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xl.c
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1 /*
2  * Miro VideoXL codec
3  * Copyright (c) 2004 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  * Miro VideoXL codec.
25  */
26 
27 #include "libavutil/common.h"
28 #include "libavutil/intreadwrite.h"
29 #include "avcodec.h"
30 #include "internal.h"
31 
32 typedef struct VideoXLContext{
36 
37 static const int xl_table[32] = {
38  0, 1, 2, 3, 4, 5, 6, 7,
39  8, 9, 12, 15, 20, 25, 34, 46,
40  64, 82, 94, 103, 108, 113, 116, 119,
41  120, 121, 122, 123, 124, 125, 126, 127
42 };
43 
44 static int decode_frame(AVCodecContext *avctx,
45  void *data, int *got_frame,
46  AVPacket *avpkt)
47 {
48  const uint8_t *buf = avpkt->data;
49  int buf_size = avpkt->size;
50  VideoXLContext * const a = avctx->priv_data;
51  AVFrame * const p = &a->pic;
52  uint8_t *Y, *U, *V;
53  int i, j, ret;
54  int stride;
55  uint32_t val;
56  int y0, y1, y2, y3 = 0, c0 = 0, c1 = 0;
57 
58  if (avctx->width & 3) {
59  av_log(avctx, AV_LOG_ERROR, "width is not a multiple of 4\n");
60  return AVERROR_INVALIDDATA;
61  }
62 
63  if (buf_size < avctx->width * avctx->height) {
64  av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
65  return AVERROR_INVALIDDATA;
66  }
67 
68  if (p->data[0])
69  avctx->release_buffer(avctx, p);
70 
71  p->reference = 0;
72  if ((ret = ff_get_buffer(avctx, p)) < 0){
73  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
74  return ret;
75  }
77  p->key_frame = 1;
78 
79  Y = a->pic.data[0];
80  U = a->pic.data[1];
81  V = a->pic.data[2];
82 
83  stride = avctx->width - 4;
84 
85  for (i = 0; i < avctx->height; i++) {
86  /* lines are stored in reversed order */
87  buf += stride;
88 
89  for (j = 0; j < avctx->width; j += 4) {
90  /* value is stored in LE dword with word swapped */
91  val = AV_RL32(buf);
92  buf -= 4;
93  val = ((val >> 16) & 0xFFFF) | ((val & 0xFFFF) << 16);
94 
95  if(!j)
96  y0 = (val & 0x1F) << 2;
97  else
98  y0 = y3 + xl_table[val & 0x1F];
99  val >>= 5;
100  y1 = y0 + xl_table[val & 0x1F];
101  val >>= 5;
102  y2 = y1 + xl_table[val & 0x1F];
103  val >>= 6; /* align to word */
104  y3 = y2 + xl_table[val & 0x1F];
105  val >>= 5;
106  if(!j)
107  c0 = (val & 0x1F) << 2;
108  else
109  c0 += xl_table[val & 0x1F];
110  val >>= 5;
111  if(!j)
112  c1 = (val & 0x1F) << 2;
113  else
114  c1 += xl_table[val & 0x1F];
115 
116  Y[j + 0] = y0 << 1;
117  Y[j + 1] = y1 << 1;
118  Y[j + 2] = y2 << 1;
119  Y[j + 3] = y3 << 1;
120 
121  U[j >> 2] = c0 << 1;
122  V[j >> 2] = c1 << 1;
123  }
124 
125  buf += avctx->width + 4;
126  Y += a->pic.linesize[0];
127  U += a->pic.linesize[1];
128  V += a->pic.linesize[2];
129  }
130 
131  *got_frame = 1;
132  *(AVFrame*)data = a->pic;
133 
134  return buf_size;
135 }
136 
138 {
139  VideoXLContext * const a = avctx->priv_data;
140 
142  avctx->pix_fmt = AV_PIX_FMT_YUV411P;
143 
144  return 0;
145 }
146 
148 {
149  VideoXLContext * const a = avctx->priv_data;
150  AVFrame *pic = &a->pic;
151 
152  if (pic->data[0])
153  avctx->release_buffer(avctx, pic);
154 
155  return 0;
156 }
157 
159  .name = "xl",
160  .type = AVMEDIA_TYPE_VIDEO,
161  .id = AV_CODEC_ID_VIXL,
162  .priv_data_size = sizeof(VideoXLContext),
163  .init = decode_init,
164  .close = decode_end,
165  .decode = decode_frame,
166  .capabilities = CODEC_CAP_DR1,
167  .long_name = NULL_IF_CONFIG_SMALL("Miro VideoXL"),
168 };