SIMD vector optimizations. 3% faster overall decoding.

[ffmpeg] / libavcodec / bitstream.c

diff --git a/libavcodec/bitstream.c b/libavcodec/bitstream.c
index 2678772c4998a252b2da2a3b713dcd113650d9b4..49c6ece1b0d0de57f2cacf2ccb5dc52791b3047d 100644 (file)
--- a/libavcodec/bitstream.c
+++ b/libavcodec/bitstream.c
@@ -15,7 +15,7 @@
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  *
  * alternative bitstream reader & writer by Michael Niedermayer <michaelni@gmx.at>
  */
@@ -24,7 +24,7 @@
  * @file bitstream.c
  * bitstream api.
  */
- 
+
 #include "avcodec.h"
 #include "bitstream.h"
 
@@ -37,7 +37,7 @@ void align_put_bits(PutBitContext *s)
 #endif
 }
 
-void put_string(PutBitContext * pbc, char *s, int put_zero)
+void ff_put_string(PutBitContext * pbc, char *s, int put_zero)
 {
     while(*s){
         put_bits(pbc, 8, *s);
@@ -49,7 +49,7 @@ void put_string(PutBitContext * pbc, char *s, int put_zero)
 
 /* bit input functions */
 
-/** 
+/**
  * reads 0-32 bits.
  */
 unsigned int get_bits_long(GetBitContext *s, int n){
@@ -60,7 +60,7 @@ unsigned int get_bits_long(GetBitContext *s, int n){
     }
 }
 
-/** 
+/**
  * shows 0-32 bits.
  */
 unsigned int show_bits_long(GetBitContext *s, int n){
@@ -83,7 +83,7 @@ int check_marker(GetBitContext *s, const char *msg)
 {
     int bit= get_bits1(s);
     if(!bit)
-           av_log(NULL, AV_LOG_INFO, "Marker bit missing %s\n", msg);
+            av_log(NULL, AV_LOG_INFO, "Marker bit missing %s\n", msg);
 
     return bit;
 }
@@ -132,14 +132,14 @@ static int build_table(VLC *vlc, int table_nb_bits,
                        int nb_codes,
                        const void *bits, int bits_wrap, int bits_size,
                        const void *codes, int codes_wrap, int codes_size,
-                       uint32_t code_prefix, int n_prefix, int use_static)
+                       uint32_t code_prefix, int n_prefix, int flags)
 {
-    int i, j, k, n, table_size, table_index, nb, n1, index;
+    int i, j, k, n, table_size, table_index, nb, n1, index, code_prefix2;
     uint32_t code;
     VLC_TYPE (*table)[2];
 
     table_size = 1 << table_nb_bits;
-    table_index = alloc_table(vlc, table_size, use_static);
+    table_index = alloc_table(vlc, table_size, flags & INIT_VLC_USE_STATIC);
 #ifdef DEBUG_VLC
     printf("new table index=%d size=%d code_prefix=%x n=%d\n",
            table_index, table_size, code_prefix, n_prefix);
@@ -165,12 +165,18 @@ static int build_table(VLC *vlc, int table_nb_bits,
 #endif
         /* if code matches the prefix, it is in the table */
         n -= n_prefix;
-        if (n > 0 && (code >> n) == code_prefix) {
+        if(flags & INIT_VLC_LE)
+            code_prefix2= code & (n_prefix>=32 ? 0xffffffff : (1 << n_prefix)-1);
+        else
+            code_prefix2= code >> n;
+        if (n > 0 && code_prefix2 == code_prefix) {
             if (n <= table_nb_bits) {
                 /* no need to add another table */
                 j = (code << (table_nb_bits - n)) & (table_size - 1);
                 nb = 1 << (table_nb_bits - n);
                 for(k=0;k<nb;k++) {
+                    if(flags & INIT_VLC_LE)
+                        j = (code >> n_prefix) + (k<<n);
 #ifdef DEBUG_VLC
                     av_log(NULL, AV_LOG_DEBUG, "%4x: code=%d n=%d\n",
                            j, i, n);
@@ -185,7 +191,7 @@ static int build_table(VLC *vlc, int table_nb_bits,
                 }
             } else {
                 n -= table_nb_bits;
-                j = (code >> n) & ((1 << table_nb_bits) - 1);
+                j = (code >> ((flags & INIT_VLC_LE) ? n_prefix : n)) & ((1 << table_nb_bits) - 1);
 #ifdef DEBUG_VLC
                 printf("%4x: n=%d (subtable)\n",
                        j, n);
@@ -211,8 +217,8 @@ static int build_table(VLC *vlc, int table_nb_bits,
             index = build_table(vlc, n, nb_codes,
                                 bits, bits_wrap, bits_size,
                                 codes, codes_wrap, codes_size,
-                                (code_prefix << table_nb_bits) | i,
-                                n_prefix + table_nb_bits, use_static);
+                                (flags & INIT_VLC_LE) ? (code_prefix | (i << n_prefix)) : ((code_prefix << table_nb_bits) | i),
+                                n_prefix + table_nb_bits, flags);
             if (index < 0)
                 return -1;
             /* note: realloc has been done, so reload tables */
@@ -229,7 +235,7 @@ static int build_table(VLC *vlc, int table_nb_bits,
    'nb_bits' set thee decoding table size (2^nb_bits) entries. The
    bigger it is, the faster is the decoding. But it should not be too
    big to save memory and L1 cache. '9' is a good compromise.
-   
+
    'nb_codes' : number of vlcs codes
 
    'bits' : table which gives the size (in bits) of each vlc code.
@@ -243,7 +249,7 @@ static int build_table(VLC *vlc, int table_nb_bits,
    or 'codes' tables.
 
    'wrap' and 'size' allows to use any memory configuration and types
-   (byte/word/long) to store the 'bits' and 'codes' tables.  
+   (byte/word/long) to store the 'bits' and 'codes' tables.
 
    'use_static' should be set to 1 for tables, which should be freed
    with av_free_static(), 0 if free_vlc() will be used.