| 1 | /* |
| 2 | * Microsoft Video-1 Decoder |
| 3 | * Copyright (c) 2003 The FFmpeg Project |
| 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 | * Microsoft Video-1 Decoder by Mike Melanson (melanson@pcisys.net) |
| 25 | * For more information about the MS Video-1 format, visit: |
| 26 | * http://www.pcisys.net/~melanson/codecs/ |
| 27 | * |
| 28 | */ |
| 29 | |
| 30 | #include <stdio.h> |
| 31 | #include <stdlib.h> |
| 32 | #include <string.h> |
| 33 | |
| 34 | #include "libavutil/internal.h" |
| 35 | #include "libavutil/intreadwrite.h" |
| 36 | #include "avcodec.h" |
| 37 | #include "internal.h" |
| 38 | |
| 39 | #define PALETTE_COUNT 256 |
| 40 | #define CHECK_STREAM_PTR(n) \ |
| 41 | if ((stream_ptr + n) > s->size ) { \ |
| 42 | av_log(s->avctx, AV_LOG_ERROR, " MS Video-1 warning: stream_ptr out of bounds (%d >= %d)\n", \ |
| 43 | stream_ptr + n, s->size); \ |
| 44 | return; \ |
| 45 | } |
| 46 | |
| 47 | typedef struct Msvideo1Context { |
| 48 | |
| 49 | AVCodecContext *avctx; |
| 50 | AVFrame *frame; |
| 51 | |
| 52 | const unsigned char *buf; |
| 53 | int size; |
| 54 | |
| 55 | int mode_8bit; /* if it's not 8-bit, it's 16-bit */ |
| 56 | |
| 57 | uint32_t pal[256]; |
| 58 | } Msvideo1Context; |
| 59 | |
| 60 | static av_cold int msvideo1_decode_init(AVCodecContext *avctx) |
| 61 | { |
| 62 | Msvideo1Context *s = avctx->priv_data; |
| 63 | |
| 64 | s->avctx = avctx; |
| 65 | |
| 66 | /* figure out the colorspace based on the presence of a palette */ |
| 67 | if (s->avctx->bits_per_coded_sample == 8) { |
| 68 | s->mode_8bit = 1; |
| 69 | avctx->pix_fmt = AV_PIX_FMT_PAL8; |
| 70 | if (avctx->extradata_size >= AVPALETTE_SIZE) |
| 71 | memcpy(s->pal, avctx->extradata, AVPALETTE_SIZE); |
| 72 | } else { |
| 73 | s->mode_8bit = 0; |
| 74 | avctx->pix_fmt = AV_PIX_FMT_RGB555; |
| 75 | } |
| 76 | |
| 77 | s->frame = av_frame_alloc(); |
| 78 | if (!s->frame) |
| 79 | return AVERROR(ENOMEM); |
| 80 | |
| 81 | return 0; |
| 82 | } |
| 83 | |
| 84 | static void msvideo1_decode_8bit(Msvideo1Context *s) |
| 85 | { |
| 86 | int block_ptr, pixel_ptr; |
| 87 | int total_blocks; |
| 88 | int pixel_x, pixel_y; /* pixel width and height iterators */ |
| 89 | int block_x, block_y; /* block width and height iterators */ |
| 90 | int blocks_wide, blocks_high; /* width and height in 4x4 blocks */ |
| 91 | int block_inc; |
| 92 | int row_dec; |
| 93 | |
| 94 | /* decoding parameters */ |
| 95 | int stream_ptr; |
| 96 | unsigned char byte_a, byte_b; |
| 97 | unsigned short flags; |
| 98 | int skip_blocks; |
| 99 | unsigned char colors[8]; |
| 100 | unsigned char *pixels = s->frame->data[0]; |
| 101 | int stride = s->frame->linesize[0]; |
| 102 | |
| 103 | stream_ptr = 0; |
| 104 | skip_blocks = 0; |
| 105 | blocks_wide = s->avctx->width / 4; |
