Exhibit 99.1

CERTIFICATION PURSUANT TO
18 U.S.C. SECTION 1350,
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Sonic Solutions (the “Company”) on Form 10-Q for the period ending December 31, 2002 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Robert J. Doris, President of the Company, certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, that, to the best of my knowledge:

          (1) The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

          (2) The information contained in the Report fairly presents, in all material respects, the financial condition and result of operations of the Company.

By:	/s/  ROBERT J. DORIS
Name:	Robert J. Doris
Title:	President

In connection with the Quarterly Report of Sonic Solutions (the “Company”) on Form 10-Q for the period ending December 31, 2002 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, A. Clay Leighton, Chief Financial Officer of the Company, certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, that, to the best of my knowledge:

          (1) The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

          (2) The information contained in the Report fairly presents, in all material respects, the financial condition and result of operations of the Company.

By:	/s/  A. CLAY LEIGHTON
Name:	A. Clay Leighton
Title:	Senior Vice President of Worldwide Operations and Finance and Chief Financial Officer