blob: c98774f27b47215dbf853ea02c07a0b305c60a47 [file] [log] [blame]
* Copyright 2012 Google Inc. All Rights Reserved.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* See the License for the specific language governing permissions and
* limitations under the License.
#include "base/basictypes.h"
#include "base/logging.h"
#include "base/memory/ref_counted.h"
#include "media/base/decoder_buffer.h"
#include "media/base/limits.h"
#include "media/base/media_export.h"
#include "media/base/shell_buffer_factory.h"
#include "media/base/shell_video_data_allocator.h"
#include "media/base/shell_video_frame_provider.h"
namespace media {
// This class is meant to be the single point to attach platform specific media
// classes and settings. Each platform should implement its own implementation
// and provide it through ShellMediaPlatform::Instance.
class MEDIA_EXPORT ShellMediaPlatform {
ShellMediaPlatform() {}
virtual ~ShellMediaPlatform() {}
// Individual platforms should implement the following two functions to
// ensure that a valid ShellMediaPlatform instance is available during the
// life time of media stack
static void Initialize();
static void Terminate();
static ShellMediaPlatform* Instance();
// Media stack buffer allocate/free functions currently only used by
// ShellBufferFactory.
virtual void* AllocateBuffer(size_t size) = 0;
virtual void FreeBuffer(void* ptr) = 0;
// The maximum audio and video buffer size used by SourceBufferStream.
// See implementation of SourceBufferStream for more details.
virtual size_t GetSourceBufferStreamAudioMemoryLimit() const = 0;
virtual size_t GetSourceBufferStreamVideoMemoryLimit() const = 0;
virtual scoped_refptr<ShellVideoFrameProvider> GetVideoFrameProvider() {
return NULL;
// Total number of video frames which are populating in the pipeline when
// prerolling.
// You can expect more start delay by increasing this.
virtual int GetMaxVideoPrerollFrames() const {
return limits::kMaxVideoFrames;
// When the video frame backlog contains less frames than this value, the
// video renderer will send out underflow notification to the video decoder.
virtual int GetVideoUnderflowFrames() const {
return GetMaxVideoPrerollFrames();
// Total number of video frames which are populating in the pipeline.
// You can expect more memory usage and less jitter by increasing this.
virtual int GetMaxVideoFrames() const { return limits::kMaxVideoFrames; }
// This function is called before the decoder buffer leaves the demuxer and
// is being sent to the media pipeline for decrypting and decoding. The
// default implementation simply returns the buffer indicateing that there is
// no processing necessary.
virtual scoped_refptr<DecoderBuffer> ProcessBeforeLeavingDemuxer(
const scoped_refptr<DecoderBuffer>& buffer) {
return buffer;
// Returns true if output is protected (i.e. HDCP is present).
virtual bool IsOutputProtected() = 0;
static void SetInstance(ShellMediaPlatform* shell_media_platform);
// Platform specific media Init and Tear down.
virtual void InternalInitialize() {}
virtual void InternalTerminate() {}
} // namespace media
namespace media { \
void ShellMediaPlatform::Initialize() { \
DCHECK(!Instance()); \
SetInstance(new ClassName); \
ShellBufferFactory::Initialize(); \
Instance()->InternalInitialize(); \
} \
void ShellMediaPlatform::Terminate() { \
DCHECK(Instance()); \
Instance()->InternalTerminate(); \
ShellBufferFactory::Terminate(); \
delete Instance(); \
SetInstance(NULL); \
} \
} // namespace media