Sync codeclib bitstream code with upstream ffmpeg code. Build ffmpeg_bitstream.c as a part of the codec lib. Use this codeclib implementation in libffmpegFLAC. Implement adapted version of the unaligned longword reading optimization for coldfire from the libwma version of this code. Speeds up cook decoding by 2-3% on h300 and flac by 25% on h300, also speeds up flac decoding by 2% on c200 (decoding speed of cook on c200 is unchanged).

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@27430 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 750 insertions, 0 deletions

diff --git a/apps/codecs/lib/ffmpeg_get_bits.h b/apps/codecs/lib/ffmpeg_get_bits.h
new file mode 100644
index 0000000000..1a461e9e25
--- /dev/null
+++ b/apps/codecs/lib/ffmpeg_get_bits.h
@@ -0,0 +1,750 @@
+/*
+ * copyright (c) 2004 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
+ */
+
+/**
+ * @file
+ * bitstream reader API header.
+ */
+
+#ifndef AVCODEC_GET_BITS_H
+#define AVCODEC_GET_BITS_H
+
+#include <stdint.h>
+#include <stdlib.h>
+//#include <assert.h>
+//#include "libavutil/bswap.h"
+//#include "libavutil/common.h"
+//#include "libavutil/intreadwrite.h"
+//#include "libavutil/log.h"
+//#include "mathops.h"
+
+#include "codecs.h"
+
+/* rockbox' optimised inline functions */
+#define bswap_16(x) swap16(x)
+#define bswap_32(x) swap32(x)
+
+#ifdef ROCKBOX_BIG_ENDIAN
+#define be2me_16(x) (x)
+#define be2me_32(x) (x)
+#define le2me_16(x) bswap_16(x)
+#define le2me_32(x) bswap_32(x)
+#else
+#define be2me_16(x) bswap_16(x)
+#define be2me_32(x) bswap_32(x)
+#define le2me_16(x) (x)
+#define le2me_32(x) (x)
+#endif
+
+#define av_const __attribute__((const))
+#define av_always_inline inline __attribute__((always_inline))
+
+/* Coldfire cpu's support unaligned long reads */ 
+#ifdef CPU_COLDFIRE
+#define AV_RB32(x)  (*(const uint32_t*)(x))
+#else
+/* The following define is taken from libavutil/intreadwrite.h */
+#define AV_RB32(x)  ((((const uint8_t*)(x))[0] << 24) | \
+                     (((const uint8_t*)(x))[1] << 16) | \
+                     (((const uint8_t*)(x))[2] <<  8) | \
+                      ((const uint8_t*)(x))[3])
+#endif
+/* The following is taken from mathops.h */
+
+#ifndef sign_extend
+static inline av_const int sign_extend(int val, unsigned bits)
+{
+    return (val << ((8 * sizeof(int)) - bits)) >> ((8 * sizeof(int)) - bits);
+}
+#endif
+
+#ifndef NEG_SSR32
+#   define NEG_SSR32(a,s) ((( int32_t)(a))>>(32-(s)))
+#endif
+
+#ifndef NEG_USR32
+#   define NEG_USR32(a,s) (((uint32_t)(a))>>(32-(s)))
+#endif
+
+/* these 2 are from libavutil/common.h */
+
+#define FFMAX(a,b) ((a) > (b) ? (a) : (b))
+#define FFMIN(a,b) ((a) > (b) ? (b) : (a))
+
+#if defined(ALT_BITSTREAM_READER_LE) && !defined(ALT_BITSTREAM_READER)
+#   define ALT_BITSTREAM_READER
+#endif
+
+/*
+#if !defined(LIBMPEG2_BITSTREAM_READER) && !defined(A32_BITSTREAM_READER) && !defined(ALT_BITSTREAM_READER)
+#   if ARCH_ARM && !HAVE_FAST_UNALIGNED
+#       define A32_BITSTREAM_READER
+#   else
