + 1] = abs_bord_trail;
     }
 
@@ -749,14 +740,14 @@ static int read_sbr_grid(AACContext *ac, SpectralBandReplication *sbr,
         if (ch_data->bs_frame_class == FIXFIX) {
             idx = ch_data->bs_num_env[1] >> 1;
         } else if (ch_data->bs_frame_class & 1) { // FIXVAR or VARVAR
-            idx = ch_data->bs_num_env[1] - FFMAX(ch_data->bs_pointer - 1, 1);
+            idx = ch_data->bs_num_env[1] - FFMAX(bs_pointer - 1, 1);
         } else { // VARFIX
-            if (!ch_data->bs_pointer)
+            if (!bs_pointer)
                 idx = 1;
-            else if (ch_data->bs_pointer == 1)
+            else if (bs_pointer == 1)
                 idx = ch_data->bs_num_env[1] - 1;
             else // bs_pointer > 1
-                idx = ch_data->bs_pointer - 1;
+                idx = bs_pointer - 1;
         }
         ch_data->t_q[1] = ch_data->t_env[idx];
         ch_data->t_q[2] = ch_data->t_env[ch_data->bs_num_env[1]];
@@ -765,10 +756,10 @@ static int read_sbr_grid(AACContext *ac, SpectralBandReplication *sbr,
 
     ch_data->e_a[0] = -(ch_data->e_a[1] != ch_data->bs_num_env[0]); // l_APrev
     ch_data->e_a[1] = -1;
-    if ((ch_data->bs_frame_class & 1) && ch_data->bs_pointer) { // FIXVAR or VARVAR and bs_pointer != 0
-        ch_data->e_a[1] = ch_data->bs_num_env[1] + 1 - ch_data->bs_pointer;
-    } else if ((ch_data->bs_frame_class == 2) && (ch_data->bs_pointer > 1)) // VARFIX and bs_pointer > 1
-        ch_data->e_a[1] = ch_data->bs_pointer - 1;
+    if ((ch_data->bs_frame_class & 1) && bs_pointer) { // FIXVAR or VARVAR and bs_pointer != 0
+        ch_data->e_a[1] = ch_data->bs_num_env[1] + 1 - bs_pointer;
+    } else if ((ch_data->bs_frame_class == 2) && (bs_pointer > 1)) // VARFIX and bs_pointer > 1
+        ch_data->e_a[1] = bs_pointer - 1;
 
     return 0;
 }
@@ -783,14 +774,10 @@ static void copy_sbr_grid(SBRData *dst, const SBRData *src) {
     //These variables are read from the bitstream and therefore copied
     memcpy(dst->bs_freq_res+1, src->bs_freq_res+1, sizeof(dst->bs_freq_res)-sizeof(*dst->bs_freq_res));
     memcpy(dst->bs_num_env+1,  src->bs_num_env+1,  sizeof(dst->bs_num_env)- sizeof(*dst->bs_num_env));
-    memcpy(dst->bs_var_bord,   src->bs_var_bord,   sizeof(dst->bs_var_bord));
-    memcpy(dst->bs_rel_bord,   src->bs_rel_bord,   sizeof(dst->bs_rel_bord));
-    memcpy(dst->bs_num_rel,    src->bs_num_rel,    sizeof(dst->bs_rel_bord));
     memcpy(dst->t_env,         src->t_env,         sizeof(dst->t_env));
     memcpy(dst->t_q,           src->t_q,           sizeof(dst->t_q));
     dst->bs_amp_res     = src->bs_amp_res;
     dst->bs_num_noise   = src->bs_num_noise;
-    dst->bs_pointer     = src->bs_pointer;
     dst->bs_frame_class = src->bs_frame_class;
     dst->e_a[1]         = src->e_a[1];
 }