<PAGE>   1
                                                                    EXHIBIT 10.7


                                                                  EXECUTION COPY












                          SECURITIES PURCHASE AGREEMENT




                                 BY AND BETWEEN


                            C-CUBE SEMICONDUCTOR INC.

                             A DELAWARE CORPORATION


                                       AND


                             THOMSON MULTIMEDIA S.A.

                            A FRENCH SOCIETE ANONYME








                                FEBRUARY 10, 2000



<PAGE>   2


                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                              PAGE
                                                                                              ----
<S>     <C>                                                                                     <C>
1.      Issuance and Sale of the Securities......................................................1
        1.1    Issuance and Sale of Common Stock and Warrant.....................................1
        1.2    Closing...........................................................................2
        1.3    Closing Deliveries................................................................2

2.      Representations and Warranties of the Company............................................3

        2.1    Organization, Standing and Power..................................................3
        2.2    Authority; No Conflicts...........................................................3
        2.3    Capitalization....................................................................3
        2.4    Subsidiaries......................................................................4
        2.5    Valid Issuance of Securities......................................................4
        2.6    Governmental Consents.............................................................4
        2.7    Litigation........................................................................4
        2.8    Intellectual Property.............................................................5
        2.9    Compliance with Other Instruments.................................................5
        2.10   Material Contracts and Commitments................................................5
        2.11   Title to Property.................................................................6
        2.12   Financial Statements..............................................................6
        2.13   Changes...........................................................................6
        2.14   Outstanding Indebtedness; Material Liabilities....................................7
        2.15   Permits...........................................................................8
        2.16   Environmental and Safety Laws.....................................................8
        2.17   SEC Filings.......................................................................8
        2.18   Brokers' and Finder's Fees........................................................8

3.      Representations and Warranties of the Purchaser..........................................8

        3.1    Organization and Standing.........................................................8
        3.2    Authority.........................................................................8
        3.3    No Conflicts......................................................................9
        3.4    Brokers' and Finder's Fees........................................................9
        3.5    Purchase Entirely for Own Account.................................................9
        3.6    Accredited Investor; Investment Experience........................................9
        3.7    Restricted Securities.............................................................9
        3.8    Legends..........................................................................10

4.      Standstill Restrictions.................................................................10

        4.1    Scope of Restrictions............................................................10

5.      The Company's Right of First Refusal....................................................11

        5.1    Exercise of Right................................................................11
</TABLE>


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                                       9
<PAGE>   3

                                TABLE OF CONTENTS
                                   (CONTINUED)

<TABLE>
<CAPTION>
                                                                                              PAGE
                                                                                              ----
<S>     <C>                                                                                     <C>
        5.2    Assignment of Right..............................................................12

6.      Conditions to the Issuance and Sale of the Securities...................................12

        6.1    Conditions to Obligations of the Parties.........................................12
        6.2    Additional Conditions of Purchaser's Obligations at Closing......................12
        6.3    Additional Conditions of the Company's Obligations at the Closing................13

7.      Additional Agreements...................................................................13

        7.1    Expenses.........................................................................13
        7.2    Public Disclosure................................................................13
        7.3    Additional Documents and Further Assurances......................................13

8.      Termination.............................................................................13


9.      Miscellaneous...........................................................................14

        9.1    Survival of Warranties...........................................................14
        9.2    Transfer, Successors and Assigns.................................................14
        9.3    Governing Law....................................................................14
        9.4    Counterparts.....................................................................14
        9.5    Titles and Subtitles; Headings...................................................14
        9.6    Notices..........................................................................14
        9.7    Attorneys' Fees..................................................................15
        9.8    Amendments and Waivers...........................................................15
        9.9    Severability.....................................................................15
        9.10   Entire Agreement.................................................................15
        9.11   Remedies.........................................................................15
        9.12   Extension; Waiver................................................................16
        9.13   Mutual Drafting..................................................................16
        9.14   Venue............................................................................16
</TABLE>

                                    EXHIBITS


EXHIBIT A  Form of Warrant
EXHIBIT B  Memorandum of Understanding



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                          SECURITIES PURCHASE AGREEMENT


        THIS SECURITIES PURCHASE AGREEMENT (the "AGREEMENT") is made as of
February 10, 2000 by and between C-Cube Semiconductor Inc., a Delaware
corporation (the "COMPANY") and wholly owned subsidiary of C-Cube Microsystems
Inc., a Delaware corporation (the "PARENT"), and Thomson Multimedia S.A., a
French societe anonyme (the "PURCHASER").

                                   WITNESSETH

        WHEREAS, Parent and Harmonic Inc., a Delaware corporation ("HARMONIC"),
have entered into an Amended and Restated Agreement and Plan of Merger and
Reorganization, dated as of December 9, 1999 (the "MERGER AGREEMENT"), which
provides that: (i) all shares of capital stock of the Company will be
distributed to Parent's stockholders, on a pro rata, as converted basis in
accordance with the shares of Parent common stock held (the "DISTRIBUTION"), and
(ii) shortly after the Distribution, Parent will merge with and into Harmonic
(the "MERGER");

        WHEREAS, subject to the terms and conditions set forth herein, the
Company wishes to issue and sell to the Purchaser, and the Purchaser wishes to
purchase from the Company, conditioned upon and promptly after the Distribution,
certain shares of common stock of the Company ("COMMON STOCK") and a warrant to
purchase shares of Common Stock in the quantities and at the price more fully
set forth herein;

        WHEREAS, the Company and the Purchaser desire to make certain
representations and warranties in connection with the transactions contemplated
hereby.

