Blame view

ffmpeg-4.2.2/libavcodec/frwu.c 4.15 KB
aac5773f   hucm   功能基本完成,接口待打磨
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
  /*
   * Forward Uncompressed
   *
   * Copyright (c) 2009 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
   *
   * This file is part of FFmpeg.
   *
   * FFmpeg is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * FFmpeg is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with FFmpeg; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  #include "avcodec.h"
  #include "bytestream.h"
  #include "internal.h"
  #include "libavutil/opt.h"
  
  typedef struct {
      AVClass *av_class;
      int change_field_order;
  } FRWUContext;
  
  static av_cold int decode_init(AVCodecContext *avctx)
  {
      if (avctx->width & 1) {
          av_log(avctx, AV_LOG_ERROR, "frwu needs even width\n");
          return AVERROR(EINVAL);
      }
      avctx->pix_fmt = AV_PIX_FMT_UYVY422;
  
      return 0;
  }
  
  static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
                          AVPacket *avpkt)
  {
      FRWUContext *s = avctx->priv_data;
      int field, ret;
      AVFrame *pic = data;
      const uint8_t *buf = avpkt->data;
      const uint8_t *buf_end = buf + avpkt->size;
  
      if (avpkt->size < avctx->width * 2 * avctx->height + 4 + 2*8) {
          av_log(avctx, AV_LOG_ERROR, "Packet is too small.\n");
          return AVERROR_INVALIDDATA;
      }
      if (bytestream_get_le32(&buf) != MKTAG('F', 'R', 'W', '1')) {
          av_log(avctx, AV_LOG_ERROR, "incorrect marker\n");
          return AVERROR_INVALIDDATA;
      }
  
      if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
          return ret;
  
      pic->pict_type = AV_PICTURE_TYPE_I;
      pic->key_frame = 1;
  
      for (field = 0; field < 2; field++) {
          int i;
          int field_h = (avctx->height + !field) >> 1;
          int field_size, min_field_size = avctx->width * 2 * field_h;
          uint8_t *dst = pic->data[0];
          if (buf_end - buf < 8)
              return AVERROR_INVALIDDATA;
          buf += 4; // flags? 0x80 == bottom field maybe?
          field_size = bytestream_get_le32(&buf);
          if (field_size < min_field_size) {
              av_log(avctx, AV_LOG_ERROR, "Field size %i is too small (required %i)\n", field_size, min_field_size);
              return AVERROR_INVALIDDATA;
          }
          if (buf_end - buf < field_size) {
              av_log(avctx, AV_LOG_ERROR, "Packet is too small, need %i, have %i\n", field_size, (int)(buf_end - buf));
              return AVERROR_INVALIDDATA;
          }
          if (field ^ s->change_field_order) {
              dst += pic->linesize[0];
          } else if (s->change_field_order) {
              dst += 2 * pic->linesize[0];
          }
          for (i = 0; i < field_h; i++) {
              if (s->change_field_order && field && i == field_h - 1)
                  dst = pic->data[0];
              memcpy(dst, buf, avctx->width * 2);
              buf += avctx->width * 2;
              dst += pic->linesize[0] << 1;
          }
          buf += field_size - min_field_size;
      }
  
      *got_frame = 1;
  
      return avpkt->size;
  }
  
  static const AVOption frwu_options[] = {
      {"change_field_order", "Change field order", offsetof(FRWUContext, change_field_order), AV_OPT_TYPE_BOOL,
       {.i64 = 0}, 0, 1, AV_OPT_FLAG_DECODING_PARAM | AV_OPT_FLAG_VIDEO_PARAM},
      {NULL}
  };
  
  static const AVClass frwu_class = {
      .class_name = "frwu Decoder",
      .item_name  = av_default_item_name,
      .option     = frwu_options,
      .version    = LIBAVUTIL_VERSION_INT,
  };
  
  AVCodec ff_frwu_decoder = {
      .name           = "frwu",
      .long_name      = NULL_IF_CONFIG_SMALL("Forward Uncompressed"),
      .type           = AVMEDIA_TYPE_VIDEO,
      .id             = AV_CODEC_ID_FRWU,
      .priv_data_size = sizeof(FRWUContext),
      .init           = decode_init,
      .decode         = decode_frame,
      .capabilities   = AV_CODEC_CAP_DR1,
      .priv_class     = &frwu_class,
  };