From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sfi-mx-4.v28.ch3.sourceforge.com ([172.29.28.124] helo=mx.sourceforge.net) by 235xhf1.ch3.sourceforge.com with esmtp (Exim 4.69) (envelope-from ) id 1MuY8m-0004YJ-5F for ltp-list@lists.sourceforge.net; Sun, 04 Oct 2009 20:57:12 +0000 Received: from mail00d.mail.t-online.hu ([84.2.42.5]) by 1b2kzd1.ch3.sourceforge.com with esmtp (Exim 4.69) id 1MuY8e-00042B-Q9 for ltp-list@lists.sourceforge.net; Sun, 04 Oct 2009 20:57:11 +0000 Message-ID: <4AC90C17.70103@freemail.hu> Date: Sun, 04 Oct 2009 22:56:55 +0200 From: =?UTF-8?B?TsOpbWV0aCBNw6FydG9u?= MIME-Version: 1.0 References: <4AC90BBF.9040803@freemail.hu> In-Reply-To: <4AC90BBF.9040803@freemail.hu> Content-Type: multipart/mixed; boundary="------------010600030802050504020505" Subject: Re: [LTP] [PATCH] pac_common: redesign function for finding Start Of Frame List-Id: Linux Test Project General Discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: ltp-list-bounces@lists.sourceforge.net To: Jean-Francois Moine , Thomas Kaiser , Kyle Guinn , Theodore Kilgore , ltp-list@lists.sourceforge.net Cc: LKML , V4L Mailing List This is a multi-part message in MIME format. --------------010600030802050504020505 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Hi, I wrote a simple test for pac_find_sof(). I implemented a user-space test which takes the implementation from the source file and calls it directly= . You can find the source code of the test attached. The test results for the pac_find_sof() implementation in the Linux kerne= l 2.6.32-rc1 is the following: Test case 1: exact match PDEBUG: SOF found, bytes to analyze: 5. Frame starts at byte #5 PASSED Test case 2: offset 1 PDEBUG: SOF found, bytes to analyze: 6. Frame starts at byte #6 PASSED Test case 3: offset 1, first byte may be misleading FAILED Test case 4: offset 2, first two bytes may be misleading PDEBUG: SOF found, bytes to analyze: 7. Frame starts at byte #7 PASSED Test case 5: offset 3, first three bytes may be misleading FAILED Test case 6: offset 4, first four bytes may be misleading FAILED Test case 7: pattern starts at end of packet and continues in the next on= e PDEBUG: SOF found, bytes to analyze: 1. Frame starts at byte #1 PASSED Test case 8: splited pattern, with misleading first byte FAILED Test case 9: splited pattern, with misleading first three bytes FAILED Test case 10: no match, extra byte at offset 1 PASSED Test case 11: no match, extra byte at offset 2 PASSED Test case 12: no match, extra byte at offset 3 PASSED Test case 13: no match, extra byte at offset 4 PASSED I also executed the test with the patched pac_find_sof() implementation and that one passes all these test cases. Regards, M=C3=A1rton N=C3=A9meth N=C3=A9meth M=C3=A1rton wrote: > From: M=C3=A1rton N=C3=A9meth >=20 > The original implementation of pac_find_sof() does not always find > the Start Of Frame (SOF) marker. Replace it with a state machine > based design. >=20 > The change was tested with Labtec Webcam 2200. >=20 > Signed-off-by: M=C3=A1rton N=C3=A9meth > --- > --- linux-2.6.32-rc1.orig/drivers/media/video/gspca/pac_common.h 2009-0= 