        NOW, THEREFORE, in consideration of the foregoing premises, the
representations and warranties, covenants and other agreements hereinafter set
forth, the mutual benefits to be gained by the performance thereof, and other
good and valuable consideration, the receipt and legal sufficiency of which are
hereby acknowledged and accepted, the parties hereto hereby agree as follows:

        1. Issuance and Sale of the Securities.

               1.1 Issuance and Sale of Common Stock and Warrant. On the
Closing Date and effective as of the Closing (each as defined in Section 1.2
hereof), upon the terms and subject to the conditions of this Agreement, the
Company shall issue and sell to the Purchaser, and the Purchaser shall purchase
from the Company, 474,747 shares of Common Stock (the "SHARES") and a warrant
substantially in the form attached as Exhibit A hereof, with the terms and
conditions set forth therein, with an exercise price per share equal to the Per
Share Price (as defined below), and exercisable for up to 949,494 shares of
Common Stock (the "WARRANT"). The Shares and the Warrant (together, the
"SECURITIES") will be issued and sold by the Company in exchange from the
Purchaser of cash equal to the Purchase Price (as defined in Section 1.1(a)
hereof).



<PAGE>   5

                      (a) Purchase Price; Per Share Price. The "PURCHASE PRICE"
shall equal the product of (i) 474,747, multiplied by (ii) the Per Share Price.
The "PER SHARE PRICE" shall equal $19.78.

               1.2 Closing. Subject to the satisfaction or waiver of the
conditions set forth in Section 6 hereof, the consummation of the transactions
contemplated hereby pursuant to the terms and provisions hereof (the "CLOSING")
shall take place at the offices of Wilson Sonsini Goodrich & Rosati,
Professional Corporation, located at Spear Street Tower, One Market, San
Francisco, California 94105, unless another place or time is agreed to in
writing by the Company and the Purchaser. The date upon which the Closing occurs
shall be referred to herein as the "CLOSING DATE."

               1.3 Closing Deliveries.

                      (a) Purchaser. At the Closing, on the terms and subject to
the conditions set forth herein and in reliance on the representations and
warranties, covenants and other agreements set forth herein, the Purchaser shall
deliver, or cause to be delivered, to the Company each of the following:

                                 (i) An executed copy of the certificate signed
by an authorized officer of the Company, as described in Section 6.2 (b);

                                 (ii) the Purchase Price, payable by wire
transfer of immediately available funds, to an account or accounts designated in
writing at least five business days prior to the Closing by the Company;

                                 (iii) the executed Memorandum of Understanding,
substantially in the form attached hereto as Exhibit B (the "MOU"); and

                                 (iv) such other agreements, instruments,
certificates and other documents as may be necessary or reasonably appropriate
to effectuate completely the transactions contemplated hereby.

                      (b) Company. At the Closing, on the terms and subject to
the conditions set forth herein and in reliance on the representations and
warranties, covenants and other agreements set forth herein, the Company shall
deliver, or cause to be delivered, to the Purchaser each of the following:

                                 (i) certificate(s) representing the Shares,
validly executed by the appropriate duly authorized officers of the Purchaser
registered in the name of the Purchaser;

                                 (ii) the executed Warrants;

                                 (iii) the executed MOU; and



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                                 (iv) such other agreements, instruments,
certificates and other documents as may be necessary or reasonably appropriate
to effectuate completely the transactions contemplated hereby.

        2. Representations and Warranties of the Company. Except as specifically
set forth in the Disclosure Schedule delivered by the Company herewith (the
"DISCLOSURE SCHEDULE"), the Company hereby represents and warrants to the
Purchaser as follows:

               2.1 Organization, Standing and Power. The Company is a
corporation duly organized, validly existing and in good standing under the laws
of the State of Delaware. The Company has the corporate power to own its
properties and to carry on its business as now being conducted and is duly
qualified to do business and is in good standing in each jurisdiction in which
the failure to be so qualified would have a material adverse effect on the
ability of the Company to consummate the transactions contemplated hereby. The
Company has made available a true and correct copy of the Certificate of
Incorporation and Bylaws of the Company, as amended to date, to counsel for the
Purchaser.

               2.2 Authority; No Conflicts. The Company has all requisite
corporate power and authority to enter into this Agreement, the MOU and, upon
the Closing, to issue the Shares and the Warrant and to consummate the
transactions contemplated hereby and thereby. The execution and delivery of this
Agreement and the MOU and, upon the Closing, the Shares, and the Warrant and the
consummation of the transactions contemplated hereby and thereby have been duly
authorized by all necessary corporate action on the part of the Company, and no
further action is required on the part of Parent to authorize the Agreement and
the MOU, to issue the Shares, and the Warrant and to consummate the transactions
contemplated hereby and thereby. This Agreement and the MOU have been duly
executed and delivered by the Company and constitute or, in the case of the
Warrant, when executed will constitute, a valid and binding obligation of the
Company, enforceable in accordance with their respective terms, except as such
enforceability may be limited by principles of public policy and subject to the
laws of general application relating to bankruptcy, insolvency and the relief of
debtors and to rules of law governing specific performance, injunctive relief or
other equitable remedies. The execution and delivery by the Company of this
Agreement and the MOU and, upon the Closing, the Shares and the Warrant do not,
and the performance and consummation of the transactions contemplated hereby and
thereby will not result in any conflict with (i) any provisions of its
Certificate of Incorporation or Bylaws, (ii) any mortgage, indenture, lease,
contract or other agreement or instrument, permit, concession, franchise or
license to which the Company is subject or (iii) any judgment, order, decree,
statute, law, ordinance, rule or regulation applicable to the Company or its
properties or assets.

