1/* 2 * AVS video decoder. 3 * Copyright (c) 2006 Aurelien Jacobs <aurel@gnuage.org> 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22#include "avcodec.h" 23#include "get_bits.h" 24 25 26typedef struct { 27 AVFrame picture; 28} AvsContext; 29 30typedef enum { 31 AVS_VIDEO = 0x01, 32 AVS_AUDIO = 0x02, 33 AVS_PALETTE = 0x03, 34 AVS_GAME_DATA = 0x04, 35} AvsBlockType; 36 37typedef enum { 38 AVS_I_FRAME = 0x00, 39 AVS_P_FRAME_3X3 = 0x01, 40 AVS_P_FRAME_2X2 = 0x02, 41 AVS_P_FRAME_2X3 = 0x03, 42} AvsVideoSubType; 43 44 45static int 46avs_decode_frame(AVCodecContext * avctx, 47 void *data, int *data_size, AVPacket *avpkt) 48{ 49 const uint8_t *buf = avpkt->data; 50 int buf_size = avpkt->size; 51 AvsContext *const avs = avctx->priv_data; 52 AVFrame *picture = data; 53 AVFrame *const p = (AVFrame *) & avs->picture; 54 const uint8_t *table, *vect; 55 uint8_t *out; 56 int i, j, x, y, stride, vect_w = 3, vect_h = 3; 57 AvsVideoSubType sub_type; 58 AvsBlockType type; 59 GetBitContext change_map; 60 61 if (avctx->reget_buffer(avctx, p)) { 62 av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n"); 63 return -1; 64 } 65 p->reference = 1; 66 p->pict_type = FF_P_TYPE; 67 p->key_frame = 0; 68 69 out = avs->picture.data[0]; 70 stride = avs->picture.linesize[0]; 71 72 sub_type = buf[0]; 73 type = buf[1]; 74 buf += 4; 75 76 if (type == AVS_PALETTE) { 77 int first, last; 78 uint32_t *pal = (uint32_t *) avs->picture.data[1]; 79 80 first = AV_RL16(buf); 81 last = first + AV_RL16(buf + 2); 82 buf += 4; 83 for (i=first; i<last; i++, buf+=3) 84 pal[i] = (buf[0] << 18) | (buf[1] << 10) | (buf[2] << 2); 85 86 sub_type = buf[0]; 87 type = buf[1]; 88 buf += 4; 89 } 90 91 if (type != AVS_VIDEO) 92 return -1; 93 94 switch (sub_type) { 95 case AVS_I_FRAME: 96 p->pict_type = FF_I_TYPE; 97 p->key_frame = 1; 98 case AVS_P_FRAME_3X3: 99 vect_w = 3; 100 vect_h = 3; 101 break; 102 103 case AVS_P_FRAME_2X2: 104 vect_w = 2; 105 vect_h = 2; 106 break; 107 108 case AVS_P_FRAME_2X3: 109 vect_w = 2; 110 vect_h = 3; 111 break; 112 113 default: 114 return -1; 115 } 116 117 table = buf + (256 * vect_w * vect_h); 118 if (sub_type != AVS_I_FRAME) { 119 int map_size = ((318 / vect_w + 7) / 8) * (198 / vect_h); 120 init_get_bits(&change_map, table, map_size); 121 table += map_size; 122 } 123 124 for (y=0; y<198; y+=vect_h) { 125 for (x=0; x<318; x+=vect_w) { 126 if (sub_type == AVS_I_FRAME || get_bits1(&change_map)) { 127 vect = &buf[*table++ * (vect_w * vect_h)]; 128 for (j=0; j<vect_w; j++) { 129 out[(y + 0) * stride + x + j] = vect[(0 * vect_w) + j]; 130 out[(y + 1) * stride + x + j] = vect[(1 * vect_w) + j]; 131 if (vect_h == 3) 132 out[(y + 2) * stride + x + j] = 133 vect[(2 * vect_w) + j]; 134 } 135 } 136 } 137 if (sub_type != AVS_I_FRAME) 138 align_get_bits(&change_map); 139 } 140 141 *picture = *(AVFrame *) & avs->picture; 142 *data_size = sizeof(AVPicture); 143 144 return buf_size; 145} 146 147static av_cold int avs_decode_init(AVCodecContext * avctx) 148{ 149 avctx->pix_fmt = PIX_FMT_PAL8; 150 return 0; 151} 152 153AVCodec avs_decoder = { 154 "avs", 155 AVMEDIA_TYPE_VIDEO, 156 CODEC_ID_AVS, 157 sizeof(AvsContext), 158 avs_decode_init, 159 NULL, 160 NULL, 161 avs_decode_frame, 162 CODEC_CAP_DR1, 163 .long_name = NULL_IF_CONFIG_SMALL("AVS (Audio Video Standard) video"), 164}; 165