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 "codec_internal.h" 24#include "get_bits.h" 25#include "internal.h" 26 27typedef struct AvsContext { 28 AVFrame *frame; 29} AvsContext; 30 31typedef enum { 32 AVS_VIDEO = 0x01, 33 AVS_AUDIO = 0x02, 34 AVS_PALETTE = 0x03, 35 AVS_GAME_DATA = 0x04, 36} AvsBlockType; 37 38typedef enum { 39 AVS_I_FRAME = 0x00, 40 AVS_P_FRAME_3X3 = 0x01, 41 AVS_P_FRAME_2X2 = 0x02, 42 AVS_P_FRAME_2X3 = 0x03, 43} AvsVideoSubType; 44 45 46static int avs_decode_frame(AVCodecContext * avctx, AVFrame *picture, 47 int *got_frame, 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 *const p = avs->frame; 54 const uint8_t *table, *vect; 55 uint8_t *out; 56 int i, j, x, y, stride, ret, vect_w = 3, vect_h = 3; 57 AvsVideoSubType sub_type; 58 AvsBlockType type; 59 GetBitContext change_map = {0}; //init to silence warning 60 61 if ((ret = ff_reget_buffer(avctx, p, 0)) < 0) 62 return ret; 63 p->pict_type = AV_PICTURE_TYPE_P; 64 p->key_frame = 0; 65 66 out = p->data[0]; 67 stride = p->linesize[0]; 68 69 if (buf_end - buf < 4) 70 return AVERROR_INVALIDDATA; 71 sub_type = buf[0]; 72 type = buf[1]; 73 buf += 4; 74 75 if (type == AVS_PALETTE) { 76 int first, last; 77 uint32_t *pal = (uint32_t *) p->data[1]; 78 79 first = AV_RL16(buf); 80 last = first + AV_RL16(buf + 2); 81 if (first >= 256 || last > 256 || buf_end - buf < 4 + 4 + 3 * (last - first)) 82 return AVERROR_INVALIDDATA; 83 buf += 4; 84 for (i=first; i<last; i++, buf+=3) { 85 pal[i] = (buf[0] << 18) | (buf[1] << 10) | (buf[2] << 2); 86 pal[i] |= 0xFFU << 24 | (pal[i] >> 6) & 0x30303; 87 } 88 89 sub_type = buf[0]; 90 type = buf[1]; 91 buf += 4; 92 } 93 94 if (type != AVS_VIDEO) 95 return AVERROR_INVALIDDATA; 96 97 switch (sub_type) { 98 case AVS_I_FRAME: 99 p->pict_type = AV_PICTURE_TYPE_I; 100 p->key_frame = 1; 101 case AVS_P_FRAME_3X3: 102 vect_w = 3; 103 vect_h = 3; 104 break; 105 106 case AVS_P_FRAME_2X2: 107 vect_w = 2; 108 vect_h = 2; 109 break; 110 111 case AVS_P_FRAME_2X3: 112 vect_w = 2; 113 vect_h = 3; 114 break; 115 116 default: 117 return AVERROR_INVALIDDATA; 118 } 119 120 if (buf_end - buf < 256 * vect_w * vect_h) 121 return AVERROR_INVALIDDATA; 122 table = buf + (256 * vect_w * vect_h); 123 if (sub_type != AVS_I_FRAME) { 124 int map_size = ((318 / vect_w + 7) / 8) * (198 / vect_h); 125 if (buf_end - table < map_size) 126 return AVERROR_INVALIDDATA; 127 init_get_bits(&change_map, table, map_size * 8); 128 table += map_size; 129 } 130 131 for (y=0; y<198; y+=vect_h) { 132 for (x=0; x<318; x+=vect_w) { 133 if (sub_type == AVS_I_FRAME || get_bits1(&change_map)) { 134 if (buf_end - table < 1) 135 return AVERROR_INVALIDDATA; 136 vect = &buf[*table++ * (vect_w * vect_h)]; 137 for (j=0; j<vect_w; j++) { 138 out[(y + 0) * stride + x + j] = vect[(0 * vect_w) + j]; 139 out[(y + 1) * stride + x + j] = vect[(1 * vect_w) + j]; 140 if (vect_h == 3) 141 out[(y + 2) * stride + x + j] = 142 vect[(2 * vect_w) + j]; 143 } 144 } 145 } 146 if (sub_type != AVS_I_FRAME) 147 align_get_bits(&change_map); 148 } 149 150 if ((ret = av_frame_ref(picture, p)) < 0) 151 return ret; 152 *got_frame = 1; 153 154 return buf_size; 155} 156 157static av_cold int avs_decode_init(AVCodecContext * avctx) 158{ 159 AvsContext *s = avctx->priv_data; 160 161 s->frame = av_frame_alloc(); 162 if (!s->frame) 163 return AVERROR(ENOMEM); 164 165 avctx->pix_fmt = AV_PIX_FMT_PAL8; 166 167 return ff_set_dimensions(avctx, 318, 198); 168} 169 170static av_cold int avs_decode_end(AVCodecContext *avctx) 171{ 172 AvsContext *s = avctx->priv_data; 173 av_frame_free(&s->frame); 174 return 0; 175} 176 177 178const FFCodec ff_avs_decoder = { 179 .p.name = "avs", 180 .p.long_name = NULL_IF_CONFIG_SMALL("AVS (Audio Video Standard) video"), 181 .p.type = AVMEDIA_TYPE_VIDEO, 182 .p.id = AV_CODEC_ID_AVS, 183 .priv_data_size = sizeof(AvsContext), 184 .init = avs_decode_init, 185 FF_CODEC_DECODE_CB(avs_decode_frame), 186 .close = avs_decode_end, 187 .p.capabilities = AV_CODEC_CAP_DR1, 188 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE, 189}; 190