               2.3 Capitalization

                      (a) C-Cube Semiconductor. As of January 31, 2000, the
authorized capital of the Company consisted of the following: (i) 10,000,000
shares of preferred stock, $0.001 par value, of which no shares are issued and
outstanding; and (ii) 200,000,000 shares of common stock, $0.001 par value, of
which no shares are issued and outstanding. There are no outstanding



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options, warrants, rights (including conversion or preemptive rights) or
agreements for the purchase or acquisition from the Company of any shares of its
capital stock.

                      (b) C-Cube Microsystems. As of January 31, 2000, the
authorized capital stock of the C-Cube Microsystems Inc. ("C-CUBE MICROSYSTEMS")
consisted of the following: (i) 5,000,000 shares of preferred stock, $ 0.001 par
value, of which no shares are issued and outstanding; and (ii) 150,000,000
shares of common stock, $0.001 par value, of which 40,052,172 shares are issued
and outstanding. All shares of capital stock of C-Cube Microsystems have been
duly authorized and validly issued and are fully paid and nonassessable and were
not issued in violation of any preemptive rights. As of January 31, 2000, there
were outstanding options to purchase 14,105,200 shares of common stock of C-Cube
Microsystems. Except for the Merger transactions, for items set forth in this
Section 2.3 (b), for certain convertible notes from C-Cube Microsystems, and for
changes since January 31, 2000 resulting from the exercise of options
outstanding on such date, there are no other outstanding options, warrants,
rights (including conversion or preemptive rights) or agreements for the
purchase or acquisition from C-Cube Microsystems of any shares of its capital
stock.

               2.4 Subsidiaries. The Company does not currently own or control,
directly or indirectly, any interest in any other corporation, association, or
other business entity which is material to the Company's business.

               2.5 Valid Issuance of Securities. The Shares being issued
hereunder and the shares of Common Stock to be issued pursuant to the Warrant
(collectively, the "TRANSACTION SHARES"), when issued, sold and delivered in
accordance with the terms hereof or thereof, as applicable, for the
consideration expressed herein, will be duly and validly issued, fully paid and
nonassessable. Based in part upon the representations of the Purchaser in this
Agreement and subject to the provisions of Section 2.6 below, the Transaction
Shares will be issued in compliance with all applicable federal and state
securities laws. The Transaction Shares shall be free of any liens or
encumbrances, other than any liens or encumbrances created by the Purchasers;
provided, however, that the Transaction Shares may be subject to restrictions on
transfer under state and/or federal securities laws. The Transaction Shares are
not and will not be subject to any preemptive rights, rights of first refusal,
rights of first offer or other similar rights that have not been properly waived
or complied with.

               2.6 Governmental Consents. No consent, approval or authorization
of or designation, declaration or filing with any governmental authority on the
part of the Company is required in connection with the valid execution and
delivery of this Agreement, the Transaction Shares, or the Warrant or the
consummation of the transactions contemplated hereby or thereby except those
which may be required under applicable federal and state securities laws.

               2.7 Litigation. There is no action, suit, arbitration, proceeding
or investigation pending or to the Company's knowledge, currently threatened
against the Company or its properties before any court, arbitrator or
governmental agency. The Company is not a party or subject to the provisions of
any order, writ, injunction, judgment or decree of any court of government
agency or instrumentality.



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               2.8 Intellectual Property. As of the date of this Agreement, to
the Company's knowledge, the Company has legally enforceable rights to use all
patents, trademarks, service marks, trade names, copyrights, trade secrets,
information, proprietary rights, know-how and processes necessary for its
business as now conducted without any infringement on the rights of others.
Except pursuant to Contracts (as defined in Section 2.10 below) listed in the
Disclosure Schedule, there are no outstanding material options, licenses, or
agreements of any kind relating to the foregoing, nor is the Company bound by or
a party to any options, licenses or agreements of any kind with respect to the
patents, trademarks, service marks, trade names, copyrights, trade secrets,
licenses, information, proprietary rights, know-how and processes of any other
person or entity. To the Company's knowledge, the Company has not violated any
of the patents, trademarks, service marks, trade names, copyrights or trade
secrets or other proprietary rights of any other person or entity. The Company
is not aware that any of its employees is obligated under any contract
(including licenses, covenants or commitments of any nature) or other agreement,
or subject to any judgment, decree or order of any court or administrative
agency, that would interfere with the use of his or her best efforts to promote
the interests of the Company or that would conflict with the Company's business
as currently conducted. Neither the execution nor delivery of this Agreement or
the MOU, nor the carrying on of the Company's business as conducted will, to the
Company's knowledge, conflict with or result in a breach of the terms,
conditions or provisions of, or constitute a default under, any contract,
covenant or instrument under which any of such employees is now obligated.

               2.9 Compliance with Other Instruments. The Company is not in
violation or default of any provisions of its charter documents or of any
instrument, judgment, order, writ, decree or contract to which it is a party or
by which it is bound or, of any provision of federal, state or foreign statute,
rule, regulation, order or restriction applicable to the Company. The execution,
delivery and performance of this Agreement and the MOU will not result in any
such violation or be in conflict with or constitute, with or without the passage
of time and giving of notice, either a default under any such provision,
instrument, judgment, order, writ, decree or contract or an event which results
in the creation of any lien, charge or encumbrance upon any of the properties or
assets of the Company or the suspension, revocation, impairment, forfeiture, or
nonrenewal of any material permit, license, authorization, or approval
applicable to the Company, its business or operations or any of its assets or
properties. No consent, approval, qualification, order or authorization of, or
filing with, any governmental authority, or any consent or approval of any third
party person or entity is required in connection with the Company's valid
execution, delivery or performance of this Agreement, the MOU or the offer, sale
or issuance of the Transaction Shares, or the Warrant, or the consummation of
any other transaction contemplated on the part of the Company hereby, except
those filings which may be required under federal and state securities laws.

