FFmpeg
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 #include "mux.h"
27 
28 typedef struct CRCState {
29  uint32_t crcval;
30 } CRCState;
31 
32 static int crc_init(struct AVFormatContext *s)
33 {
34  CRCState *crc = s->priv_data;
35 
36  /* init CRC */
37  crc->crcval = 1;
38 
39  return 0;
40 }
41 
43 {
44  CRCState *crc = s->priv_data;
45  crc->crcval = av_adler32_update(crc->crcval, pkt->data, pkt->size);
46  return 0;
47 }
48 
49 static int crc_write_trailer(struct AVFormatContext *s)
50 {
51  CRCState *crc = s->priv_data;
52 
53  avio_printf(s->pb, "CRC=0x%08"PRIx32"\n", crc->crcval);
54 
55  return 0;
56 }
57 
59  .p.name = "crc",
60  .p.long_name = NULL_IF_CONFIG_SMALL("CRC testing"),
61  .priv_data_size = sizeof(CRCState),
62  .p.audio_codec = AV_CODEC_ID_PCM_S16LE,
63  .p.video_codec = AV_CODEC_ID_RAWVIDEO,
64  .init = crc_init,
65  .write_packet = crc_write_packet,
66  .write_trailer = crc_write_trailer,
67  .p.flags = AVFMT_NOTIMESTAMPS,
68 };
AV_CODEC_ID_PCM_S16LE
@ AV_CODEC_ID_PCM_S16LE
Definition: codec_id.h:331
AVOutputFormat::name
const char * name
Definition: avformat.h:511
AVFMT_NOTIMESTAMPS
#define AVFMT_NOTIMESTAMPS
Format does not need / have any timestamps.
Definition: avformat.h:480
AV_CODEC_ID_RAWVIDEO
@ AV_CODEC_ID_RAWVIDEO
Definition: codec_id.h:65
AVPacket::data
uint8_t * data
Definition: packet.h:522
crc_init
static int crc_init(struct AVFormatContext *s)
Definition: crcenc.c:32
FFOutputFormat::p
AVOutputFormat p
The public AVOutputFormat.
Definition: mux.h:36
crc_write_packet
static int crc_write_packet(struct AVFormatContext *s, AVPacket *pkt)
Definition: crcenc.c:42
pkt
AVPacket * pkt
Definition: movenc.c:59
s
#define s(width, name)
Definition: cbs_vp9.c:198
AVFormatContext
Format I/O context.
Definition: avformat.h:1363
ff_crc_muxer
const FFOutputFormat ff_crc_muxer
Definition: crcenc.c:58
FFOutputFormat
Definition: mux.h:32
adler32.h
av_adler32_update
AVAdler av_adler32_update(AVAdler adler, const uint8_t *buf, size_t len)
Calculate the Adler32 checksum of a buffer.
Definition: adler32.c:44
AVPacket::size
int size
Definition: packet.h:523
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:106
crc_write_trailer
static int crc_write_trailer(struct AVFormatContext *s)
Definition: crcenc.c:49
CRCState::crcval
uint32_t crcval
Definition: crcenc.c:29
avformat.h
avio_printf
int avio_printf(AVIOContext *s, const char *fmt,...) av_printf_format(2
Writes a formatted string to the context.
AVPacket
This structure stores compressed data.
Definition: packet.h:499
CRCState
Definition: crcenc.c:28
mux.h