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dxtory.c
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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 
29 {
30  avctx->pix_fmt = AV_PIX_FMT_YUV420P;
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 
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 
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 
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 };