libavcodec/dxtory.c

   1 /*
   2  * Dxtory decoder
   3  *
   4  * Copyright (c) 2011 Konstantin Shishkov
   5  *
   6  * This file is part of Libav.
   7  *
   8  * Libav is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * Libav is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with Libav; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #include "avcodec.h"
  24 #include "internal.h"
  25 #include "libavutil/common.h"
  26 #include "libavutil/intreadwrite.h"
  27
  28 static av_cold int decode_init(AVCodecContext *avctx)
  29 {
  30     avctx->pix_fmt     = AV_PIX_FMT_YUV420P;
  31     avctx->coded_frame = avcodec_alloc_frame();
  32     if (!avctx->coded_frame)
  33         return AVERROR(ENOMEM);
  34
  35     return 0;
  36 }
  37
  38 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
  39                         AVPacket *avpkt)
  40 {
  41     int h, w;
  42     AVFrame *pic = avctx->coded_frame;
  43     const uint8_t *src = avpkt->data;
  44     uint8_t *Y1, *Y2, *U, *V;
  45     int ret;
  46
  47     if (pic->data[0])
  48         avctx->release_buffer(avctx, pic);
  49
  50     if (avpkt->size < avctx->width * avctx->height * 3 / 2 + 16) {
  51         av_log(avctx, AV_LOG_ERROR, "packet too small\n");
  52         return AVERROR_INVALIDDATA;
  53     }
  54
  55     pic->reference = 0;
  56     if ((ret = ff_get_buffer(avctx, pic)) < 0)
  57         return ret;
  58
  59     pic->pict_type = AV_PICTURE_TYPE_I;
  60     pic->key_frame = 1;
  61
  62     if (AV_RL32(src) != 0x01000002) {
  63         av_log_ask_for_sample(avctx, "Unknown frame header %X\n", AV_RL32(src));
  64         return AVERROR_PATCHWELCOME;
  65     }
  66     src += 16;
  67
  68     Y1 = pic->data[0];
  69     Y2 = pic->data[0] + pic->linesize[0];
  70     U  = pic->data[1];
  71     V  = pic->data[2];
  72     for (h = 0; h < avctx->height; h += 2) {
  73         for (w = 0; w < avctx->width; w += 2) {
  74             AV_COPY16(Y1 + w, src);
  75             AV_COPY16(Y2 + w, src + 2);
  76             U[w >> 1] = src[4] + 0x80;
  77             V[w >> 1] = src[5] + 0x80;
  78             src += 6;
  79         }
  80         Y1 += pic->linesize[0] << 1;
  81         Y2 += pic->linesize[0] << 1;
  82         U  += pic->linesize[1];
  83         V  += pic->linesize[2];
  84     }
  85
  86     *got_frame = 1;
  87     *(AVFrame*)data = *pic;
  88
  89     return avpkt->size;
  90 }
  91
  92 static av_cold int decode_close(AVCodecContext *avctx)
  93 {
  94     AVFrame *pic = avctx->coded_frame;
  95     if (pic->data[0])
  96         avctx->release_buffer(avctx, pic);
  97     av_freep(&avctx->coded_frame);
  98
  99     return 0;
 100 }
 101
 102 AVCodec ff_dxtory_decoder = {
 103     .name           = "dxtory",
 104     .long_name      = NULL_IF_CONFIG_SMALL("Dxtory"),
 105     .type           = AVMEDIA_TYPE_VIDEO,
 106     .id             = AV_CODEC_ID_DXTORY,
 107     .init           = decode_init,
 108     .close          = decode_close,
 109     .decode         = decode_frame,
 110     .capabilities   = CODEC_CAP_DR1,
 111 };