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 "codec_internal.h"
  30 #include "decode.h"
  31 #include "internal.h"
  32
  33 typedef struct QpegContext{
  34     AVCodecContext *avctx;
  35     AVFrame *ref;
  36     uint32_t pal[256];
  37     GetByteContext buffer;
  38 } QpegContext;
  39
  40 static void qpeg_decode_intra(QpegContext *qctx, uint8_t *dst,
  41                               int stride, int width, int height)
  42 {
  43     int i;
  44     int code;
  45     int c0, c1;
  46     int run, copy;
  47     int filled = 0;
  48     int rows_to_go;
  49
  50     rows_to_go = height;
  51     height--;
  52     dst = dst + height * stride;
  53
  54     while ((bytestream2_get_bytes_left(&qctx->buffer) > 0) && (rows_to_go > 0)) {
  55         code = bytestream2_get_byte(&qctx->buffer);
  56         run = copy = 0;
  57         if(code == 0xFC) /* end-of-picture code */
  58             break;
  59         if(code >= 0xF8) { /* very long run */
  60             c0 = bytestream2_get_byte(&qctx->buffer);
  61             c1 = bytestream2_get_byte(&qctx->buffer);
  62             run = ((code & 0x7) << 16) + (c0 << 8) + c1 + 2;
  63         } else if (code >= 0xF0) { /* long run */
  64             c0 = bytestream2_get_byte(&qctx->buffer);
  65             run = ((code & 0xF) << 8) + c0 + 2;
  66         } else if (code >= 0xE0) { /* short run */
  67             run = (code & 0x1F) + 2;
  68         } else if (code >= 0xC0) { /* very long copy */
  69             c0 = bytestream2_get_byte(&qctx->buffer);
  70             c1 = bytestream2_get_byte(&qctx->buffer);
  71             copy = ((code & 0x3F) << 16) + (c0 << 8) + c1 + 1;
  72         } else if (code >= 0x80) { /* long copy */
  73             c0 = bytestream2_get_byte(&qctx->buffer);
  74             copy = ((code & 0x7F) << 8) + c0 + 1;
  75         } else { /* short copy */
  76             copy = code + 1;
  77         }
  78
  79         /* perform actual run or copy */
  80         if(run) {
  81             int p;
  82
  83             p = bytestream2_get_byte(&qctx->buffer);
  84             for(i = 0; i < run; i++) {
  85                 int step = FFMIN(run - i, width - filled);
  86                 memset(dst+filled, p, step);
  87                 filled += step;
  88                 i      += step - 1;
  89                 if (filled >= width) {
  90                     filled = 0;
  91                     dst -= stride;
  92                     rows_to_go--;
  93                     while (run - i > width && rows_to_go > 0) {
  94                         memset(dst, p, width);
  95                         dst -= stride;
  96                         rows_to_go--;
  97                         i += width;
  98                     }
  99                     if(rows_to_go <= 0)
 100                         break;
 101                 }
 102             }
 103         } else {
 104             if (bytestream2_get_bytes_left(&qctx->buffer) < copy)
 105                 copy = bytestream2_get_bytes_left(&qctx->buffer);
 106             while (copy > 0) {
 107                 int step = FFMIN(copy, width - filled);
 108                 bytestream2_get_bufferu(&qctx->buffer, dst + filled, step);
 109                 filled += step;
 110                 copy -= step;
 111                 if (filled >= width) {
 112                     filled = 0;
 113                     dst -= stride;
 114                     rows_to_go--;
 115                     if(rows_to_go <= 0)
 116                         break;
 117                 }
 118             }
 119         }
 120     }
 121 }
 122
 123 static const uint8_t qpeg_table_h[16] =
 124  { 0x00, 0x20, 0x20, 0x20, 0x18, 0x10, 0x10, 0x20, 0x10, 0x08, 0x18, 0x08, 0x08, 0x18, 0x10, 0x04};
 125 static const uint8_t qpeg_table_w[16] =
 126  { 0x00, 0x20, 0x18, 0x08, 0x18, 0x10, 0x20, 0x10, 0x08, 0x10, 0x20, 0x20, 0x08, 0x10, 0x18, 0x04};
 127
 128 /* Decodes delta frames */
 129 static void av_noinline qpeg_decode_inter(QpegContext *qctx, uint8_t *dst,
 130                               int stride, int width, int height,
 131                               int delta, const uint8_t *ctable,
 132                               uint8_t *refdata)
