1/* 2 * AVS video decoder. 3 * Copyright (c) 2006 Aurelien Jacobs <aurel@gnuage.org> 4 * 5 * This file is part of Libav. 6 * 7 * Libav 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 * Libav 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 Libav; 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 const uint8_t *buf_end = avpkt->data + avpkt->size; 51 int buf_size = avpkt->size; 52 AvsContext *const avs = avctx->priv_data; 53 AVFrame *picture = data; 54 AVFrame *const p = (AVFrame *) & avs->picture; 55 const uint8_t *table, *vect; 56 uint8_t *out; 57 int i, j, x, y, stride, vect_w = 3, vect_h = 3; 58 AvsVideoSubType sub_type; 59 AvsBlockType type; 60 GetBitContext change_map; 61 62 if (avctx->reget_buffer(avctx, p)) { 63 av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n"); 64 return -1; 65 } 66 p->reference = 1; 67 p->pict_type = AV_PICTURE_TYPE_P; 68 p->key_frame = 0; 69 70 out = avs->picture.data[0]; 71 stride = avs->picture.linesize[0]; 72 73 if (buf_end - buf < 4) 74 return AVERROR_INVALIDDATA; 75 sub_type = buf[0]; 76 type = buf[1]; 77 buf += 4; 78 79 if (type == AVS_PALETTE) { 80 int first, last; 81 uint32_t *pal = (uint32_t *) avs->picture.data[1]; 82 83 first = AV_RL16(buf); 84 last = first + AV_RL16(buf + 2); 85 if (first >= 256 || last > 256 || buf_end - buf < 4 + 4 + 3 * (last - first)) 86 return AVERROR_INVALIDDATA; 87 buf += 4; 88 for (i=first; i<last; i++, buf+=3) 89 pal[i] = (buf[0] << 18) | (buf[1] << 10) | (buf[2] << 2); 90 91 sub_type = buf[0]; 92 type = buf[1]; 93 buf += 4; 94 } 95 96 if (type != AVS_VIDEO) 97 return -1; 98 99 switch (sub_type) { 100 case AVS_I_FRAME: 101 p->pict_type = AV_PICTURE_TYPE_I; 102 p->key_frame = 1; 103 case AVS_P_FRAME_3X3: 104 vect_w = 3; 105 vect_h = 3; 106 break; 107 108 case AVS_P_FRAME_2X2: 109 vect_w = 2; 110 vect_h = 2; 111 break; 112 113 case AVS_P_FRAME_2X3: 114 vect_w = 2; 115 vect_h = 3; 116 break; 117 118 default: 119 return -1; 120 } 121 122 if (buf_end - buf < 256 * vect_w * vect_h) 123 return AVERROR_INVALIDDATA; 124 table = buf + (256 * vect_w * vect_h); 125 if (sub_type != AVS_I_FRAME) { 126 int map_size = ((318 / vect_w + 7) / 8) * (198 / vect_h); 127 if (buf_end - table < map_size) 128 return AVERROR_INVALIDDATA; 129 init_get_bits(&change_map, table, map_size * 8); 130 table += map_size; 131 } 132 133 for (y=0; y<198; y+=vect_h) { 134 for (x=0; x<318; x+=vect_w) { 135 if (sub_type == AVS_I_FRAME || get_bits1(&change_map)) { 136 if (buf_end - table < 1) 137 return AVERROR_INVALIDDATA; 138 vect = &buf[*table++ * (vect_w * vect_h)]; 139 for (j=0; j<vect_w; j++) { 140 out[(y + 0) * stride + x + j] = vect[(0 * vect_w) + j]; 141 out[(y + 1) * stride + x + j] = vect[(1 * vect_w) + j]; 142 if (vect_h == 3) 143 out[(y + 2) * stride + x + j] = 144 vect[(2 * vect_w) + j]; 145 } 146 } 147 } 148 if (sub_type != AVS_I_FRAME) 149 align_get_bits(&change_map); 150 } 151 152 *picture = *(AVFrame *) & avs->picture; 153 *data_size = sizeof(AVPicture); 154 155 return buf_size; 156} 157 158static av_cold int avs_decode_init(AVCodecContext * avctx) 159{ 160 avctx->pix_fmt = PIX_FMT_PAL8; 161 avcodec_set_dimensions(avctx, 318, 198); 162 return 0; 163} 164 165static av_cold int avs_decode_end(AVCodecContext *avctx) 166{ 167 AvsContext *s = avctx->priv_data; 168 if (s->picture.data[0]) 169 avctx->release_buffer(avctx, &s->picture); 170 return 0; 171} 172 173 174AVCodec ff_avs_decoder = { 175 .name = "avs", 176 .type = AVMEDIA_TYPE_VIDEO, 177 .id = CODEC_ID_AVS, 178 .priv_data_size = sizeof(AvsContext), 179 .init = avs_decode_init, 180 .decode = avs_decode_frame, 181 .close = avs_decode_end, 182 .capabilities = CODEC_CAP_DR1, 183 .long_name = NULL_IF_CONFIG_SMALL("AVS (Audio Video Standard) video"), 184}; 185