| 1 | /* |
| 2 | * Tiertex Limited SEQ Video Decoder |
| 3 | * Copyright (c) 2006 Gregory Montoir (cyx@users.sourceforge.net) |
| 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 | * Tiertex Limited SEQ video decoder |
| 25 | */ |
| 26 | |
| 27 | #include "avcodec.h" |
| 28 | #define BITSTREAM_READER_LE |
| 29 | #include "get_bits.h" |
| 30 | #include "internal.h" |
| 31 | |
| 32 | |
| 33 | typedef struct SeqVideoContext { |
| 34 | AVCodecContext *avctx; |
| 35 | AVFrame *frame; |
| 36 | } SeqVideoContext; |
| 37 | |
| 38 | |
| 39 | static const unsigned char *seq_unpack_rle_block(const unsigned char *src, |
| 40 | const unsigned char *src_end, |
| 41 | unsigned char *dst, int dst_size) |
| 42 | { |
| 43 | int i, len, sz; |
| 44 | GetBitContext gb; |
| 45 | int code_table[64]; |
| 46 | |
| 47 | /* get the rle codes */ |
| 48 | init_get_bits(&gb, src, (src_end - src) * 8); |
| 49 | for (i = 0, sz = 0; i < 64 && sz < dst_size; i++) { |
| 50 | if (get_bits_left(&gb) < 4) |
| 51 | return NULL; |
| 52 | code_table[i] = get_sbits(&gb, 4); |
| 53 | sz += FFABS(code_table[i]); |
| 54 | } |
| 55 | src += (get_bits_count(&gb) + 7) / 8; |
| 56 | |
| 57 | /* do the rle unpacking */ |
| 58 | for (i = 0; i < 64 && dst_size > 0; i++) { |
| 59 | len = code_table[i]; |
| 60 | if (len < 0) { |
| 61 | len = -len; |
| 62 | if (src_end - src < 1) |
| 63 | return NULL; |
| 64 | memset(dst, *src++, FFMIN(len, dst_size)); |
| 65 | } else { |
| 66 | if (src_end - src < len) |
| 67 | return NULL; |
| 68 | memcpy(dst, src, FFMIN(len, dst_size)); |
| 69 | src += len; |
| 70 | } |
| 71 | dst += len; |
| 72 | dst_size -= len; |
| 73 | } |
| 74 | return src; |
| 75 | } |
| 76 | |
| 77 | static const unsigned char *seq_decode_op1(SeqVideoContext *seq, |
| 78 | const unsigned char *src, |
| 79 | const unsigned char *src_end, |
| 80 | unsigned char *dst) |
| 81 | { |
| 82 | const unsigned char *color_table; |
| 83 | int b, i, len, bits; |
| 84 | GetBitContext gb; |
| 85 | unsigned char block[8 * 8]; |
| 86 | |
| 87 | if (src_end - src < 1) |
| 88 | return NULL; |
| 89 | len = *src++; |
| 90 | if (len & 0x80) { |
| 91 | switch (len & 3) { |
| 92 | case 1: |
| 93 | src = seq_unpack_rle_block(src, src_end, block, sizeof(block)); |
| 94 | for (b = 0; b < 8; b++) { |
| 95 | memcpy(dst, &block[b * 8], 8); |
| 96 | dst += seq->frame->linesize[0]; |
| 97 | } |
| 98 | break; |
| 99 | case 2: |
| 100 | src = seq_unpack_rle_block(src, src_end, block, sizeof(block)); |
| 101 | for (i = 0; i < 8; i++) { |
| 102 | for (b = 0; b < 8; b++) |
| 103 | dst[b * seq->frame->linesize[0]] = block[i * 8 + b]; |
| 104 | ++dst; |
| 105 | } |
| 106 | break; |
| 107 | } |
| 108 | } else { |
| 109 | if (len <= 0) |
| 110 | return NULL; |
| 111 | bits = ff_log2_tab[len - 1] + 1; |
| 112 | if (src_end - src < len + 8 * bits) |
| 113 | return NULL; |
| 114 | color_table = src; |
| 115 | src += len; |
| 116 | init_get_bits(&gb, src, bits * 8 * 8); src += bits * 8; |
| 117 | for (b = 0; b < 8; b++) { |
| 118 | for (i = 0; i < 8; i++) |
| 119 | dst[i] = color_table[get_bits(&gb, bits)]; |
| 120 | dst += seq->frame->linesize[0]; |
| 121 | } |
| 122 | } |
| 123 | |
| 124 | return src; |
| 125 | } |
| 126 | |
| 127 | static const unsigned char *seq_decode_op2(SeqVideoContext *seq, |
| 128 | const unsigned char *src, |
| 129 | const unsigned char *src_end, |
| 130 | unsigned char *dst) |
| 131 | { |
| 132 | int i; |
| 133 | |
| 134 | if (src_end - src < 8 * 8) |
| 135 | return NULL; |
| 136 | |
| 137 | for (i = 0; i < 8; i++) { |
| 138 | memcpy(dst, src, 8); |
| 139 | src += 8; |
| 140 | dst += seq->frame->linesize[0]; |
| 141 | } |
| 142 | |
| 143 | return src; |
| 144 | } |
| 145 | |
| 146 | static const unsigned char *seq_decode_op3(SeqVideoContext *seq, |
