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/*
This file is part of libextractor.
Copyright (C) 2004, 2009, 2012 Vidyut Samanta and Christian Grothoff
libextractor is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
by the Free Software Foundation; either version 3, or (at your
option) any later version.
libextractor is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with libextractor; see the file COPYING. If not, write to the
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.
This code was based on AVInfo 1.0 alpha 11
(c) George Shuklin, gs]AT[shounen.ru, 2002-2004
http://shounen.ru/soft/avinfo/
and bitcollider 0.6.0
(PD) 2004 The Bitzi Corporation
http://bitzi.com/
*/
/**
* @file plugins/riff_extractor.c
* @brief plugin to support RIFF files (ms-video)
* @author Christian Grothoff
*/
#include "platform.h"
#include "extractor.h"
#include <math.h>
/**
* Read an uint32_t as a little-endian (least
* significant byte first) integer from @a data.
*
* @param data input data
* @return integer read
*/
static uint32_t
fread_le (const char *data)
{
unsigned int x;
uint32_t result = 0;
for (x = 0; x < 4; x++)
result |= ((unsigned char) data[x]) << (x * 8);
return result;
}
/**
* We implement our own rounding function, because the availability of
* C99's round(), nearbyint(), rint(), etc. seems to be spotty, whereas
* floor() is available in math.h on all C compilers.
*
* @param num value to round
* @return rounded-to-nearest value
*/
static double
round_double (double num)
{
return floor (num + 0.5);
}
/**
* Pass the given UTF-8 string to the 'proc' callback using
* the given type. Uses 'return' if 'proc' returns non-0.
*
* @param s 0-terminated UTF8 string value with the meta data
* @param t libextractor type for the meta data
*/
#define ADD(s,t) do { if (0 != ec->proc (ec->cls, "riff", t, \
EXTRACTOR_METAFORMAT_UTF8, \
"text/plain", s, strlen (s) \
+ 1)) return; \
} while (0)
/**
* Main entry method for the 'video/x-msvideo' extraction plugin.
*
* @param ec extraction context provided to the plugin
*/
void
EXTRACTOR_riff_extract_method (struct EXTRACTOR_ExtractContext *ec)
{
ssize_t xsize;
void *data;
char *xdata;
uint32_t blockLen;
unsigned int fps;
unsigned int duration;
uint64_t pos;
uint32_t width;
uint32_t height;
char codec[5];
char format[256];
/* read header */
if (72 > (xsize = ec->read (ec->cls, &data, 72)))
return;
xdata = data;
/* check magic values */
if ( (0 != memcmp (&xdata[0],
"RIFF", 4)) ||
(0 != memcmp (&xdata[8], "AVI ", 4)) ||
(0 != memcmp (&xdata[12], "LIST", 4)) ||
(0 != memcmp (&xdata[20], "hdrlavih", 8)) )
return;
blockLen = fread_le (&xdata[28]);
/* begin of AVI header at 32 */
fps = (unsigned int) round_double ((double) 1.0e6 / fread_le (&xdata[32]));
duration = (unsigned int) round_double ((double) fread_le (&xdata[48])
* 1000 / fps);
width = fread_le (&xdata[64]);
height = fread_le (&xdata[68]);
/* pos: begin of video stream header */
pos = blockLen + 32;
if (pos !=
ec->seek (ec->cls, pos, SEEK_SET))
return;
if (32 > ec->read (ec->cls, &data, 32))
return;
xdata = data;
/* check magic */
if ( (0 != memcmp (xdata, "LIST", 4)) ||
(0 != memcmp (&xdata[8], "strlstrh", 8)) ||
(0 != memcmp (&xdata[20], "vids", 4)) )
return;
/* pos + 24: video stream header with codec */
memcpy (codec, &xdata[24], 4);
codec[4] = '\0';
snprintf (format,
sizeof (format),
_ ("codec: %s, %u fps, %u ms"),
codec, fps, duration);
ADD (format, EXTRACTOR_METATYPE_FORMAT);
snprintf (format,
sizeof (format),
"%ux%u",
(unsigned int) width,
(unsigned int) height);
ADD (format, EXTRACTOR_METATYPE_IMAGE_DIMENSIONS);
ADD ("video/x-msvideo", EXTRACTOR_METATYPE_MIMETYPE);
}
/* end of riff_extractor.c */
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