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sp5xdec.c
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1 /*
2  * Sunplus JPEG decoder (SP5X)
3  * Copyright (c) 2003 Alex Beregszaszi
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  * Sunplus JPEG decoder (SP5X).
25  */
26 
27 #include "avcodec.h"
28 #include "mjpeg.h"
29 #include "mjpegdec.h"
30 #include "sp5x.h"
31 
32 
34  void *data, int *got_frame,
35  AVPacket *avpkt)
36 {
37  const uint8_t *buf = avpkt->data;
38  int buf_size = avpkt->size;
39  AVPacket avpkt_recoded;
40  const int qscale = 5;
41  uint8_t *recoded;
42  int i = 0, j = 0;
43 
44  if (!avctx->width || !avctx->height)
45  return -1;
46 
47  recoded = av_mallocz(buf_size + 1024);
48  if (!recoded)
49  return -1;
50 
51  /* SOI */
52  recoded[j++] = 0xFF;
53  recoded[j++] = 0xD8;
54 
55  memcpy(recoded+j, &sp5x_data_dqt[0], sizeof(sp5x_data_dqt));
56  memcpy(recoded+j+5, &sp5x_quant_table[qscale * 2], 64);
57  memcpy(recoded+j+70, &sp5x_quant_table[(qscale * 2) + 1], 64);
58  j += sizeof(sp5x_data_dqt);
59 
60  memcpy(recoded+j, &sp5x_data_dht[0], sizeof(sp5x_data_dht));
61  j += sizeof(sp5x_data_dht);
62 
63  memcpy(recoded+j, &sp5x_data_sof[0], sizeof(sp5x_data_sof));
64  AV_WB16(recoded+j+5, avctx->coded_height);
65  AV_WB16(recoded+j+7, avctx->coded_width);
66  j += sizeof(sp5x_data_sof);
67 
68  memcpy(recoded+j, &sp5x_data_sos[0], sizeof(sp5x_data_sos));
69  j += sizeof(sp5x_data_sos);
70 
71  if(avctx->codec_id==AV_CODEC_ID_AMV)
72  for (i = 2; i < buf_size-2 && j < buf_size+1024-2; i++)
73  recoded[j++] = buf[i];
74  else
75  for (i = 14; i < buf_size && j < buf_size+1024-3; i++)
76  {
77  recoded[j++] = buf[i];
78  if (buf[i] == 0xff)
79  recoded[j++] = 0;
80  }
81 
82  /* EOI */
83  recoded[j++] = 0xFF;
84  recoded[j++] = 0xD9;
85 
86  av_init_packet(&avpkt_recoded);
87  avpkt_recoded.data = recoded;
88  avpkt_recoded.size = j;
89  i = ff_mjpeg_decode_frame(avctx, data, got_frame, &avpkt_recoded);
90 
91  av_free(recoded);
92 
93  return i < 0 ? i : avpkt->size;
94 }
95 
96 #if CONFIG_SP5X_DECODER
97 AVCodec ff_sp5x_decoder = {
98  .name = "sp5x",
99  .long_name = NULL_IF_CONFIG_SMALL("Sunplus JPEG (SP5X)"),
100  .type = AVMEDIA_TYPE_VIDEO,
101  .id = AV_CODEC_ID_SP5X,
102  .priv_data_size = sizeof(MJpegDecodeContext),
104  .close = ff_mjpeg_decode_end,
106  .capabilities = CODEC_CAP_DR1,
107  .max_lowres = 3,
108 };
109 #endif
110 #if CONFIG_AMV_DECODER
111 AVCodec ff_amv_decoder = {
112  .name = "amv",
113  .long_name = NULL_IF_CONFIG_SMALL("AMV Video"),
114  .type = AVMEDIA_TYPE_VIDEO,
115  .id = AV_CODEC_ID_AMV,
116  .priv_data_size = sizeof(MJpegDecodeContext),
118  .close = ff_mjpeg_decode_end,
120  .max_lowres = 3,
121 };
122 #endif