LCOV - code coverage report
Current view: top level - libavcodec - wnv1.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 43 59 72.9 %
Date: 2017-12-15 11:05:35 Functions: 3 3 100.0 %

          Line data    Source code
       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     3302400 : static inline int wnv1_get_code(WNV1Context *w, int base_value)
      49             : {
      50     3302400 :     int v = get_vlc2(&w->gb, code_vlc.table, CODE_VLC_BITS, 1);
      51             : 
      52     3302400 :     if (v == 15)
      53       70676 :         return ff_reverse[get_bits(&w->gb, 8 - w->shift)];
      54             :     else
      55     3231724 :         return base_value + ((v - 7U) << w->shift);
      56             : }
      57             : 
      58          86 : static int decode_frame(AVCodecContext *avctx,
      59             :                         void *data, int *got_frame,
      60             :                         AVPacket *avpkt)
      61             : {
      62          86 :     WNV1Context * const l = avctx->priv_data;
      63          86 :     const uint8_t *buf    = avpkt->data;
      64          86 :     int buf_size          = avpkt->size;
      65          86 :     AVFrame * const p     = data;
      66             :     unsigned char *Y,*U,*V;
      67             :     int i, j, ret;
      68          86 :     int prev_y = 0, prev_u = 0, prev_v = 0;
      69             :     uint8_t *rbuf;
      70             : 
      71          86 :     if (buf_size < 8 + avctx->height * (avctx->width/2)/8) {
      72           0 :         av_log(avctx, AV_LOG_ERROR, "Packet size %d is too small\n", buf_size);
      73           0 :         return AVERROR_INVALIDDATA;
      74             :     }
      75             : 
      76          86 :     rbuf = av_malloc(buf_size + AV_INPUT_BUFFER_PADDING_SIZE);
      77          86 :     if (!rbuf) {
      78           0 :         av_log(avctx, AV_LOG_ERROR, "Cannot allocate temporary buffer\n");
      79           0 :         return AVERROR(ENOMEM);
      80             :     }
      81          86 :     memset(rbuf + buf_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
      82             : 
      83          86 :     if ((ret = ff_get_buffer(avctx, p, 0)) < 0) {
      84           0 :         av_free(rbuf);
      85           0 :         return ret;
      86             :     }
      87          86 :     p->key_frame = 1;
      88             : 
      89      872534 :     for (i = 8; i < buf_size; i++)
      90      872448 :         rbuf[i] = ff_reverse[buf[i]];
      91             : 
      92          86 :     if ((ret = init_get_bits8(&l->gb, rbuf + 8, buf_size - 8)) < 0)
      93           0 :         return ret;
      94             : 
      95          86 :     if (buf[2] >> 4 == 6)
      96          86 :         l->shift = 2;
      97             :     else {
      98           0 :         l->shift = 8 - (buf[2] >> 4);
      99           0 :         if (l->shift > 4) {
     100           0 :             avpriv_request_sample(avctx,
     101             :                                   "Unknown WNV1 frame header value %i",
     102           0 :                                   buf[2] >> 4);
     103           0 :             l->shift = 4;
     104             :         }
     105           0 :         if (l->shift < 1) {
     106           0 :             avpriv_request_sample(avctx,
     107             :                                   "Unknown WNV1 frame header value %i",
     108           0 :                                   buf[2] >> 4);
     109           0 :             l->shift = 1;
     110             :         }
     111             :     }
     112             : 
     113          86 :     Y = p->data[0];
     114          86 :     U = p->data[1];
     115          86 :     V = p->data[2];
     116       10406 :     for (j = 0; j < avctx->height; j++) {
     117      835920 :         for (i = 0; i < avctx->width / 2; i++) {
     118      825600 :             Y[i * 2] = wnv1_get_code(l, prev_y);
     119      825600 :             prev_u = U[i] = wnv1_get_code(l, prev_u);
     120      825600 :             prev_y = Y[(i * 2) + 1] = wnv1_get_code(l, Y[i * 2]);
     121      825600 :             prev_v = V[i] = wnv1_get_code(l, prev_v);
     122             :         }
     123       10320 :         Y += p->linesize[0];
     124       10320 :         U += p->linesize[1];
     125       10320 :         V += p->linesize[2];
     126             :     }
     127             : 
     128             : 
     129          86 :     *got_frame      = 1;
     130          86 :     av_free(rbuf);
     131             : 
     132          86 :     return buf_size;
     133             : }
     134             : 
     135           2 : static av_cold int decode_init(AVCodecContext *avctx)
     136             : {
     137             :     static VLC_TYPE code_table[1 << CODE_VLC_BITS][2];
     138             : 
     139           2 :     avctx->pix_fmt = AV_PIX_FMT_YUV422P;
     140             : 
     141           2 :     code_vlc.table           = code_table;
     142           2 :     code_vlc.table_allocated = 1 << CODE_VLC_BITS;
     143           2 :     init_vlc(&code_vlc, CODE_VLC_BITS, 16,
     144             :              &code_tab[0][1], 4, 2,
     145             :              &code_tab[0][0], 4, 2, INIT_VLC_USE_NEW_STATIC);
     146             : 
     147           2 :     return 0;
     148             : }
     149             : 
     150             : AVCodec ff_wnv1_decoder = {
     151             :     .name           = "wnv1",
     152             :     .long_name      = NULL_IF_CONFIG_SMALL("Winnov WNV1"),
     153             :     .type           = AVMEDIA_TYPE_VIDEO,
     154             :     .id             = AV_CODEC_ID_WNV1,
     155             :     .priv_data_size = sizeof(WNV1Context),
     156             :     .init           = decode_init,
     157             :     .decode         = decode_frame,
     158             :     .capabilities   = AV_CODEC_CAP_DR1,
     159             : };

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