| 106 | blocks_high = s->avctx->height / 4; |
| 107 | total_blocks = blocks_wide * blocks_high; |
| 108 | block_inc = 4; |
| 109 | row_dec = stride + 4; |
| 110 | |
| 111 | for (block_y = blocks_high; block_y > 0; block_y--) { |
| 112 | block_ptr = ((block_y * 4) - 1) * stride; |
| 113 | for (block_x = blocks_wide; block_x > 0; block_x--) { |
| 114 | /* check if this block should be skipped */ |
| 115 | if (skip_blocks) { |
| 116 | block_ptr += block_inc; |
| 117 | skip_blocks--; |
| 118 | total_blocks--; |
| 119 | continue; |
| 120 | } |
| 121 | |
| 122 | pixel_ptr = block_ptr; |
| 123 | |
| 124 | /* get the next two bytes in the encoded data stream */ |
| 125 | CHECK_STREAM_PTR(2); |
| 126 | byte_a = s->buf[stream_ptr++]; |
| 127 | byte_b = s->buf[stream_ptr++]; |
| 128 | |
| 129 | /* check if the decode is finished */ |
| 130 | if ((byte_a == 0) && (byte_b == 0) && (total_blocks == 0)) |
| 131 | return; |
| 132 | else if ((byte_b & 0xFC) == 0x84) { |
| 133 | /* skip code, but don't count the current block */ |
| 134 | skip_blocks = ((byte_b - 0x84) << 8) + byte_a - 1; |
| 135 | } else if (byte_b < 0x80) { |
| 136 | /* 2-color encoding */ |
| 137 | flags = (byte_b << 8) | byte_a; |
| 138 | |
| 139 | CHECK_STREAM_PTR(2); |
| 140 | colors[0] = s->buf[stream_ptr++]; |
| 141 | colors[1] = s->buf[stream_ptr++]; |
| 142 | |
| 143 | for (pixel_y = 0; pixel_y < 4; pixel_y++) { |
| 144 | for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1) |
| 145 | pixels[pixel_ptr++] = colors[(flags & 0x1) ^ 1]; |
| 146 | pixel_ptr -= row_dec; |
| 147 | } |
| 148 | } else if (byte_b >= 0x90) { |
| 149 | /* 8-color encoding */ |
| 150 | flags = (byte_b << 8) | byte_a; |
| 151 | |
| 152 | CHECK_STREAM_PTR(8); |
| 153 | memcpy(colors, &s->buf[stream_ptr], 8); |
| 154 | stream_ptr += 8; |
| 155 | |
| 156 | for (pixel_y = 0; pixel_y < 4; pixel_y++) { |
| 157 | for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1) |
| 158 | pixels[pixel_ptr++] = |
| 159 | colors[((pixel_y & 0x2) << 1) + |
| 160 | (pixel_x & 0x2) + ((flags & 0x1) ^ 1)]; |
| 161 | pixel_ptr -= row_dec; |
| 162 | } |
| 163 | } else { |
| 164 | /* 1-color encoding */ |
| 165 | colors[0] = byte_a; |
| 166 | |
| 167 | for (pixel_y = 0; pixel_y < 4; pixel_y++) { |
| 168 | for (pixel_x = 0; pixel_x < 4; pixel_x++) |
| 169 | pixels[pixel_ptr++] = colors[0]; |
| 170 | pixel_ptr -= row_dec; |
| 171 | } |
| 172 | } |
| 173 | |
| 174 | block_ptr += block_inc; |
| 175 | total_blocks--; |
| 176 | } |
| 177 | } |
| 178 | |
| 179 | /* make the palette available on the way out */ |
| 180 | if (s->avctx->pix_fmt == AV_PIX_FMT_PAL8) |
| 181 | memcpy(s->frame->data[1], s->pal, AVPALETTE_SIZE); |
| 182 | } |
| 183 | |
| 184 | static void msvideo1_decode_16bit(Msvideo1Context *s) |
| 185 | { |