               2.10 Material Contracts and Commitments. Except for agreements
explicitly contemplated hereby (the "CONTRACTS"), there are no agreements,
instruments, leases, licenses, commitments or contracts to which the Company is
a party or by which it is bound, which (i) involve provisions restricting the
development, manufacture or distribution of the Company's products or services,
or (ii) involve indemnification by the Company with respect to infringements of
proprietary rights (other than indemnification obligations arising from purchase
and sale



                                      -5-
<PAGE>   9

agreements entered into in the ordinary course of business and ordinary course
licensing agreements entered into with customers of the Company). All of the
Contracts are valid, binding and in full force and effect in all material
respects and enforceable by the Company in accordance with their respective
terms in all material respects, subject to the effect of applicable bankruptcy,
insolvency, reorganization, fraudulent conveyance, moratorium, usury or other
laws of general application relating to or affecting enforcement of creditors'
rights and rules or laws concerning equitable remedies. The Company is not in
material default under any of such Contracts, nor has the Company received
notice that any third party does not intend to renew any material contract it
currently has with the Company, or that any third party intends to terminate any
material contract currently in place with the Company. To the knowledge of the
Company, no other party to any of the Contracts is in material default
thereunder.

               2.11 Title to Property. The Company has good and marketable title
to its property and assets, free and clear of all mortgages, liens, loans and
encumbrances, except such encumbrances and liens which arise in the ordinary
course of business and do not materially impair the Company's ownership or use
of such property or assets. With respect to the property and assets it leases,
the Company is in compliance with such leases and, to its knowledge, holds a
valid leasehold interest free of any liens, claims or encumbrances.

               2.12 Financial Statements. The Purchaser has received the
Company's audited consolidated balance sheet, statements of income, cash flow
and shareholders' equity for the fiscal year ended December 31, 1998, together
with the related opinion of its independent public accountants, and the
Company's unaudited consolidated balance sheet, statement of income cash flow
and shareholders' equity for the nine-month period ended September 30, 1999 (the
"FINANCIAL STATEMENTS"), which are complete and correct in all material respects
and have been prepared in accordance with generally accepted accounting
principles applied on a basis consistent throughout the periods indicated and
consistent with each other, subject to normal end-of-period adjustments. The
Financial Statements fairly present the consolidated financial condition,
operating results and cash flows of the Company as of the respective dates and
for the respective periods indicated.

               2.13 Changes. Except as otherwise disclosed in the Financial
Statements, since September 30, 1999, there has not been:

                      (a) any change in the assets, liabilities, financial
condition or operating results of the Company from that reflected in the
Financial Statements, except changes in the ordinary course of business that
have not been, in the aggregate, materially adverse;

                      (b) any incurrence of any indebtedness for money borrowed;

                      (c) any damage, destruction or loss, whether or not
covered by insurance, materially and adversely affecting the assets, properties,
financial condition, operating results, prospects or business of the Company (as
such business is presently conducted and as it is proposed to be conducted);



                                      -6-
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                      (d) any waiver by the Company of a valuable right or of a
material debt owed to it;

                      (e) any satisfaction or discharge of any lien, claim or
encumbrance or payment of any obligation by the Company, except in the ordinary
course of business and that is not material to the assets, properties, financial
condition, operating results or business of the Company (as such business is
presently conducted and as it is proposed to be conducted);

                      (f) any material change or amendment to a Contract by
which the Company or any of its assets or properties is bound or subject;

                      (g) any material change in any compensation arrangement or
agreement with any employee, contractor or director;

                      (h) any material change in the Company's accounting
methods, principles, or practices;

                      (i) any sale, assignment or transfer of any patents,
trademarks, copyrights, trade secrets or other intangible assets, except
licenses entered into in the ordinary course of business and consistent with
past practices;

                      (j) any mortgage, pledge, transfer of a security interest
in, or lien, created by the Company with respect to any of its material
properties or assets, except liens for taxes not yet payable;

                      (k) any loans or guarantees made by the Company to or for
the benefit of its employees, officers or directors, or any members of their
immediate families, other than travel advances and other advances made in the
ordinary course of its business;

                      (l) any declaration, setting aside or payment of dividends
or other distribution with respect to any of the Company's capital stock or any
direct or indirect redemption, purchase or other acquisition of any of such
stock by the Company; or

                      (m) any agreement or commitment by the Company to perform
any of the acts described in this Section 2.13.

               2.14 Outstanding Indebtedness; Material Liabilities. Except
pursuant to the Contracts or as disclosed in the Financial Statements, the
Company has no material liabilities or obligations exceeding $1,000,000 in the
aggregate, absolute or contingent (individually or in the aggregate), except (i)
liabilities and obligations under a lease for its principal offices and leases
for equipment which do not exceed $5,000,000 in the aggregate, (ii) liabilities
and obligations under sales, procurement and other contracts and arrangements
entered into in the normal course of business, which do not exceed $50,000
individually, or $100,000 in the aggregate, (iii) liabilities incurred in the
ordinary course of business subsequent to September 30, 1999, and (iv)
obligations under contracts and commitments incurred in the ordinary course of
business and not required under



                                      -7-
<PAGE>   11

generally accepted accounting principles to be reflected in the Financial
Statements, which, in all cases, individually or in the aggregate, are not
material to the financial condition or operating results of the Company.

               2.15 Permits. The Company has all franchises, permits, licenses,
and any similar authority necessary for the conduct of its business as now being
conducted by it, the lack of which could reasonably be expected to have a
material adverse effect on the Company. The Company is not in default in any
material respect under any of such franchises, permits, licenses, or other
similar authority.

