libavcodec/tdsc.c

   1 /*
   2  * TDSC decoder
   3  * Copyright (C) 2015 Vittorio Giovara <vittorio.giovara@gmail.com>
   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  * TDSC decoder
  25  *
  26  * Fourcc: TSDC
  27  *
  28  * TDSC is very simple. It codes picture by tiles, storing them in raw BGR24
  29  * format or compressing them in JPEG. Frames can be full pictures or just
  30  * updates to the previous frame. Cursor is found in its own frame or at the
  31  * bottom of the picture. Every frame is then packed with zlib.
  32  *
  33  * Supports: BGR24
  34  */
  35
  36 #include <stdint.h>
  37 #include <zlib.h>
  38
  39 #include "libavutil/imgutils.h"
  40 #include "libavutil/mem.h"
  41
  42 #include "avcodec.h"
  43 #include "bytestream.h"
  44 #include "codec_internal.h"
  45 #include "decode.h"
  46
  47 #define BITMAPINFOHEADER_SIZE 0x28
  48 #define TDSF_HEADER_SIZE      0x56
  49 #define TDSB_HEADER_SIZE      0x08
  50
  51 typedef struct TDSCContext {
  52     AVCodecContext *jpeg_avctx;   // wrapper context for MJPEG
  53
  54     int width, height;
  55     GetByteContext gbc;
  56
  57     AVFrame *refframe;          // full decoded frame (without cursor)
  58     AVPacket *jpkt;             // encoded JPEG tile
  59     AVFrame *jpgframe;          // decoded JPEG tile
  60     uint8_t *tilebuffer;        // buffer containing tile data
  61
  62     /* zlib interaction */
  63     uint8_t *deflatebuffer;
  64     uLongf deflatelen;
  65
  66     /* All that is cursor */
  67     uint8_t    *cursor;
  68     int        cursor_stride;
  69     int        cursor_w, cursor_h, cursor_x, cursor_y;
  70     int        cursor_hot_x, cursor_hot_y;
  71 } TDSCContext;
  72
  73 /* 1 byte bits, 1 byte planes, 2 bytes format (probably) */
  74 enum TDSCCursorFormat {
  75     CUR_FMT_MONO = 0x01010004,
  76     CUR_FMT_BGRA = 0x20010004,
  77     CUR_FMT_RGBA = 0x20010008,
  78 };
  79
  80 static av_cold int tdsc_close(AVCodecContext *avctx)
  81 {
  82     TDSCContext *ctx = avctx->priv_data;
  83
  84     av_frame_free(&ctx->refframe);
  85     av_frame_free(&ctx->jpgframe);
  86     av_packet_free(&ctx->jpkt);
  87     av_freep(&ctx->deflatebuffer);
  88     av_freep(&ctx->tilebuffer);
  89     av_freep(&ctx->cursor);
  90     avcodec_free_context(&ctx->jpeg_avctx);
  91
  92     return 0;
  93 }
  94
  95 static av_cold int tdsc_init(AVCodecContext *avctx)
  96 {
  97     TDSCContext *ctx = avctx->priv_data;
  98     const AVCodec *codec;
  99     int ret;
 100
 101     avctx->pix_fmt = AV_PIX_FMT_BGR24;
 102
 103     /* These needs to be set to estimate buffer and frame size */
 104     if (!(avctx->width && avctx->height)) {
 105         av_log(avctx, AV_LOG_ERROR, "Video size not set.\n");
 106         return AVERROR_INVALIDDATA;
 107     }
 108
 109     /* This value should be large enough for a RAW-only frame plus headers */
 110     ctx->deflatelen = avctx->width * avctx->height * (3 + 1);
 111     ret = av_reallocp(&ctx->deflatebuffer, ctx->deflatelen);
 112     if (ret < 0)
 113         return ret;
 114
 115     /* Allocate reference and JPEG frame */
 116     ctx->refframe = av_frame_alloc();
 117     ctx->jpgframe = av_frame_alloc();
 118     ctx->jpkt     = av_packet_alloc();
 119     if (!ctx->refframe || !ctx->jpgframe || !ctx->jpkt)
 120         return AVERROR(ENOMEM);
