libavcodec/tscc2.c

   1 /*
   2  * TechSmith Screen Codec 2 (aka Dora) decoder
   3  * Copyright (c) 2012 Konstantin Shishkov
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav 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  * Libav 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 Libav; 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  * TechSmith Screen Codec 2 decoder
  25  */
  26
  27 #include <inttypes.h>
  28
  29 #define BITSTREAM_READER_LE
  30 #include "avcodec.h"
  31 #include "bitstream.h"
  32 #include "bytestream.h"
  33 #include "internal.h"
  34 #include "mathops.h"
  35 #include "tscc2data.h"
  36 #include "vlc.h"
  37
  38 typedef struct TSCC2Context {
  39     AVCodecContext *avctx;
  40     AVFrame       *pic;
  41     int            mb_width, mb_height;
  42     uint8_t        *slice_quants;
  43     int            quant[2];
  44     int            q[2][3];
  45     BitstreamContext bc;
  46
  47     VLC            dc_vlc, nc_vlc[NUM_VLC_SETS], ac_vlc[NUM_VLC_SETS];
  48     int            block[16];
  49 } TSCC2Context;
  50
  51 static av_cold void free_vlcs(TSCC2Context *c)
  52 {
  53     int i;
  54
  55     ff_free_vlc(&c->dc_vlc);
  56     for (i = 0; i < NUM_VLC_SETS; i++) {
  57         ff_free_vlc(c->nc_vlc + i);
  58         ff_free_vlc(c->ac_vlc + i);
  59     }
  60 }
  61
  62 static av_cold int init_vlcs(TSCC2Context *c)
  63 {
  64     int i, ret;
  65
  66     ret = ff_init_vlc_sparse(&c->dc_vlc, 9, DC_VLC_COUNT,
  67                              tscc2_dc_vlc_bits,  1, 1,
  68                              tscc2_dc_vlc_codes, 2, 2,
  69                              tscc2_dc_vlc_syms,  2, 2, INIT_VLC_LE);
  70     if (ret)
  71         return ret;
  72
  73     for (i = 0; i < NUM_VLC_SETS; i++) {
  74         ret = ff_init_vlc_sparse(c->nc_vlc + i, 9, 16,
  75                                  tscc2_nc_vlc_bits[i],  1, 1,
  76                                  tscc2_nc_vlc_codes[i], 2, 2,
  77                                  tscc2_nc_vlc_syms,     1, 1, INIT_VLC_LE);
  78         if (ret) {
  79             free_vlcs(c);
  80             return ret;
  81         }
  82         ret = ff_init_vlc_sparse(c->ac_vlc + i, 9, tscc2_ac_vlc_sizes[i],
  83                                  tscc2_ac_vlc_bits[i],  1, 1,
  84                                  tscc2_ac_vlc_codes[i], 2, 2,
  85                                  tscc2_ac_vlc_syms[i],  2, 2, INIT_VLC_LE);
  86         if (ret) {
  87             free_vlcs(c);
  88             return ret;
  89         }
  90     }
  91
  92     return 0;
  93 }
  94
  95 #define DEQUANT(val, q) ((q * val + 0x80) >> 8)
  96 #define DCT1D(d0, d1, d2, d3, s0, s1, s2, s3, OP) \
  97     OP(d0, 5 * ((s0) + (s1) + (s2)) + 2 * (s3));  \
  98     OP(d1, 5 * ((s0) - (s2) - (s3)) + 2 * (s1));  \
  99     OP(d2, 5 * ((s0) - (s2) + (s3)) - 2 * (s1));  \
 100     OP(d3, 5 * ((s0) - (s1) + (s2)) - 2 * (s3));  \
 101
 102 #define COL_OP(a, b)  a = b
 103 #define ROW_OP(a, b)  a = ((b) + 0x20) >> 6
 104
 105 static void tscc2_idct4_put(int *in, int q[3], uint8_t *dst, int stride)
 106 {
 107     int i;
 108     int tblk[4 * 4];
 109     int t0, t1, t2, t3;
 110
 111     for (i = 0; i < 4; i++) {
 112         t0 = DEQUANT(q[0 + (i & 1)], in[0 * 4 + i]);