               2.16 Environmental and Safety Laws. To the Company's knowledge,
the Company is not in violation of any applicable federal, state or local
statute, law or regulation relating to the environment or occupational health
and safety.

               2.17 SEC Filings. The Company has timely and properly filed all
forms, reports, prospectuses and documents required to be filed with the
Securities and Exchange Commission (the "SEC") pursuant to the Securities
Exchange Act of 1934, as amended, including the Report on Form 10, filed with
the SEC on October 29, 1999 (File No. 000-23596), as amended on January 24, 2000
(the "FORM 10") (collectively, the "COMPANY SEC DOCUMENT"). As of its filing
date, each Company SEC Document complied as to form in all material respects
with the applicable requirements of the 1933 Securities Act, as amended (the
"SECURITIES ACT"), and the 1934 Securities Exchange Act, as amended (the
"EXCHANGE ACT"), as the case may be. As of its filing date, each Company SEC
Document filed pursuant to the Exchange Act did not contain any untrue statement
of a material fact or omit to state any material fact necessary in order to make
the statements made therein, in light of the circumstances under which they were
made, not misleading.

               2.18 Brokers' and Finder's Fees. The Company has not incurred,
nor will it incur, directly or indirectly, any liability for brokerage or
finders' fees or agents' commissions or any similar charges in connection with
this Agreement or the MOU, or the consummation of the transactions contemplated
hereby.

        3. Representations and Warranties of the Purchaser. The Purchaser hereby
represents and warrants to the Company that:

               3.1 Organization and Standing. The Purchaser is a corporation
duly organized, validly existing and in good standing under the laws of France.

               3.2 Authority. The Purchaser has all requisite power and
authority to enter into this Agreement and the MOU, to perform its obligations
hereunder, and to consummate the transactions contemplated hereby. The execution
and delivery by the Purchaser of this Agreement and the MOU, the performance by
the Purchaser of its obligations hereunder, and the consummation by the
Purchaser of the transactions contemplated hereby, have been duly authorized by
all necessary corporate action on the part of the Purchaser. This Agreement and
the MOU have been duly executed and delivered by the Purchaser, and constitute a
valid and binding obligation of the Purchaser enforceable against it in
accordance with the terms hereof, except as such enforceability



                                      -8-
<PAGE>   12

may be limited by principles of general application relating to bankruptcy,
insolvency, creditor's rights, and the relief of debtors, and rules of law
governing specific performance, injunctive relief or other equitable remedies.

               3.3 No Conflicts. The execution and delivery by the Purchaser of
this Agreement and the MOU, the performance by the Purchaser of its obligations
hereunder, and the consummation by the Purchaser of the transactions
contemplated hereby, will not (i) give rise to any conflict, violation, default,
termination, cancellation, modification, acceleration or loss under any
provision of the Certificate of Incorporation or Bylaws of the Purchaser, or
(ii) violate any order, injunction, judgment, ruling, law or regulation of any
governmental authority applicable to the Purchaser or any of its properties or
assets. No consent, approval, order or authorization of, or registration,
declaration or filing with, any governmental authority is required by or with
respect to the Purchaser in connection with the execution and delivery by the
Purchaser of this Agreement and the MOU, the performance by the Purchaser of its
obligations hereunder, and the consummation by the Purchaser of the transactions
contemplated hereby, except for such consents, approvals, orders,
authorizations, registrations, declarations and filings as may be required under
applicable state and federal securities and antitrust laws.

               3.4 Brokers' and Finder's Fees. The Purchaser has not incurred,
nor will it incur, directly or indirectly, any liability for brokerage or
finders' fees or agents' commissions or any similar charges in connection with
this Agreement or the MOU, or the consummation of the transactions contemplated
hereby.

               3.5 Purchase Entirely for Own Account. Securities to be acquired
by the Purchaser will be acquired for investment for the Purchaser's own
account, not as a nominee or agent, and not with a view to the resale,
distribution or offering of any part thereof, and the Purchaser has no present
intention of selling, granting any participation in, or otherwise distributing
the same. The Purchaser does not presently have any contract, undertaking,
agreement or arrangement with any person to sell, transfer or grant
participations to such person or to any third person, with respect to any of the
Securities.

               3.6 Accredited Investor; Investment Experience. The Purchaser has
such knowledge and experience in financial and business matters that it is
capable of evaluating the merits and risks of the prospective investment in the
Securities, it is able to bear the economic consequences thereof, and it
qualifies as an "accredited investor" as such term is defined in Rule 501 of
Regulation D promulgated under the Securities Act. Purchaser is experienced in
evaluating and investing in securities of emerging publicly traded high
technology companies and acknowledges that it can bear the economic risk of its
investment. Purchaser has not been formed for the specific purpose of acquiring
the Securities.

               3.7 Restricted Securities. Purchaser understands that the
Securities have not been, and will not be, registered under the Securities Act
or any state securities ("BLUE SKY") law, by reason of a specific exemption from
the registration provisions of the Securities Act and the applicable Blue Sky
laws, which depend upon, among other things, the bona fide nature of the
investment intent and the accuracy of such Purchaser's representations as
expressed herein. Such



                                      -9-
<PAGE>   13

Purchaser understands that as such the Securities are characterized as
"restricted securities" under the Securities Act and that under the Securities
Act and applicable regulations such Securities may be resold without
registration under the Securities Act only in certain limited circumstances. In
this connection, such Purchaser represents that it is familiar with Rule 144
promulgated under the Securities Act, as presently in effect, and understands
the resale limitations imposed thereby and by the Securities Act.