 121
 122     /* Prepare everything needed for JPEG decoding */
 123     codec = avcodec_find_decoder(AV_CODEC_ID_MJPEG);
 124     if (!codec)
 125         return AVERROR_BUG;
 126     ctx->jpeg_avctx = avcodec_alloc_context3(codec);
 127     if (!ctx->jpeg_avctx)
 128         return AVERROR(ENOMEM);
 129     ctx->jpeg_avctx->flags = avctx->flags;
 130     ctx->jpeg_avctx->flags2 = avctx->flags2;
 131     ctx->jpeg_avctx->idct_algo = avctx->idct_algo;
 132     ret = avcodec_open2(ctx->jpeg_avctx, codec, NULL);
 133     if (ret < 0)
 134         return ret;
 135
 136     /* Set the output pixel format on the reference frame */
 137     ctx->refframe->format = avctx->pix_fmt;
 138
 139     return 0;
 140 }
 141
 142 #define APPLY_ALPHA(src, new, alpha) \
 143     src = (src * (256 - alpha) + new * alpha) >> 8
 144
 145 /* Paint a region over a buffer, without drawing out of its bounds. */
 146 static void tdsc_paint_cursor(AVCodecContext *avctx, uint8_t *dst, int stride)
 147 {
 148     TDSCContext *ctx = avctx->priv_data;
 149     const uint8_t *cursor = ctx->cursor;
 150     int x = ctx->cursor_x - ctx->cursor_hot_x;
 151     int y = ctx->cursor_y - ctx->cursor_hot_y;
 152     int w = ctx->cursor_w;
 153     int h = ctx->cursor_h;
 154     int i, j;
 155
 156     if (!ctx->cursor)
 157         return;
 158
 159     if (x + w > ctx->width)
 160         w = ctx->width - x;
 161     if (y + h > ctx->height)
 162         h = ctx->height - y;
 163     if (x < 0) {
 164         w      +=  x;
 165         cursor += -x * 4;
 166     } else {
 167         dst    +=  x * 3;
 168     }
 169     if (y < 0) {
 170         h      +=  y;
 171         cursor += -y * ctx->cursor_stride;
 172     } else {
 173         dst    +=  y * stride;
 174     }
 175     if (w < 0 || h < 0)
 176         return;
 177
 178     for (j = 0; j < h; j++) {
 179         for (i = 0; i < w; i++) {
 180             uint8_t alpha = cursor[i * 4];
 181             APPLY_ALPHA(dst[i * 3 + 0], cursor[i * 4 + 1], alpha);
 182             APPLY_ALPHA(dst[i * 3 + 1], cursor[i * 4 + 2], alpha);
 183             APPLY_ALPHA(dst[i * 3 + 2], cursor[i * 4 + 3], alpha);
 184         }
 185         dst    += stride;
 186         cursor += ctx->cursor_stride;
 187     }
 188 }
 189
 190 /* Load cursor data and store it in ABGR mode. */
 191 static int tdsc_load_cursor(AVCodecContext *avctx)
 192 {
 193     TDSCContext *ctx  = avctx->priv_data;
 194     int i, j, k, ret, cursor_fmt;
 195     uint8_t *dst;
 196
 197     ctx->cursor_hot_x = bytestream2_get_le16(&ctx->gbc);
 198     ctx->cursor_hot_y = bytestream2_get_le16(&ctx->gbc);
 199     ctx->cursor_w     = bytestream2_get_le16(&ctx->gbc);
 200     ctx->cursor_h     = bytestream2_get_le16(&ctx->gbc);
 201
 202     ctx->cursor_stride = FFALIGN(ctx->cursor_w, 32) * 4;
 203     cursor_fmt = bytestream2_get_le32(&ctx->gbc);
 204
 205     if (ctx->cursor_x >= avctx->width || ctx->cursor_y >= avctx->height) {
 206         av_log(avctx, AV_LOG_ERROR,
 207                "Invalid cursor position (%d.%d outside %dx%d).\n",
 208                ctx->cursor_x, ctx->cursor_y, avctx->width, avctx->height);
 209         return AVERROR_INVALIDDATA;
 210     }
 211     if (ctx->cursor_w < 1 || ctx->cursor_w > 256 ||
 212         ctx->cursor_h < 1 || ctx->cursor_h > 256) {
