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crcenc.c
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1 /*
2  * CRC encoder (for codec/format testing)
3  * Copyright (c) 2002 Fabrice Bellard
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 #include "libavutil/adler32.h"
23 #include "avformat.h"
24 
25 typedef struct CRCState {
26  uint32_t crcval;
27 } CRCState;
28 
29 static int crc_write_header(struct AVFormatContext *s)
30 {
31  CRCState *crc = s->priv_data;
32 
33  /* init CRC */
34  crc->crcval = 1;
35 
36  return 0;
37 }
38 
40 {
41  CRCState *crc = s->priv_data;
42  crc->crcval = av_adler32_update(crc->crcval, pkt->data, pkt->size);
43  return 0;
44 }
45 
46 static int crc_write_trailer(struct AVFormatContext *s)
47 {
48  CRCState *crc = s->priv_data;
49  char buf[64];
50 
51  snprintf(buf, sizeof(buf), "CRC=0x%08x\n", crc->crcval);
52  avio_write(s->pb, buf, strlen(buf));
53 
54  return 0;
55 }
56 
58  .name = "crc",
59  .long_name = NULL_IF_CONFIG_SMALL("CRC testing"),
60  .priv_data_size = sizeof(CRCState),
61  .audio_codec = AV_CODEC_ID_PCM_S16LE,
62  .video_codec = AV_CODEC_ID_RAWVIDEO,
67 };