ffmpeg/libavcodec/qpeg.c

   1 /*
   2  * QPEG codec
   3  * Copyright (c) 2004 Konstantin Shishkov
   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  * QPEG codec.
  25  */
  26
  27 #include "avcodec.h"
  28 #include "bytestream.h"
  29 #include "internal.h"
  30
  31 typedef struct QpegContext{
  32     AVCodecContext *avctx;
  33     AVFrame *pic, *ref;
  34     uint32_t pal[256];
  35     GetByteContext buffer;
  36 } QpegContext;
  37
  38 static void qpeg_decode_intra(QpegContext *qctx, uint8_t *dst,
  39                               int stride, int width, int height)
  40 {
  41     int i;
  42     int code;
  43     int c0, c1;
  44     int run, copy;
  45     int filled = 0;
  46     int rows_to_go;
  47
  48     rows_to_go = height;
  49     height--;
  50     dst = dst + height * stride;
  51
  52     while ((bytestream2_get_bytes_left(&qctx->buffer) > 0) && (rows_to_go > 0)) {
  53         code = bytestream2_get_byte(&qctx->buffer);
  54         run = copy = 0;
  55         if(code == 0xFC) /* end-of-picture code */
  56             break;
  57         if(code >= 0xF8) { /* very long run */
  58             c0 = bytestream2_get_byte(&qctx->buffer);
  59             c1 = bytestream2_get_byte(&qctx->buffer);
  60             run = ((code & 0x7) << 16) + (c0 << 8) + c1 + 2;
  61         } else if (code >= 0xF0) { /* long run */
  62             c0 = bytestream2_get_byte(&qctx->buffer);
  63             run = ((code & 0xF) << 8) + c0 + 2;
  64         } else if (code >= 0xE0) { /* short run */
  65             run = (code & 0x1F) + 2;
  66         } else if (code >= 0xC0) { /* very long copy */
  67             c0 = bytestream2_get_byte(&qctx->buffer);
  68             c1 = bytestream2_get_byte(&qctx->buffer);
  69             copy = ((code & 0x3F) << 16) + (c0 << 8) + c1 + 1;
  70         } else if (code >= 0x80) { /* long copy */
  71             c0 = bytestream2_get_byte(&qctx->buffer);
  72             copy = ((code & 0x7F) << 8) + c0 + 1;
  73         } else { /* short copy */
  74             copy = code + 1;
  75         }
  76
  77         /* perform actual run or copy */
  78         if(run) {
  79             int p;
  80
  81             p = bytestream2_get_byte(&qctx->buffer);
  82             for(i = 0; i < run; i++) {
  83                 dst[filled++] = p;
  84                 if (filled >= width) {
  85                     filled = 0;
  86                     dst -= stride;
  87                     rows_to_go--;
  88                     if(rows_to_go <= 0)
  89                         break;
  90                 }
  91             }
  92         } else {
  93             for(i = 0; i < copy; i++) {
  94                 dst[filled++] = bytestream2_get_byte(&qctx->buffer);
  95                 if (filled >= width) {
  96                     filled = 0;
  97                     dst -= stride;
  98                     rows_to_go--;
  99                     if(rows_to_go <= 0)
 100                         break;
 101                 }
 102             }
 103         }
 104     }
 105 }
 106
 107 static const int qpeg_table_h[16] =
 108  { 0x00, 0x20, 0x20, 0x20, 0x18, 0x10, 0x10, 0x20, 0x10, 0x08, 0x18, 0x08, 0x08, 0x18, 0x10, 0x04};
 109 static const int qpeg_table_w[16] =
 110  { 0x00, 0x20, 0x18, 0x08, 0x18, 0x10, 0x20, 0x10, 0x08, 0x10, 0x20, 0x20, 0x08, 0x10, 0x18, 0x04};
 111
 112 /* Decodes delta frames */
 113 static void av_noinline qpeg_decode_inter(QpegContext *qctx, uint8_t *dst,
 114                               int stride, int width, int height,
 115                               int delta, const uint8_t *ctable,
 116                               uint8_t *refdata)
 117 {
 118     int i, j;
 119     int code;
 120     int filled = 0;
 121     int orig_height;
 122
 123     if(!refdata)
 124         refdata= dst;
 125
 126     /* copy prev frame */
 127     for(i = 0; i < height; i++)
 128         memcpy(dst + (i * stride), refdata + (i * stride), width);
 129
 130     orig_height = height;
 131     height--;
