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/* a very simple AVI writer - no fancy stuff
Tridge, July 2000
*/
/*
Copyright (C) Andrew Tridgell 2000
This program 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 2 of the License, or
(at your option) any later version.
This program 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 this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "capture.h"
static int nframes;
static int totalsize;
/* start writing an AVI file */
void avi_start(int fd)
{
int ofs = sizeof(struct riff_head)+
sizeof(struct list_head)+
sizeof(struct avi_head)+
sizeof(struct list_head)+
sizeof(struct stream_head)+
sizeof(struct frame_head)+
sizeof(struct list_head);
lseek(fd, ofs, SEEK_SET);
nframes = 0;
totalsize = 0;
}
/* add a jpeg frame to an AVI file */
void avi_add(int fd, u8 *buf, int size)
{
struct db_head db = {"00db", size};
write(fd, &db, sizeof(db));
write(fd, buf, size);
nframes++;
totalsize += size;
}
/* finish writing the AVI file - filling in the header */
void avi_end(int fd, int width, int height, int fps)
{
struct riff_head rh = {"RIFF", 0, "AVI "};
struct list_head lh1 = {"LIST", 0, "hdrl"};
struct avi_head ah;
struct list_head lh2 = {"LIST", 0, "strl"};
struct stream_head sh;
struct frame_head fh;
struct list_head lh3 = {"LIST", 0, "movi"};
bzero(&ah, sizeof(ah));
strcpy(ah.avih, "avih");
ah.time = 1e6 / fps;
ah.numstreams = 1;
ah.scale = 1;
ah.rate = fps;
ah.length = fps * nframes;
bzero(&sh, sizeof(sh));
strcpy(sh.strh, "strh");
strcpy(sh.vids, "vids");
strcpy(sh.codec, "MJPG");
sh.scale = 1;
sh.rate = fps;
sh.length = fps * nframes;
sh.quality = -1;
bzero(&fh, sizeof(fh));
strcpy(fh.strf, "strf");
fh.width = width;
fh.height = height;
fh.planes = 1;
fh.bitcount = 24;
strcpy(fh.codec,"MJPG");
fh.unpackedsize = 3*width*height;
rh.size = sizeof(lh1)+sizeof(ah)+sizeof(lh2)+sizeof(sh)+
sizeof(fh)+sizeof(lh3)+
nframes*sizeof(struct db_head)+
totalsize;
lh1.size = 4+sizeof(ah)+sizeof(lh2)+sizeof(sh)+sizeof(fh);
ah.size = sizeof(ah)-8;
lh2.size = 4+sizeof(sh)+sizeof(fh);
sh.size = sizeof(sh)-8;
fh.size = sizeof(fh)-8;
fh.size2 = fh.size;
lh3.size = 4+
nframes*sizeof(struct db_head)+
totalsize;
lseek(fd, 0, SEEK_SET);
write(fd, &rh, sizeof(rh));
write(fd, &lh1, sizeof(lh1));
write(fd, &ah, sizeof(ah));
write(fd, &lh2, sizeof(lh2));
write(fd, &sh, sizeof(sh));
write(fd, &fh, sizeof(fh));
write(fd, &lh3, sizeof(lh3));
}
/* NOTE: This is not a general purpose routine - it is meant to only
cope with AVIs saved using the other functions in this file */
void avi_explode(char *fname)
{
struct riff_head rh;
struct list_head lh1;
struct avi_head ah;
struct list_head lh2;
struct stream_head sh;
struct frame_head fh;
struct list_head lh3;
int hsize, qsize;
u16 *htables = jpeg_huffman_tables(&hsize);
u16 *qtables = jpeg_quantisation_tables(&qsize, image_quality);
int fd, i;
fd = open(fname,O_RDONLY);
if (fd == -1) {
perror(fname);
return;
}
read(fd, &rh, sizeof(rh));
read(fd, &lh1, sizeof(lh1));
read(fd, &ah, sizeof(ah));
read(fd, &lh2, sizeof(lh2));
read(fd, &sh, sizeof(sh));
read(fd, &fh, sizeof(fh));
read(fd, &lh3, sizeof(lh3));
for (i=0; ; i++) {
u8 buf[500*1024];
struct db_head db;
char fname[100];
int fd2;
if (read(fd, &db, sizeof(db)) != sizeof(db) ||
read(fd, buf, db.size) != db.size) break;
snprintf(fname, sizeof(fname)-1,"frame.%d", i);
fd2 = open(fname,O_WRONLY|O_CREAT, 0644);
if (fd2 == -1) {
perror(fname);
continue;
}
write(fd2, buf, 2);
write(fd2, qtables, qsize);
write(fd2, htables, hsize);
write(fd2, buf+2, db.size-2);
close(fd2);
}
close(fd);
printf("exploded %d frames\n", i);
}
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