+*/
+#       define ALT_BITSTREAM_READER
+/*
+//#define LIBMPEG2_BITSTREAM_READER
+//#define A32_BITSTREAM_READER
+#   endif
+#endif
+*/
+
+/* bit input */
+/* buffer, buffer_end and size_in_bits must be present and used by every reader */
+typedef struct GetBitContext {
+    const uint8_t *buffer, *buffer_end;
+#ifdef ALT_BITSTREAM_READER
+    int index;
+#elif defined LIBMPEG2_BITSTREAM_READER
+    uint8_t *buffer_ptr;
+    uint32_t cache;
+    int bit_count;
+#elif defined A32_BITSTREAM_READER
+    uint32_t *buffer_ptr;
+    uint32_t cache0;
+    uint32_t cache1;
+    int bit_count;
+#endif
+    int size_in_bits;
+} GetBitContext;
+
+#define VLC_TYPE int16_t
+
+typedef struct VLC {
+    int bits;
+    VLC_TYPE (*table)[2]; ///< code, bits
+    int table_size, table_allocated;
+} VLC;
+
+typedef struct RL_VLC_ELEM {
+    int16_t level;
+    int8_t len;
+    uint8_t run;
+} RL_VLC_ELEM;
+
+/* Bitstream reader API docs:
+name
+    arbitrary name which is used as prefix for the internal variables
+
+gb
+    getbitcontext
+
+OPEN_READER(name, gb)
+    loads gb into local variables
+
+CLOSE_READER(name, gb)
+    stores local vars in gb
+
+UPDATE_CACHE(name, gb)
+    refills the internal cache from the bitstream
+    after this call at least MIN_CACHE_BITS will be available,
+
+GET_CACHE(name, gb)
+    will output the contents of the internal cache, next bit is MSB of 32 or 64 bit (FIXME 64bit)
+
+SHOW_UBITS(name, gb, num)
+    will return the next num bits
+
+SHOW_SBITS(name, gb, num)
+    will return the next num bits and do sign extension
+
+SKIP_BITS(name, gb, num)
+    will skip over the next num bits
+    note, this is equivalent to SKIP_CACHE; SKIP_COUNTER
+
+SKIP_CACHE(name, gb, num)
+    will remove the next num bits from the cache (note SKIP_COUNTER MUST be called before UPDATE_CACHE / CLOSE_READER)
+
+SKIP_COUNTER(name, gb, num)
+    will increment the internal bit counter (see SKIP_CACHE & SKIP_BITS)
+
+LAST_SKIP_CACHE(name, gb, num)
+    will remove the next num bits from the cache if it is needed for UPDATE_CACHE otherwise it will do nothing
+
+LAST_SKIP_BITS(name, gb, num)
+    is equivalent to LAST_SKIP_CACHE; SKIP_COUNTER
+
+for examples see get_bits, show_bits, skip_bits, get_vlc
+*/
+
+#ifdef ALT_BITSTREAM_READER
+#   define MIN_CACHE_BITS 25
+
+#   define OPEN_READER(name, gb)\
+        unsigned int name##_index= (gb)->index;\
+        int name##_cache= 0;\
+
+#   define CLOSE_READER(name, gb)\
+        (gb)->index= name##_index;\
+
+# ifdef ALT_BITSTREAM_READER_LE
+#   define UPDATE_CACHE(name, gb)\
+        name##_cache= AV_RL32( ((const uint8_t *)(gb)->buffer)+(name##_index>>3) ) >> (name##_index&0x07);\
+
+#   define SKIP_CACHE(name, gb, num)\
+        name##_cache >>= (num);
+# else
+#   define UPDATE_CACHE(name, gb)\
+        name##_cache= AV_RB32( ((const uint8_t *)(gb)->buffer)+(name##_index>>3) ) << (name##_index&0x07);\
+
+#   define SKIP_CACHE(name, gb, num)\
+        name##_cache <<= (num);
+# endif
+
+// FIXME name?
