xl.c
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1 /*
2  * Miro VideoXL codec
3  * Copyright (c) 2004 Konstantin Shishkov
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
27 #include "libavutil/common.h"
28 #include "libavutil/intreadwrite.h"
29 #include "avcodec.h"
30 #include "internal.h"
31 
32 typedef struct VideoXLContext{
33  AVCodecContext *avctx;
34  AVFrame pic;
35 } 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 static int decode_frame(AVCodecContext *avctx,
44  void *data, int *got_frame,
45  AVPacket *avpkt)
46 {
47  const uint8_t *buf = avpkt->data;
48  int buf_size = avpkt->size;
49  VideoXLContext * const a = avctx->priv_data;
50  AVFrame * const p = &a->pic;
51  uint8_t *Y, *U, *V;
52  int i, j;
53  int stride;
54  uint32_t val;
55  int y0, y1, y2, y3 = 0, c0 = 0, c1 = 0;
56 
57  if(p->data[0])
58  avctx->release_buffer(avctx, p);
59 
60  p->reference = 0;
61  if(ff_get_buffer(avctx, p) < 0){
62  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
63  return -1;
64  }
65  p->pict_type= AV_PICTURE_TYPE_I;
66  p->key_frame= 1;
67 
68  Y = a->pic.data[0];
69  U = a->pic.data[1];
70  V = a->pic.data[2];
71 
72  stride = avctx->width - 4;
73 
74  if (buf_size < avctx->width * avctx->height) {
75  av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
76  return AVERROR_INVALIDDATA;
77  }
78 
79  for (i = 0; i < avctx->height; i++) {
80  /* lines are stored in reversed order */
81  buf += stride;
82 
83  for (j = 0; j < avctx->width; j += 4) {
84  /* value is stored in LE dword with word swapped */
85  val = AV_RL32(buf);
86  buf -= 4;
87  val = ((val >> 16) & 0xFFFF) | ((val & 0xFFFF) << 16);
88 
89  if(!j)
90  y0 = (val & 0x1F) << 2;
91  else
92  y0 = y3 + xl_table[val & 0x1F];
93  val >>= 5;
94  y1 = y0 + xl_table[val & 0x1F];
95  val >>= 5;
96  y2 = y1 + xl_table[val & 0x1F];
97  val >>= 6; /* align to word */
98  y3 = y2 + xl_table[val & 0x1F];
99  val >>= 5;
100  if(!j)
101  c0 = (val & 0x1F) << 2;
102  else
103  c0 += xl_table[val & 0x1F];
104  val >>= 5;
105  if(!j)
106  c1 = (val & 0x1F) << 2;
107  else
108  c1 += xl_table[val & 0x1F];
109 
110  Y[j + 0] = y0 << 1;
111  Y[j + 1] = y1 << 1;
112  Y[j + 2] = y2 << 1;
113  Y[j + 3] = y3 << 1;
114 
115  U[j >> 2] = c0 << 1;
116  V[j >> 2] = c1 << 1;
117  }
118 
119  buf += avctx->width + 4;
120  Y += a->pic.linesize[0];
121  U += a->pic.linesize[1];
122  V += a->pic.linesize[2];
123  }
124 
125  *got_frame = 1;
126  *(AVFrame*)data = a->pic;
127 
128  return buf_size;
129 }
130 
131 static av_cold int decode_init(AVCodecContext *avctx){
132 // VideoXLContext * const a = avctx->priv_data;
133 
134  avctx->pix_fmt= AV_PIX_FMT_YUV411P;
135 
136  return 0;
137 }
138 
139 static av_cold int decode_end(AVCodecContext *avctx){
140  VideoXLContext * const a = avctx->priv_data;
141  AVFrame *pic = &a->pic;
142 
143  if (pic->data[0])
144  avctx->release_buffer(avctx, pic);
145 
146  return 0;
147 }
148 
149 AVCodec ff_xl_decoder = {
150  .name = "xl",
151  .type = AVMEDIA_TYPE_VIDEO,
152  .id = AV_CODEC_ID_VIXL,
153  .priv_data_size = sizeof(VideoXLContext),
154  .init = decode_init,
155  .close = decode_end,
156  .decode = decode_frame,
157  .capabilities = CODEC_CAP_DR1,
158  .long_name = NULL_IF_CONFIG_SMALL("Miro VideoXL"),
159 };