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moves fraps huffman decoder to its own file, making it more generic
Originally committed as revision 10736 to svn://svn.ffmpeg.org/ffmpeg/trunk
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,103 @@ | ||
| /** | ||
| * @file huffman.c | ||
| * huffman tree builder and VLC generator | ||
| * Copyright (c) 2006 Konstantin Shishkov | ||
| * | ||
| * 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 | ||
| */ | ||
|
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| #include "avcodec.h" | ||
| #include "bitstream.h" | ||
| #include "huffman.h" | ||
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| /* symbol for Huffman tree node */ | ||
| #define HNODE -1 | ||
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| static void get_tree_codes(uint32_t *bits, int16_t *lens, uint8_t *xlat, Node *nodes, int node, uint32_t pfx, int pl, int *pos) | ||
| { | ||
| int s; | ||
|
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| s = nodes[node].sym; | ||
| if(s != HNODE || !nodes[node].count){ | ||
| bits[*pos] = pfx; | ||
| lens[*pos] = pl; | ||
| xlat[*pos] = s; | ||
| (*pos)++; | ||
| }else{ | ||
| pfx <<= 1; | ||
| pl++; | ||
| get_tree_codes(bits, lens, xlat, nodes, nodes[node].n0, pfx, pl, pos); | ||
| pfx |= 1; | ||
| get_tree_codes(bits, lens, xlat, nodes, nodes[node].n0+1, pfx, pl, pos); | ||
| } | ||
| } | ||
|
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| static int build_huff_tree(VLC *vlc, Node *nodes, int head) | ||
| { | ||
| uint32_t bits[256]; | ||
| int16_t lens[256]; | ||
| uint8_t xlat[256]; | ||
| int pos = 0; | ||
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| get_tree_codes(bits, lens, xlat, nodes, head, 0, 0, &pos); | ||
| return init_vlc_sparse(vlc, 9, pos, lens, 2, 2, bits, 4, 4, xlat, 1, 1, 0); | ||
| } | ||
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| /** | ||
| * first nb_codes nodes.count must be set | ||
| */ | ||
| int ff_huff_build_tree(AVCodecContext *avctx, VLC *vlc, int nb_codes, | ||
| Node nodes[2*nb_codes], huff_cmp_t cmp, int hnode_first) | ||
| { | ||
| int i, j; | ||
| int cur_node; | ||
| int64_t sum = 0; | ||
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| for(i = 0; i < nb_codes; i++){ | ||
| nodes[i].sym = i; | ||
| nodes[i].n0 = -2; | ||
| sum += nodes[i].count; | ||
| } | ||
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| if(sum >> 31) { | ||
| av_log(avctx, AV_LOG_ERROR, "Too high symbol frequencies. Tree construction is not possible\n"); | ||
| return -1; | ||
| } | ||
| qsort(nodes, nb_codes, sizeof(Node), cmp); | ||
| cur_node = nb_codes; | ||
| for(i = 0; i < nb_codes*2-1; i += 2){ | ||
| nodes[cur_node].sym = HNODE; | ||
| nodes[cur_node].count = nodes[i].count + nodes[i+1].count; | ||
| nodes[cur_node].n0 = i; | ||
| for(j = cur_node; j > 0; j--){ | ||
| if(nodes[j].count > nodes[j-1].count || | ||
| (nodes[j].count == nodes[j-1].count && | ||
| (!hnode_first || nodes[j].n0==j-1 || nodes[j].n0==j-2 || | ||
| (nodes[j].sym!=HNODE && nodes[j-1].sym!=HNODE)))) | ||
| break; | ||
| FFSWAP(Node, nodes[j], nodes[j-1]); | ||
| } | ||
| cur_node++; | ||
| } | ||
| if(build_huff_tree(vlc, nodes, nb_codes*2-2) < 0){ | ||
| av_log(avctx, AV_LOG_ERROR, "Error building tree\n"); | ||
| return -1; | ||
| } | ||
| return 0; | ||
| } |
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,38 @@ | ||
| /** | ||
| * @file huffman.h | ||
| * huffman tree builder and VLC generator | ||
| * Copyright (C) 2007 Aurelien Jacobs <aurel@gnuage.org> | ||
| * | ||
| * 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 | ||
| */ | ||
|
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| #ifndef AVCODEC_HUFFMAN_H | ||
| #define AVCODEC_HUFFMAN_H | ||
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| #include "avcodec.h" | ||
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| typedef struct { | ||
| int16_t sym; | ||
| int16_t n0; | ||
| uint32_t count; | ||
| } Node; | ||
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| typedef int (*huff_cmp_t)(const void *va, const void *vb); | ||
| int ff_huff_build_tree(AVCodecContext *avctx, VLC *vlc, int nb_codes, | ||
| Node nodes[2*nb_codes], huff_cmp_t cmp, int hnode_first); | ||
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| #endif /* AVCODEC_HUFFMAN_H */ |