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/intreadwrite.h"
28 #include "avcodec.h"
29 
30 typedef struct VideoXLContext{
34 
35 static const int xl_table[32] = {
36  0, 1, 2, 3, 4, 5, 6, 7,
37  8, 9, 12, 15, 20, 25, 34, 46,
38  64, 82, 94, 103, 108, 113, 116, 119,
39  120, 121, 122, 123, 124, 125, 126, 127};
40 
41 static int decode_frame(AVCodecContext *avctx,
42  void *data, int *data_size,
43  AVPacket *avpkt)
44 {
45  const uint8_t *buf = avpkt->data;
46  int buf_size = avpkt->size;
47  VideoXLContext * const a = avctx->priv_data;
48  AVFrame * const p= (AVFrame*)&a->pic;
49  uint8_t *Y, *U, *V;
50  int i, j;
51  int stride;
52  uint32_t val;
53  int y0, y1, y2, y3 = 0, c0 = 0, c1 = 0;
54 
55  if(p->data[0])
56  avctx->release_buffer(avctx, p);
57 
58  p->reference = 0;
59  if(avctx->get_buffer(avctx, p) < 0){
60  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
61  return -1;
62  }
64  p->key_frame= 1;
65 
66  Y = a->pic.data[0];
67  U = a->pic.data[1];
68  V = a->pic.data[2];
69 
70  stride = avctx->width - 4;
71 
72  if (avctx->width % 4) {
73  av_log(avctx, AV_LOG_ERROR, "Width not a multiple of 4.\n");
74  return AVERROR_INVALIDDATA;
75  }
76 
77  if (buf_size < avctx->width * avctx->height) {
78  av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
79  return AVERROR_INVALIDDATA;
80  }
81 
82  for (i = 0; i < avctx->height; i++) {
83  /* lines are stored in reversed order */
84  buf += stride;
85 
86  for (j = 0; j < avctx->width; j += 4) {
87  /* value is stored in LE dword with word swapped */
88  val = AV_RL32(buf);
89  buf -= 4;
90  val = ((val >> 16) & 0xFFFF) | ((val & 0xFFFF) << 16);
91 
92  if(!j)
93  y0 = (val & 0x1F) << 2;
94  else
95  y0 = y3 + xl_table[val & 0x1F];
96  val >>= 5;
97  y1 = y0 + xl_table[val & 0x1F];
98  val >>= 5;
99  y2 = y1 + xl_table[val & 0x1F];
100  val >>= 6; /* align to word */
101  y3 = y2 + xl_table[val & 0x1F];
102  val >>= 5;
103  if(!j)
104  c0 = (val & 0x1F) << 2;
105  else
106  c0 += xl_table[val & 0x1F];
107  val >>= 5;
108  if(!j)
109  c1 = (val & 0x1F) << 2;
110  else
111  c1 += xl_table[val & 0x1F];
112 
113  Y[j + 0] = y0 << 1;
114  Y[j + 1] = y1 << 1;
115  Y[j + 2] = y2 << 1;
116  Y[j + 3] = y3 << 1;
117 
118  U[j >> 2] = c0 << 1;
119  V[j >> 2] = c1 << 1;
120  }
121 
122  buf += avctx->width + 4;
123  Y += a->pic.linesize[0];
124  U += a->pic.linesize[1];
125  V += a->pic.linesize[2];
126  }
127 
128  *data_size = sizeof(AVFrame);
129  *(AVFrame*)data = a->pic;
130 
131  return buf_size;
132 }
133 
134 static av_cold int decode_init(AVCodecContext *avctx){
135 // VideoXLContext * const a = avctx->priv_data;
136 
137  avctx->pix_fmt= PIX_FMT_YUV411P;
138 
139  return 0;
140 }
141 
142 static av_cold int decode_end(AVCodecContext *avctx){
143  VideoXLContext * const a = avctx->priv_data;
144  AVFrame *pic = &a->pic;
145 
146  if (pic->data[0])
147  avctx->release_buffer(avctx, pic);
148 
149  return 0;
150 }
151 
153  .name = "xl",
154  .type = AVMEDIA_TYPE_VIDEO,
155  .id = CODEC_ID_VIXL,
156  .priv_data_size = sizeof(VideoXLContext),
157  .init = decode_init,
158  .close = decode_end,
159  .decode = decode_frame,
160  .capabilities = CODEC_CAP_DR1,
161  .long_name = NULL_IF_CONFIG_SMALL("Miro VideoXL"),
162 };