tvsread.c - dump contents of KEY chunks in TeamViewer ".tvs" videos

tvsread.c

/* tvsread.c: lists KEY chunks in video and uncompresses them to ./key1.data, ./key2.data, ... */
/* See also http://www.jerrysguide.com/tips/demystify-tvs-file-format.html, https://stackoverflow.com/a/53135938/446106 */
/* Fairly quick and dirty.  Tested with a Version 5 video from TeamViewer 13. */

/* compile with gcc -lz tvsread.c */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <zlib.h>

int main(int arg_c, char **arg_v) {
	FILE *infile, *outfile;
	void *cbuf = 0, *ubuf = 0;
	int clen, ulen; uLongf ulen2;
	int keycount = 0;
	char keyfilename[256];
	unsigned char line[1024];
	char name[4];

	infile = fopen(arg_v[1], "rb"); if (!infile) return 1;

	/* plain text at beginning */
	while (memcmp(line, "BEGIN", 5) && !feof(infile)) {
		fgets(line, 1024, infile);
		strtok(line, "\n");
		puts(line);
	}

	/* list of "KEY" chunks - 3-byte name, compressed length, uncompressed length */
	printf("%s:\t%3s\t%s\t%s\n", "offset", "name", "len", "ulen");

	while (!feof(infile)) {

		unsigned char key[11];
		fread(key, 1, 11, infile);
		memcpy(name, key, 3); name[3] = '\0';
		if (memcmp(name, "KEY", 3)) break;

		clen = key[3] | key[4] << 8 | key[5] << 16 | key[6] << 24;
		ulen = key[7] | key[8] << 8 | key[9] << 16 | key[10] << 24;

		printf("%8x:\t%s\t%d\t%d\n", ftell(infile), name, clen, ulen);

		if (!(cbuf = realloc(cbuf, clen))) return -1;
		if (!(ubuf = realloc(ubuf, ulen))) return -1;

#if 0
		/* skip chunk data */
		fseek(infile, clen, SEEK_CUR);
#else
		/* uncompress chunk data and dump to file */
		fread(cbuf, 1, clen, infile);

		ulen2 = ulen;
		uncompress(ubuf, &ulen2, cbuf, clen);
		sprintf(keyfilename, "key%d.data", ++keycount);
		outfile = fopen(keyfilename, "wb"); if (!outfile) break;
		fwrite(ubuf, 1, ulen2, outfile);
		fclose(outfile);
#endif

	}

	fclose(infile);
}