| 147 | const unsigned char *src, |
| 148 | const unsigned char *src_end, |
| 149 | unsigned char *dst) |
| 150 | { |
| 151 | int pos, offset; |
| 152 | |
| 153 | do { |
| 154 | if (src_end - src < 2) |
| 155 | return NULL; |
| 156 | pos = *src++; |
| 157 | offset = ((pos >> 3) & 7) * seq->frame->linesize[0] + (pos & 7); |
| 158 | dst[offset] = *src++; |
| 159 | } while (!(pos & 0x80)); |
| 160 | |
| 161 | return src; |
| 162 | } |
| 163 | |
| 164 | static int seqvideo_decode(SeqVideoContext *seq, const unsigned char *data, int data_size) |
| 165 | { |
| 166 | const unsigned char *data_end = data + data_size; |
| 167 | GetBitContext gb; |
| 168 | int flags, i, j, x, y, op; |
| 169 | unsigned char c[3]; |
| 170 | unsigned char *dst; |
| 171 | uint32_t *palette; |
| 172 | |
| 173 | flags = *data++; |
| 174 | |
| 175 | if (flags & 1) { |
| 176 | palette = (uint32_t *)seq->frame->data[1]; |
| 177 | if (data_end - data < 256 * 3) |
| 178 | return AVERROR_INVALIDDATA; |
| 179 | for (i = 0; i < 256; i++) { |
| 180 | for (j = 0; j < 3; j++, data++) |
| 181 | c[j] = (*data << 2) | (*data >> 4); |
| 182 | palette[i] = 0xFFU << 24 | AV_RB24(c); |
| 183 | } |
| 184 | seq->frame->palette_has_changed = 1; |
| 185 | } |
| 186 | |
| 187 | if (flags & 2) { |
| 188 | if (data_end - data < 128) |
| 189 | return AVERROR_INVALIDDATA; |
| 190 | init_get_bits(&gb, data, 128 * 8); data += 128; |
| 191 | for (y = 0; y < 128; y += 8) |
| 192 | for (x = 0; x < 256; x += 8) { |
| 193 | dst = &seq->frame->data[0][y * seq->frame->linesize[0] + x]; |
| 194 | op = get_bits(&gb, 2); |
| 195 | switch (op) { |
| 196 | case 1: |
| 197 | data = seq_decode_op1(seq, data, data_end, dst); |
| 198 | break; |
| 199 | case 2: |
| 200 | data = seq_decode_op2(seq, data, data_end, dst); |
| 201 | break; |
| 202 | case 3: |
| 203 | data = seq_decode_op3(seq, data, data_end, dst); |
| 204 | break; |
| 205 | } |
| 206 | if (!data) |
| 207 | return AVERROR_INVALIDDATA; |
| 208 | } |
| 209 | } |
| 210 | return 0; |
| 211 | } |
| 212 | |
| 213 | static av_cold int seqvideo_decode_init(AVCodecContext *avctx) |
| 214 | { |
| 215 | SeqVideoContext *seq = avctx->priv_data; |
| 216 | |
| 217 | seq->avctx = avctx; |
| 218 | avctx->pix_fmt = AV_PIX_FMT_PAL8; |
| 219 | |
| 220 | seq->frame = av_frame_alloc(); |
| 221 | if (!seq->frame) |
| 222 | return AVERROR(ENOMEM); |
| 223 | |
| 224 | return 0; |
| 225 | } |
| 226 | |
| 227 | static int seqvideo_decode_frame(AVCodecContext *avctx, |
| 228 | void *data, int *got_frame, |
| 229 | AVPacket *avpkt) |
| 230 | { |
| 231 | const uint8_t *buf = avpkt->data; |
| 232 | int buf_size = avpkt->size; |
| 233 | int ret; |
| 234 | |
| 235 | SeqVideoContext *seq = avctx->priv_data; |
| 236 | |
| 237 | if ((ret = ff_reget_buffer(avctx, seq->frame)) < 0) |
| 238 | return ret; |
| 239 | |
| 240 | if (seqvideo_decode(seq, buf, buf_size)) |
| 241 | return AVERROR_INVALIDDATA; |
| 242 | |
| 243 | if ((ret = av_frame_ref(data, seq->frame)) < 0) |
| 244 | return ret; |
| 245 | *got_frame = 1; |
| 246 | |
| 247 | return buf_size; |
| 248 | } |
| 249 | |
| 250 | static av_cold int seqvideo_decode_end(AVCodecContext *avctx) |
| 251 | { |
| 252 | SeqVideoContext *seq = avctx->priv_data; |
| 253 | |
| 254 | av_frame_free(&seq->frame); |
| 255 | |
| 256 | return 0; |
| 257 | } |
| 258 | |
| 259 | AVCodec ff_tiertexseqvideo_decoder = { |
| 260 | .name = "tiertexseqvideo", |
| 261 | .long_name = NULL_IF_CONFIG_SMALL("Tiertex Limited SEQ video"), |
| 262 | .type = AVMEDIA_TYPE_VIDEO, |
| 263 | .id = AV_CODEC_ID_TIERTEXSEQVIDEO, |
| 264 | .priv_data_size = sizeof(SeqVideoContext), |
| 265 | .init = seqvideo_decode_init, |
| 266 | .close = seqvideo_decode_end, |
| 267 | .decode = seqvideo_decode_frame, |
| 268 | .capabilities = CODEC_CAP_DR1, |
| 269 | }; |