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vcr1.c
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1 /*
2  * ATI VCR1 codec
3  * Copyright (c) 2003 Michael Niedermayer
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  * ATI VCR1 codec
25  */
26 
27 #include "avcodec.h"
28 #include "internal.h"
29 #include "libavutil/internal.h"
30 
31 typedef struct VCR1Context {
32  int delta[16];
33  int offset[4];
34 } VCR1Context;
35 
37 {
38  avctx->pix_fmt = AV_PIX_FMT_YUV410P;
39 
40  if (avctx->width % 8 || avctx->height%4) {
41  avpriv_request_sample(avctx, "odd dimensions support");
42  return AVERROR_PATCHWELCOME;
43  }
44  return 0;
45 }
46 
47 static int vcr1_decode_frame(AVCodecContext *avctx, void *data,
48  int *got_frame, AVPacket *avpkt)
49 {
50  const uint8_t *buf = avpkt->data;
51  int buf_size = avpkt->size;
52  VCR1Context *const a = avctx->priv_data;
53  AVFrame *const p = data;
54  const uint8_t *bytestream = buf;
55  int i, x, y, ret;
56 
57  if(buf_size < 16 + avctx->height + avctx->width*avctx->height*5/8){
58  av_log(avctx, AV_LOG_ERROR, "Insufficient input data.\n");
59  return AVERROR(EINVAL);
60  }
61 
62  if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
63  return ret;
65  p->key_frame = 1;
66 
67  for (i = 0; i < 16; i++) {
68  a->delta[i] = *bytestream++;
69  bytestream++;
70  }
71 
72  for (y = 0; y < avctx->height; y++) {
73  int offset;
74  uint8_t *luma = &p->data[0][y * p->linesize[0]];
75 
76  if ((y & 3) == 0) {
77  uint8_t *cb = &p->data[1][(y >> 2) * p->linesize[1]];
78  uint8_t *cr = &p->data[2][(y >> 2) * p->linesize[2]];
79 
80  for (i = 0; i < 4; i++)
81  a->offset[i] = *bytestream++;
82 
83  offset = a->offset[0] - a->delta[bytestream[2] & 0xF];
84  for (x = 0; x < avctx->width; x += 4) {
85  luma[0] = offset += a->delta[bytestream[2] & 0xF];
86  luma[1] = offset += a->delta[bytestream[2] >> 4];
87  luma[2] = offset += a->delta[bytestream[0] & 0xF];
88  luma[3] = offset += a->delta[bytestream[0] >> 4];
89  luma += 4;
90 
91  *cb++ = bytestream[3];
92  *cr++ = bytestream[1];
93 
94  bytestream += 4;
95  }
96  } else {
97  offset = a->offset[y & 3] - a->delta[bytestream[2] & 0xF];
98 
99  for (x = 0; x < avctx->width; x += 8) {
100  luma[0] = offset += a->delta[bytestream[2] & 0xF];
101  luma[1] = offset += a->delta[bytestream[2] >> 4];
102  luma[2] = offset += a->delta[bytestream[3] & 0xF];
103  luma[3] = offset += a->delta[bytestream[3] >> 4];
104  luma[4] = offset += a->delta[bytestream[0] & 0xF];
105  luma[5] = offset += a->delta[bytestream[0] >> 4];
106  luma[6] = offset += a->delta[bytestream[1] & 0xF];
107  luma[7] = offset += a->delta[bytestream[1] >> 4];
108  luma += 8;
109  bytestream += 4;
110  }
111  }
112  }
113 
114  *got_frame = 1;
115 
116  return buf_size;
117 }
118 
120  .name = "vcr1",
121  .type = AVMEDIA_TYPE_VIDEO,
122  .id = AV_CODEC_ID_VCR1,
123  .priv_data_size = sizeof(VCR1Context),
126  .capabilities = CODEC_CAP_DR1,
127  .long_name = NULL_IF_CONFIG_SMALL("ATI VCR1"),
128 };