libavformat/crcenc.c

   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
  39 static int crc_write_packet(struct AVFormatContext *s, AVPacket *pkt)
  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     put_buffer(s->pb, buf, strlen(buf));
  53     put_flush_packet(s->pb);
  54     return 0;
  55 }
  56
  57 AVOutputFormat crc_muxer = {
  58     "crc",
  59     NULL_IF_CONFIG_SMALL("CRC testing format"),
  60     NULL,
  61     "",
  62     sizeof(CRCState),
  63     CODEC_ID_PCM_S16LE,
  64     CODEC_ID_RAWVIDEO,
  65     crc_write_header,
  66     crc_write_packet,
  67     crc_write_trailer,
  68 };