 113         t1 = DEQUANT(q[1 + (i & 1)], in[1 * 4 + i]);
 114         t2 = DEQUANT(q[0 + (i & 1)], in[2 * 4 + i]);
 115         t3 = DEQUANT(q[1 + (i & 1)], in[3 * 4 + i]);
 116         DCT1D(tblk[0 * 4 + i], tblk[1 * 4 + i],
 117               tblk[2 * 4 + i], tblk[3 * 4 + i],
 118               t0, t1, t2, t3, COL_OP);
 119     }
 120     for (i = 0; i < 4; i++) {
 121         DCT1D(dst[0], dst[1], dst[2], dst[3],
 122               tblk[i * 4 + 0], tblk[i * 4 + 1],
 123               tblk[i * 4 + 2], tblk[i * 4 + 3], ROW_OP);
 124         dst += stride;
 125     }
 126 }
 127
 128 static int tscc2_decode_mb(TSCC2Context *c, int *q, int vlc_set,
 129                            uint8_t *dst, int stride, int plane)
 130 {
 131     BitstreamContext *bc = &c->bc;
 132     int prev_dc, dc, nc, ac, bpos, val;
 133     int i, j, k, l;
 134
 135     if (bitstream_read_bit(bc)) {
 136         if (bitstream_read_bit(bc)) {
 137             val = bitstream_read(bc, 8);
 138             for (i = 0; i < 8; i++, dst += stride)
 139                 memset(dst, val, 16);
 140         } else {
 141             if (bitstream_bits_left(bc) < 16 * 8 * 8)
 142                 return AVERROR_INVALIDDATA;
 143             for (i = 0; i < 8; i++) {
 144                 for (j = 0; j < 16; j++)
 145                     dst[j] = bitstream_read(bc, 8);
 146                 dst += stride;
 147             }
 148         }
 149         return 0;
 150     }
 151
 152     prev_dc = 0;
 153     for (j = 0; j < 2; j++) {
 154         for (k = 0; k < 4; k++) {
 155             if (!(j | k)) {
 156                 dc = bitstream_read(bc, 8);
 157             } else {
 158                 dc = bitstream_read_vlc(bc, c->dc_vlc.table, 9, 2);
 159                 if (dc == -1)
 160                     return AVERROR_INVALIDDATA;
 161                 if (dc == 0x100)
 162                     dc = bitstream_read(bc, 8);
 163             }
 164             dc          = (dc + prev_dc) & 0xFF;
 165             prev_dc     = dc;
 166             c->block[0] = dc;
 167
 168             nc = bitstream_read_vlc(bc, c->nc_vlc[vlc_set].table, 9, 1);
 169             if (nc == -1)
 170                 return AVERROR_INVALIDDATA;
 171
 172             bpos = 1;
 173             memset(c->block + 1, 0, 15 * sizeof(*c->block));
 174             for (l = 0; l < nc; l++) {
 175                 ac = bitstream_read_vlc(bc, c->ac_vlc[vlc_set].table, 9, 2);
 176                 if (ac == -1)
 177                     return AVERROR_INVALIDDATA;
 178                 if (ac == 0x1000)
 179                     ac = bitstream_read(bc, 12);
 180                 bpos += ac & 0xF;
 181                 if (bpos >= 16)
 182                     return AVERROR_INVALIDDATA;
 183                 val = sign_extend(ac >> 4, 8);
 184                 c->block[ff_zigzag_scan[bpos++]] = val;
 185             }
 186             tscc2_idct4_put(c->block, q, dst + k * 4, stride);
 187         }
 188         dst += 4 * stride;
 189     }
 190     return 0;
 191 }
 192
 193 static int tscc2_decode_slice(TSCC2Context *c, int mb_y,
 194                               const uint8_t *buf, int buf_size)
 195 {
 196     int i, mb_x, q, ret;
 197     int off;
 198
 199     bitstream_init8(&c->bc, buf, buf_size);
 200