 133 {
 134     int i, j;
 135     int code;
 136     int filled = 0;
 137     int orig_height;
 138
 139     if (refdata) {
 140         /* copy prev frame */
 141         for (i = 0; i < height; i++)
 142             memcpy(dst + (i * stride), refdata + (i * stride), width);
 143     } else {
 144         refdata = dst;
 145     }
 146
 147     orig_height = height;
 148     height--;
 149     dst = dst + height * stride;
 150
 151     while ((bytestream2_get_bytes_left(&qctx->buffer) > 0) && (height >= 0)) {
 152         code = bytestream2_get_byte(&qctx->buffer);
 153
 154         if(delta) {
 155             /* motion compensation */
 156             while(bytestream2_get_bytes_left(&qctx->buffer) > 0 && (code & 0xF0) == 0xF0) {
 157                 if(delta == 1) {
 158                     int me_idx;
 159                     int me_w, me_h, me_x, me_y;
 160                     uint8_t *me_plane;
 161                     int corr, val;
 162
 163                     /* get block size by index */
 164                     me_idx = code & 0xF;
 165                     me_w = qpeg_table_w[me_idx];
 166                     me_h = qpeg_table_h[me_idx];
 167
 168                     /* extract motion vector */
 169                     corr = bytestream2_get_byte(&qctx->buffer);
 170
 171                     val = corr >> 4;
 172                     if(val > 7)
 173                         val -= 16;
 174                     me_x = val;
 175
 176                     val = corr & 0xF;
 177                     if(val > 7)
 178                         val -= 16;
 179                     me_y = val;
 180
 181                     /* check motion vector */
 182                     if ((me_x + filled < 0) || (me_x + me_w + filled > width) ||
 183                        (height - me_y - me_h < 0) || (height - me_y >= orig_height) ||
 184                        (filled + me_w > width) || (height - me_h < 0))
 185                         av_log(qctx->avctx, AV_LOG_ERROR, "Bogus motion vector (%i,%i), block size %ix%i at %i,%i\n",
 186                                me_x, me_y, me_w, me_h, filled, height);
 187                     else {
 188                         /* do motion compensation */
 189                         me_plane = refdata + (filled + me_x) + (height - me_y) * stride;
 190                         for(j = 0; j < me_h; j++) {
 191                             for(i = 0; i < me_w; i++)
 192                                 dst[filled + i - (j * stride)] = me_plane[i - (j * stride)];
 193                         }
 194                     }
 195                 }
 196                 code = bytestream2_get_byte(&qctx->buffer);
 197             }
 198         }
 199
 200         if(code == 0xE0) /* end-of-picture code */
 201             break;
 202         if(code > 0xE0) { /* run code: 0xE1..0xFF */
 203             int p;
 204
 205             code &= 0x1F;
 206             p = bytestream2_get_byte(&qctx->buffer);
 207             for(i = 0; i <= code; i++) {
 208                 dst[filled++] = p;
 209                 if(filled >= width) {
 210                     filled = 0;
 211                     dst -= stride;
 212                     height--;
 213                     if (height < 0)
 214                         break;
 215                 }
 216             }
 217         } else if(code >= 0xC0) { /* copy code: 0xC0..0xDF */
 218             code &= 0x1F;
 219
 220             if(code + 1 > bytestream2_get_bytes_left(&qctx->buffer))
 221                 break;
 222
 223             for(i = 0; i <= code; i++) {
 224                 dst[filled++] = bytestream2_get_byte(&qctx->buffer);
 225                 if(filled >= width) {
 226                     filled = 0;
 227                     dst -= stride;
 228                     height--;
 229                     if (height < 0)
 230                         break;
 231                 }
 232             }
 233         } else if(code >= 0x80) { /* skip code: 0x80..0xBF */
 234             int skip;
 235
 236             code &= 0x3F;
 237             /* codes 0x80 and 0x81 are actually escape codes,
 238                skip value minus constant is in the next byte */
