frwu.c
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1 /*
2  * Forward Uncompressed
3  *
4  * Copyright (c) 2009 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
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 "bytestream.h"
25 #include "libavutil/intreadwrite.h"
26 
28 {
29  if (avctx->width & 1) {
30  av_log(avctx, AV_LOG_ERROR, "FRWU needs even width\n");
31  return -1;
32  }
33  avctx->pix_fmt = PIX_FMT_UYVY422;
34 
36 
37  return 0;
38 }
39 
40 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
41  AVPacket *avpkt)
42 {
43  int field;
44  AVFrame *pic = avctx->coded_frame;
45  const uint8_t *buf = avpkt->data;
46  const uint8_t *buf_end = buf + avpkt->size;
47 
48  if (pic->data[0])
49  avctx->release_buffer(avctx, pic);
50 
51  if (avpkt->size < avctx->width * 2 * avctx->height + 4 + 2*8) {
52  av_log(avctx, AV_LOG_ERROR, "Packet is too small.\n");
53  return -1;
54  }
55  if (bytestream_get_le32(&buf) != AV_RL32("FRW1")) {
56  av_log(avctx, AV_LOG_ERROR, "incorrect marker\n");
57  return -1;
58  }
59 
60  pic->reference = 0;
61  if (avctx->get_buffer(avctx, pic) < 0)
62  return -1;
63 
65  pic->key_frame = 1;
66  pic->interlaced_frame = 1;
67  pic->top_field_first = 1;
68 
69  for (field = 0; field < 2; field++) {
70  int i;
71  int field_h = (avctx->height + !field) >> 1;
72  int field_size, min_field_size = avctx->width * 2 * field_h;
73  uint8_t *dst = pic->data[0];
74  if (buf_end - buf < 8)
75  return -1;
76  buf += 4; // flags? 0x80 == bottom field maybe?
77  field_size = bytestream_get_le32(&buf);
78  if (field_size < min_field_size) {
79  av_log(avctx, AV_LOG_ERROR, "Field size %i is too small (required %i)\n", field_size, min_field_size);
80  return -1;
81  }
82  if (buf_end - buf < field_size) {
83  av_log(avctx, AV_LOG_ERROR, "Packet is too small, need %i, have %i\n", field_size, (int)(buf_end - buf));
84  return -1;
85  }
86  if (field)
87  dst += pic->linesize[0];
88  for (i = 0; i < field_h; i++) {
89  memcpy(dst, buf, avctx->width * 2);
90  buf += avctx->width * 2;
91  dst += pic->linesize[0] << 1;
92  }
93  buf += field_size - min_field_size;
94  }
95 
96  *data_size = sizeof(AVFrame);
97  *(AVFrame*)data = *pic;
98 
99  return avpkt->size;
100 }
101 
103 {
104  AVFrame *pic = avctx->coded_frame;
105  if (pic->data[0])
106  avctx->release_buffer(avctx, pic);
107  av_freep(&avctx->coded_frame);
108 
109  return 0;
110 }
111 
113  .name = "FRWU",
114  .type = AVMEDIA_TYPE_VIDEO,
115  .id = CODEC_ID_FRWU,
116  .init = decode_init,
117  .close = decode_close,
118  .decode = decode_frame,
119  .capabilities = CODEC_CAP_DR1,
120  .long_name = NULL_IF_CONFIG_SMALL("Forward Uncompressed"),
121 };