avcodec/mpc7, mpc7data: Avoid gaps in array

The Musepack decoder uses static VLC tables to parse the bitstream.
There are 14 different quant tables VLCs and each of them has a varying
number of codes. The maximum number is 63, the average number is 25.3.
Up until now, the array containing the raw data was of type
uint16_t [7][2][64 * 2] (the 14 tables come in pairs of two, hence [7][2]
instead of [14]) and from this it follows that there were large gaps in
said array. This commit changes this by making it a continuous array
instead. Doing so saves about 2KB.

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>

1 files changed, 10 insertions, 7 deletions

diff --git a/libavcodec/mpc7.c b/libavcodec/mpc7.c
index 3c9ef6a600..6482029efc 100644
--- a/libavcodec/mpc7.c
+++ b/libavcodec/mpc7.c
@@ -38,10 +38,9 @@
 
 static VLC scfi_vlc, dscf_vlc, hdr_vlc, quant_vlc[MPC7_QUANT_VLC_TABLES][2];
 
-static const uint16_t quant_offsets[MPC7_QUANT_VLC_TABLES*2 + 1] =
+static const uint16_t quant_sizes[MPC7_QUANT_VLC_TABLES*2] =
 {
-       0, 512, 1024, 1536, 2052, 2564, 3076, 3588, 4100, 4612, 5124,
-       5636, 6164, 6676, 7224
+    512, 512, 512, 516, 512, 512, 512, 512, 512, 512, 512, 528, 512, 548
 };
 
 
@@ -54,6 +53,8 @@ static av_cold int mpc7_decode_init(AVCodecContext * avctx)
     static int vlc_initialized = 0;
 
     static VLC_TYPE quant_tables[7224][2];
+    VLC_TYPE (*quant_table)[2] = quant_tables;
+    const uint16_t *raw_quant_table = mpc7_quant_vlcs;
 
     /* Musepack SV7 is always stereo */
     if (avctx->channels != 2) {
@@ -103,11 +104,13 @@ static av_cold int mpc7_decode_init(AVCodecContext * avctx)
                     &mpc7_hdr[0], 2, 1, 1 << MPC7_HDR_BITS);
     for(i = 0; i < MPC7_QUANT_VLC_TABLES; i++){
         for(j = 0; j < 2; j++){
-            quant_vlc[i][j].table = &quant_tables[quant_offsets[i*2 + j]];
-            quant_vlc[i][j].table_allocated = quant_offsets[i*2 + j + 1] - quant_offsets[i*2 + j];
+            quant_vlc[i][j].table = quant_table;
+            quant_vlc[i][j].table_allocated = quant_sizes[i * 2 + j];
+            quant_table += quant_sizes[i * 2 + j];
             init_vlc(&quant_vlc[i][j], 9, mpc7_quant_vlc_sizes[i],
-                        &mpc7_quant_vlc[i][j][1], 4, 2,
-                     &mpc7_quant_vlc[i][j][0], 4, 2, INIT_VLC_USE_NEW_STATIC);
+                     raw_quant_table + 1, 4, 2,
+                     raw_quant_table, 4, 2, INIT_VLC_USE_NEW_STATIC);
+            raw_quant_table += 2 * mpc7_quant_vlc_sizes[i];
         }
     }
     vlc_initialized = 1;