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/intreadwrite.h"
26 
28 {
29  avctx->pix_fmt = PIX_FMT_YUV420P;
31  if (!avctx->coded_frame)
32  return AVERROR(ENOMEM);
33 
34  return 0;
35 }
36 
37 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
38  AVPacket *avpkt)
39 {
40  int h, w;
41  AVFrame *pic = avctx->coded_frame;
42  const uint8_t *src = avpkt->data;
43  uint8_t *Y1, *Y2, *U, *V;
44  int ret;
45 
46  if (pic->data[0])
47  avctx->release_buffer(avctx, pic);
48 
49  if (avpkt->size < avctx->width * avctx->height * 3 / 2 + 16) {
50  av_log(avctx, AV_LOG_ERROR, "packet too small\n");
51  return AVERROR_INVALIDDATA;
52  }
53 
54  pic->reference = 0;
55  if ((ret = ff_get_buffer(avctx, pic)) < 0)
56  return ret;
57 
59  pic->key_frame = 1;
60 
61  if (AV_RL32(src) != 0x01000002) {
62  av_log_ask_for_sample(avctx, "Unknown frame header %X\n", AV_RL32(src));
63  return AVERROR_PATCHWELCOME;
64  }
65  src += 16;
66 
67  Y1 = pic->data[0];
68  Y2 = pic->data[0] + pic->linesize[0];
69  U = pic->data[1];
70  V = pic->data[2];
71  for (h = 0; h < avctx->height; h += 2) {
72  for (w = 0; w < avctx->width; w += 2) {
73  AV_WN16A(Y1 + w, AV_RN16A(src));
74  AV_WN16A(Y2 + w, AV_RN16A(src + 2));
75  U[w >> 1] = src[4] + 0x80;
76  V[w >> 1] = src[5] + 0x80;
77  src += 6;
78  }
79  Y1 += pic->linesize[0] << 1;
80  Y2 += pic->linesize[0] << 1;
81  U += pic->linesize[1];
82  V += pic->linesize[2];
83  }
84 
85  *data_size = sizeof(AVFrame);
86  *(AVFrame*)data = *pic;
87 
88  return avpkt->size;
89 }
90 
92 {
93  AVFrame *pic = avctx->coded_frame;
94  if (pic->data[0])
95  avctx->release_buffer(avctx, pic);
96  av_freep(&avctx->coded_frame);
97 
98  return 0;
99 }
100 
102  .name = "dxtory",
103  .long_name = NULL_IF_CONFIG_SMALL("Dxtory"),
104  .type = AVMEDIA_TYPE_VIDEO,
105  .id = CODEC_ID_DXTORY,
106  .init = decode_init,
107  .close = decode_close,
108  .decode = decode_frame,
109  .capabilities = CODEC_CAP_DR1,
110 };