+#   define SKIP_COUNTER(name, gb, num)\
+        name##_index += (num);\
+
+#   define SKIP_BITS(name, gb, num)\
+        {\
+            SKIP_CACHE(name, gb, num)\
+            SKIP_COUNTER(name, gb, num)\
+        }\
+
+#   define LAST_SKIP_BITS(name, gb, num) SKIP_COUNTER(name, gb, num)
+#   define LAST_SKIP_CACHE(name, gb, num) ;
+
+# ifdef ALT_BITSTREAM_READER_LE
+#   define SHOW_UBITS(name, gb, num)\
+        zero_extend(name##_cache, num)
+
+#   define SHOW_SBITS(name, gb, num)\
+        sign_extend(name##_cache, num)
+# else
+#   define SHOW_UBITS(name, gb, num)\
+        NEG_USR32(name##_cache, num)
+
+#   define SHOW_SBITS(name, gb, num)\
+        NEG_SSR32(name##_cache, num)
+# endif
+
+#   define GET_CACHE(name, gb)\
+        ((uint32_t)name##_cache)
+
+static inline int get_bits_count(const GetBitContext *s){
+    return s->index;
+}
+
+static inline void skip_bits_long(GetBitContext *s, int n){
+    s->index += n;
+}
+
+#elif defined LIBMPEG2_BITSTREAM_READER
+//libmpeg2 like reader
+
+#   define MIN_CACHE_BITS 17
+
+#   define OPEN_READER(name, gb)\
+        int name##_bit_count=(gb)->bit_count;\
+        int name##_cache= (gb)->cache;\
+        uint8_t * name##_buffer_ptr=(gb)->buffer_ptr;\
+
+#   define CLOSE_READER(name, gb)\
+        (gb)->bit_count= name##_bit_count;\
+        (gb)->cache= name##_cache;\
+        (gb)->buffer_ptr= name##_buffer_ptr;\
+
+#   define UPDATE_CACHE(name, gb)\
+    if(name##_bit_count >= 0){\
+        name##_cache+= AV_RB16(name##_buffer_ptr) << name##_bit_count; \
+        name##_buffer_ptr+=2;\
+        name##_bit_count-= 16;\
+    }\
+
+#   define SKIP_CACHE(name, gb, num)\
+        name##_cache <<= (num);\
+
+#   define SKIP_COUNTER(name, gb, num)\
+        name##_bit_count += (num);\
+
+#   define SKIP_BITS(name, gb, num)\
+        {\
+            SKIP_CACHE(name, gb, num)\
+            SKIP_COUNTER(name, gb, num)\
+        }\
+
+#   define LAST_SKIP_BITS(name, gb, num) SKIP_BITS(name, gb, num)
+#   define LAST_SKIP_CACHE(name, gb, num) SKIP_CACHE(name, gb, num)
+
+#   define SHOW_UBITS(name, gb, num)\
+        NEG_USR32(name##_cache, num)
+
+#   define SHOW_SBITS(name, gb, num)\
+        NEG_SSR32(name##_cache, num)
+
+#   define GET_CACHE(name, gb)\
+        ((uint32_t)name##_cache)
+
+static inline int get_bits_count(const GetBitContext *s){
+    return (s->buffer_ptr - s->buffer)*8 - 16 + s->bit_count;
+}
+
+static inline void skip_bits_long(GetBitContext *s, int n){
+    OPEN_READER(re, s)
+    re_bit_count += n;
+    re_buffer_ptr += 2*(re_bit_count>>4);
+    re_bit_count &= 15;
+    re_cache = ((re_buffer_ptr[-2]<<8) + re_buffer_ptr[-1]) << (16+re_bit_count);
+    UPDATE_CACHE(re, s)
+    CLOSE_READER(re, s)
+}
+
+#elif defined A32_BITSTREAM_READER
+
+#   define MIN_CACHE_BITS 32
+
+#   define OPEN_READER(name, gb)\
+        int name##_bit_count=(gb)->bit_count;\
+        uint32_t name##_cache0= (gb)->cache0;\