9-10 00:13:59.000000000 +0200 > +++ linux-2.6.32-rc1/drivers/media/video/gspca/pac_common.h 2009-10-04 = 21:49:19.000000000 +0200 > @@ -33,6 +33,45 @@ > static const unsigned char pac_sof_marker[5] =3D > { 0xff, 0xff, 0x00, 0xff, 0x96 }; >=20 > +/* > + The following state machine finds the SOF marker sequence > + 0xff, 0xff, 0x00, 0xff, 0x96 in a byte stream. > + > + +----------+ > + | 0: START |<---------------\ > + +----------+<-\ | > + | \---/otherwise | > + v 0xff | > + +----------+ otherwise | > + | 1 |--------------->* > + | | ^ > + +----------+ | > + | | > + v 0xff | > + +----------+<-\0xff | > + /->| |--/ | > + | | 2 |--------------->* > + | | | otherwise ^ > + | +----------+ | > + | | | > + | v 0x00 | > + | +----------+ | > + | | 3 | | > + | | |--------------->* > + | +----------+ otherwise ^ > + | | | > + 0xff | v 0xff | > + | +----------+ | > + \--| 4 | | > + | |----------------/ > + +----------+ otherwise > + | > + v 0x96 > + +----------+ > + | FOUND | > + +----------+ > +*/ > + > static unsigned char *pac_find_sof(struct gspca_dev *gspca_dev, > unsigned char *m, int len) > { > @@ -41,17 +80,54 @@ static unsigned char *pac_find_sof(struc >=20 > /* Search for the SOF marker (fixed part) in the header */ > for (i =3D 0; i < len; i++) { > - if (m[i] =3D=3D pac_sof_marker[sd->sof_read]) { > - sd->sof_read++; > - if (sd->sof_read =3D=3D sizeof(pac_sof_marker)) { > + switch (sd->sof_read) { > + case 0: > + if (m[i] =3D=3D 0xff) > + sd->sof_read =3D 1; > + break; > + case 1: > + if (m[i] =3D=3D 0xff) > + sd->sof_read =3D 2; > + else > + sd->sof_read =3D 0; > + break; > + case 2: > + switch (m[i]) { > + case 0x00: > + sd->sof_read =3D 3; > + break; > + case 0xff: > + /* stay in this state */ > + break; > + default: > + sd->sof_read =3D 0; > + } > + break; > + case 3: > + if (m[i] =3D=3D 0xff) > + sd->sof_read =3D 4; > + else > + sd->sof_read =3D 0; > + break; > + case 4: > + switch (m[i]) { > + case 0x96: > + /* Pattern found */ > PDEBUG(D_FRAM, > "SOF found, bytes to analyze: %u." > " Frame starts at byte #%u", > len, i + 1); > sd->sof_read =3D 0; > return m + i + 1; > + break; > + case 0xff: > + sd->sof_read =3D 2; > + break; > + default: > + sd->sof_read =3D 0; > } > - } else { > + break; > + default: > sd->sof_read =3D 0; > } > } >=20 --------------010600030802050504020505 Content-Type: text/x-csrc; name="test_pac_find_sof.c" Content-Disposition: inline; filename="test_pac_find_sof.c" Content-Transfer-Encoding: quoted-printable /* Test the function pac_find_sof() from file linux/drivers/media/video/gspca/pac_common.h Test based on Linux kernel 2.6.32-rc1 Written by M=C3=A1rton N=C3=A9meth , 4 Oct 2009 Released under GPL */ #include struct sd { unsigned int sof_read; }; struct gspca_dev { struct sd* sd; }; #define PDEBUG(level, fmt, args...) \ do {\ printf("PDEBUG: " fmt "\n", ## args); \ } while (0) #include "pac_common.h" int tc1() { static unsigned char test[] =3D { 0xff, 0xff, 0x00, 0xff, 0x96 }; unsigned char* p; struct sd sd; int result =3D 0; printf("Test case 1: exact match\n"); sd.sof_read =3D 0; p =3D pac_find_sof((struct gspca_dev*)&sd, test, sizeof(test)); if (p =3D=3D &test[5]) { printf("PASSED\n"); } else { printf("FAILED\n"); result =3D 1; } printf("\n"); return result; } int tc2() { static unsigned char test[] =3D { 0x00, 0xff, 0xff, 0x00, 0xff, 0x96 }; unsigned char* p; struct sd sd; int result =3D 0; printf("Test case 2: offset 1\n"); sd.sof_read =3D 0; p =3D pac_find_sof((struct gspca_dev*)&sd, test, sizeof(test)); if (p =3D=3D &test[6]) { printf("PASSED\n"); } else { printf("FAILED\n"); result =3D 1; } printf("\n"); return result; } int tc3() { static unsigned char test[] =3D { 0xff, 0xff, 0xff, 0x00, 0xff, 0x96 }; unsigned char* p; struct sd sd; int result =3D 0; printf("Test case 3: offset 1, first byte may be misleading\n"); sd.sof_read =3D 0; p =3D pac_find_sof((struct gspca_dev*)&sd, test, sizeof(test)); if (p =3D=3D &test[6]) { printf("PASSED\n"); } else { printf("FAILED\n"); result =3D 1; } printf("\n"); return result; } int tc4() { static unsigned char test[] =3D { 0xff, 0x00, 0xff, 0xff, 0x00, 0xff, 0x= 96 }; unsigned char* p; struct sd sd; int result =3D 0; printf("Test case 4: offset 2, first two bytes may be misleading\n"); sd.sof_read =3D 0; p =3D pac_find_sof((struct gspca_dev*)&sd, test, sizeof(test)); if (p =3D=3D &test[7]) { printf("PASSED\n"); } else { printf("FAILED\n"); result =3D 1; } printf("\n"); return result; } int tc5() { static unsigned char test[] =3D { 0xff, 0xff, 0x00, 0xff, 0xff, 0x00, 0x= ff, 0x96 }; unsigned char* p; struct sd sd; int result =3D 0; printf("Test case 5: offset 3, first three bytes may be misleading\n"); sd.sof_read =3D 0; p =3D pac_find_sof((struct gspca_dev*)&sd, test, sizeof(test)); if (p =3D=3D &test[8]) { printf("PASSED\n"); } else { printf("FAILED\n"); result =3D 1; } printf("\n"); return result; } int tc6() { static unsigned char test[] =3D { 0xff, 0xff, 0x00, 0xff, 0xff, 0xff, 0x= 00, 0xff, 0x96 }; unsigned char* p; struct sd sd; int result =3D 0; printf("Test case 6: offset 4, first four bytes may be misleading\n"); sd.sof_read =3D 0; p =3D pac_find_sof((struct gspca_dev*)&sd, test, sizeof(test)); if (p =3D=3D &test[9]) { printf("PASSED\n"); } else { printf("FAILED\n"); result =3D 1; } printf("\n"); return result; } int tc7() { static unsigned char test1[] =3D { 0xff, 0xff, 0x00, 0xff }; static unsigned char test2[] =3D { 0x96 }; unsigned char* p1; unsigned char* p2; struct sd sd; int result =3D 0; printf("Test case 7: pattern starts at end of packet and continues in th= e next one\n"); sd.sof_read =3D 0; p1 =3D pac_find_sof((struct gspca_dev*)&sd, test1, sizeof(test1)); p2 =3D pac_find_sof((struct gspca_dev*)&sd, test2, sizeof(test2)); if (p1 =3D=3D NULL && p2 =3D=3D &test2[1]) { printf("PASSED\n"); } else { printf("FAILED\n"); result =3D 1; } printf("\n"); return result; } int tc8() { static unsigned char test1[] =3D { 0xff, 0xff, 0xff, 0x00, 0xff }; static unsigned char test2[] =3D { 0x96 }; unsigned char* p1; unsigned char* p2; struct sd sd; int result =3D 0; printf("Test case 8: splited pattern, with misleading first byte\n"); sd.sof_read =3D 0; p1 =3D pac_find_sof((struct gspca_dev*)&sd, test1, sizeof(test1)); p2 =3D pac_find_sof((struct gspca_dev*)&sd, test2, sizeof(test2)); if (p1 =3D=3D NULL && p2 =3D=3D &test2[1]) { printf("PASSED\n"); } else { printf("FAILED\n"); result =3D 1; } printf("\n"); return result; } int tc9() { static unsigned char test1[] =3D { 0xff, 0xff, 0x00, 0xff, 0xff, 0x00, 0= xff }; static unsigned char test2[] =3D { 0x96 }; unsigned char* p1; unsigned char* p2; struct sd sd; int result =3D 0; printf("Test case 9: splited pattern, with misleading first three bytes\= n"); sd.sof_read =3D 0; p1 =3D pac_find_sof((struct gspca_dev*)&sd, test1, sizeof(test1)); p2 =3D pac_find_sof((struct gspca_dev*)&sd, test2, sizeof(test2)); if (p1 =3D=3D NULL && p2 =3D=3D &test2[1]) { printf("PASSED\n"); } else { printf("FAILED\n"); result =3D 1; } printf("\n"); return result; } int tc10() { static unsigned char test[] =3D { 0xff, 0xaa, 0xff, 0x00, 0xff, 0x96 }; unsigned char* p; struct sd sd; int result =3D 0; printf("Test case 10: no match, extra byte at offset 1\n"); sd.sof_read =3D 0; p =3D pac_find_sof((struct gspca_dev*)&sd, test, sizeof(test)); if (p =3D=3D NULL) { printf("PASSED\n"); } else { printf("FAILED\n"); result =3D 1; } printf("\n"); return result; } int tc11() { static unsigned char test[] =3D { 0xff, 0xff, 0xaa, 0x00, 0xff, 0x96 }; unsigned char* p; struct sd sd; int result =3D 0; printf("Test case 11: no match, extra byte at offset 2\n"); sd.sof_read =3D 0; p =3D pac_find_sof((struct gspca_dev*)&sd, test, sizeof(test)); if (p =3D=3D NULL) { printf("PASSED\n"); } else { printf("FAILED\n"); result =3D 1; } printf("\n"); return result; } int tc12() { static unsigned char test[] =3D { 0xff, 0xff, 0x00, 0xaa, 0xff, 0x96 }; unsigned char* p; struct sd sd; int result =3D 0; printf("Test case 12: no match, extra byte at offset 3\n"); sd.sof_read =3D 0; p =3D pac_find_sof((struct gspca_dev*)&sd, test, sizeof(test)); if (p =3D=3D NULL) { printf("PASSED\n"); } else { printf("FAILED\n"); result =3D 1; } printf("\n"); return result; } int tc13() { static unsigned char test[] =3D { 0xff, 0xff, 0x00, 0xff, 0xaa, 0x96 }; unsigned char* p; struct sd sd; int result =3D 0; printf("Test case 13: no match, extra byte at offset 4\n"); sd.sof_read =3D 0; p =3D pac_find_sof((struct gspca_dev*)&sd, test, sizeof(test)); if (p =3D=3D NULL) { printf("PASSED\n"); } else { printf("FAILED\n"); result =3D 1; } printf("\n"); return result; } int main() { int result =3D 0; result +=3D tc1(); result +=3D tc2(); result +=3D tc3(); result +=3D tc4(); result +=3D tc5(); result +=3D tc6(); result +=3D tc7(); result +=3D tc8(); result +=3D tc9(); result +=3D tc10(); result +=3D tc11(); result +=3D tc12(); result +=3D tc13(); return result; } --------------010600030802050504020505 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline ------------------------------------------------------------------------------ Come build with us! The BlackBerry® Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9-12, 2009. Register now! http://p.sf.net/sfu/devconf --------------010600030802050504020505 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Ltp-list mailing list Ltp-list@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ltp-list --------------010600030802050504020505--