| 1 | /* |
| 2 | * American Laser Games MM Video Decoder |
| 3 | * Copyright (c) 2006,2008 Peter Ross |
| 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 | /** |
| 23 | * @file |
| 24 | * American Laser Games MM Video Decoder |
| 25 | * by Peter Ross (pross@xvid.org) |
| 26 | * |
| 27 | * The MM format was used by IBM-PC ports of ALG's "arcade shooter" games, |
| 28 | * including Mad Dog McCree and Crime Patrol. |
| 29 | * |
| 30 | * Technical details here: |
| 31 | * http://wiki.multimedia.cx/index.php?title=American_Laser_Games_MM |
| 32 | */ |
| 33 | |
| 34 | #include "libavutil/intreadwrite.h" |
| 35 | #include "avcodec.h" |
| 36 | #include "bytestream.h" |
| 37 | #include "internal.h" |
| 38 | |
| 39 | #define MM_PREAMBLE_SIZE 6 |
| 40 | |
| 41 | #define MM_TYPE_INTER 0x5 |
| 42 | #define MM_TYPE_INTRA 0x8 |
| 43 | #define MM_TYPE_INTRA_HH 0xc |
| 44 | #define MM_TYPE_INTER_HH 0xd |
| 45 | #define MM_TYPE_INTRA_HHV 0xe |
| 46 | #define MM_TYPE_INTER_HHV 0xf |
| 47 | #define MM_TYPE_PALETTE 0x31 |
| 48 | |
| 49 | typedef struct MmContext { |
| 50 | AVCodecContext *avctx; |
| 51 | AVFrame *frame; |
| 52 | unsigned int palette[AVPALETTE_COUNT]; |
| 53 | GetByteContext gb; |
| 54 | } MmContext; |
| 55 | |
| 56 | static av_cold int mm_decode_init(AVCodecContext *avctx) |
| 57 | { |
| 58 | MmContext *s = avctx->priv_data; |
| 59 | |
| 60 | s->avctx = avctx; |
| 61 | |
| 62 | avctx->pix_fmt = AV_PIX_FMT_PAL8; |
| 63 | |
| 64 | s->frame = av_frame_alloc(); |
| 65 | if (!s->frame) |
| 66 | return AVERROR(ENOMEM); |
| 67 | |
| 68 | return 0; |
| 69 | } |
| 70 | |
| 71 | static void mm_decode_pal(MmContext *s) |
| 72 | { |
| 73 | int i; |
| 74 | |
| 75 | bytestream2_skip(&s->gb, 4); |
| 76 | for (i = 0; i < 128; i++) { |
| 77 | s->palette[i] = 0xFFU << 24 | bytestream2_get_be24(&s->gb); |
| 78 | s->palette[i+128] = s->palette[i]<<2; |
| 79 | } |
| 80 | } |
| 81 | |
| 82 | /** |
| 83 | * @param half_horiz Half horizontal resolution (0 or 1) |
| 84 | * @param half_vert Half vertical resolution (0 or 1) |
| 85 | */ |
| 86 | static int mm_decode_intra(MmContext * s, int half_horiz, int half_vert) |
| 87 | { |
| 88 | int x = 0, y = 0; |
| 89 | |
| 90 | while (bytestream2_get_bytes_left(&s->gb) > 0) { |
| 91 | int run_length, color; |
| 92 | |
| 93 | if (y >= s->avctx->height) |
| 94 | return 0; |
| 95 | |
| 96 | color = bytestream2_get_byte(&s->gb); |
| 97 | if (color & 0x80) { |
| 98 | run_length = 1; |
| 99 | }else{ |
| 100 | run_length = (color & 0x7f) + 2; |
| 101 | color = bytestream2_get_byte(&s->gb); |
| 102 | } |
| 103 | |
| 104 | if (half_horiz) |
| 105 | run_length *=2; |
| 106 | |
| 107 | if (run_length > s->avctx->width - x) |
| 108 | return AVERROR_INVALIDDATA; |
| 109 | |
| 110 | if (color) { |
| 111 | memset(s->frame->data[0] + y*s->frame->linesize[0] + x, color, run_length); |
| 112 | if (half_vert && y + half_vert < s->avctx->height) |
| 113 | memset(s->frame->data[0] + (y+1)*s->frame->linesize[0] + x, color, run_length); |
| 114 | } |
| 115 | x+= run_length; |
| 116 | |
| 117 | if (x >= s->avctx->width) { |
| 118 | x=0; |
| 119 | y += 1 + half_vert; |
| 120 | } |
| 121 | } |
| 122 | |
| 123 | return 0; |
| 124 | } |
| 125 | |
| 126 | /** |
| 127 | * @param half_horiz Half horizontal resolution (0 or 1) |
| 128 | * @param half_vert Half vertical resolution (0 or 1) |
| 129 | */ |
| 130 | static int mm_decode_inter(MmContext * s, int half_horiz, int half_vert) |
| 131 | { |
| 132 | int data_off = bytestream2_get_le16(&s->gb); |
| 133 | int y = 0; |
| 134 | GetByteContext data_ptr; |
| 135 | |
| 136 | if (bytestream2_get_bytes_left(&s->gb) < data_off) |
