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aligned bitstream support (optional) - patch by ichael Niedermayer <michaelni@gmx.at>
Originally committed as revision 253 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer
Arpi
parent
27a3e2c5e0
commit
3587d501a3
@ -505,41 +505,3 @@ void free_vlc(VLC *vlc)
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free(vlc->table_codes);
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}
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int get_vlc(GetBitContext *s, VLC *vlc)
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{
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int bit_cnt, code, n, nb_bits, index;
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UINT32 bit_buf;
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INT16 *table_codes;
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INT8 *table_bits;
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UINT8 *buf_ptr;
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SAVE_BITS(s);
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nb_bits = vlc->bits;
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table_codes = vlc->table_codes;
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table_bits = vlc->table_bits;
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for(;;) {
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SHOW_BITS(s, index, nb_bits);
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code = table_codes[index];
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n = table_bits[index];
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if (n > 0) {
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/* most common case */
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FLUSH_BITS(n);
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#ifdef STATS
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st_bit_counts[st_current_index] += n;
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#endif
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break;
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} else if (n == 0) {
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return -1;
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} else {
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FLUSH_BITS(nb_bits);
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#ifdef STATS
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st_bit_counts[st_current_index] += nb_bits;
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#endif
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nb_bits = -n;
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table_codes = vlc->table_codes + code;
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table_bits = vlc->table_bits + code;
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}
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}
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RESTORE_BITS(s);
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return code;
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}
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@ -9,6 +9,7 @@
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#endif
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//#define ALT_BITSTREAM_READER
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//#define ALIGNED_BITSTREAM
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#ifdef HAVE_AV_CONFIG_H
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/* only include the following when compiling package */
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@ -200,6 +201,29 @@ typedef struct VLC {
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int table_size, table_allocated;
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} VLC;
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/* used to avoid missaligned exceptions on some archs (alpha, ...) */
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#ifdef ARCH_X86
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#define unaligned32(a) (*(UINT32*)(a))
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#else
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#ifdef __GNUC__
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static inline uint32_t unaligned32(const void *v) {
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struct Unaligned {
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uint32_t i;
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} __attribute__((packed));
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return ((const struct Unaligned *) v)->i;
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}
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#elif defined(__DECC)
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static inline uint32_t unaligned32(const void *v) {
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return *(const __unaligned uint32_t *) v;
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}
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#else
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static inline uint32_t unaligned32(const void *v) {
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return *(const uint32_t *) v;
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}
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#endif
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#endif //!ARCH_X86
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void init_get_bits(GetBitContext *s,
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UINT8 *buffer, int buffer_size);
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@ -210,8 +234,27 @@ unsigned int show_bits_long(GetBitContext *s, int n);
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static inline unsigned int get_bits(GetBitContext *s, int n){
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#ifdef ALT_BITSTREAM_READER
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#ifdef ALIGNED_BITSTREAM
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int index= s->index;
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uint32_t result= be2me_32( *(uint32_t *)(((uint8_t *)s->buffer)+(index>>3)) );
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uint32_t result1= be2me_32( ((uint32_t *)s->buffer)[index>>5] );
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uint32_t result2= be2me_32( ((uint32_t *)s->buffer)[(index>>5) + 1] );
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#ifdef ARCH_X86
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asm ("shldl %%cl, %2, %0\n\t"
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: "=r" (result1)
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: "0" (result1), "r" (result2), "c" (index));
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#else
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result1<<= (index&0x1F);
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result2>>= 32-(index&0x1F);
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if((index&0x1F)!=0) result1|= result2;
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#endif
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result1>>= 32 - n;
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index+= n;
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s->index= index;
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return result1;
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#else //ALIGNED_BITSTREAM
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int index= s->index;
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uint32_t result= be2me_32( unaligned32( ((uint8_t *)s->buffer)+(index>>3) ) );
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result<<= (index&0x07);
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result>>= 32 - n;
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@ -219,7 +262,8 @@ static inline unsigned int get_bits(GetBitContext *s, int n){
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s->index= index;
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return result;
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#else
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#endif //!ALIGNED_BITSTREAM
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#else //ALT_BITSTREAM_READER
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if(s->bit_cnt>=n){
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/* most common case here */
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unsigned int val = s->bit_buf >> (32 - n);
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@ -231,16 +275,15 @@ static inline unsigned int get_bits(GetBitContext *s, int n){
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return val;
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}
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return get_bits_long(s,n);
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#endif
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#endif //!ALT_BITSTREAM_READER
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}
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static inline unsigned int get_bits1(GetBitContext *s){
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#ifdef ALT_BITSTREAM_READER