               3.8 Legends. It is understood that the Securities, and any
securities issued in respect thereof or conversion thereof, may bear one or all
of the following legends:

                      (a) "THIS SECURITY AND ANY SHARES OF COMMON STOCK ISSUED
UPON EXERCISE HEREOF HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933,
AS AMENDED, AND HAVE BEEN ACQUIRED FOR INVESTMENT AND NOT WITH A VIEW TO, OR IN
CONNECTION WITH, THE SALE OR DISTRIBUTION THEREOF. NO SUCH SALE OR DISPOSITION
MAY BE EFFECTED WITHOUT AN EFFECTIVE REGISTRATION STATEMENT RELATED THERETO OR
AN OPINION OF COUNSEL SATISFACTORY IN FORM AND SUBSTANCE TO THE COMPANY THAT
SUCH REGISTRATION IS NOT REQUIRED UNDER THE SECURITIES ACT OF 1933, AS AMENDED."

                      (b) Any legend required by the laws of the State of
Delaware or the State of California, including any legend required by the
California Department of Corporations.

                      (c) Any legend required by the Blue Sky laws of any other
state to the extent such laws are applicable to the shares represented by the
certificate so legended.

        4. Standstill Restrictions

               4.1 Scope of Restrictions. At and after the Closing Date, neither
Purchaser nor its directors, officers, employees, agents and advisors
(including, without limitation, financial advisors, attorneys and accountants)
of the Purchaser shall, on behalf of Purchaser or Purchaser's affiliates,
without the prior written consent of the Company:

                      (a) Acquire, offer to acquire, or agree to acquire,
directly or indirectly, by purchase or otherwise, any voting securities or
direct or indirect rights to acquire any voting securities of the Company any
subsidiary thereof, or of any successor to or person in control of the Company,
or any assets of the Company or any subsidiary or division thereof or of any
such successor or controlling person;

                      (b) Make, or in any way participate, directly or
indirectly, in any "solicitation" of "proxies" to vote (as such terms are used
in the rules of the SEC), or seek to advise or influence any person or entity
with respect to the voting of any voting securities of the Company;



                                      -10-
<PAGE>   14

                      (c) Make any public announcement with respect to, or
submit a proposal for, or offer of (with or without conditions) any
extraordinary transaction involving the Company or any of its securities or
assets;

                      (d) Form, join or in any way participate in a "group" as
defined in Section 13(d)(3) of the Exchange Act, in connection with any of the
foregoing;

                      (e) Otherwise act or seek to control or influence the
management, board of directors or policies of the Company;

                      (f) Take any action that could reasonably be expected to
require the Company to make a public announcement regarding the possibility of
any of the events described in clauses (a) through (e) above; or

                      (g) Request the Company directly or indirectly, to amend
or waive any provision of this paragraph.

        5. The Company's Right of First Refusal.

               5.1 Exercise of Right. Prior to Purchaser effecting any direct
or indirect, sale, transfer, pledge, contract to sell, sale of any option or
contract to purchase, purchase of any option or contract to sell, grant of any
option, right or warrant to purchase, transfer the economic risk of ownership
of, or otherwise dispose of, Shares representing 33% or more of the total shares
of Common Stock of the Company originally held by Purchaser immediately after
the Closing, on an as-converted to Common Stock basis (a "TRANSFER"), the
Company shall have a first refusal right to purchase such Shares on the
following terms and conditions:

                      (a) Purchaser shall give prior notice (the "TRANSFER
NOTICE") to the Company in writing of such intention, specifying the name of the
proposed purchaser or transferee, the number of Shares proposed to be the
subject of such Transfer, the proposed price therefor and the other material
terms upon which such disposition is proposed to be made.

                      (b) The Company shall have the right, exercisable by
written notice given by the Company to Purchaser within ten (10) business days
after receipt of such Transfer Notice (the "RESPONSE NOTICE"), to purchase all
or any portion of the Shares specified in such Transfer Notice for cash at the
price per share specified in the Transfer Notice or, if consideration other than
cash is specified in the Transfer Notice, in an amount equal to the fair market
value of such non-cash consideration. Such right shall not be conditional upon
the Company having sufficient financing, at the time the right arises, to
purchase the Shares; provided, however, in any event, the Company is required to
obtain such financing within the time period set forth in Section 5.1(c).

                      (c) If the Company exercises its right of first refusal
hereunder, the closing of the purchase of the Shares with respect to which such
right has been exercised shall take place within thirty (30) calendar days after
the Company gives the Response Notice to Purchaser. Upon exercise of its right
of first refusal, the Company and Purchaser shall be legally obligated to



                                      -11-
<PAGE>   15

consummate the purchase and sale contemplated thereby and shall use their best
efforts to secure any approvals required in connection therewith.

                      (d) If the Company does not exercise its right of first
refusal hereunder within the time specified for such exercise in subparagraph
(b) above or close within the time period specified in Section 5.1(c) with
respect to all of the Shares specified in such Transfer Notice, such Purchaser
shall be free, during the period of ninety (90) calendar days following the
expiration of such time for exercise, to Transfer or tender for Transfer those
Shares specified in such Transfer Notice with respect to which the Company has
not exercised its first refusal rights to the proposed purchaser or transferee
specified in such Transfer Notice and on terms not materially less favorable to
Purchaser than the terms specified in such Transfer Notice.

                      (e) Notwithstanding the above, a transfer of Common Stock
by Purchaser either to a "qualified institutional buyer," as such term is
defined in Rule 144A of the Securities Act of 1933, as amended, or to a wholly
owned subsidiary, or direct or indirect corporate parent, of Purchaser shall not
be deemed a "Transfer" for purposes of this Section 5.

