diff options
Diffstat (limited to 'apps/codecs/lib/ffmpeg_bitstream.c')
| -rw-r--r-- | apps/codecs/lib/ffmpeg_bitstream.c | 321 |
1 files changed, 205 insertions, 116 deletions
diff --git a/apps/codecs/lib/ffmpeg_bitstream.c b/apps/codecs/lib/ffmpeg_bitstream.c index 88e3cbf..c879661 100644 --- a/apps/codecs/lib/ffmpeg_bitstream.c +++ b/apps/codecs/lib/ffmpeg_bitstream.c @@ -2,6 +2,7 @@ * Common bit i/o utils * Copyright (c) 2000, 2001 Fabrice Bellard * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at> + * Copyright (c) 2010 Loren Merritt * * alternative bitstream reader & writer by Michael Niedermayer <michaelni@gmx.at> * @@ -22,7 +23,16 @@ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ -#include "ffmpeg_bitstream.h" +/** + * @file + * bitstream api. + */ + +//#include "avcodec.h" +#include "ffmpeg_get_bits.h" +//#include "put_bits.h" + +#define av_log(...) #ifdef ROCKBOX #undef DEBUGF @@ -36,27 +46,47 @@ const uint8_t ff_log2_run[32]={ 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 - */ - +#if 0 // unused in rockbox +void align_put_bits(PutBitContext *s) +{ +#ifdef ALT_BITSTREAM_WRITER + put_bits(s,( - s->index) & 7,0); +#else + put_bits(s,s->bit_left & 7,0); +#endif +} -void ff_put_string(PutBitContext * pbc, const char *s, int put_zero) +void ff_put_string(PutBitContext *pb, const char *string, int terminate_string) { - while(*s){ - put_bits(pbc, 8, *s); - s++; + while(*string){ + put_bits(pb, 8, *string); + string++; } - if(put_zero) - put_bits(pbc, 8, 0); + if(terminate_string) + put_bits(pb, 8, 0); } +void ff_copy_bits(PutBitContext *pb, const uint8_t *src, int length) +{ + int words= length>>4; + int bits= length&15; + int i; + + if(length==0) return; + + if(CONFIG_SMALL || words < 16 || put_bits_count(pb)&7){ + for(i=0; i<words; i++) put_bits(pb, 16, AV_RB16(src + 2*i)); + }else{ + for(i=0; put_bits_count(pb)&31; i++) + put_bits(pb, 8, src[i]); + flush_put_bits(pb); + memcpy(put_bits_ptr(pb), src+i, 2*words-i); + skip_put_bytes(pb, 2*words-i); + } + + put_bits(pb, bits, AV_RB16(src + 2*words)>>(16-bits)); +} +#endif /* VLC decoding */ //#define DEBUG_VLC @@ -84,118 +114,143 @@ static int alloc_table(VLC *vlc, int size, int use_static) index = vlc->table_size; vlc->table_size += size; if (vlc->table_size > vlc->table_allocated) { - if(use_static>1){ + if(use_static) + { DEBUGF("init_vlc() used with too little memory : table_size > allocated_memory\n"); + return -1; } - +// abort(); //cant do anything, init_vlc() is used with too little memory +// vlc->table_allocated += (1 << vlc->bits); +// vlc->table = av_realloc(vlc->table, +// sizeof(VLC_TYPE) * 2 * vlc->table_allocated); 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; +/* +static av_always_inline uint32_t bitswap_32(uint32_t x) { + return av_reverse[x&0xFF]<<24 + | av_reverse[(x>>8)&0xFF]<<16 + | av_reverse[(x>>16)&0xFF]<<8 + | av_reverse[x>>24]; +} +*/ + +typedef struct { + uint8_t bits; + uint16_t symbol; + /** codeword, with the first bit-to-be-read in the msb + * (even if intended for a little-endian bitstream reader) */ uint32_t code; +} VLCcode; + +static int compare_vlcspec(const void *a, const void *b) +{ + const VLCcode *sa=a, *sb=b; + return (sa->code >> 1) - (sb->code >> 1); +} + +/** + * Build VLC decoding tables suitable for use with get_vlc(). + * + * @param vlc the context to be initted + * + * @param table_nb_bits max length of vlc codes to store directly in this table + * (Longer codes are delegated to subtables.) + * + * @param nb_codes number of elements in codes[] + * + * @param codes descriptions of the vlc codes + * These must be ordered such that codes going into the same subtable are contiguous. + * Sorting by VLCcode.code is sufficient, though not necessary. + */ +static int build_table(VLC *vlc, int table_nb_bits, int nb_codes, + VLCcode *codes, int flags) +{ + int table_size, table_index, index, symbol, subtable_bits; + int i, j, k, n, nb, inc; + uint32_t code, code_prefix; 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)); + table_index = alloc_table(vlc, table_size, flags & 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); + av_log(NULL,AV_LOG_DEBUG,"new table index=%d size=%d\n", + table_index, table_size); #endif if (table_index < 0) return -1; table = &vlc->table[table_index]; - for(i=0;i<table_size;i++) { + 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); + for (i = 0; i < nb_codes; i++) { + n = codes[i].bits; + code = codes[i].code; + symbol = codes[i].symbol; #if defined(DEBUG_VLC) && 0 - DEBUGF("i=%d n=%d code=0x%x\n", i, n, code); + av_log(NULL,AV_LOG_DEBUG,"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); + if (n <= table_nb_bits) { + /* no need to add another table */ + j = code >> (32 - table_nb_bits); + nb = 1 << (table_nb_bits - n); + inc = 1; +/* if (flags & INIT_VLC_LE) { + j = bitswap_32(code); + inc = 1 << n; + } */ + for (k = 0; k < nb; k++) { #ifdef DEBUG_VLC - DEBUGF("%4x: code=%d n=%d\n", - j, i, n); + av_log(NULL, AV_LOG_DEBUG, "%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++; + if (table[j][1] /*bits*/ != 0) { + av_log(NULL, AV_LOG_ERROR, "incorrect codes\n"); + return -1; } - } 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 + table[j][1] = n; //bits + table[j][0] = symbol; + j += inc; } - } - } - - /* 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 + } else { + /* fill auxiliary table recursively */ + n -= table_nb_bits; + code_prefix = code >> (32 - table_nb_bits); + subtable_bits = n; + codes[i].bits = n; + codes[i].code = code << table_nb_bits; + for (k = i+1; k < nb_codes; k++) { + n = codes[k].bits - table_nb_bits; + if (n <= 0) + break; + code = codes[k].code; + if (code >> (32 - table_nb_bits) != code_prefix) + break; + codes[k].bits = n; + codes[k].code = code << table_nb_bits; + subtable_bits = FFMAX(subtable_bits, n); } - 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); + subtable_bits = FFMIN(subtable_bits, table_nb_bits); + j = /*(flags & INIT_VLC_LE) ? bitswap_32(code_prefix) >> (32 - table_nb_bits) :*/ code_prefix; + table[j][1] = -subtable_bits; +#ifdef DEBUG_VLC + av_log(NULL,AV_LOG_DEBUG,"%4x: n=%d (subtable)\n", + j, codes[i].bits + table_nb_bits); +#endif + index = build_table(vlc, subtable_bits, k-i, codes+i, flags); if (index < 0) return -1; /* note: realloc has been done, so reload tables */ table = &vlc->table[table_index]; - table[i][0] = index; //code + table[j][0] = index; //code + i = k-1; } } return table_index; @@ -228,49 +283,83 @@ static int build_table(VLC *vlc, int table_nb_bits, 'use_static' should be set to 1 for tables, which should be freed with av_free_static(), 0 if free_vlc() will be used. */ + +/* Rockbox: support for INIT_VLC_LE is currently disabled since none of our + codecs use it, there's a LUT based bit reverse function for this commented + out above (bitswap_32) and an inline asm version in libtremor/codebook.c + if we ever want this */ 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) { + VLCcode buf[nb_codes+1]; /* worst case from cook seems to be nb_codes == 607 + which would make this about 4.8k... */ + int i, j, ret; + 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 + DEBUGF("fatal error, we are called on a partially initialized table\n"); + return -1; +// abort(); // fatal error, we are called on a partially initialized table } - }else if(!(flags & INIT_VLC_USE_STATIC)) { + }else { 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); + av_log(NULL,AV_LOG_DEBUG,"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); +// buf = av_malloc((nb_codes+1)*sizeof(VLCcode)); + +// assert(symbols_size <= 2 || !symbols); + j = 0; +#define COPY(condition)\ + for (i = 0; i < nb_codes; i++) {\ + GET_DATA(buf[j].bits, bits, i, bits_wrap, bits_size);\ + if (!(condition))\ + continue;\ + GET_DATA(buf[j].code, codes, i, codes_wrap, codes_size);\ +/* if (flags & INIT_VLC_LE)*/\ +/* buf[j].code = bitswap_32(buf[j].code);*/\ +/* else*/\ + buf[j].code <<= 32 - buf[j].bits;\ + if (symbols)\ + GET_DATA(buf[j].symbol, symbols, i, symbols_wrap, symbols_size)\ + else\ + buf[j].symbol = i;\ + j++;\ + } + COPY(buf[j].bits > nb_bits); + // qsort is the slowest part of init_vlc, and could probably be improved or avoided + qsort(buf, j, sizeof(VLCcode), compare_vlcspec); + COPY(buf[j].bits && buf[j].bits <= nb_bits); + nb_codes = j; + + ret = build_table(vlc, nb_bits, nb_codes, buf, flags); + +// av_free(buf); + if (ret < 0) { +// av_freep(&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 + if((flags & INIT_VLC_USE_NEW_STATIC) && vlc->table_size != vlc->table_allocated) { + av_log(NULL, AV_LOG_ERROR, "needed %d had %d\n", vlc->table_size, vlc->table_allocated); + } return 0; } +/* not used in rockbox +void free_vlc(VLC *vlc) +{ + av_freep(&vlc->table); +} +*/ + |