| 137 | return AVERROR_INVALIDDATA; |
| 138 | |
| 139 | bytestream2_init(&data_ptr, s->gb.buffer + data_off, bytestream2_get_bytes_left(&s->gb) - data_off); |
| 140 | while (s->gb.buffer < data_ptr.buffer_start) { |
| 141 | int i, j; |
| 142 | int length = bytestream2_get_byte(&s->gb); |
| 143 | int x = bytestream2_get_byte(&s->gb) + ((length & 0x80) << 1); |
| 144 | length &= 0x7F; |
| 145 | |
| 146 | if (length==0) { |
| 147 | y += x; |
| 148 | continue; |
| 149 | } |
| 150 | |
| 151 | if (y + half_vert >= s->avctx->height) |
| 152 | return 0; |
| 153 | |
| 154 | for(i=0; i<length; i++) { |
| 155 | int replace_array = bytestream2_get_byte(&s->gb); |
| 156 | for(j=0; j<8; j++) { |
| 157 | int replace = (replace_array >> (7-j)) & 1; |
| 158 | if (x + half_horiz >= s->avctx->width) |
| 159 | return AVERROR_INVALIDDATA; |
| 160 | if (replace) { |
| 161 | int color = bytestream2_get_byte(&data_ptr); |
| 162 | s->frame->data[0][y*s->frame->linesize[0] + x] = color; |
| 163 | if (half_horiz) |
| 164 | s->frame->data[0][y*s->frame->linesize[0] + x + 1] = color; |
| 165 | if (half_vert) { |
| 166 | s->frame->data[0][(y+1)*s->frame->linesize[0] + x] = color; |
| 167 | if (half_horiz) |
| 168 | s->frame->data[0][(y+1)*s->frame->linesize[0] + x + 1] = color; |
| 169 | } |
| 170 | } |
| 171 | x += 1 + half_horiz; |
| 172 | } |
| 173 | } |
| 174 | |
| 175 | y += 1 + half_vert; |
| 176 | } |
| 177 | |
| 178 | return 0; |
| 179 | } |
| 180 | |
| 181 | static int mm_decode_frame(AVCodecContext *avctx, |
| 182 | void *data, int *got_frame, |
| 183 | AVPacket *avpkt) |
| 184 | { |
| 185 | const uint8_t *buf = avpkt->data; |
| 186 | int buf_size = avpkt->size; |
| 187 | MmContext *s = avctx->priv_data; |
| 188 | int type, res; |
| 189 | |
| 190 | if (buf_size < MM_PREAMBLE_SIZE) |
| 191 | return AVERROR_INVALIDDATA; |
| 192 | type = AV_RL16(&buf[0]); |
| 193 | buf += MM_PREAMBLE_SIZE; |
| 194 | buf_size -= MM_PREAMBLE_SIZE; |
| 195 | bytestream2_init(&s->gb, buf, buf_size); |
| 196 | |
| 197 | if ((res = ff_reget_buffer(avctx, s->frame)) < 0) |
| 198 | return res; |
| 199 | |
| 200 | switch(type) { |
| 201 | case MM_TYPE_PALETTE : mm_decode_pal(s); return avpkt->size; |
| 202 | case MM_TYPE_INTRA : res = mm_decode_intra(s, 0, 0); break; |
| 203 | case MM_TYPE_INTRA_HH : res = mm_decode_intra(s, 1, 0); break; |
| 204 | case MM_TYPE_INTRA_HHV : res = mm_decode_intra(s, 1, 1); break; |
| 205 | case MM_TYPE_INTER : res = mm_decode_inter(s, 0, 0); break; |
| 206 | case MM_TYPE_INTER_HH : res = mm_decode_inter(s, 1, 0); break; |
| 207 | case MM_TYPE_INTER_HHV : res = mm_decode_inter(s, 1, 1); break; |
| 208 | default: |
| 209 | res = AVERROR_INVALIDDATA; |
| 210 | break; |
| 211 | } |
| 212 | if (res < 0) |
| 213 | return res; |
| 214 | |
| 215 | memcpy(s->frame->data[1], s->palette, AVPALETTE_SIZE); |
| 216 | |
| 217 | if ((res = av_frame_ref(data, s->frame)) < 0) |
| 218 | return res; |
| 219 | |
| 220 | *got_frame = 1; |
| 221 | |
| 222 | return avpkt->size; |
| 223 | } |
| 224 | |
| 225 | static av_cold int mm_decode_end(AVCodecContext *avctx) |
| 226 | { |
| 227 | MmContext *s = avctx->priv_data; |
| 228 | |
| 229 | av_frame_free(&s->frame); |
| 230 | |
| 231 | return 0; |
| 232 | } |
| 233 | |
| 234 | AVCodec ff_mmvideo_decoder = { |
| 235 | .name = "mmvideo", |
| 236 | .long_name = NULL_IF_CONFIG_SMALL("American Laser Games MM Video"), |
| 237 | .type = AVMEDIA_TYPE_VIDEO, |
| 238 | .id = AV_CODEC_ID_MMVIDEO, |
| 239 | .priv_data_size = sizeof(MmContext), |
| 240 | .init = mm_decode_init, |
| 241 | .close = mm_decode_end, |
| 242 | .decode = mm_decode_frame, |
| 243 | .capabilities = CODEC_CAP_DR1, |
| 244 | }; |