 132     dst = dst + height * stride;
 133
 134     while ((bytestream2_get_bytes_left(&qctx->buffer) > 0) && (height >= 0)) {
 135         code = bytestream2_get_byte(&qctx->buffer);
 136
 137         if(delta) {
 138             /* motion compensation */
 139             while(bytestream2_get_bytes_left(&qctx->buffer) > 0 && (code & 0xF0) == 0xF0) {
 140                 if(delta == 1) {
 141                     int me_idx;
 142                     int me_w, me_h, me_x, me_y;
 143                     uint8_t *me_plane;
 144                     int corr, val;
 145
 146                     /* get block size by index */
 147                     me_idx = code & 0xF;
 148                     me_w = qpeg_table_w[me_idx];
 149                     me_h = qpeg_table_h[me_idx];
 150
 151                     /* extract motion vector */
 152                     corr = bytestream2_get_byte(&qctx->buffer);
 153
 154                     val = corr >> 4;
 155                     if(val > 7)
 156                         val -= 16;
 157                     me_x = val;
 158
 159                     val = corr & 0xF;
 160                     if(val > 7)
 161                         val -= 16;
 162                     me_y = val;
 163
 164                     /* check motion vector */
 165                     if ((me_x + filled < 0) || (me_x + me_w + filled > width) ||
 166                        (height - me_y - me_h < 0) || (height - me_y >= orig_height) ||
 167                        (filled + me_w > width) || (height - me_h < 0))
 168                         av_log(NULL, AV_LOG_ERROR, "Bogus motion vector (%i,%i), block size %ix%i at %i,%i\n",
 169                                me_x, me_y, me_w, me_h, filled, height);
 170                     else {
 171                         /* do motion compensation */
 172                         me_plane = refdata + (filled + me_x) + (height - me_y) * stride;
 173                         for(j = 0; j < me_h; j++) {
 174                             for(i = 0; i < me_w; i++)
 175                                 dst[filled + i - (j * stride)] = me_plane[i - (j * stride)];
 176                         }
 177                     }
 178                 }
 179                 code = bytestream2_get_byte(&qctx->buffer);
 180             }
 181         }
 182
 183         if(code == 0xE0) /* end-of-picture code */
 184             break;
 185         if(code > 0xE0) { /* run code: 0xE1..0xFF */
 186             int p;
 187
 188             code &= 0x1F;
 189             p = bytestream2_get_byte(&qctx->buffer);
 190             for(i = 0; i <= code; i++) {
 191                 dst[filled++] = p;
 192                 if(filled >= width) {
 193                     filled = 0;
 194                     dst -= stride;
 195                     height--;
 196                     if (height < 0)
 197                         break;
 198                 }
 199             }
 200         } else if(code >= 0xC0) { /* copy code: 0xC0..0xDF */
 201             code &= 0x1F;
 202
 203             if(code + 1 > bytestream2_get_bytes_left(&qctx->buffer))
 204                 break;
 205
 206             for(i = 0; i <= code; i++) {
 207                 dst[filled++] = bytestream2_get_byte(&qctx->buffer);
 208                 if(filled >= width) {
 209                     filled = 0;
 210                     dst -= stride;
 211                     height--;
 212                     if (height < 0)
 213                         break;
 214                 }
 215             }
 216         } else if(code >= 0x80) { /* skip code: 0x80..0xBF */
 217             int skip;
 218
 219             code &= 0x3F;
 220             /* codes 0x80 and 0x81 are actually escape codes,
 221                skip value minus constant is in the next byte */
 222             if(!code)
 223                 skip = bytestream2_get_byte(&qctx->buffer) +  64;
 224             else if(code == 1)
 225                 skip = bytestream2_get_byte(&qctx->buffer) + 320;
 226             else
