libavcodec/eatgv.c

   1 /*
   2  * Electronic Arts TGV Video Decoder
   3  * Copyright (c) 2007-2008 Peter Ross
   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 St, Fifth Floor, Boston, MA  02110-1301  USA
  20  */
  21
  22 /**
  23  * @file
  24  * Electronic Arts TGV Video Decoder
  25  * by Peter Ross (pross@xvid.org)
  26  *
  27  * Technical details here:
  28  * http://wiki.multimedia.cx/index.php?title=Electronic_Arts_TGV
  29  */
  30
  31 #include "libavutil/imgutils.h"
  32 #include "libavutil/mem.h"
  33
  34 #define BITSTREAM_READER_LE
  35 #include "avcodec.h"
  36 #include "bitstream.h"
  37 #include "internal.h"
  38
  39 #define EA_PREAMBLE_SIZE    8
  40 #define kVGT_TAG MKTAG('k', 'V', 'G', 'T')
  41
  42 typedef struct TgvContext {
  43     AVCodecContext *avctx;
  44     AVFrame *last_frame;
  45     uint8_t *frame_buffer;
  46     int width,height;
  47     uint32_t palette[AVPALETTE_COUNT];
  48
  49     int (*mv_codebook)[2];
  50     uint8_t (*block_codebook)[16];
  51     int num_mvs;           ///< current length of mv_codebook
  52     int num_blocks_packed; ///< current length of block_codebook
  53 } TgvContext;
  54
  55 static av_cold int tgv_decode_init(AVCodecContext *avctx)
  56 {
  57     TgvContext *s = avctx->priv_data;
  58     s->avctx         = avctx;
  59     avctx->framerate = (AVRational){ 15, 1 };
  60     avctx->pix_fmt   = AV_PIX_FMT_PAL8;
  61
  62     s->last_frame = av_frame_alloc();
  63     if (!s->last_frame)
  64         return AVERROR(ENOMEM);
  65
  66     return 0;
  67 }
  68
  69 /**
  70  * Unpack buffer
  71  * @return 0 on success, -1 on critical buffer underflow
  72  */
  73 static int unpack(const uint8_t *src, const uint8_t *src_end,
  74                   uint8_t *dst, int width, int height)
  75 {
  76     uint8_t *dst_end = dst + width*height;
  77     int size, size1, size2, offset, run;
  78     uint8_t *dst_start = dst;
  79
  80     if (src[0] & 0x01)
  81         src += 5;
  82     else
  83         src += 2;
  84
  85     if (src + 3 > src_end)
  86         return AVERROR_INVALIDDATA;
  87     size = AV_RB24(src);
  88     src += 3;
  89
  90     while (size > 0 && src < src_end) {
  91
  92         /* determine size1 and size2 */
  93         size1 = (src[0] & 3);
  94         if (src[0] & 0x80) {  // 1
  95             if (src[0] & 0x40 ) {  // 11
  96                 if (src[0] & 0x20) {  // 111
  97                     if (src[0] < 0xFC)  // !(111111)
  98                         size1 = (((src[0] & 31) + 1) << 2);
  99                     src++;
 100                     size2 = 0;
 101                 } else {  // 110
 102                     offset = ((src[0] & 0x10) << 12) + AV_RB16(&src[1]) + 1;
 103                     size2  = ((src[0] & 0xC) << 6) + src[3] + 5;
 104                     src   += 4;
 105                 }
 106             } else {  // 10
 107                 size1  = ((src[1] & 0xC0) >> 6);
 108                 offset = (AV_RB16(&src[1]) & 0x3FFF) + 1;
 109                 size2  = (src[0] & 0x3F) + 4;
 110                 src   += 3;
 111             }
 112         } else {  // 0
 113             offset = ((src[0] & 0x60) << 3) + src[1] + 1;
 114             size2  = ((src[0] & 0x1C) >> 2) + 3;
 115             src   += 2;
 116         }
 117
 118
 119         /* fetch strip from src */
 120         if (size1 > src_end - src)
 121             break;
 122
 123         if (size1 > 0) {
 124             size -= size1;
 125             run   = FFMIN(size1, dst_end - dst);
 126             memcpy(dst, src, run);
 127             dst += run;
 128             src += run;
 129         }
 130
 131         if (size2 > 0) {
 132             if (dst - dst_start < offset)
 133                 return 0;
 134             size -= size2;
 135             run   = FFMIN(size2, dst_end - dst);
 136             av_memcpy_backptr(dst, offset, run);
 137             dst += run;
 138         }
 139     }
 140
 141     return 0;
 142 }
 143
 144 /**
 145  * Decode inter-frame
