diff options
Diffstat (limited to 'plugins/wma/libwma/ffmpeg_bitstream.c')
| -rw-r--r-- | plugins/wma/libwma/ffmpeg_bitstream.c | 356 |
1 files changed, 356 insertions, 0 deletions
diff --git a/plugins/wma/libwma/ffmpeg_bitstream.c b/plugins/wma/libwma/ffmpeg_bitstream.c new file mode 100644 index 00000000..9adf9a45 --- /dev/null +++ b/plugins/wma/libwma/ffmpeg_bitstream.c @@ -0,0 +1,356 @@ +/* + * 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> + * + * 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 api. + */ + +//#include "avcodec.h" +#include "ffmpeg_get_bits.h" +#include "ffmpeg_intreadwrite.h" + +#define av_log(...) + +#ifdef ROCKBOX +#undef DEBUGF +#define DEBUGF(...) +#endif +#define trace(...) { fprintf (stderr, __VA_ARGS__); } +//#define trace(fmt,...) +#define DEBUGF trace + +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 +}; + +#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 *pb, const char *string, int terminate_string) +{ + while(*string){ + put_bits(pb, 8, *string); + string++; + } + if(terminate_string) + put_bits(pb, 8, 0); +} +#endif + + +/* 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) + { + 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 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; +} __attribute__((__packed__)) VLCcode; /* packed to save space */ + +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_NEW_STATIC); +#ifdef DEBUG_VLC + 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++) { + 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++) { + n = codes[i].bits; + code = codes[i].code; + symbol = codes[i].symbol; +#if defined(DEBUG_VLC) && 0 + av_log(NULL,AV_LOG_DEBUG,"i=%d n=%d code=0x%x\n", i, n, code); +#endif + 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 + av_log(NULL, AV_LOG_DEBUG, "%4x: code=%d n=%d\n", + j, i, n); +#endif + if (table[j][1] /*bits*/ != 0) { + av_log(NULL, AV_LOG_ERROR, "incorrect codes\n"); + return -1; + } + table[j][1] = n; //bits + table[j][0] = symbol; + j += inc; + } + } 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); + } + 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[j][0] = index; //code + i = k-1; + } + } + 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. +*/ + +/* 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 */ + +static VLCcode buf[1336+1]; /* worst case is wma, which has one table with 1336 entries */ + +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) +{ + if (nb_codes+1 > (int)(sizeof (buf)/ sizeof (VLCcode))) + { + DEBUGF("Table is larger than temp buffer!\n"); + return -1; + } + + 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){ + 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 { + vlc->table = NULL; + vlc->table_allocated = 0; + vlc->table_size = 0; + } + +#ifdef DEBUG_VLC + av_log(NULL,AV_LOG_DEBUG,"build table nb_codes=%d\n", nb_codes); +#endif + +// 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; + } + 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); +} +*/ + |