Move bitstream.[ch] to codecs/lib/ffmpeg_bitstream.[ch] to avoid duplicate copies across codecs.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@22337 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 276 insertions, 0 deletions

diff --git a/apps/codecs/lib/ffmpeg_bitstream.c b/apps/codecs/lib/ffmpeg_bitstream.c
new file mode 100644
index 0000000..88e3cbf
--- /dev/null
+++ b/apps/codecs/lib/ffmpeg_bitstream.c
@@ -0,0 +1,276 @@
+/*
+ * Common bit i/o utils
+ * Copyright (c) 2000, 2001 Fabrice Bellard
+ * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
+ *
+ * alternative bitstream reader & writer by Michael Niedermayer <michaelni@gmx.at>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "ffmpeg_bitstream.h"
+
+#ifdef ROCKBOX
+#undef DEBUGF
+#define DEBUGF(...)
+#endif
+
+const uint8_t ff_log2_run[32]={
+ 0, 0, 0, 0, 1, 1, 1, 1,
+ 2, 2, 2, 2, 3, 3, 3, 3,
+ 4, 4, 5, 5, 6, 6, 7, 7,
+ 8, 9,10,11,12,13,14,15
+};
+
+/**
+ * Same as av_mallocz_static(), but does a realloc.
+ *
+ * @param[in] ptr The block of memory to reallocate.
+ * @param[in] size The requested size.
+ * @return Block of memory of requested size.
+ * @deprecated. Code which uses ff_realloc_static is broken/misdesigned
+ * and should correctly use static arrays
+ */
+
+
+void ff_put_string(PutBitContext * pbc, const char *s, int put_zero)
+{
+    while(*s){
+        put_bits(pbc, 8, *s);
+        s++;
+    }
+    if(put_zero)
+        put_bits(pbc, 8, 0);
+}
+
+/* VLC decoding */
+
+//#define DEBUG_VLC
+
+#define GET_DATA(v, table, i, wrap, size) \
+{\
+    const uint8_t *ptr = (const uint8_t *)table + i * wrap;\
+    switch(size) {\
+    case 1:\
+        v = *(const uint8_t *)ptr;\
+        break;\
+    case 2:\
+        v = *(const uint16_t *)ptr;\
+        break;\
+    default:\
+        v = *(const uint32_t *)ptr;\
+        break;\
+    }\
+}
+
+
+static int alloc_table(VLC *vlc, int size, int use_static)
+{
+    int index;
+    index = vlc->table_size;
+    vlc->table_size += size;
+    if (vlc->table_size > vlc->table_allocated) {
+        if(use_static>1){
+            DEBUGF("init_vlc() used with too little memory : table_size > allocated_memory\n");
+        }
+
+        if (!vlc->table)
+            return -1;
+    }
+    return index;
+}
+
+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,
+                       const void *symbols, int symbols_wrap, int symbols_size,
+                       uint32_t code_prefix, int n_prefix, int flags)
+{
+    int i, j, k, n, table_size, table_index, nb, n1, index, code_prefix2, symbol;
+    uint32_t code;
+    VLC_TYPE (*table)[2];
+
+    table_size = 1 << table_nb_bits;
+    table_index = alloc_table(vlc, table_size, flags & (INIT_VLC_USE_STATIC|INIT_VLC_USE_NEW_STATIC));
+#ifdef DEBUG_VLC
+    DEBUGF("new table index=%d size=%d code_prefix=%x n=%d\n",
+           table_index, table_size, code_prefix, n_prefix);
+#endif
+    if (table_index < 0)
+        return -1;
+    table = &vlc->table[table_index];
+
+    for(i=0;i<table_size;i++) {
+        table[i][1] = 0; //bits
+        table[i][0] = -1; //codes
+    }
+
+    /* first pass: map codes and compute auxillary table sizes */
+    for(i=0;i<nb_codes;i++) {
+        GET_DATA(n, bits, i, bits_wrap, bits_size);
+        GET_DATA(code, codes, i, codes_wrap, codes_size);
+        /* we accept tables with holes */
+        if (n <= 0)
+            continue;
+        if (!symbols)
+            symbol = i;
+        else
+            GET_DATA(symbol, symbols, i, symbols_wrap, symbols_size);
+#if defined(DEBUG_VLC) && 0
+        DEBUGF("i=%d n=%d code=0x%x\n", i, n, code);
+#endif
+        /* if code matches the prefix, it is in the table */
+        n -= n_prefix;
+        if(flags & INIT_VLC_LE)
+            code_prefix2= code & (n_prefix>=32 ? (int)0xffffffff : (1 << n_prefix)-1);
+        else
+            code_prefix2= code >> n;
+        if (n > 0 && code_prefix2 == (int)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
+                    DEBUGF("%4x: code=%d n=%d\n",
