ffmpeg/libavcodec/tiertexseqv.c

   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 };