 239             if(!code)
 240                 skip = bytestream2_get_byte(&qctx->buffer) +  64;
 241             else if(code == 1)
 242                 skip = bytestream2_get_byte(&qctx->buffer) + 320;
 243             else
 244                 skip = code;
 245             filled += skip;
 246             while( filled >= width) {
 247                 filled -= width;
 248                 dst -= stride;
 249                 height--;
 250                 if(height < 0)
 251                     break;
 252             }
 253         } else {
 254             /* zero code treated as one-pixel skip */
 255             if(code) {
 256                 dst[filled++] = ctable[code & 0x7F];
 257             }
 258             else
 259                 filled++;
 260             if(filled >= width) {
 261                 filled = 0;
 262                 dst -= stride;
 263                 height--;
 264             }
 265         }
 266     }
 267 }
 268
 269 static int decode_frame(AVCodecContext *avctx, AVFrame *p,
 270                         int *got_frame, AVPacket *avpkt)
 271 {
 272     uint8_t ctable[128];
 273     QpegContext * const a = avctx->priv_data;
 274     AVFrame * const ref = a->ref;
 275     uint8_t* outdata;
 276     int delta, intra, ret;
 277
 278     if (avpkt->size < 0x86) {
 279         av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
 280         return AVERROR_INVALIDDATA;
 281     }
 282
 283     bytestream2_init(&a->buffer, avpkt->data, avpkt->size);
 284
 285     if ((ret = ff_get_buffer(avctx, p, AV_GET_BUFFER_FLAG_REF)) < 0)
 286         return ret;
 287     outdata = p->data[0];
 288     bytestream2_skip(&a->buffer, 4);
 289     bytestream2_get_buffer(&a->buffer, ctable, 128);
 290     bytestream2_skip(&a->buffer, 1);
 291
 292     delta = bytestream2_get_byte(&a->buffer);
 293     intra = delta == 0x10;
 294     if (intra) {
 295         qpeg_decode_intra(a, outdata, p->linesize[0], avctx->width, avctx->height);
 296     } else {
 297         qpeg_decode_inter(a, outdata, p->linesize[0], avctx->width, avctx->height, delta, ctable, ref->data[0]);
 298     }
 299
 300     /* make the palette available on the way out */
 301     p->palette_has_changed = ff_copy_palette(a->pal, avpkt, avctx);
 302     memcpy(p->data[1], a->pal, AVPALETTE_SIZE);
 303
 304     av_frame_unref(ref);
 305     if ((ret = av_frame_ref(ref, p)) < 0)
 306         return ret;
 307
 308     p->key_frame = intra;
 309     p->pict_type = intra ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
 310
 311     *got_frame      = 1;
 312
 313     return avpkt->size;
 314 }
 315
 316 static void decode_flush(AVCodecContext *avctx){
 317     QpegContext * const a = avctx->priv_data;
 318     int i, pal_size;
 319     const uint8_t *pal_src;
 320
 321     av_frame_unref(a->ref);
 322
 323     pal_size = FFMIN(1024U, avctx->extradata_size);
 324     pal_src = avctx->extradata + avctx->extradata_size - pal_size;
 325
 326     for (i=0; i<pal_size/4; i++)
 327         a->pal[i] = 0xFFU<<24 | AV_RL32(pal_src+4*i);
 328 }
 329
 330 static av_cold int decode_end(AVCodecContext *avctx)
 331 {
 332     QpegContext * const a = avctx->priv_data;
 333
 334     av_frame_free(&a->ref);
 335
 336     return 0;
 337 }
 338
 339 static av_cold int decode_init(AVCodecContext *avctx){
 340     QpegContext * const a = avctx->priv_data;
 341
 342     a->avctx = avctx;
 343     avctx->pix_fmt= AV_PIX_FMT_PAL8;
 344
 345     a->ref = av_frame_alloc();
 346     if (!a->ref)
 347         return AVERROR(ENOMEM);
 348
 349     decode_flush(avctx);
 350
 351     return 0;
 352 }
 353
 354 const FFCodec ff_qpeg_decoder = {
 355     .p.name         = "qpeg",
 356     .p.long_name    = NULL_IF_CONFIG_SMALL("Q-team QPEG"),
 357     .p.type         = AVMEDIA_TYPE_VIDEO,
 358     .p.id           = AV_CODEC_ID_QPEG,
 359     .priv_data_size = sizeof(QpegContext),
 360     .init           = decode_init,
 361     .close          = decode_end,
 362     FF_CODEC_DECODE_CB(decode_frame),
 363     .flush          = decode_flush,
 364     .p.capabilities = AV_CODEC_CAP_DR1,
 365     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE |
 366                       FF_CODEC_CAP_INIT_CLEANUP,
 367 };