| 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 | #include "internal.h" |
| 25 | |
| 26 | |
| 27 | typedef struct { |
| 28 | AVFrame *frame; |
| 29 | } AvsContext; |
| 30 | |
| 31 | typedef enum { |
| 32 | AVS_VIDEO = 0x01, |
| 33 | AVS_AUDIO = 0x02, |
| 34 | AVS_PALETTE = 0x03, |
| 35 | AVS_GAME_DATA = 0x04, |
| 36 | } AvsBlockType; |
| 37 | |
| 38 | typedef 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 | |
| 46 | static int |
| 47 | avs_decode_frame(AVCodecContext * avctx, |
| 48 | void *data, int *got_frame, AVPacket *avpkt) |
| 49 | { |
| 50 | const uint8_t *buf = avpkt->data; |
| 51 | const uint8_t *buf_end = avpkt->data + avpkt->size; |
| 52 | int buf_size = avpkt->size; |
| 53 | AvsContext *const avs = avctx->priv_data; |
| 54 | AVFrame *picture = data; |
| 55 | AVFrame *const p = avs->frame; |
| 56 | const uint8_t *table, *vect; |
| 57 | uint8_t *out; |
| 58 | int i, j, x, y, stride, ret, vect_w = 3, vect_h = 3; |
| 59 | AvsVideoSubType sub_type; |
| 60 | AvsBlockType type; |
| 61 | GetBitContext change_map = {0}; //init to silence warning |
| 62 | |
| 63 | if ((ret = ff_reget_buffer(avctx, p)) < 0) |
| 64 | return ret; |
| 65 | p->pict_type = AV_PICTURE_TYPE_P; |
| 66 | p->key_frame = 0; |
| 67 | |
| 68 | out = p->data[0]; |
| 69 | stride = p->linesize[0]; |
| 70 | |
| 71 | if (buf_end - buf < 4) |
| 72 | return AVERROR_INVALIDDATA; |
| 73 | sub_type = buf[0]; |
| 74 | type = buf[1]; |
| 75 | buf += 4; |
| 76 | |
| 77 | if (type == AVS_PALETTE) { |
| 78 | int first, last; |
| 79 | uint32_t *pal = (uint32_t *) p->data[1]; |
| 80 | |
| 81 | first = AV_RL16(buf); |
| 82 | last = first + AV_RL16(buf + 2); |
| 83 | if (first >= 256 || last > 256 || buf_end - buf < 4 + 4 + 3 * (last - first)) |
| 84 | return AVERROR_INVALIDDATA; |
| 85 | buf += 4; |
| 86 | for (i=first; i<last; i++, buf+=3) { |
| 87 | pal[i] = (buf[0] << 18) | (buf[1] << 10) | (buf[2] << 2); |
| 88 | pal[i] |= 0xFFU << 24 | (pal[i] >> 6) & 0x30303; |
| 89 | } |
| 90 | |
| 91 | sub_type = buf[0]; |
| 92 | type = buf[1]; |
| 93 | buf += 4; |
| 94 | } |
| 95 | |
| 96 | if (type != AVS_VIDEO) |
| 97 | return AVERROR_INVALIDDATA; |
| 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 AVERROR_INVALIDDATA; |
| 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 | if ((ret = av_frame_ref(picture, p)) < 0) |
| 153 | return ret; |
| 154 | *got_frame = 1; |
| 155 | |
| 156 | return buf_size; |
| 157 | } |
| 158 | |
| 159 | static av_cold int avs_decode_init(AVCodecContext * avctx) |
| 160 | { |
| 161 | AvsContext *s = avctx->priv_data; |
| 162 | |
| 163 | s->frame = av_frame_alloc(); |
| 164 | if (!s->frame) |
| 165 | return AVERROR(ENOMEM); |
| 166 | |
| 167 | avctx->pix_fmt = AV_PIX_FMT_PAL8; |
| 168 | |
| 169 | return ff_set_dimensions(avctx, 318, 198); |
| 170 | } |
| 171 | |
| 172 | static av_cold int avs_decode_end(AVCodecContext *avctx) |
| 173 | { |
| 174 | AvsContext *s = avctx->priv_data; |
| 175 | av_frame_free(&s->frame); |
| 176 | return 0; |
| 177 | } |
| 178 | |
| 179 | |
| 180 | AVCodec ff_avs_decoder = { |
| 181 | .name = "avs", |
| 182 | .long_name = NULL_IF_CONFIG_SMALL("AVS (Audio Video Standard) video"), |
| 183 | .type = AVMEDIA_TYPE_VIDEO, |
| 184 | .id = AV_CODEC_ID_AVS, |
| 185 | .priv_data_size = sizeof(AvsContext), |
| 186 | .init = avs_decode_init, |
| 187 | .decode = avs_decode_frame, |
| 188 | .close = avs_decode_end, |
| 189 | .capabilities = CODEC_CAP_DR1, |
| 190 | }; |