 146  * @return 0 on success, -1 on critical buffer underflow
 147  */
 148 static int tgv_decode_inter(TgvContext *s, AVFrame *frame,
 149                             const uint8_t *buf, const uint8_t *buf_end)
 150 {
 151     int num_mvs;
 152     int num_blocks_raw;
 153     int num_blocks_packed;
 154     int vector_bits;
 155     int i,j,x,y;
 156     BitstreamContext bc;
 157     int mvbits;
 158     const uint8_t *blocks_raw;
 159
 160     if (buf + 12 > buf_end)
 161         return AVERROR_INVALIDDATA;
 162
 163     num_mvs           = AV_RL16(&buf[0]);
 164     num_blocks_raw    = AV_RL16(&buf[2]);
 165     num_blocks_packed = AV_RL16(&buf[4]);
 166     vector_bits       = AV_RL16(&buf[6]);
 167     buf += 12;
 168
 169     if (vector_bits > 32 || !vector_bits) {
 170         av_log(s->avctx, AV_LOG_ERROR,
 171                "Invalid value for motion vector bits: %d\n", vector_bits);
 172         return AVERROR_INVALIDDATA;
 173     }
 174
 175     /* allocate codebook buffers as necessary */
 176     if (num_mvs > s->num_mvs) {
 177         int err = av_reallocp(&s->mv_codebook, num_mvs * 2 * sizeof(int));
 178         if (err < 0)
 179             return err;
 180         s->num_mvs = num_mvs;
 181     }
 182
 183     if (num_blocks_packed > s->num_blocks_packed) {
 184         int err;
 185         if ((err = av_reallocp(&s->block_codebook, num_blocks_packed * 16)) < 0) {
 186             s->num_blocks_packed = 0;
 187             return err;
 188         }
 189         s->num_blocks_packed = num_blocks_packed;
 190     }
 191
 192     /* read motion vectors */
 193     mvbits = (num_mvs * 2 * 10 + 31) & ~31;
 194
 195     if (buf + (mvbits >> 3) + 16 * num_blocks_raw + 8 * num_blocks_packed > buf_end)
 196         return AVERROR_INVALIDDATA;
 197
 198     bitstream_init(&bc, buf, mvbits);
 199     for (i = 0; i < num_mvs; i++) {
 200         s->mv_codebook[i][0] = bitstream_read_signed(&bc, 10);
 201         s->mv_codebook[i][1] = bitstream_read_signed(&bc, 10);
 202     }
 203     buf += mvbits >> 3;
 204
 205     /* note ptr to uncompressed blocks */
 206     blocks_raw = buf;
 207     buf       += num_blocks_raw * 16;
 208
 209     /* read compressed blocks */
 210     bitstream_init8(&bc, buf, buf_end - buf);
 211     for (i = 0; i < num_blocks_packed; i++) {
 212         int tmp[4];
 213         for (j = 0; j < 4; j++)
 214             tmp[j] = bitstream_read(&bc, 8);
 215         for (j = 0; j < 16; j++)
 216             s->block_codebook[i][15-j] = tmp[bitstream_read(&bc, 2)];
 217     }
 218
 219     if (bitstream_bits_left(&bc) < vector_bits *
 220         (s->avctx->height / 4) * (s->avctx->width / 4))
 221         return AVERROR_INVALIDDATA;
 222
 223     /* read vectors and build frame */
 224     for (y = 0; y < s->avctx->height / 4; y++)
 225         for (x = 0; x < s->avctx->width / 4; x++) {
 226             unsigned int vector = bitstream_read(&bc, vector_bits);
 227             const uint8_t *src;
 228             ptrdiff_t src_stride;
 229
 230             if (vector < num_mvs) {
 231                 int mx = x * 4 + s->mv_codebook[vector][0];
 232                 int my = y * 4 + s->mv_codebook[vector][1];
 233
 234                 if (mx < 0 || mx + 4 > s->avctx->width ||
 235                     my < 0 || my + 4 > s->avctx->height)
 236                     continue;
 237
 238                 src = s->last_frame->data[0] + mx + my * s->last_frame->linesize[0];
 239                 src_stride = s->last_frame->linesize[0];
 240             } else {
 241                 int offset = vector - num_mvs;
 242                 if (offset < num_blocks_raw)
 243                     src = blocks_raw + 16*offset;
 244                 else if (offset - num_blocks_raw < num_blocks_packed)
 245                     src = s->block_codebook[offset - num_blocks_raw];
 246                 else
 247                     continue;
 248                 src_stride = 4;
 249             }
 250
 251             for (j = 0; j < 4; j++)