 213         av_log(avctx, AV_LOG_ERROR,
 214                "Invalid cursor dimensions %dx%d.\n",
 215                ctx->cursor_w, ctx->cursor_h);
 216         return AVERROR_INVALIDDATA;
 217     }
 218     if (ctx->cursor_hot_x > ctx->cursor_w ||
 219         ctx->cursor_hot_y > ctx->cursor_h) {
 220         av_log(avctx, AV_LOG_WARNING, "Invalid hotspot position %d.%d.\n",
 221                ctx->cursor_hot_x, ctx->cursor_hot_y);
 222         ctx->cursor_hot_x = FFMIN(ctx->cursor_hot_x, ctx->cursor_w - 1);
 223         ctx->cursor_hot_y = FFMIN(ctx->cursor_hot_y, ctx->cursor_h - 1);
 224     }
 225
 226     ret = av_reallocp(&ctx->cursor, ctx->cursor_stride * ctx->cursor_h);
 227     if (ret < 0) {
 228         av_log(avctx, AV_LOG_ERROR, "Cannot allocate cursor buffer.\n");
 229         return ret;
 230     }
 231
 232     dst = ctx->cursor;
 233     /* here data is packed in BE */
 234     switch (cursor_fmt) {
 235     case CUR_FMT_MONO:
 236         for (j = 0; j < ctx->cursor_h; j++) {
 237             for (i = 0; i < ctx->cursor_w; i += 32) {
 238                 uint32_t bits = bytestream2_get_be32(&ctx->gbc);
 239                 for (k = 0; k < 32; k++) {
 240                     dst[0] = !!(bits & 0x80000000);
 241                     dst   += 4;
 242                     bits <<= 1;
 243                 }
 244             }
 245             dst += ctx->cursor_stride - ctx->cursor_w * 4;
 246         }
 247
 248         dst = ctx->cursor;
 249         for (j = 0; j < ctx->cursor_h; j++) {
 250             for (i = 0; i < ctx->cursor_w; i += 32) {
 251                 uint32_t bits = bytestream2_get_be32(&ctx->gbc);
 252                 for (k = 0; k < 32; k++) {
 253                     int mask_bit = !!(bits & 0x80000000);
 254                     switch (dst[0] * 2 + mask_bit) {
 255                     case 0:
 256                         dst[0] = 0xFF;
 257                         dst[1] = 0x00;
 258                         dst[2] = 0x00;
 259                         dst[3] = 0x00;
 260                         break;
 261                     case 1:
 262                         dst[0] = 0xFF;
 263                         dst[1] = 0xFF;
 264                         dst[2] = 0xFF;
 265                         dst[3] = 0xFF;
 266                         break;
 267                     default:
 268                         dst[0] = 0x00;
 269                         dst[1] = 0x00;
 270                         dst[2] = 0x00;
 271                         dst[3] = 0x00;
 272                     }
 273                     dst   += 4;
 274                     bits <<= 1;
 275                 }
 276             }
 277             dst += ctx->cursor_stride - ctx->cursor_w * 4;
 278         }
 279         break;
 280     case CUR_FMT_BGRA:
 281     case CUR_FMT_RGBA:
 282         /* Skip monochrome version of the cursor */
 283         bytestream2_skip(&ctx->gbc,
 284                          ctx->cursor_h * (FFALIGN(ctx->cursor_w, 32) >> 3));
 285         if (cursor_fmt & 8) { // RGBA -> ABGR
 286             for (j = 0; j < ctx->cursor_h; j++) {
 287                 for (i = 0; i < ctx->cursor_w; i++) {
 288                     int val = bytestream2_get_be32(&ctx->gbc);
 289                     *dst++ = val >> 24;
 290                     *dst++ = val >> 16;
 291                     *dst++ = val >>  8;