 201     for (mb_x = 0; mb_x < c->mb_width; mb_x++) {
 202         q = c->slice_quants[mb_x + c->mb_width * mb_y];
 203
 204         if (q == 0 || q == 3) // skip block
 205             continue;
 206         for (i = 0; i < 3; i++) {
 207             off = mb_x * 16 + mb_y * 8 * c->pic->linesize[i];
 208             ret = tscc2_decode_mb(c, c->q[q - 1], c->quant[q - 1] - 2,
 209                                   c->pic->data[i] + off, c->pic->linesize[i], i);
 210             if (ret)
 211                 return ret;
 212         }
 213     }
 214
 215     return 0;
 216 }
 217
 218 static int tscc2_decode_frame(AVCodecContext *avctx, void *data,
 219                               int *got_frame, AVPacket *avpkt)
 220 {
 221     const uint8_t *buf = avpkt->data;
 222     int buf_size = avpkt->size;
 223     TSCC2Context *c = avctx->priv_data;
 224     GetByteContext gb;
 225     uint32_t frame_type, size;
 226     int i, val, len, pos = 0;
 227     int num_mb = c->mb_width * c->mb_height;
 228     int ret;
 229
 230     bytestream2_init(&gb, buf, buf_size);
 231     frame_type = bytestream2_get_byte(&gb);
 232     if (frame_type > 1) {
 233         av_log(avctx, AV_LOG_ERROR, "Incorrect frame type %"PRIu32"\n",
 234                frame_type);
 235         return AVERROR_INVALIDDATA;
 236     }
 237
 238     if ((ret = ff_reget_buffer(avctx, c->pic)) < 0) {
 239         av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
 240         return ret;
 241     }
 242
 243     if (frame_type == 0) {
 244         *got_frame      = 1;
 245         if ((ret = av_frame_ref(data, c->pic)) < 0)
 246             return ret;
 247
 248         return buf_size;
 249     }
 250
 251     if (bytestream2_get_bytes_left(&gb) < 4) {
 252         av_log(avctx, AV_LOG_ERROR, "Frame is too short\n");
 253         return AVERROR_INVALIDDATA;
 254     }
 255
 256     c->quant[0] = bytestream2_get_byte(&gb);
 257     c->quant[1] = bytestream2_get_byte(&gb);
 258     if (c->quant[0] < 2 || c->quant[0] > NUM_VLC_SETS + 1 ||
 259         c->quant[1] < 2 || c->quant[1] > NUM_VLC_SETS + 1) {
 260         av_log(avctx, AV_LOG_ERROR, "Invalid quantisers %d / %d\n",
 261                c->quant[0], c->quant[1]);
 262         return AVERROR_INVALIDDATA;
 263     }
 264
 265     for (i = 0; i < 3; i++) {
 266         c->q[0][i] = tscc2_quants[c->quant[0] - 2][i];
 267         c->q[1][i] = tscc2_quants[c->quant[1] - 2][i];
 268     }
 269
 270     bytestream2_skip(&gb, 1);
 271
 272     size = bytestream2_get_le32(&gb);
 273     if (size > bytestream2_get_bytes_left(&gb)) {
 274         av_log(avctx, AV_LOG_ERROR, "Slice properties chunk is too large\n");
 275         return AVERROR_INVALIDDATA;
 276     }
 277
 278     for (i = 0; i < size; i++) {
 279         val   = bytestream2_get_byte(&gb);
 280         len   = val & 0x3F;
 281         val >>= 6;
 282         if (pos + len > num_mb) {
 283             av_log(avctx, AV_LOG_ERROR, "Too many slice properties\n");
 284             return AVERROR_INVALIDDATA;
 285         }
 286         memset(c->slice_quants + pos, val, len);
 287         pos += len;
 288     }
 289     if (pos < num_mb) {
 290         av_log(avctx, AV_LOG_ERROR, "Too few slice properties (%d / %d)\n",
 291                pos, num_mb);
 292         return AVERROR_INVALIDDATA;
 293     }
