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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 <inttypes.h>
23 
24 #include "libavutil/adler32.h"
25 #include "avformat.h"
26 
27 typedef struct CRCState {
28  uint32_t crcval;
29 } CRCState;
30 
31 static int crc_write_header(struct AVFormatContext *s)
32 {
33  CRCState *crc = s->priv_data;
34 
35  /* init CRC */
36  crc->crcval = 1;
37 
38  return 0;
39 }
40 
42 {
43  CRCState *crc = s->priv_data;
44  crc->crcval = av_adler32_update(crc->crcval, pkt->data, pkt->size);
45  return 0;
46 }
47 
48 static int crc_write_trailer(struct AVFormatContext *s)
49 {
50  CRCState *crc = s->priv_data;
51  char buf[64];
52 
53  snprintf(buf, sizeof(buf), "CRC=0x%08"PRIx32"\n", crc->crcval);
54  avio_write(s->pb, buf, strlen(buf));
55 
56  return 0;
57 }
58 
60  .name = "crc",
61  .long_name = NULL_IF_CONFIG_SMALL("CRC testing"),
62  .priv_data_size = sizeof(CRCState),
63  .audio_codec = AV_CODEC_ID_PCM_S16LE,
64  .video_codec = AV_CODEC_ID_RAWVIDEO,
69 };
const char * s
Definition: avisynth_c.h:631
int size
Definition: avcodec.h:1575
static int crc_write_header(struct AVFormatContext *s)
Definition: crcenc.c:31
static AVPacket pkt
Format I/O context.
Definition: avformat.h:1319
unsigned long av_adler32_update(unsigned long adler, const uint8_t *buf, unsigned int len)
Calculate the Adler32 checksum of a buffer.
Definition: adler32.c:44
uint8_t * data
Definition: avcodec.h:1574
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:187
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:176
static int write_trailer(AVFormatContext *s1)
Definition: v4l2enc.c:94
const char * name
Definition: avformat.h:522
static int crc_write_packet(struct AVFormatContext *s, AVPacket *pkt)
Definition: crcenc.c:41
#define AVFMT_NOTIMESTAMPS
Format does not need / have any timestamps.
Definition: avformat.h:484
Public header for libavutil Adler32 hasher.
AVIOContext * pb
I/O context.
Definition: avformat.h:1361
uint32_t crcval
Definition: crcenc.c:28
void * buf
Definition: avisynth_c.h:553
#define snprintf
Definition: snprintf.h:34
static int flags
Definition: cpu.c:47
Main libavformat public API header.
static int crc_write_trailer(struct AVFormatContext *s)
Definition: crcenc.c:48
AVOutputFormat ff_crc_muxer
Definition: crcenc.c:59
void * priv_data
Format private data.
Definition: avformat.h:1347
static void write_header(FFV1Context *f)
Definition: ffv1enc.c:497
This structure stores compressed data.
Definition: avcodec.h:1551
static int write_packet(AVFormatContext *s1, AVPacket *pkt)
Definition: v4l2enc.c:86