| 186 | int block_ptr, pixel_ptr; |
| 187 | int total_blocks; |
| 188 | int pixel_x, pixel_y; /* pixel width and height iterators */ |
| 189 | int block_x, block_y; /* block width and height iterators */ |
| 190 | int blocks_wide, blocks_high; /* width and height in 4x4 blocks */ |
| 191 | int block_inc; |
| 192 | int row_dec; |
| 193 | |
| 194 | /* decoding parameters */ |
| 195 | int stream_ptr; |
| 196 | unsigned char byte_a, byte_b; |
| 197 | unsigned short flags; |
| 198 | int skip_blocks; |
| 199 | unsigned short colors[8]; |
| 200 | unsigned short *pixels = (unsigned short *)s->frame->data[0]; |
| 201 | int stride = s->frame->linesize[0] / 2; |
| 202 | |
| 203 | stream_ptr = 0; |
| 204 | skip_blocks = 0; |
| 205 | blocks_wide = s->avctx->width / 4; |
| 206 | blocks_high = s->avctx->height / 4; |
| 207 | total_blocks = blocks_wide * blocks_high; |
| 208 | block_inc = 4; |
| 209 | row_dec = stride + 4; |
| 210 | |
| 211 | for (block_y = blocks_high; block_y > 0; block_y--) { |
| 212 | block_ptr = ((block_y * 4) - 1) * stride; |
| 213 | for (block_x = blocks_wide; block_x > 0; block_x--) { |
| 214 | /* check if this block should be skipped */ |
| 215 | if (skip_blocks) { |
| 216 | block_ptr += block_inc; |
| 217 | skip_blocks--; |
| 218 | total_blocks--; |
| 219 | continue; |
| 220 | } |
| 221 | |
| 222 | pixel_ptr = block_ptr; |
| 223 | |
| 224 | /* get the next two bytes in the encoded data stream */ |
| 225 | CHECK_STREAM_PTR(2); |
| 226 | byte_a = s->buf[stream_ptr++]; |
| 227 | byte_b = s->buf[stream_ptr++]; |
| 228 | |
| 229 | /* check if the decode is finished */ |
| 230 | if ((byte_a == 0) && (byte_b == 0) && (total_blocks == 0)) { |
| 231 | return; |
| 232 | } else if ((byte_b & 0xFC) == 0x84) { |
| 233 | /* skip code, but don't count the current block */ |
| 234 | skip_blocks = ((byte_b - 0x84) << 8) + byte_a - 1; |
| 235 | } else if (byte_b < 0x80) { |
| 236 | /* 2- or 8-color encoding modes */ |
| 237 | flags = (byte_b << 8) | byte_a; |
| 238 | |
| 239 | CHECK_STREAM_PTR(4); |
| 240 | colors[0] = AV_RL16(&s->buf[stream_ptr]); |
| 241 | stream_ptr += 2; |
| 242 | colors[1] = AV_RL16(&s->buf[stream_ptr]); |
| 243 | stream_ptr += 2; |
| 244 | |
| 245 | if (colors[0] & 0x8000) { |
| 246 | /* 8-color encoding */ |
| 247 | CHECK_STREAM_PTR(12); |
| 248 | colors[2] = AV_RL16(&s->buf[stream_ptr]); |
| 249 | stream_ptr += 2; |
| 250 | colors[3] = AV_RL16(&s->buf[stream_ptr]); |
| 251 | stream_ptr += 2; |
| 252 | colors[4] = AV_RL16(&s->buf[stream_ptr]); |
| 253 | stream_ptr += 2; |
| 254 | colors[5] = AV_RL16(&s->buf[stream_ptr]); |
| 255 | stream_ptr += 2; |
| 256 | colors[6] = AV_RL16(&s->buf[stream_ptr]); |
| 257 | stream_ptr += 2; |
| 258 | colors[7] = AV_RL16(&s->buf[stream_ptr]); |
| 259 | stream_ptr += 2; |
| 260 | |