+        uint32_t name##_cache1= (gb)->cache1;\
+        uint32_t * name##_buffer_ptr=(gb)->buffer_ptr;\
+
+#   define CLOSE_READER(name, gb)\
+        (gb)->bit_count= name##_bit_count;\
+        (gb)->cache0= name##_cache0;\
+        (gb)->cache1= name##_cache1;\
+        (gb)->buffer_ptr= name##_buffer_ptr;\
+
+#   define UPDATE_CACHE(name, gb)\
+    if(name##_bit_count > 0){\
+        const uint32_t next= av_be2ne32( *name##_buffer_ptr );\
+        name##_cache0 |= NEG_USR32(next,name##_bit_count);\
+        name##_cache1 |= next<<name##_bit_count;\
+        name##_buffer_ptr++;\
+        name##_bit_count-= 32;\
+    }\
+
+#if ARCH_X86
+#   define SKIP_CACHE(name, gb, num)\
+        __asm__(\
+            "shldl %2, %1, %0          \n\t"\
+            "shll %2, %1               \n\t"\
+            : "+r" (name##_cache0), "+r" (name##_cache1)\
+            : "Ic" ((uint8_t)(num))\
+           );
+#else
+#   define SKIP_CACHE(name, gb, num)\
+        name##_cache0 <<= (num);\
+        name##_cache0 |= NEG_USR32(name##_cache1,num);\
+        name##_cache1 <<= (num);
+#endif
+
+#   define SKIP_COUNTER(name, gb, num)\
+        name##_bit_count += (num);\
+
+#   define SKIP_BITS(name, gb, num)\
+        {\
+            SKIP_CACHE(name, gb, num)\
+            SKIP_COUNTER(name, gb, num)\
+        }\
+
+#   define LAST_SKIP_BITS(name, gb, num) SKIP_BITS(name, gb, num)
+#   define LAST_SKIP_CACHE(name, gb, num) SKIP_CACHE(name, gb, num)
+
+#   define SHOW_UBITS(name, gb, num)\
+        NEG_USR32(name##_cache0, num)
+
+#   define SHOW_SBITS(name, gb, num)\
+        NEG_SSR32(name##_cache0, num)
+
+#   define GET_CACHE(name, gb)\
+        (name##_cache0)
+
+static inline int get_bits_count(const GetBitContext *s){
+    return ((uint8_t*)s->buffer_ptr - s->buffer)*8 - 32 + s->bit_count;
+}
+
+static inline void skip_bits_long(GetBitContext *s, int n){
+    OPEN_READER(re, s)
+    re_bit_count += n;
+    re_buffer_ptr += re_bit_count>>5;
+    re_bit_count &= 31;
+    re_cache0 = av_be2ne32( re_buffer_ptr[-1] ) << re_bit_count;
+    re_cache1 = 0;
+    UPDATE_CACHE(re, s)
+    CLOSE_READER(re, s)
+}
+
+#endif
+
+/**
+ * read mpeg1 dc style vlc (sign bit + mantisse with no MSB).
+ * if MSB not set it is negative
+ * @param n length in bits
+ * @author BERO
+ */
+static inline int get_xbits(GetBitContext *s, int n){
+    register int sign;
+    register int32_t cache;
+    OPEN_READER(re, s)
+    UPDATE_CACHE(re, s)
+    cache = GET_CACHE(re,s);
+    sign=(~cache)>>31;
+    LAST_SKIP_BITS(re, s, n)
+    CLOSE_READER(re, s)
+    return (NEG_USR32(sign ^ cache, n) ^ sign) - sign;
+}
+
+static inline int get_sbits(GetBitContext *s, int n){
+    register int tmp;
+    OPEN_READER(re, s)
+    UPDATE_CACHE(re, s)
+    tmp= SHOW_SBITS(re, s, n);
+    LAST_SKIP_BITS(re, s, n)
+    CLOSE_READER(re, s)
+    return tmp;
+}
+
+/**
+ * reads 1-17 bits.