               5.2 Assignment of Right. The Company may assign its right of
first refusal under this Section 5 to any direct affiliate of Company or a
successor entity in a merger acquisition that succeeds to all of the Company's
rights and obligations under this Agreement; provided, however, in the event of
a sale of the substantially all of the assets, share purchase or other business
combination that the Company shall be liable for the timely performance of any
obligations in this Section 5 by such assignee.

        6. Conditions to the Issuance and Sale of the Securities.

               6.1 Conditions to Obligations of the Parties. The respective
obligations of each party to this Agreement shall be subject to the satisfaction
at or prior to the Closing Date of the following conditions:

                      (a) Government Approvals. The Company and Purchaser shall
have obtained all authorizations, consents, orders and approvals required from
or of, or declarations or filings with, or expirations of waiting periods
imposed by, any governmental body required for the consummation of the
transactions contemplated by this Agreement.

                      (b) Consummation of the Distribution. The Distribution,
pursuant to the terms described in the Form 10, shall have been consummated.

               6.2 Additional Conditions of Purchaser's Obligations at Closing.
The obligations of the Purchaser to the Company under this Agreement are
additionally subject to the fulfillment or waiver on or before the Closing, of
each of the following conditions:

                      (a) Representations and Warranties. The representations
and warranties of the Company contained in Section 2 shall be true in all
material respects on and as of



                                      -12-
<PAGE>   16

the Closing Date with the same effect as though such representations and
warranties had been made on and as of the Closing Date (other than such
representations and warranties as are made as of another date, which
representations and warranties shall continue to be true and correct as of such
particular date), except for failures to be true and correct that do not in the
aggregate constitute a Material Adverse Effect. "MATERIAL ADVERSE EFFECT" shall
mean any change in, or effect on, the business of the Company (as conducted as
of the date of this Agreement) (the "BUSINESS") that is materially adverse to
the results of operations or the financial condition of the Business, taken as a
whole.

                      (b) Officer's Certificate. The Company shall have provided
a certificate signed by a duly authorized officer of the Company to the effect
that the condition contained in Section 6.2(a) has been met.

               6.3 Additional Conditions of the Company's Obligations at the
Closing. The obligations of the Company to the Purchaser under this Agreement
are subject to the fulfillment or waiver, on or before the Closing, of the
following condition:

                      (a) Representations and Warranties. The representations
and warranties of the Purchaser contained in Section 3 shall be true in all
material respects on and as of the Closing Date with the same effect as though
such representations and warranties had been made on and as of the Closing Date
(other than such representations and warranties as are made as of another date,
which representations and warranties shall continue to be true and correct as of
such particular date).

        7. Additional Agreements.

               7.1 Expenses. Whether or not this Agreement and the transactions
contemplated hereby are consummated, all expenses incurred by a party in
connection with the transactions contemplated by this Agreement, including
without limitation, all legal, accounting, financial advisory, consulting and
all other fees and expenses of third parties ("THIRD PARTY EXPENSES") incurred
in connection with the negotiation and effectuation of the terms and conditions
of this Agreement and the transactions contemplated hereby, shall be the
obligation of the respective party incurring such fees and expenses.

               7.2 Public Disclosure. The Company and the Purchaser shall
consult with each other before issuing any press release or otherwise making any
public statements with respect to this Agreement or any of the transactions
contemplated by the foregoing and shall not issue any such press release or make
any such public statement without the other party's prior written consent,
except as may be required by law, the Nasdaq Stock Market, or any listing
agreement with a national securities exchange.

               7.3 Additional Documents and Further Assurances. Each party
hereto, at the request of the other party hereto, shall execute and deliver such
other instruments and do and perform such other acts and things as may be
necessary or desirable for effecting completely the consummation of this
Agreement and the transactions contemplated hereby.

        8. Termination. This Agreement shall terminate and the transactions
contemplated hereby abandoned at any time prior to the Closing if the Merger
Agreement is terminated pursuant to



                                      -13-
<PAGE>   17

its terms or by the mutual consent of the parties, in such case the termination
of this Agreement shall be as of the time of such termination.

        9. Miscellaneous.

               9.1 Survival of Warranties. The warranties, representations and
covenants of the Company and the Purchaser contained in or made pursuant to this
Agreement shall not survive the execution and delivery of this Agreement and the
Closing and shall in no way be affected by any investigation of the subject
matter thereof made by or on behalf of the Purchaser or the Company.

               9.2 Transfer, Successors and Assigns. The terms and conditions
of this Agreement shall inure to the benefit of and be binding upon the
respective successors and assigns of the parties. Nothing in this Agreement,
express or implied, is intended to confer upon any party other than the parties
hereto or their respective successors and assigns any rights, remedies,
obligations, or liabilities under or by reason of this Agreement, except as
expressly provided in this Agreement.

               9.3 Governing Law. This Agreement shall be governed by and
construed under the laws of the State of California as applied to agreements
among California residents entered into and to be performed entirely within
California.

               9.4 Counterparts. This Agreement may be executed in two or
more counterparts, each of which shall be deemed an original but all of which
together shall constitute one and the same instrument.

               9.5 Titles and Subtitles; Headings. The titles and subtitles
used in this Agreement are used for convenience only and are not to be
considered in construing or interpreting this Agreement. The table of contents
and headings contained in this Agreement are for convenience of reference only
and shall not affect in any way the meaning or interpretation of this Agreement,
or any of the terms and provisions hereof.