| 261 | for (pixel_y = 0; pixel_y < 4; pixel_y++) { |
| 262 | for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1) |
| 263 | pixels[pixel_ptr++] = |
| 264 | colors[((pixel_y & 0x2) << 1) + |
| 265 | (pixel_x & 0x2) + ((flags & 0x1) ^ 1)]; |
| 266 | pixel_ptr -= row_dec; |
| 267 | } |
| 268 | } else { |
| 269 | /* 2-color encoding */ |
| 270 | for (pixel_y = 0; pixel_y < 4; pixel_y++) { |
| 271 | for (pixel_x = 0; pixel_x < 4; pixel_x++, flags >>= 1) |
| 272 | pixels[pixel_ptr++] = colors[(flags & 0x1) ^ 1]; |
| 273 | pixel_ptr -= row_dec; |
| 274 | } |
| 275 | } |
| 276 | } else { |
| 277 | /* otherwise, it's a 1-color block */ |
| 278 | colors[0] = (byte_b << 8) | byte_a; |
| 279 | |
| 280 | for (pixel_y = 0; pixel_y < 4; pixel_y++) { |
| 281 | for (pixel_x = 0; pixel_x < 4; pixel_x++) |
| 282 | pixels[pixel_ptr++] = colors[0]; |
| 283 | pixel_ptr -= row_dec; |
| 284 | } |
| 285 | } |
| 286 | |
| 287 | block_ptr += block_inc; |
| 288 | total_blocks--; |
| 289 | } |
| 290 | } |
| 291 | } |
| 292 | |
| 293 | static int msvideo1_decode_frame(AVCodecContext *avctx, |
| 294 | void *data, int *got_frame, |
| 295 | AVPacket *avpkt) |
| 296 | { |
| 297 | const uint8_t *buf = avpkt->data; |
| 298 | int buf_size = avpkt->size; |
| 299 | Msvideo1Context *s = avctx->priv_data; |
| 300 | int ret; |
| 301 | |
| 302 | s->buf = buf; |
| 303 | s->size = buf_size; |
| 304 | |
| 305 | if ((ret = ff_reget_buffer(avctx, s->frame)) < 0) |
| 306 | return ret; |
| 307 | |
| 308 | if (s->mode_8bit) { |
| 309 | const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL); |
| 310 | |
| 311 | if (pal) { |
| 312 | memcpy(s->pal, pal, AVPALETTE_SIZE); |
| 313 | s->frame->palette_has_changed = 1; |
| 314 | } |
| 315 | } |
| 316 | |
| 317 | if (s->mode_8bit) |
| 318 | msvideo1_decode_8bit(s); |
| 319 | else |
| 320 | msvideo1_decode_16bit(s); |
| 321 | |
| 322 | if ((ret = av_frame_ref(data, s->frame)) < 0) |
| 323 | return ret; |
| 324 | |
| 325 | *got_frame = 1; |
| 326 | |
| 327 | /* report that the buffer was completely consumed */ |
| 328 | return buf_size; |
| 329 | } |
| 330 | |
| 331 | static av_cold int msvideo1_decode_end(AVCodecContext *avctx) |
| 332 | { |
| 333 | Msvideo1Context *s = avctx->priv_data; |
| 334 | |
| 335 | av_frame_free(&s->frame); |
| 336 | |
| 337 | return 0; |
| 338 | } |
| 339 | |
| 340 | AVCodec ff_msvideo1_decoder = { |
| 341 | .name = "msvideo1", |
| 342 | .long_name = NULL_IF_CONFIG_SMALL("Microsoft Video 1"), |
| 343 | .type = AVMEDIA_TYPE_VIDEO, |
| 344 | .id = AV_CODEC_ID_MSVIDEO1, |
| 345 | .priv_data_size = sizeof(Msvideo1Context), |
| 346 | .init = msvideo1_decode_init, |
| 347 | .close = msvideo1_decode_end, |
| 348 | .decode = msvideo1_decode_frame, |
| 349 | .capabilities = CODEC_CAP_DR1, |
| 350 | }; |