 227                 skip = code;
 228             filled += skip;
 229             while( filled >= width) {
 230                 filled -= width;
 231                 dst -= stride;
 232                 height--;
 233                 if(height < 0)
 234                     break;
 235             }
 236         } else {
 237             /* zero code treated as one-pixel skip */
 238             if(code) {
 239                 dst[filled++] = ctable[code & 0x7F];
 240             }
 241             else
 242                 filled++;
 243             if(filled >= width) {
 244                 filled = 0;
 245                 dst -= stride;
 246                 height--;
 247             }
 248         }
 249     }
 250 }
 251
 252 static int decode_frame(AVCodecContext *avctx,
 253                         void *data, int *got_frame,
 254                         AVPacket *avpkt)
 255 {
 256     uint8_t ctable[128];
 257     QpegContext * const a = avctx->priv_data;
 258     AVFrame * const p = a->pic;
 259     AVFrame * const ref = a->ref;
 260     uint8_t* outdata;
 261     int delta, ret;
 262     const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
 263
 264     if (avpkt->size < 0x86) {
 265         av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
 266         return AVERROR_INVALIDDATA;
 267     }
 268
 269     bytestream2_init(&a->buffer, avpkt->data, avpkt->size);
 270
 271     av_frame_unref(ref);
 272     av_frame_move_ref(ref, p);
 273
 274     if ((ret = ff_get_buffer(avctx, p, AV_GET_BUFFER_FLAG_REF)) < 0)
 275         return ret;
 276     outdata = p->data[0];
 277     bytestream2_skip(&a->buffer, 4);
 278     bytestream2_get_buffer(&a->buffer, ctable, 128);
 279     bytestream2_skip(&a->buffer, 1);
 280
 281     delta = bytestream2_get_byte(&a->buffer);
 282     if(delta == 0x10) {
 283         qpeg_decode_intra(a, outdata, p->linesize[0], avctx->width, avctx->height);
 284     } else {
 285         qpeg_decode_inter(a, outdata, p->linesize[0], avctx->width, avctx->height, delta, ctable, ref->data[0]);
 286     }
 287
 288     /* make the palette available on the way out */
 289     if (pal) {
 290         p->palette_has_changed = 1;
 291         memcpy(a->pal, pal, AVPALETTE_SIZE);
 292     }
 293     memcpy(p->data[1], a->pal, AVPALETTE_SIZE);
 294
 295     if ((ret = av_frame_ref(data, p)) < 0)
 296         return ret;
 297
 298     *got_frame      = 1;
 299
 300     return avpkt->size;
 301 }
 302
 303 static void decode_flush(AVCodecContext *avctx){
 304     QpegContext * const a = avctx->priv_data;
 305     int i, pal_size;
 306     const uint8_t *pal_src;
 307
 308     pal_size = FFMIN(1024U, avctx->extradata_size);
 309     pal_src = avctx->extradata + avctx->extradata_size - pal_size;
 310
 311     for (i=0; i<pal_size/4; i++)
 312         a->pal[i] = 0xFFU<<24 | AV_RL32(pal_src+4*i);
 313 }
 314
 315 static av_cold int decode_end(AVCodecContext *avctx)
 316 {
 317     QpegContext * const a = avctx->priv_data;
 318
 319     av_frame_free(&a->pic);
 320     av_frame_free(&a->ref);
 321
 322     return 0;
 323 }
 324
 325 static av_cold int decode_init(AVCodecContext *avctx){
 326     QpegContext * const a = avctx->priv_data;
 327
 328     a->avctx = avctx;
 329     avctx->pix_fmt= AV_PIX_FMT_PAL8;
 330
 331     decode_flush(avctx);
 332
 333     a->pic = av_frame_alloc();
 334     a->ref = av_frame_alloc();
 335     if (!a->pic || !a->ref) {
 336         decode_end(avctx);
 337         return AVERROR(ENOMEM);
 338     }
 339
 340     return 0;
 341 }
 342
 343 AVCodec ff_qpeg_decoder = {
 344     .name           = "qpeg",
 345     .long_name      = NULL_IF_CONFIG_SMALL("Q-team QPEG"),
 346     .type           = AVMEDIA_TYPE_VIDEO,
 347     .id             = AV_CODEC_ID_QPEG,
 348     .priv_data_size = sizeof(QpegContext),
 349     .init           = decode_init,
 350     .close          = decode_end,
 351     .decode         = decode_frame,
 352     .flush          = decode_flush,
 353     .capabilities   = CODEC_CAP_DR1,
 354 };