media/base/cdm_context.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef MEDIA_BASE_CDM_CONTEXT_H_
   6 #define MEDIA_BASE_CDM_CONTEXT_H_
   7
   8 #include "base/callback.h"
   9 #include "base/macros.h"
  10 #include "media/base/media_export.h"
  11
  12 namespace media {
  13
  14 class Decryptor;
  15
  16 // An interface representing the context that a media pipeline needs from a
  17 // content decryption module (CDM) to decrypt (and decode) encrypted buffers.
  18 // Only used for implementing SetCdm().
  19 class MEDIA_EXPORT CdmContext {
  20  public:
  21   // Indicates an invalid CDM ID. See GetCdmId() for details.
  22   static const int kInvalidCdmId = 0;
  23
  24   virtual ~CdmContext();
  25
  26   // Gets the Decryptor object associated with the CDM. Returns nullptr if the
  27   // CDM does not support a Decryptor. Must not return nullptr if GetCdmId()
  28   // returns kInvalidCdmId. The returned object is only guaranteed to be valid
  29   // during the CDM's lifetime.
  30   virtual Decryptor* GetDecryptor() = 0;
  31
  32   // Returns an ID that identifies a CDM, or kInvalidCdmId. The interpretation
  33   // is implementation-specific; current implementations use the ID to locate a
  34   // remote CDM in a different process. The return value will not be
  35   // kInvalidCdmId if GetDecryptor() returns nullptr.
  36   virtual int GetCdmId() const = 0;
  37
  38  protected:
  39   CdmContext();
  40
  41  private:
  42   DISALLOW_COPY_AND_ASSIGN(CdmContext);
  43 };
  44
  45 // An interface for looking up CdmContext objects by the CDM ID.
  46 class MEDIA_EXPORT CdmContextProvider {
  47  public:
  48   virtual ~CdmContextProvider();
  49
  50   // Returns the CdmContext corresponding to |cdm_id|. Returns nullptr if no
  51   // such CdmContext can be found.
  52   // Note: Calling GetCdmId() on the returned CdmContext returns kInvalidCdmId
  53   // (in all current cases) because the CDM will be local in the process where
  54   // GetCdmContext() is called.
  55   virtual CdmContext* GetCdmContext(int cdm_id) = 0;
  56
  57  protected:
  58   CdmContextProvider();
  59
  60  private:
  61   DISALLOW_COPY_AND_ASSIGN(CdmContextProvider);
  62 };
  63
  64 // Callback to notify that the CdmContext has been completely attached to
  65 // the media pipeline. Parameter indicates whether the operation succeeded.
  66 typedef base::Callback<void(bool)> CdmAttachedCB;
  67
  68 // A dummy implementation of CdmAttachedCB.
  69 MEDIA_EXPORT void IgnoreCdmAttached(bool success);
  70
  71 }  // namespace media
  72
  73 #endif  // MEDIA_BASE_CDM_CONTEXT_H_