 292                     *dst++ = val >>  0;
 293                 }
 294                 dst += ctx->cursor_stride - ctx->cursor_w * 4;
 295             }
 296         } else { // BGRA -> ABGR
 297             for (j = 0; j < ctx->cursor_h; j++) {
 298                 for (i = 0; i < ctx->cursor_w; i++) {
 299                     int val = bytestream2_get_be32(&ctx->gbc);
 300                     *dst++ = val >>  0;
 301                     *dst++ = val >> 24;
 302                     *dst++ = val >> 16;
 303                     *dst++ = val >>  8;
 304                 }
 305                 dst += ctx->cursor_stride - ctx->cursor_w * 4;
 306             }
 307         }
 308         break;
 309     default:
 310         avpriv_request_sample(avctx, "Cursor format %08x", cursor_fmt);
 311         return AVERROR_PATCHWELCOME;
 312     }
 313
 314     return 0;
 315 }
 316
 317 /* Convert a single YUV pixel to RGB. */
 318 static inline void tdsc_yuv2rgb(uint8_t *out, int Y, int U, int V)
 319 {
 320     out[0] = av_clip_uint8(Y + (             91881 * V + 32768 >> 16));
 321     out[1] = av_clip_uint8(Y + (-22554 * U - 46802 * V + 32768 >> 16));
 322     out[2] = av_clip_uint8(Y + (116130 * U             + 32768 >> 16));
 323 }
 324
 325 /* Convert a YUV420 buffer to a RGB buffer. */
 326 static av_always_inline void tdsc_blit(uint8_t *dst, int dst_stride,
 327                                        const uint8_t *srcy, int srcy_stride,
 328                                        const uint8_t *srcu, const uint8_t *srcv,
 329                                        int srcuv_stride, int width, int height)
 330 {
 331     int col, line;
 332     for (line = 0; line < height; line++) {
 333         for (col = 0; col < width; col++)
 334             tdsc_yuv2rgb(dst + col * 3, srcy[col],
 335                          srcu[col >> 1] - 128, srcv[col >> 1] - 128);
 336
 337         dst  +=   dst_stride;
 338         srcy +=  srcy_stride;
 339         srcu += srcuv_stride * (line & 1);
 340         srcv += srcuv_stride * (line & 1);
 341     }
 342 }
 343
 344 /* Invoke the MJPEG decoder to decode the tile. */
 345 static int tdsc_decode_jpeg_tile(AVCodecContext *avctx, int tile_size,
 346                                  int x, int y, int w, int h)
 347 {
 348     TDSCContext *ctx = avctx->priv_data;
 349     int ret;
 350
 351     /* Prepare a packet and send to the MJPEG decoder */
 352     av_packet_unref(ctx->jpkt);
 353     ctx->jpkt->data = ctx->tilebuffer;
 354     ctx->jpkt->size = tile_size;
 355
 356     ret = avcodec_send_packet(ctx->jpeg_avctx, ctx->jpkt);
 357     if (ret < 0) {
 358         av_log(avctx, AV_LOG_ERROR, "Error submitting a packet for decoding\n");
 359         return ret;
 360     }
 361
 362     ret = avcodec_receive_frame(ctx->jpeg_avctx, ctx->jpgframe);
 363     if (ret < 0 || ctx->jpgframe->format != AV_PIX_FMT_YUVJ420P) {
 364         av_log(avctx, AV_LOG_ERROR,
 365                "JPEG decoding error (%d).\n", ret);
 366
 367         /* Normally skip, error if explode */
 368         if (avctx->err_recognition & AV_EF_EXPLODE)
 369             return AVERROR_INVALIDDATA;
 370         else
 371             return 0;
 372     }
 373
 374     /* Let's paint onto the buffer */
 375     tdsc_blit(ctx->refframe->data[0] + x * 3 + ctx->refframe->linesize[0] * y,
