live
MediaTranscodingTable.hh
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16 // "liveMedia"
17 // Copyright (c) 1996-2021 Live Networks, Inc. All rights reserved.
18 // A class that implements a database that can be accessed to create
19 // "FramedFilter" (subclass) objects that transcode one codec into another.
20 // The implementation of this class just returns NULL for each codec lookup;
21 // To actually implement transcoding, you would subclass it.
22 // C++ header
23 
24 #ifndef _MEDIA_TRANSCODING_TABLE_HH
25 #define _MEDIA_TRANSCODING_TABLE_HH
26 
27 #ifndef _FRAMED_FILTER_HH
28 #include "FramedFilter.hh"
29 #endif
30 #ifndef _MEDIA_SESSION_HH
31 #include "MediaSession.hh"
32 #endif
33 
35 public:
36  virtual FramedFilter*
37  lookupTranscoder(MediaSubsession& /*inputCodecDescription*/, // in
38  char*& outputCodecName/* out; must be delete[]d later */) {
39  // Default implementation: Return NULL (indicating: no transcoding).
40  // You would reimplement this virtual function in a subclass to return a new 'transcoding'
41  // "FramedFilter" (subclass) object for each ("mediumName","codecName") that you wish to
42  // transcode (or return NULL for no transcoding).
43  // (Note that "inputCodecDescription" must have a non-NULL "readSource()"; this is used
44  // as the input to the new "FramedFilter" (subclass) object.)
45  outputCodecName = NULL;
46  return NULL;
47  }
48 
49  virtual Boolean weWillTranscode(char const* /*mediumName*/, char const* /*codecName*/) {
50  // Default implementation: Return False.
51  // You would reimplement this in a subclass - returning True for each
52  // <mediumName>/<codecName> for which you'll do transcoding.
53  // Note: Unlike "lookupTranscoder()", this function does not actually create any 'transcoding'
54  // filter objects. (It may be called before "MediaSubsession::initiate()".)
55  return False;
56  }
57 
58 protected: // we are to be subclassed only
60  : Medium(env) {
61  }
63  }
64 };
65 
66 #endif
const Boolean False
Definition: Boolean.hh:28
unsigned char Boolean
Definition: Boolean.hh:25
#define NULL
virtual FramedFilter * lookupTranscoder(MediaSubsession &, char *&outputCodecName)
MediaTranscodingTable(UsageEnvironment &env)
virtual Boolean weWillTranscode(char const *, char const *)
Definition: Media.hh:50