 294
 295     for (i = 0; i < c->mb_height; i++) {
 296         size = bytestream2_peek_byte(&gb);
 297         if (size & 1) {
 298             size = bytestream2_get_byte(&gb) - 1;
 299         } else {
 300             size = bytestream2_get_le32(&gb) >> 1;
 301         }
 302         if (!size) {
 303             int skip_row = 1, j, off = i * c->mb_width;
 304             for (j = 0; j < c->mb_width; j++) {
 305                 if (c->slice_quants[off + j] == 1 ||
 306                     c->slice_quants[off + j] == 2) {
 307                     skip_row = 0;
 308                     break;
 309                 }
 310             }
 311             if (!skip_row) {
 312                 av_log(avctx, AV_LOG_ERROR, "Non-skip row with zero size\n");
 313                 return AVERROR_INVALIDDATA;
 314             }
 315         }
 316         if (bytestream2_get_bytes_left(&gb) < size) {
 317             av_log(avctx, AV_LOG_ERROR, "Invalid slice size (%"PRIu32"/%u)\n",
 318                    size, bytestream2_get_bytes_left(&gb));
 319             return AVERROR_INVALIDDATA;
 320         }
 321         ret = tscc2_decode_slice(c, i, buf + bytestream2_tell(&gb), size);
 322         if (ret) {
 323             av_log(avctx, AV_LOG_ERROR, "Error decoding slice %d\n", i);
 324             return ret;
 325         }
 326         bytestream2_skip(&gb, size);
 327     }
 328
 329     *got_frame      = 1;
 330     if ((ret = av_frame_ref(data, c->pic)) < 0)
 331         return ret;
 332
 333     /* always report that the buffer was completely consumed */
 334     return buf_size;
 335 }
 336
 337 static av_cold int tscc2_decode_end(AVCodecContext *avctx)
 338 {
 339     TSCC2Context * const c = avctx->priv_data;
 340
 341     av_frame_free(&c->pic);
 342     av_freep(&c->slice_quants);
 343     free_vlcs(c);
 344
 345     return 0;
 346 }
 347
 348 static av_cold int tscc2_decode_init(AVCodecContext *avctx)
 349 {
 350     TSCC2Context * const c = avctx->priv_data;
 351     int ret;
 352
 353     c->avctx = avctx;
 354
 355     avctx->pix_fmt = AV_PIX_FMT_YUV444P;
 356
 357     if ((ret = init_vlcs(c)) < 0) {
 358         av_log(avctx, AV_LOG_ERROR, "Cannot initialise VLCs\n");
 359         return ret;
 360     }
 361
 362     c->mb_width     = FFALIGN(avctx->width,  16) >> 4;
 363     c->mb_height    = FFALIGN(avctx->height,  8) >> 3;
 364     c->slice_quants = av_malloc(c->mb_width * c->mb_height);
 365     if (!c->slice_quants) {
 366         av_log(avctx, AV_LOG_ERROR, "Cannot allocate slice information\n");
 367         free_vlcs(c);
 368         return AVERROR(ENOMEM);
 369     }
 370
 371     c->pic = av_frame_alloc();
 372     if (!c->pic) {
 373         tscc2_decode_end(avctx);
 374         return AVERROR(ENOMEM);
 375     }
 376
 377     return 0;
 378 }
 379
 380 AVCodec ff_tscc2_decoder = {
 381     .name           = "tscc2",
 382     .long_name      = NULL_IF_CONFIG_SMALL("TechSmith Screen Codec 2"),
 383     .type           = AVMEDIA_TYPE_VIDEO,
 384     .id             = AV_CODEC_ID_TSCC2,
 385     .priv_data_size = sizeof(TSCC2Context),
 386     .init           = tscc2_decode_init,
 387     .close          = tscc2_decode_end,
 388     .decode         = tscc2_decode_frame,
 389     .capabilities   = AV_CODEC_CAP_DR1,
 390 };