+ * Note, the alt bitstream reader can read up to 25 bits, but the libmpeg2 reader can't
+ */
+static inline unsigned int get_bits(GetBitContext *s, int n){
+    register int tmp;
+    OPEN_READER(re, s)
+    UPDATE_CACHE(re, s)
+    tmp= SHOW_UBITS(re, s, n);
+    LAST_SKIP_BITS(re, s, n)
+    CLOSE_READER(re, s)
+    return tmp;
+}
+
+/**
+ * shows 1-17 bits.
+ * Note, the alt bitstream reader can read up to 25 bits, but the libmpeg2 reader can't
+ */
+static inline unsigned int show_bits(GetBitContext *s, int n){
+    register int tmp;
+    OPEN_READER(re, s)
+    UPDATE_CACHE(re, s)
+    tmp= SHOW_UBITS(re, s, n);
+//    CLOSE_READER(re, s)
+    return tmp;
+}
+
+static inline void skip_bits(GetBitContext *s, int n){
+ //Note gcc seems to optimize this to s->index+=n for the ALT_READER :))
+    OPEN_READER(re, s)
+    UPDATE_CACHE(re, s)
+    LAST_SKIP_BITS(re, s, n)
+    CLOSE_READER(re, s)
+}
+
+static inline unsigned int get_bits1(GetBitContext *s){
+#ifdef ALT_BITSTREAM_READER
+    unsigned int index= s->index;
+    uint8_t result= s->buffer[ index>>3 ];
+#ifdef ALT_BITSTREAM_READER_LE
+    result>>= (index&0x07);
+    result&= 1;
+#else
+    result<<= (index&0x07);
+    result>>= 8 - 1;
+#endif
+    index++;
+    s->index= index;
+
+    return result;
+#else
+    return get_bits(s, 1);
+#endif
+}
+
+static inline unsigned int show_bits1(GetBitContext *s){
+    return show_bits(s, 1);
+}
+
+static inline void skip_bits1(GetBitContext *s){
+    skip_bits(s, 1);
+}
+
+/**
+ * reads 0-32 bits.
+ */
+static inline unsigned int get_bits_long(GetBitContext *s, int n){
+    if(n<=MIN_CACHE_BITS) return get_bits(s, n);
+    else{
+#ifdef ALT_BITSTREAM_READER_LE
+        int ret= get_bits(s, 16);
+        return ret | (get_bits(s, n-16) << 16);
+#else
+        int ret= get_bits(s, 16) << (n-16);
+        return ret | get_bits(s, n-16);
+#endif
+    }
+}
+
+/**
+ * reads 0-32 bits as a signed integer.
+ */
+static inline int get_sbits_long(GetBitContext *s, int n) {
+    return sign_extend(get_bits_long(s, n), n);
+}
+
+/**
+ * shows 0-32 bits.
+ */
+static inline unsigned int show_bits_long(GetBitContext *s, int n){
+    if(n<=MIN_CACHE_BITS) return show_bits(s, n);
+    else{
+        GetBitContext gb= *s;
+        return get_bits_long(&gb, n);
+    }
+}
+
+/* not used
+static inline 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);
+
+    return bit;
+}
+*/
+
+/**
+ * init GetBitContext.
+ * @param buffer bitstream buffer, must be FF_INPUT_BUFFER_PADDING_SIZE bytes larger then the actual read bits
+ * because some optimized bitstream readers read 32 or 64 bit at once and could read over the end
+ * @param bit_size the size of the buffer in bits
+ *
+ * While GetBitContext stores the buffer size, for performance reasons you are
+ * responsible for checking for the buffer end yourself (take advantage of the padding)!
