Subversion Repositories Kolibri OS

Rev

Go to most recent revision | Blame | Last modification | View Log | RSS feed

  1. /*
  2.  * AVS video decoder.
  3.  * Copyright (c) 2006  Aurelien Jacobs <aurel@gnuage.org>
  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. #include "avcodec.h"
  23. #include "get_bits.h"
  24. #include "internal.h"
  25.  
  26.  
  27. typedef struct {
  28.     AVFrame picture;
  29. } AvsContext;
  30.  
  31. typedef enum {
  32.     AVS_VIDEO     = 0x01,
  33.     AVS_AUDIO     = 0x02,
  34.     AVS_PALETTE   = 0x03,
  35.     AVS_GAME_DATA = 0x04,
  36. } AvsBlockType;
  37.  
  38. typedef enum {
  39.     AVS_I_FRAME     = 0x00,
  40.     AVS_P_FRAME_3X3 = 0x01,
  41.     AVS_P_FRAME_2X2 = 0x02,
  42.     AVS_P_FRAME_2X3 = 0x03,
  43. } AvsVideoSubType;
  44.  
  45.  
  46. static int
  47. avs_decode_frame(AVCodecContext * avctx,
  48.                  void *data, int *got_frame, AVPacket *avpkt)
  49. {
  50.     const uint8_t *buf = avpkt->data;
  51.     const uint8_t *buf_end = avpkt->data + avpkt->size;
  52.     int buf_size = avpkt->size;
  53.     AvsContext *const avs = avctx->priv_data;
  54.     AVFrame *picture = data;
  55.     AVFrame *const p =  &avs->picture;
  56.     const uint8_t *table, *vect;
  57.     uint8_t *out;
  58.     int i, j, x, y, stride, ret, vect_w = 3, vect_h = 3;
  59.     AvsVideoSubType sub_type;
  60.     AvsBlockType type;
  61.     GetBitContext change_map = {0}; //init to silence warning
  62.  
  63.     if ((ret = ff_reget_buffer(avctx, p)) < 0)
  64.         return ret;
  65.     p->pict_type = AV_PICTURE_TYPE_P;
  66.     p->key_frame = 0;
  67.  
  68.     out = avs->picture.data[0];
  69.     stride = avs->picture.linesize[0];
  70.  
  71.     if (buf_end - buf < 4)
  72.         return AVERROR_INVALIDDATA;
  73.     sub_type = buf[0];
  74.     type = buf[1];
  75.     buf += 4;
  76.  
  77.     if (type == AVS_PALETTE) {
  78.         int first, last;
  79.         uint32_t *pal = (uint32_t *) avs->picture.data[1];
  80.  
  81.         first = AV_RL16(buf);
  82.         last = first + AV_RL16(buf + 2);
  83.         if (first >= 256 || last > 256 || buf_end - buf < 4 + 4 + 3 * (last - first))
  84.             return AVERROR_INVALIDDATA;
  85.         buf += 4;
  86.         for (i=first; i<last; i++, buf+=3) {
  87.             pal[i] = (buf[0] << 18) | (buf[1] << 10) | (buf[2] << 2);
  88.             pal[i] |= 0xFFU << 24 | (pal[i] >> 6) & 0x30303;
  89.         }
  90.  
  91.         sub_type = buf[0];
  92.         type = buf[1];
  93.         buf += 4;
  94.     }
  95.  
  96.     if (type != AVS_VIDEO)
  97.         return AVERROR_INVALIDDATA;
  98.  
  99.     switch (sub_type) {
  100.     case AVS_I_FRAME:
  101.         p->pict_type = AV_PICTURE_TYPE_I;
  102.         p->key_frame = 1;
  103.     case AVS_P_FRAME_3X3:
  104.         vect_w = 3;
  105.         vect_h = 3;
  106.         break;
  107.  
  108.     case AVS_P_FRAME_2X2:
  109.         vect_w = 2;
  110.         vect_h = 2;
  111.         break;
  112.  
  113.     case AVS_P_FRAME_2X3:
  114.         vect_w = 2;
  115.         vect_h = 3;
  116.         break;
  117.  
  118.     default:
  119.       return AVERROR_INVALIDDATA;
  120.     }
  121.  
  122.     if (buf_end - buf < 256 * vect_w * vect_h)
  123.         return AVERROR_INVALIDDATA;
  124.     table = buf + (256 * vect_w * vect_h);
  125.     if (sub_type != AVS_I_FRAME) {
  126.         int map_size = ((318 / vect_w + 7) / 8) * (198 / vect_h);
  127.         if (buf_end - table < map_size)
  128.             return AVERROR_INVALIDDATA;
  129.         init_get_bits(&change_map, table, map_size * 8);
  130.         table += map_size;
  131.     }
  132.  
  133.     for (y=0; y<198; y+=vect_h) {
  134.         for (x=0; x<318; x+=vect_w) {
  135.             if (sub_type == AVS_I_FRAME || get_bits1(&change_map)) {
  136.                 if (buf_end - table < 1)
  137.                     return AVERROR_INVALIDDATA;
  138.                 vect = &buf[*table++ * (vect_w * vect_h)];
  139.                 for (j=0; j<vect_w; j++) {
  140.                     out[(y + 0) * stride + x + j] = vect[(0 * vect_w) + j];
  141.                     out[(y + 1) * stride + x + j] = vect[(1 * vect_w) + j];
  142.                     if (vect_h == 3)
  143.                         out[(y + 2) * stride + x + j] =
  144.                             vect[(2 * vect_w) + j];
  145.                 }
  146.             }
  147.         }
  148.         if (sub_type != AVS_I_FRAME)
  149.             align_get_bits(&change_map);
  150.     }
  151.  
  152.     if ((ret = av_frame_ref(picture, &avs->picture)) < 0)
  153.         return ret;
  154.     *got_frame = 1;
  155.  
  156.     return buf_size;
  157. }
  158.  
  159. static av_cold int avs_decode_init(AVCodecContext * avctx)
  160. {
  161.     AvsContext *s = avctx->priv_data;
  162.     avctx->pix_fmt = AV_PIX_FMT_PAL8;
  163.     avcodec_set_dimensions(avctx, 318, 198);
  164.     avcodec_get_frame_defaults(&s->picture);
  165.     return 0;
  166. }
  167.  
  168. static av_cold int avs_decode_end(AVCodecContext *avctx)
  169. {
  170.     AvsContext *s = avctx->priv_data;
  171.     av_frame_unref(&s->picture);
  172.     return 0;
  173. }
  174.  
  175.  
  176. AVCodec ff_avs_decoder = {
  177.     .name           = "avs",
  178.     .long_name      = NULL_IF_CONFIG_SMALL("AVS (Audio Video Standard) video"),
  179.     .type           = AVMEDIA_TYPE_VIDEO,
  180.     .id             = AV_CODEC_ID_AVS,
  181.     .priv_data_size = sizeof(AvsContext),
  182.     .init           = avs_decode_init,
  183.     .decode         = avs_decode_frame,
  184.     .close          = avs_decode_end,
  185.     .capabilities   = CODEC_CAP_DR1,
  186. };
  187.