               9.6 Notices. All notices and other communications hereunder
shall be in writing and shall be deemed given if delivered personally or by a
recognized commercial overnight delivery service, or mailed by registered or
certified mail (return receipt requested) or sent via facsimile (with
acknowledgment of complete transmission) to the parties at the following
addresses (or at such other address for a party as shall be specified by like
notice):

                (a) if to the Purchaser, to:  Thomson Multimedia S.A.
                                              46 Quai A LeGallo
                                              92100 Boulogne
                                              France
                                              Attention: Chief Executive Officer
                                              Facsimile No.: 331-4126-6400



                                      -14-
<PAGE>   18

                    with a copy to:           Morrison & Foerster LLP
                                              425 Market Street
                                              San Francisco, CA 94105
                                              Attention: Robert Townsend, Esq.
                                              Facsimile No.: (415) 268-7522

                (b) if to the Company, to:    C-Cube Semiconductor Inc.
                                              1778 McCarthy Boulevard
                                              Milpitas, CA 95035
                                              Attention: Chief Executive Officer
                                              Facsimile No.: (408) 490-8402

                       with a copy to:        Wilson Sonsini Goodrich & Rosati
                                              Professional Corporation
                                              Spear Street Tower, One Market
                                              San Francisco, CA 94105
                                              Attention: Steve L. Camahort, Esq.
                                              Facsimile No.: (415) 947-2099

               9.7 Attorneys' Fees. If any action at law or in equity is
necessary to enforce the terms of this Agreement, the prevailing party shall be
entitled to reasonable attorney's fees, costs and necessary disbursements in
addition to any other relief to which such party may be entitled.

               9.8 Amendments and Waivers. Any term of this Agreement may be
amended and the observance of any term of this Agreement may be waived (either
generally or in a particular instance and either retroactively or
prospectively), only with the written consent of the Company and the Purchaser.
Any amendment or waiver effected in accordance with this Section shall be
binding upon each transferee of any Securities, each future holder of all such
Securities, and the Company.

               9.9 Severability. In the event that any provision of this
Agreement or the application thereof, becomes or is declared by a court of
competent jurisdiction to be illegal, void or unenforceable, the remainder of
this Agreement will continue in full force and effect and the application of
such provision to other persons or circumstances will be interpreted so as
reasonably to effect the intent of the parties hereto. The parties further agree
to replace such void or unenforceable provision of this Agreement with a valid
and enforceable provision that will achieve, to the extent possible, the
economic, business and other purposes of such void or unenforceable provision.

               9.10 Entire Agreement. This Agreement and the exhibits hereto,
together with the MOU and the Warrant, constitute the entire agreement between
the parties hereto pertaining to the purchase of the Securities.

               9.11 Remedies. The Purchaser and the Company agree that
monetary damages would not be adequate compensation for any loss incurred by
reason of a breach by it of the provisions of this Agreement and each hereby
agrees to waive the defense in any action for specific



                                      -15-
<PAGE>   19

performance that a remedy at law would be adequate. Accordingly, it is agreed
that the Company or the Purchaser, as the case may be, shall be entitled to an
injunction, restraining order or other equitable relief to prevent breaches of
this Agreement and to enforce specifically the terms and provisions hereof in
any court of competent jurisdiction in the United States or any state thereof.
Such remedies shall be cumulative and non-exclusive and shall be in addition to
any other rights and remedies the parties may have under the Agreement.

               9.12 Extension; Waiver. At any time, the Purchaser and the
Company may, to the extent legally allowed, (i) extend the time for the
performance of any of the obligations of the other party hereto, (ii) waive any
inaccuracies in the representations and warranties made to such party contained
herein or in any document delivered pursuant hereto, and (iii) waive compliance
with any of the agreements or conditions for the benefit of such party contained
herein. Any agreement on the part of a party hereto to any such extension or
waiver shall be valid only if set forth in an instrument in writing signed on
behalf of such party.

               9.13 Mutual Drafting. Both parties waive the application of any
law, resolution, holding or rule of construction providing that ambiguities in
an agreement or other document will be construed against the party drafting such
agreement or document.

               9.14 Venue. Any legal action or other legal proceeding relating
to this Agreement, the MOU (as to the confidentiality and publicity provisions
only), or the Warrant, or the transactions contemplated hereby or thereby, may
be brought or otherwise commenced in any state or federal court located in the
County of San Francisco, California. Each of the parties hereto (i) expressly
and irrevocably consents and submits to the jurisdiction of each state and
federal court located in the County of San Francisco, California in connection
with any such legal proceeding, including to enforce any settlement, order or
award, (ii) agrees that each state and federal court located in the County of
San Francisco, California shall be deemed to be a convenient forum, and (iii)
waives and agrees not to assert (by way of motion, as a defense or otherwise),
in any such legal proceeding commenced in any state or federal court located in
the County of San Francisco, California, any claim that such party is not
subject personally to the jurisdiction of such court, that such legal proceeding
has been brought in an inconvenient forum, that the venue of such proceeding is
improper or that the subject matter hereof or thereof may not be enforced by
such court. Each party hereto agrees to the entry of any order to enforce any
resolution, settlement, order or award made pursuant to this Section 9.14 by the
state and federal courts located in the County of San Francisco, California and
in connection therewith hereby waives, and agrees not to assert by way of
motion, as a defense, or otherwise, any claim that such resolution, settlement,
order or award is inconsistent with or violative of the laws or public policy of
the laws of the State of California or any other jurisdiction.


                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]




                                      -16-
<PAGE>   20


        IN WITNESS WHEREOF, the parties have executed this Securities Purchase
Agreement as of the date first above written.

COMPANY:

C-CUBE SEMICONDUCTOR INC.
a Delaware corporation


By: ________________________________
    Name:
    Title:


PURCHASER:

THOMSON MULTIMEDIA S.A.
a French societe anonyme


By: ________________________________
    Name:
    Title:











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