 252                 for (i = 0; i < 4; i++)
 253                     frame->data[0][(y * 4 + j) * frame->linesize[0] + (x * 4 + i)] =
 254                         src[j * src_stride + i];
 255     }
 256
 257     return 0;
 258 }
 259
 260 static int tgv_decode_frame(AVCodecContext *avctx,
 261                             void *data, int *got_frame,
 262                             AVPacket *avpkt)
 263 {
 264     const uint8_t *buf     = avpkt->data;
 265     int buf_size           = avpkt->size;
 266     TgvContext *s          = avctx->priv_data;
 267     const uint8_t *buf_end = buf + buf_size;
 268     AVFrame *frame         = data;
 269     int chunk_type, ret;
 270
 271     chunk_type = AV_RL32(&buf[0]);
 272     buf       += EA_PREAMBLE_SIZE;
 273
 274     if (chunk_type == kVGT_TAG) {
 275         int pal_count, i;
 276         if (buf + 12 > buf_end) {
 277             av_log(avctx, AV_LOG_WARNING, "truncated header\n");
 278             return AVERROR_INVALIDDATA;
 279         }
 280
 281         s->width  = AV_RL16(&buf[0]);
 282         s->height = AV_RL16(&buf[2]);
 283         if (s->avctx->width != s->width || s->avctx->height != s->height) {
 284             av_freep(&s->frame_buffer);
 285             av_frame_unref(s->last_frame);
 286             if ((ret = ff_set_dimensions(s->avctx, s->width, s->height)) < 0)
 287                 return ret;
 288         }
 289
 290         pal_count = AV_RL16(&buf[6]);
 291         buf += 12;
 292         for (i = 0; i < pal_count && i < AVPALETTE_COUNT && buf + 2 < buf_end; i++) {
 293             s->palette[i] = AV_RB24(buf);
 294             buf += 3;
 295         }
 296     }
 297
 298     if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
 299         return ret;
 300
 301     memcpy(frame->data[1], s->palette, AVPALETTE_SIZE);
 302
 303     if (chunk_type == kVGT_TAG) {
 304         int y;
 305         frame->key_frame = 1;
 306         frame->pict_type = AV_PICTURE_TYPE_I;
 307
 308         if (!s->frame_buffer &&
 309             !(s->frame_buffer = av_malloc(s->width * s->height)))
 310             return AVERROR(ENOMEM);
 311
 312         if (unpack(buf, buf_end, s->frame_buffer, s->avctx->width, s->avctx->height) < 0) {
 313             av_log(avctx, AV_LOG_WARNING, "truncated intra frame\n");
 314             return AVERROR_INVALIDDATA;
 315         }
 316         for (y = 0; y < s->height; y++)
 317             memcpy(frame->data[0]  + y * frame->linesize[0],
 318                    s->frame_buffer + y * s->width,
 319                    s->width);
 320     } else {
 321         if (!s->last_frame->data[0]) {
 322             av_log(avctx, AV_LOG_WARNING, "inter frame without corresponding intra frame\n");
 323             return buf_size;
 324         }
 325         frame->key_frame = 0;
 326         frame->pict_type = AV_PICTURE_TYPE_P;
 327         if (tgv_decode_inter(s, frame, buf, buf_end) < 0) {
 328             av_log(avctx, AV_LOG_WARNING, "truncated inter frame\n");
 329             return AVERROR_INVALIDDATA;
 330         }
 331     }
 332
 333     av_frame_unref(s->last_frame);
 334     if ((ret = av_frame_ref(s->last_frame, frame)) < 0)
 335         return ret;
 336
 337     *got_frame = 1;
 338
 339     return buf_size;
 340 }
 341
 342 static av_cold int tgv_decode_end(AVCodecContext *avctx)
 343 {
 344     TgvContext *s = avctx->priv_data;
 345     av_frame_free(&s->last_frame);
 346     av_freep(&s->frame_buffer);
 347     av_free(s->mv_codebook);
 348     av_free(s->block_codebook);
 349     return 0;
 350 }
 351
 352 AVCodec ff_eatgv_decoder = {
 353     .name           = "eatgv",
 354     .long_name      = NULL_IF_CONFIG_SMALL("Electronic Arts TGV video"),
 355     .type           = AVMEDIA_TYPE_VIDEO,
 356     .id             = AV_CODEC_ID_TGV,
 357     .priv_data_size = sizeof(TgvContext),
 358     .init           = tgv_decode_init,
 359     .close          = tgv_decode_end,
 360     .decode         = tgv_decode_frame,
 361     .capabilities   = AV_CODEC_CAP_DR1,
 362 };