 376               ctx->refframe->linesize[0],
 377               ctx->jpgframe->data[0], ctx->jpgframe->linesize[0],
 378               ctx->jpgframe->data[1], ctx->jpgframe->data[2],
 379               ctx->jpgframe->linesize[1], w, h);
 380
 381     av_frame_unref(ctx->jpgframe);
 382
 383     return 0;
 384 }
 385
 386 /* Parse frame and either copy data or decode JPEG. */
 387 static int tdsc_decode_tiles(AVCodecContext *avctx, int number_tiles)
 388 {
 389     TDSCContext *ctx = avctx->priv_data;
 390     int i;
 391
 392     /* Iterate over the number of tiles */
 393     for (i = 0; i < number_tiles; i++) {
 394         int tile_size;
 395         int tile_mode;
 396         int x, y, x2, y2, w, h;
 397         int ret;
 398
 399         if (bytestream2_get_bytes_left(&ctx->gbc) < 4 ||
 400             bytestream2_get_le32(&ctx->gbc) != MKTAG('T','D','S','B') ||
 401             bytestream2_get_bytes_left(&ctx->gbc) < TDSB_HEADER_SIZE - 4) {
 402             av_log(avctx, AV_LOG_ERROR, "TDSB tag is too small.\n");
 403             return AVERROR_INVALIDDATA;
 404         }
 405
 406         tile_size = bytestream2_get_le32(&ctx->gbc);
 407         if (bytestream2_get_bytes_left(&ctx->gbc) < tile_size)
 408             return AVERROR_INVALIDDATA;
 409
 410         tile_mode = bytestream2_get_le32(&ctx->gbc);
 411         bytestream2_skip(&ctx->gbc, 4); // unknown
 412         x = bytestream2_get_le32(&ctx->gbc);
 413         y = bytestream2_get_le32(&ctx->gbc);
 414         x2 = bytestream2_get_le32(&ctx->gbc);
 415         y2 = bytestream2_get_le32(&ctx->gbc);
 416
 417         if (x < 0 || y < 0 || x2 <= x || y2 <= y ||
 418             x2 > ctx->width || y2 > ctx->height
 419         ) {
 420             av_log(avctx, AV_LOG_ERROR,
 421                    "Invalid tile position (%d.%d %d.%d outside %dx%d).\n",
 422                    x, y, x2, y2, ctx->width, ctx->height);
 423             return AVERROR_INVALIDDATA;
 424         }
 425         w = x2 - x;
 426         h = y2 - y;
 427
 428         ret = av_reallocp(&ctx->tilebuffer, tile_size);
 429         if (!ctx->tilebuffer)
 430             return ret;
 431
 432         bytestream2_get_buffer(&ctx->gbc, ctx->tilebuffer, tile_size);
 433
 434         if (tile_mode == MKTAG('G','E','P','J')) {
 435             /* Decode JPEG tile and copy it in the reference frame */
 436             ret = tdsc_decode_jpeg_tile(avctx, tile_size, x, y, w, h);
 437             if (ret < 0)
 438                 return ret;
 439         } else if (tile_mode == MKTAG(' ','W','A','R')) {
 440             /* Just copy the buffer to output */
 441             av_image_copy_plane(ctx->refframe->data[0] + x * 3 +
 442                                 ctx->refframe->linesize[0] * y,
 443                                 ctx->refframe->linesize[0], ctx->tilebuffer,
 444                                 w * 3, w * 3, h);
 445         } else {
 446             av_log(avctx, AV_LOG_ERROR, "Unknown tile type %08x.\n", tile_mode);
 447             return AVERROR_INVALIDDATA;
 448         }
 449         av_log(avctx, AV_LOG_DEBUG, "Tile %d, %dx%d (%d.%d)\n", i, w, h, x, y);
 450     }
 451
 452     return 0;
 453 }
 454
 455 static int tdsc_parse_tdsf(AVCodecContext *avctx, int number_tiles)
 456 {
 457     TDSCContext *ctx = avctx->priv_data;
