1 // Copyright 2013 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 // The file defines the symbols from OpenSLES that android is using. It then
6 // loads the library dynamically on first use.
7
8 // The openSLES API is using constant as part of the API. This file will define
9 // proxies for those constants and redefine those when the library is first
10 // loaded. For this, it need to be able to change their content and so import
11 // the headers without const. This is correct because OpenSLES.h is a C API.
12 #define const
13 #include <SLES/OpenSLES.h>
14 #include <SLES/OpenSLES_Android.h>
15 #undef const
16
17 #include "base/basictypes.h"
18 #include "base/files/file_path.h"
19 #include "base/logging.h"
20 #include "base/native_library.h"
21
22 // The constants used in chromium. SLInterfaceID is actually a pointer to
23 // SLInterfaceID_. Those symbols are defined as extern symbols in the OpenSLES
24 // headers. They will be initialized to their correct values when the library is
25 // loaded.
26 SLInterfaceID SL_IID_ENGINE = NULL;
27 SLInterfaceID SL_IID_ANDROIDSIMPLEBUFFERQUEUE = NULL;
28 SLInterfaceID SL_IID_ANDROIDCONFIGURATION = NULL;
29 SLInterfaceID SL_IID_RECORD = NULL;
30 SLInterfaceID SL_IID_BUFFERQUEUE = NULL;
31 SLInterfaceID SL_IID_VOLUME = NULL;
32 SLInterfaceID SL_IID_PLAY = NULL;
33
34 namespace {
35
36 // The name of the library to load.
37 const char kOpenSLLibraryName[] = "libOpenSLES.so";
38
39 // Loads the OpenSLES library, and initializes all the proxies.
IntializeLibraryHandle()40 base::NativeLibrary IntializeLibraryHandle() {
41 base::NativeLibrary handle =
42 base::LoadNativeLibrary(base::FilePath(kOpenSLLibraryName), NULL);
43 DCHECK(handle) << "Unable to load " << kOpenSLLibraryName;
44
45 // Setup the proxy for each symbol.
46 // Attach the symbol name to the proxy address.
47 struct SymbolDefinition {
48 const char* name;
49 SLInterfaceID* sl_iid;
50 };
51
52 // The list of defined symbols.
53 const SymbolDefinition kSymbols[] = {
54 {"SL_IID_ENGINE", &SL_IID_ENGINE},
55 {"SL_IID_ANDROIDSIMPLEBUFFERQUEUE", &SL_IID_ANDROIDSIMPLEBUFFERQUEUE},
56 {"SL_IID_ANDROIDCONFIGURATION", &SL_IID_ANDROIDCONFIGURATION},
57 {"SL_IID_RECORD", &SL_IID_RECORD},
58 {"SL_IID_BUFFERQUEUE", &SL_IID_BUFFERQUEUE},
59 {"SL_IID_VOLUME", &SL_IID_VOLUME},
60 {"SL_IID_PLAY", &SL_IID_PLAY}
61 };
62
63 for (size_t i = 0; i < sizeof(kSymbols) / sizeof(kSymbols[0]); ++i) {
64 memcpy(kSymbols[i].sl_iid,
65 base::GetFunctionPointerFromNativeLibrary(handle, kSymbols[i].name),
66 sizeof(SLInterfaceID));
67 DCHECK(*kSymbols[i].sl_iid) << "Unable to find symbol for "
68 << kSymbols[i].name;
69 }
70 return handle;
71 }
72
73 // Returns the handler to the shared library. The library itself will be lazily
74 // loaded during the first call to this function.
LibraryHandle()75 base::NativeLibrary LibraryHandle() {
76 // The handle is lazily initialized on the first call.
77 static base::NativeLibrary g_opensles_LibraryHandle =
78 IntializeLibraryHandle();
79 return g_opensles_LibraryHandle;
80 }
81
82 } // namespace
83
84 // Redefine slCreateEngine symbol.
slCreateEngine(SLObjectItf * engine,SLuint32 num_options,SLEngineOption * engine_options,SLuint32 num_interfaces,SLInterfaceID * interface_ids,SLboolean * interfaces_required)85 SLresult slCreateEngine(SLObjectItf* engine,
86 SLuint32 num_options,
87 SLEngineOption* engine_options,
88 SLuint32 num_interfaces,
89 SLInterfaceID* interface_ids,
90 SLboolean* interfaces_required) {
91 typedef SLresult (*SlCreateEngineSignature)(SLObjectItf*,
92 SLuint32,
93 SLEngineOption*,
94 SLuint32,
95 SLInterfaceID*,
96 SLboolean*);
97 static SlCreateEngineSignature g_sl_create_engine_handle =
98 reinterpret_cast<SlCreateEngineSignature>(
99 base::GetFunctionPointerFromNativeLibrary(LibraryHandle(),
100 "slCreateEngine"));
101 DCHECK(g_sl_create_engine_handle)
102 << "Unable to find symbol for slCreateEngine";
103 return g_sl_create_engine_handle(engine,
104 num_options,
105 engine_options,
106 num_interfaces,
107 interface_ids,
108 interfaces_required);
109 }
110