+                           j, i, n);
+#endif
+                    if (table[j][1] /*bits*/ != 0) {
+                        DEBUGF("incorrect codes\n");
+                        return -1;
+                    }
+                    table[j][1] = n; //bits
+                    table[j][0] = symbol;
+                    j++;
+                }
+            } else {
+                n -= table_nb_bits;
+                j = (code >> ((flags & INIT_VLC_LE) ? n_prefix : n)) & ((1 << table_nb_bits) - 1);
+#ifdef DEBUG_VLC
+                DEBUGF("%4x: n=%d (subtable)\n",
+                       j, n);
+#endif
+                /* compute table size */
+                n1 = -table[j][1]; //bits
+                if (n > n1)
+                    n1 = n;
+                table[j][1] = -n1; //bits
+            }
+        }
+    }
+
+    /* second pass : fill auxillary tables recursively */
+    for(i=0;i<table_size;i++) {
+        n = table[i][1]; //bits
+        if (n < 0) {
+            n = -n;
+            if (n > table_nb_bits) {
+                n = table_nb_bits;
+                table[i][1] = -n; //bits
+            }
+            index = build_table(vlc, n, nb_codes,
+                                bits, bits_wrap, bits_size,
+                                codes, codes_wrap, codes_size,
+                                symbols, symbols_wrap, symbols_size,
+                                (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 */
+            table = &vlc->table[table_index];
+            table[i][0] = index; //code
+        }
+    }
+    return table_index;
+}
+
+
+/* Build VLC decoding tables suitable for use with get_vlc().
+
+   '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.
+
+   'codes' : table which gives the bit pattern of of each vlc code.
+
+   'symbols' : table which gives the values to be returned from get_vlc().
+
+   'xxx_wrap' : give the number of bytes between each entry of the
+   'bits' or 'codes' tables.
+
+   'xxx_size' : gives the number of bytes of each entry of the 'bits'
+   or 'codes' tables.
+
+   'wrap' and 'size' allows to use any memory configuration and types
+   (byte/word/long) to store the 'bits', 'codes', and 'symbols' 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.
+*/
+int init_vlc_sparse(VLC *vlc, int nb_bits, int nb_codes,
+             const void *bits, int bits_wrap, int bits_size,
+             const void *codes, int codes_wrap, int codes_size,
+             const void *symbols, int symbols_wrap, int symbols_size,
+             int flags)
+{
+    vlc->bits = nb_bits;
+    if(flags & INIT_VLC_USE_NEW_STATIC){
+        if(vlc->table_size && vlc->table_size == vlc->table_allocated){
+            return 0;
+        }else if(vlc->table_size){
+            return -1; // fatal error, we are called on a partially initialized table
+        }
+    }else if(!(flags & INIT_VLC_USE_STATIC)) {
+        vlc->table = NULL;
+        vlc->table_allocated = 0;
+        vlc->table_size = 0;
+    } else {
+        /* Static tables are initially always NULL, return
+           if vlc->table != NULL to avoid double allocation */
+        if(vlc->table)
+            return 0;
+    }
+
+#ifdef DEBUG_VLC
+    DEBUGF("build table nb_codes=%d\n", nb_codes);
+#endif
+
+    if (build_table(vlc, nb_bits, nb_codes,
+                    bits, bits_wrap, bits_size,
+                    codes, codes_wrap, codes_size,
+                    symbols, symbols_wrap, symbols_size,
+                    0, 0, flags) < 0) {
+        //free(&vlc->table);
+        return -1;
+    }
+    /* Changed the following condition to be true if table_size > table_allocated. *
+     * This would be more sensible for static tables since we want warnings for    *
+     * memory shortages only.                                                      */
+#ifdef TEST
+    if((flags & INIT_VLC_USE_NEW_STATIC) && vlc->table_size > vlc->table_allocated)
+        DEBUGF("needed %d had %d\n", vlc->table_size, vlc->table_allocated);
+#endif
+    return 0;
+}
+