 458     int ret, w, h, init_refframe = !ctx->refframe->data[0];
 459
 460     /* BITMAPINFOHEADER
 461      * http://msdn.microsoft.com/en-us/library/windows/desktop/dd183376.aspx */
 462     if (bytestream2_get_le32(&ctx->gbc) != BITMAPINFOHEADER_SIZE)
 463         return AVERROR_INVALIDDATA;
 464
 465     /* Store size, but wait for context reinit before updating avctx */
 466     w =  bytestream2_get_le32(&ctx->gbc);
 467     h = -bytestream2_get_le32(&ctx->gbc);
 468
 469     if (bytestream2_get_le16(&ctx->gbc) != 1 ||  // 1 plane
 470         bytestream2_get_le16(&ctx->gbc) != 24)   // BGR24
 471         return AVERROR_INVALIDDATA;
 472
 473     bytestream2_skip(&ctx->gbc, 24); // unused fields
 474
 475     /* Update sizes */
 476     if (avctx->width != w || avctx->height != h) {
 477         av_log(avctx, AV_LOG_DEBUG, "Size update %dx%d -> %d%d.\n",
 478                avctx->width, avctx->height, ctx->width, ctx->height);
 479         ret = ff_set_dimensions(avctx, w, h);
 480         if (ret < 0)
 481             return ret;
 482         init_refframe = 1;
 483     }
 484     ctx->refframe->width  = ctx->width  = w;
 485     ctx->refframe->height = ctx->height = h;
 486
 487     /* Allocate the reference frame if not already done or on size change */
 488     if (init_refframe) {
 489         ret = av_frame_get_buffer(ctx->refframe, 0);
 490         if (ret < 0)
 491             return ret;
 492     }
 493
 494     /* Decode all tiles in a frame */
 495     return tdsc_decode_tiles(avctx, number_tiles);
 496 }
 497
 498 static int tdsc_parse_dtsm(AVCodecContext *avctx)
 499 {
 500     TDSCContext *ctx = avctx->priv_data;
 501     int ret;
 502     int action = bytestream2_get_le32(&ctx->gbc);
 503
 504     bytestream2_skip(&ctx->gbc, 4); // some kind of ID or version maybe?
 505
 506     if (action == 2 || action == 3) {
 507         /* Load cursor coordinates */
 508         ctx->cursor_x = bytestream2_get_le32(&ctx->gbc);
 509         ctx->cursor_y = bytestream2_get_le32(&ctx->gbc);
 510
 511         /* Load a full cursor sprite */
 512         if (action == 3) {
 513             ret = tdsc_load_cursor(avctx);
 514             /* Do not consider cursor errors fatal unless in explode mode */
 515             if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
 516                 return ret;
 517         }
 518     } else {
 519         avpriv_request_sample(avctx, "Cursor action %d", action);
 520     }
 521
 522     return 0;
 523 }
 524
 525 static int tdsc_decode_frame(AVCodecContext *avctx, AVFrame *frame,
 526                              int *got_frame, AVPacket *avpkt)
 527 {
 528     TDSCContext *ctx = avctx->priv_data;
 529     int ret, tag_header, keyframe = 0;
 530     uLongf dlen;
 531
 532     /* Resize deflate buffer on resolution change */
 533     if (ctx->width != avctx->width || ctx->height != avctx->height) {
 534         int deflatelen = avctx->width * avctx->height * (3 + 1);
 535         if (deflatelen != ctx->deflatelen) {
 536             ctx->deflatelen =deflatelen;
 537             ret = av_reallocp(&ctx->deflatebuffer, ctx->deflatelen);
 538             if (ret < 0) {
 539                 ctx->deflatelen = 0;
 540                 return ret;
 541             }
 542         }
 543     }
 544     dlen = ctx->deflatelen;
 545
 546     /* Frames are deflated, need to inflate them first */
