1/**********
2This library is free software; you can redistribute it and/or modify it under
3the terms of the GNU Lesser General Public License as published by the
4Free Software Foundation; either version 3 of the License, or (at your
5option) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.)
6
7This library is distributed in the hope that it will be useful, but WITHOUT
8ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
9FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
10more details.
11
12You should have received a copy of the GNU Lesser General Public License
13along with this library; if not, write to the Free Software Foundation, Inc.,
1451 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
15**********/
16// "liveMedia"
17// Copyright (c) 1996-2020 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
34class MediaTranscodingTable: public Medium {
35public:
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
58protected: // we are to be subclassed only
59 MediaTranscodingTable(UsageEnvironment& env)
60 : Medium(env) {
61 }
62 virtual ~MediaTranscodingTable() {
63 }
64};
65
66#endif
67