+ */
+static inline void init_get_bits(GetBitContext *s,
+                   const uint8_t *buffer, int bit_size)
+{
+    int buffer_size= (bit_size+7)>>3;
+    if(buffer_size < 0 || bit_size < 0) {
+        buffer_size = bit_size = 0;
+        buffer = NULL;
+    }
+
+    s->buffer= buffer;
+    s->size_in_bits= bit_size;
+    s->buffer_end= buffer + buffer_size;
+#ifdef ALT_BITSTREAM_READER
+    s->index=0;
+#elif defined LIBMPEG2_BITSTREAM_READER
+    s->buffer_ptr = (uint8_t*)((intptr_t)buffer&(~1));
+    s->bit_count = 16 + 8*((intptr_t)buffer&1);
+    skip_bits_long(s, 0);
+#elif defined A32_BITSTREAM_READER
+    s->buffer_ptr = (uint32_t*)((intptr_t)buffer&(~3));
+    s->bit_count = 32 + 8*((intptr_t)buffer&3);
+    skip_bits_long(s, 0);
+#endif
+}
+
+static inline void align_get_bits(GetBitContext *s)
+{
+    int n= (-get_bits_count(s)) & 7;
+    if(n) skip_bits(s, n);
+}
+
+#define init_vlc(vlc, nb_bits, nb_codes,\
+                 bits, bits_wrap, bits_size,\
+                 codes, codes_wrap, codes_size,\
+                 flags)\
+        init_vlc_sparse(vlc, nb_bits, nb_codes,\
+                 bits, bits_wrap, bits_size,\
+                 codes, codes_wrap, codes_size,\
+                 NULL, 0, 0, flags)
+
+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);
+#define INIT_VLC_LE         2
+#define INIT_VLC_USE_NEW_STATIC 4
+void free_vlc(VLC *vlc);
+
+#define INIT_VLC_STATIC(vlc, bits, a,b,c,d,e,f,g, static_size)\
+{\
+    static VLC_TYPE table[static_size][2];\
+    (vlc)->table= table;\
+    (vlc)->table_allocated= static_size;\
+    init_vlc(vlc, bits, a,b,c,d,e,f,g, INIT_VLC_USE_NEW_STATIC);\
+}
+
+
+/**
+ *
+ * If the vlc code is invalid and max_depth=1, then no bits will be removed.
+ * If the vlc code is invalid and max_depth>1, then the number of bits removed
+ * is undefined.
+ */
+#define GET_VLC(code, name, gb, table, bits, max_depth)\
+{\
+    int n, nb_bits;\
+    unsigned int index;\
+\
+    index= SHOW_UBITS(name, gb, bits);\
+    code = table[index][0];\
+    n    = table[index][1];\
+\
+    if(max_depth > 1 && n < 0){\
+        LAST_SKIP_BITS(name, gb, bits)\
+        UPDATE_CACHE(name, gb)\
+\
+        nb_bits = -n;\
+\
+        index= SHOW_UBITS(name, gb, nb_bits) + code;\
+        code = table[index][0];\
+        n    = table[index][1];\
+        if(max_depth > 2 && n < 0){\
+            LAST_SKIP_BITS(name, gb, nb_bits)\
+            UPDATE_CACHE(name, gb)\
+\
+            nb_bits = -n;\
+\
+            index= SHOW_UBITS(name, gb, nb_bits) + code;\
+            code = table[index][0];\
+            n    = table[index][1];\
+        }\
+    }\
+    SKIP_BITS(name, gb, n)\
+}
+
+#define GET_RL_VLC(level, run, name, gb, table, bits, max_depth, need_update)\
+{\
+    int n, nb_bits;\
+    unsigned int index;\
+\
+    index= SHOW_UBITS(name, gb, bits);\
+    level = table[index].level;\
+    n     = table[index].len;\
+\
+    if(max_depth > 1 && n < 0){\
+        SKIP_BITS(name, gb, bits)\
+        if(need_update){\
+            UPDATE_CACHE(name, gb)\
+        }\
+\
+        nb_bits = -n;\
+\
+        index= SHOW_UBITS(name, gb, nb_bits) + level;\
+        level = table[index].level;\
+        n     = table[index].len;\
+    }\