 547     ret = uncompress(ctx->deflatebuffer, &dlen, avpkt->data, avpkt->size);
 548     if (ret) {
 549         av_log(avctx, AV_LOG_ERROR, "Deflate error %d.\n", ret);
 550         return AVERROR_UNKNOWN;
 551     }
 552
 553     bytestream2_init(&ctx->gbc, ctx->deflatebuffer, dlen);
 554
 555     /* Check for tag and for size info */
 556     if (bytestream2_get_bytes_left(&ctx->gbc) < 4 + 4) {
 557         av_log(avctx, AV_LOG_ERROR, "Frame is too small.\n");
 558         return AVERROR_INVALIDDATA;
 559     }
 560
 561     /* Read tag */
 562     tag_header = bytestream2_get_le32(&ctx->gbc);
 563
 564     if (tag_header == MKTAG('T','D','S','F')) {
 565         int number_tiles;
 566         if (bytestream2_get_bytes_left(&ctx->gbc) < TDSF_HEADER_SIZE) {
 567             av_log(avctx, AV_LOG_ERROR, "TDSF tag is too small.\n");
 568             return AVERROR_INVALIDDATA;
 569         }
 570         /* First 4 bytes here are the number of GEPJ/WAR tiles in this frame */
 571         number_tiles = bytestream2_get_le32(&ctx->gbc);
 572
 573         bytestream2_skip(&ctx->gbc, 4); // internal timestamp maybe?
 574         keyframe = bytestream2_get_le32(&ctx->gbc) == 0x30;
 575
 576         ret = tdsc_parse_tdsf(avctx, number_tiles);
 577         if (ret < 0)
 578             return ret;
 579
 580         /* Check if there is anything else we are able to parse */
 581         if (bytestream2_get_bytes_left(&ctx->gbc) >= 4 + 4)
 582             tag_header = bytestream2_get_le32(&ctx->gbc);
 583     }
 584
 585     /* This tag can be after a TDSF block or on its own frame */
 586     if (tag_header == MKTAG('D','T','S','M')) {
 587         /* First 4 bytes here are the total size in bytes for this frame */
 588         int tag_size = bytestream2_get_le32(&ctx->gbc);
 589
 590         if (bytestream2_get_bytes_left(&ctx->gbc) < tag_size) {
 591             av_log(avctx, AV_LOG_ERROR, "DTSM tag is too small.\n");
 592             return AVERROR_INVALIDDATA;
 593         }
 594
 595         ret = tdsc_parse_dtsm(avctx);
 596         if (ret < 0)
 597             return ret;
 598     }
 599
 600     /* Get the output frame and copy the reference frame */
 601     ret = ff_get_buffer(avctx, frame, 0);
 602     if (ret < 0)
 603         return ret;
 604
 605     ret = av_frame_copy(frame, ctx->refframe);
 606     if (ret < 0)
 607         return ret;
 608
 609     /* Paint the cursor on the output frame */
 610     tdsc_paint_cursor(avctx, frame->data[0], frame->linesize[0]);
 611
 612     /* Frame is ready to be output */
 613     if (keyframe) {
 614         frame->pict_type = AV_PICTURE_TYPE_I;
 615         frame->flags |= AV_FRAME_FLAG_KEY;
 616     } else {
 617         frame->pict_type = AV_PICTURE_TYPE_P;
 618     }
 619     *got_frame = 1;
 620
 621     return avpkt->size;
 622 }
 623
 624 const FFCodec ff_tdsc_decoder = {
 625     .p.name         = "tdsc",
 626     CODEC_LONG_NAME("TDSC"),
 627     .p.type         = AVMEDIA_TYPE_VIDEO,
 628     .p.id           = AV_CODEC_ID_TDSC,
 629     .init           = tdsc_init,
 630     FF_CODEC_DECODE_CB(tdsc_decode_frame),
 631     .close          = tdsc_close,
 632     .priv_data_size = sizeof(TDSCContext),
 633     .p.capabilities = AV_CODEC_CAP_DR1,
 634     .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
 635 };