Subversion Repositories Kolibri OS

Rev

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

  1. /*
  2.  * Winnov WNV1 codec
  3.  * Copyright (c) 2005 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.  * Winnov WNV1 codec.
  25.  */
  26.  
  27. #include "avcodec.h"
  28. #include "get_bits.h"
  29. #include "internal.h"
  30. #include "mathops.h"
  31.  
  32.  
  33. typedef struct WNV1Context {
  34.     int shift;
  35.     GetBitContext gb;
  36. } WNV1Context;
  37.  
  38. static const uint16_t code_tab[16][2] = {
  39.     { 0x1FD, 9 }, { 0xFD, 8 }, { 0x7D, 7 }, { 0x3D, 6 }, { 0x1D, 5 }, { 0x0D, 4 }, { 0x005, 3 },
  40.     { 0x000, 1 },
  41.     { 0x004, 3 }, { 0x0C, 4 }, { 0x1C, 5 }, { 0x3C, 6 }, { 0x7C, 7 }, { 0xFC, 8 }, { 0x1FC, 9 }, { 0xFF, 8 }
  42. };
  43.  
  44. #define CODE_VLC_BITS 9
  45. static VLC code_vlc;
  46.  
  47. /* returns modified base_value */
  48. static inline int wnv1_get_code(WNV1Context *w, int base_value)
  49. {
  50.     int v = get_vlc2(&w->gb, code_vlc.table, CODE_VLC_BITS, 1);
  51.  
  52.     if (v == 15)
  53.         return ff_reverse[get_bits(&w->gb, 8 - w->shift)];
  54.     else
  55.         return base_value + ((v - 7) << w->shift);
  56. }
  57.  
  58. static int decode_frame(AVCodecContext *avctx,
  59.                         void *data, int *got_frame,
  60.                         AVPacket *avpkt)
  61. {
  62.     WNV1Context * const l = avctx->priv_data;
  63.     const uint8_t *buf    = avpkt->data;
  64.     int buf_size          = avpkt->size;
  65.     AVFrame * const p     = data;
  66.     unsigned char *Y,*U,*V;
  67.     int i, j, ret;
  68.     int prev_y = 0, prev_u = 0, prev_v = 0;
  69.     uint8_t *rbuf;
  70.  
  71.     if (buf_size <= 8) {
  72.         av_log(avctx, AV_LOG_ERROR, "Packet size %d is too small\n", buf_size);
  73.         return AVERROR_INVALIDDATA;
  74.     }
  75.  
  76.     rbuf = av_malloc(buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
  77.     if (!rbuf) {
  78.         av_log(avctx, AV_LOG_ERROR, "Cannot allocate temporary buffer\n");
  79.         return AVERROR(ENOMEM);
  80.     }
  81.  
  82.     if ((ret = ff_get_buffer(avctx, p, 0)) < 0) {
  83.         av_free(rbuf);
  84.         return ret;
  85.     }
  86.     p->key_frame = 1;
  87.  
  88.     for (i = 8; i < buf_size; i++)
  89.         rbuf[i] = ff_reverse[buf[i]];
  90.     init_get_bits(&l->gb, rbuf + 8, (buf_size - 8) * 8);
  91.  
  92.     if (buf[2] >> 4 == 6)
  93.         l->shift = 2;
  94.     else {
  95.         l->shift = 8 - (buf[2] >> 4);
  96.         if (l->shift > 4) {
  97.             avpriv_request_sample(avctx,
  98.                                   "Unknown WNV1 frame header value %i",
  99.                                   buf[2] >> 4);
  100.             l->shift = 4;
  101.         }
  102.         if (l->shift < 1) {
  103.             avpriv_request_sample(avctx,
  104.                                   "Unknown WNV1 frame header value %i",
  105.                                   buf[2] >> 4);
  106.             l->shift = 1;
  107.         }
  108.     }
  109.  
  110.     Y = p->data[0];
  111.     U = p->data[1];
  112.     V = p->data[2];
  113.     for (j = 0; j < avctx->height; j++) {
  114.         for (i = 0; i < avctx->width / 2; i++) {
  115.             Y[i * 2] = wnv1_get_code(l, prev_y);
  116.             prev_u = U[i] = wnv1_get_code(l, prev_u);
  117.             prev_y = Y[(i * 2) + 1] = wnv1_get_code(l, Y[i * 2]);
  118.             prev_v = V[i] = wnv1_get_code(l, prev_v);
  119.         }
  120.         Y += p->linesize[0];
  121.         U += p->linesize[1];
  122.         V += p->linesize[2];
  123.     }
  124.  
  125.  
  126.     *got_frame      = 1;
  127.     av_free(rbuf);
  128.  
  129.     return buf_size;
  130. }
  131.  
  132. static av_cold int decode_init(AVCodecContext *avctx)
  133. {
  134.     static VLC_TYPE code_table[1 << CODE_VLC_BITS][2];
  135.  
  136.     avctx->pix_fmt = AV_PIX_FMT_YUV422P;
  137.  
  138.     code_vlc.table           = code_table;
  139.     code_vlc.table_allocated = 1 << CODE_VLC_BITS;
  140.     init_vlc(&code_vlc, CODE_VLC_BITS, 16,
  141.              &code_tab[0][1], 4, 2,
  142.              &code_tab[0][0], 4, 2, INIT_VLC_USE_NEW_STATIC);
  143.  
  144.     return 0;
  145. }
  146.  
  147. AVCodec ff_wnv1_decoder = {
  148.     .name           = "wnv1",
  149.     .long_name      = NULL_IF_CONFIG_SMALL("Winnov WNV1"),
  150.     .type           = AVMEDIA_TYPE_VIDEO,
  151.     .id             = AV_CODEC_ID_WNV1,
  152.     .priv_data_size = sizeof(WNV1Context),
  153.     .init           = decode_init,
  154.     .decode         = decode_frame,
  155.     .capabilities   = CODEC_CAP_DR1,
  156. };
  157.