gecko-dev/content/media/wmf/WMFDecoder.h

54 lines
1.9 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#if !defined(WMFDecoder_h_)
#define WMFDecoder_h_
#include "MediaDecoder.h"
namespace mozilla {
// Decoder that uses Windows Media Foundation to playback H.264/AAC in MP4
// and M4A files, and MP3 files if the DirectShow backend is disabled.
// Playback is strictly limited to only those codecs.
class WMFDecoder : public MediaDecoder
{
public:
virtual MediaDecoder* Clone() {
if (!IsWMFEnabled()) {
return nullptr;
}
return new WMFDecoder();
}
virtual MediaDecoderStateMachine* CreateStateMachine();
// Returns true if aType is a MIME type that we render with the
// Windows Media Foundation backend. If aCodecList is non null,
// it is filled with a (static const) null-terminated list of strings
// denoting the codecs we'll playback. Note that playback is strictly
// limited to the codecs in this list.
static bool GetSupportedCodecs(const nsACString& aType,
char const *const ** aCodecList);
// Loads the DLLs required by Windows Media Foundation. If this returns
// failure, you can assume that WMF is not available on the user's system.
static nsresult LoadDLLs();
static void UnloadDLLs();
// Returns true if the WMF backend is preffed on, and we're running on a
// version of Windows which is likely to support WMF.
static bool IsEnabled();
// Returns true if MP3 decoding is enabled on this system. We block
// MP3 playback on Windows 7 SP0, since it's crashy on that platform.
static bool IsMP3Supported();
};
} // namespace mozilla
#endif