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int index= s->index;
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uint32_t result= be2me_32( *(uint32_t *)(((uint8_t *)s->buffer)+(index>>3)) );
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result<<= (index&0x07);
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result>>= 32 - 1;
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uint8_t result= s->buffer[ index>>3 ];
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result>>= 7-(index&0x07);
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result&=1;
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index++;
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s->index= index;
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@ -266,21 +309,39 @@ static inline unsigned int get_bits1(GetBitContext *s){
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static inline unsigned int show_bits(GetBitContext *s, int n)
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{
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#ifdef ALT_BITSTREAM_READER
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#ifdef ALIGNED_BITSTREAM
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int index= s->index;
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uint32_t result= be2me_32( *(uint32_t *)(((uint8_t *)s->buffer)+(index>>3)) );
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uint32_t result1= be2me_32( ((uint32_t *)s->buffer)[index>>5] );
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uint32_t result2= be2me_32( ((uint32_t *)s->buffer)[(index>>5) + 1] );
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#ifdef ARCH_X86
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asm ("shldl %%cl, %2, %0\n\t"
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: "=r" (result1)
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: "0" (result1), "r" (result2), "c" (index));
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#else
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result1<<= (index&0x1F);
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result2>>= 32-(index&0x1F);
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if((index&0x1F)!=0) result1|= result2;
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#endif
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result1>>= 32 - n;
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return result1;
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#else //ALIGNED_BITSTREAM
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int index= s->index;
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uint32_t result= be2me_32( unaligned32( ((uint8_t *)s->buffer)+(index>>3) ) );
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result<<= (index&0x07);
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result>>= 32 - n;
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return result;
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#else
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#endif //!ALIGNED_BITSTREAM
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#else //ALT_BITSTREAM_READER
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if(s->bit_cnt>=n) {
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/* most common case here */
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unsigned int val = s->bit_buf >> (32 - n);
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return val;
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}
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return show_bits_long(s,n);
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#endif
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#endif //!ALT_BITSTREAM_READER
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}
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static inline void skip_bits(GetBitContext *s, int n){
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@ -331,7 +392,6 @@ int init_vlc(VLC *vlc, int nb_bits, int nb_codes,
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const void *bits, int bits_wrap, int bits_size,
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const void *codes, int codes_wrap, int codes_size);
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void free_vlc(VLC *vlc);
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int get_vlc(GetBitContext *s, VLC *vlc);
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#ifdef ALT_BITSTREAM_READER
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#define SHOW_BITS(s, val, n) val= show_bits(s, n);
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@ -381,6 +441,67 @@ int get_vlc(GetBitContext *s, VLC *vlc);
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(s)->bit_cnt = bit_cnt;\
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}
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#endif // !ALT_BITSTREAM_READER
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static inline int get_vlc(GetBitContext *s, VLC *vlc)
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{
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int code, n, nb_bits, index;
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INT16 *table_codes;
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INT8 *table_bits;
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#ifndef ALT_BITSTREAM_READER
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int bit_cnt;
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UINT32 bit_buf;
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UINT8 *buf_ptr;
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#endif
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SAVE_BITS(s);
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nb_bits = vlc->bits;
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table_codes = vlc->table_codes;
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table_bits = vlc->table_bits;
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SHOW_BITS(s, index, nb_bits);
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code = table_codes[index];
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n = table_bits[index];
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if (n > 0) {
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/* most common case (90%)*/
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FLUSH_BITS(n);
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RESTORE_BITS(s);
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return code;
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} else if (n == 0) {
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return -1;
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} else {
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FLUSH_BITS(nb_bits);
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nb_bits = -n;
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table_codes = vlc->table_codes + code;
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table_bits = vlc->table_bits + code;
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}
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for(;;) {
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SHOW_BITS(s, index, nb_bits);
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code = table_codes[index];
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n = table_bits[index];
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if (n > 0) {
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/* most common case */
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FLUSH_BITS(n);
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#ifdef STATS
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st_bit_counts[st_current_index] += n;
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#endif
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break;
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} else if (n == 0) {
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return -1;
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} else {
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FLUSH_BITS(nb_bits);
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#ifdef STATS
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st_bit_counts[st_current_index] += nb_bits;
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#endif
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nb_bits = -n;
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table_codes = vlc->table_codes + code;
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table_bits = vlc->table_bits + code;
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}
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}
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RESTORE_BITS(s);
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return code;
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}
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/* define it to include statistics code (useful only for optimizing
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codec efficiency */
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//#define STATS
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