FFmpeg: libavcodec/mqc.c Source File

00001 /*
00002  * MQ-coder encoder and decoder common functions
00003  * Copyright (c) 2007 Kamil Nowosad
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00028 #include "mqc.h"
00029 
00030 typedef struct {
00031         uint16_t qe;
00032         uint8_t  nmps;
00033         uint8_t  nlps;
00034         uint8_t  sw;
00035 } MqcCxState;
00036 
00037 const static MqcCxState cx_states[47] = {
00038     {0x5601,  1,  1, 1},
00039     {0x3401,  2,  6, 0},
00040     {0x1801,  3,  9, 0},
00041     {0x0AC1,  4, 12, 0},
00042     {0x0521,  5, 29, 0},
00043     {0x0221, 38, 33, 0},
00044     {0x5601,  7,  6, 1},
00045     {0x5401,  8, 14, 0},
00046     {0x4801,  9, 14, 0},
00047     {0x3801, 10, 14, 0},
00048     {0x3001, 11, 17, 0},
00049     {0x2401, 12, 18, 0},
00050     {0x1C01, 13, 20, 0},
00051     {0x1601, 29, 21, 0},
00052     {0x5601, 15, 14, 1},
00053     {0x5401, 16, 14, 0},
00054     {0x5101, 17, 15, 0},
00055     {0x4801, 18, 16, 0},
00056     {0x3801, 19, 17, 0},
00057     {0x3401, 20, 18, 0},
00058     {0x3001, 21, 19, 0},
00059     {0x2801, 22, 19, 0},
00060     {0x2401, 23, 20, 0},
00061     {0x2201, 24, 21, 0},
00062     {0x1C01, 25, 22, 0},
00063     {0x1801, 26, 23, 0},
00064     {0x1601, 27, 24, 0},
00065     {0x1401, 28, 25, 0},
00066     {0x1201, 29, 26, 0},
00067     {0x1101, 30, 27, 0},
00068     {0x0AC1, 31, 28, 0},
00069     {0x09C1, 32, 29, 0},
00070     {0x08A1, 33, 30, 0},
00071     {0x0521, 34, 31, 0},
00072     {0x0441, 35, 32, 0},
00073     {0x02A1, 36, 33, 0},
00074     {0x0221, 37, 34, 0},
00075     {0x0141, 38, 35, 0},
00076     {0x0111, 39, 36, 0},
00077     {0x0085, 40, 37, 0},
00078     {0x0049, 41, 38, 0},
00079     {0x0025, 42, 39, 0},
00080     {0x0015, 43, 40, 0},
00081     {0x0009, 44, 41, 0},
00082     {0x0005, 45, 42, 0},
00083     {0x0001, 45, 43, 0},
00084     {0x5601, 46, 46, 0}
00085 };
00086 
00087 uint16_t ff_mqc_qe [2*47];
00088 uint8_t ff_mqc_nlps[2*47];
00089 uint8_t ff_mqc_nmps[2*47];
00090 
00091 void ff_mqc_init_contexts(MqcState *mqc)
00092 {
00093     int i;
00094     memset(mqc->cx_states, 0, sizeof(mqc->cx_states));
00095     mqc->cx_states[MQC_CX_UNI] = 2 * 46;
00096     mqc->cx_states[MQC_CX_RL] = 2 * 3;
00097     mqc->cx_states[0] = 2 * 4;
00098 
00099     for (i = 0; i < 47; i++){
00100         ff_mqc_qe[2*i  ] =
00101         ff_mqc_qe[2*i+1] = cx_states[i].qe;
00102 
00103         ff_mqc_nlps[2*i  ] = 2*cx_states[i].nlps + cx_states[i].sw;
00104         ff_mqc_nlps[2*i+1] = 2*cx_states[i].nlps + 1 - cx_states[i].sw;
00105         ff_mqc_nmps[2*i  ] = 2*cx_states[i].nmps;
00106         ff_mqc_nmps[2*i+1] = 2*cx_states[i].nmps + 1;
00107     }
00108 }