+    run= table[index].run;\
+    SKIP_BITS(name, gb, n)\
+}
+
+
+/**
+ * parses a vlc code, faster then get_vlc()
+ * @param bits is the number of bits which will be read at once, must be
+ *             identical to nb_bits in init_vlc()
+ * @param max_depth is the number of times bits bits must be read to completely
+ *                  read the longest vlc code
+ *                  = (max_vlc_length + bits - 1) / bits
+ */
+static av_always_inline int get_vlc2(GetBitContext *s, VLC_TYPE (*table)[2],
+                                  int bits, int max_depth)
+{
+    int code;
+
+    OPEN_READER(re, s)
+    UPDATE_CACHE(re, s)
+
+    GET_VLC(code, re, s, table, bits, max_depth)
+
+    CLOSE_READER(re, s)
+    return code;
+}
+
+//#define TRACE
+
+#ifdef TRACE
+static inline void print_bin(int bits, int n){
+    int i;
+
+    for(i=n-1; i>=0; i--){
+        av_log(NULL, AV_LOG_DEBUG, "%d", (bits>>i)&1);
+    }
+    for(i=n; i<24; i++)
+        av_log(NULL, AV_LOG_DEBUG, " ");
+}
+
+static inline int get_bits_trace(GetBitContext *s, int n, char *file, const char *func, int line){
+    int r= get_bits(s, n);
+
+    print_bin(r, n);
+    av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d bit @%5d in %s %s:%d\n", r, n, r, get_bits_count(s)-n, file, func, line);
+    return r;
+}
+static inline int get_vlc_trace(GetBitContext *s, VLC_TYPE (*table)[2], int bits, int max_depth, char *file, const char *func, int line){
+    int show= show_bits(s, 24);
+    int pos= get_bits_count(s);
+    int r= get_vlc2(s, table, bits, max_depth);
+    int len= get_bits_count(s) - pos;
+    int bits2= show>>(24-len);
+
+    print_bin(bits2, len);
+
+    av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d vlc @%5d in %s %s:%d\n", bits2, len, r, pos, file, func, line);
+    return r;
+}
+static inline int get_xbits_trace(GetBitContext *s, int n, char *file, const char *func, int line){
+    int show= show_bits(s, n);
+    int r= get_xbits(s, n);
+
+    print_bin(show, n);
+    av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d xbt @%5d in %s %s:%d\n", show, n, r, get_bits_count(s)-n, file, func, line);
+    return r;
+}
+
+#define get_bits(s, n)  get_bits_trace(s, n, __FILE__, __PRETTY_FUNCTION__, __LINE__)
+#define get_bits1(s)    get_bits_trace(s, 1, __FILE__, __PRETTY_FUNCTION__, __LINE__)
+#define get_xbits(s, n) get_xbits_trace(s, n, __FILE__, __PRETTY_FUNCTION__, __LINE__)
+#define get_vlc(s, vlc)            get_vlc_trace(s, (vlc)->table, (vlc)->bits, 3, __FILE__, __PRETTY_FUNCTION__, __LINE__)
+#define get_vlc2(s, tab, bits, max) get_vlc_trace(s, tab, bits, max, __FILE__, __PRETTY_FUNCTION__, __LINE__)
+
+#define tprintf(p, ...) av_log(p, AV_LOG_DEBUG, __VA_ARGS__)
+
+#else //TRACE
+#define tprintf(p, ...) {}
+#endif
+
+static inline int decode012(GetBitContext *gb){
+    int n;
+    n = get_bits1(gb);
+    if (n == 0)
+        return 0;
+    else
+        return get_bits1(gb) + 1;
+}
+
+static inline int decode210(GetBitContext *gb){
+    if (get_bits1(gb))
+        return 0;
+    else
+        return 2 - get_bits1(gb);
+}
+
+static inline int get_bits_left(GetBitContext *gb)
+{
+    return gb->size_in_bits - get_bits_count(gb);
+}
+
+#endif /* AVCODEC_GET_BITS_H */