audio_oss_source.h

MPEG-4编解码的实现(包括MPEG4视音频编解码)

/*
 * The contents of this file are subject to the Mozilla Public
 * License Version 1.1 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.mozilla.org/MPL/
 * 
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 * 
 * The Original Code is MPEG4IP.
 * 
 * The Initial Developer of the Original Code is Cisco Systems Inc.
 * Portions created by Cisco Systems Inc. are
 * Copyright (C) Cisco Systems Inc. 2000, 2001.  All Rights Reserved.
 * 
 * Contributor(s): 
 *		Dave Mackie		[e-mail]
 *		Bill May 		[e-mail]
 */

#ifndef __AUDIO_OSS_SOURCE_H__
#define __AUDIO_OSS_SOURCE_H__

#include <sys/types.h>
#include <sys/ioctl.h>
#include <linux/soundcard.h>

#include "media_source.h"
#include "audio_encoder.h"

class COSSAudioSource : public CMediaSource {
public:
	COSSAudioSource() : CMediaSource() {
		m_audioDevice = -1;
		m_pcmFrameBuffer = NULL;
	}
	~COSSAudioSource() {
		free(m_pcmFrameBuffer);
	}

	bool IsDone() {
		return false;	// live capture device is inexhaustible
	}

	float GetProgress() {
		return 0.0;		// live capture device is inexhaustible
	}

protected:
	int ThreadMain();

	void DoStartCapture();
	void DoStopCapture();

	bool Init();
	bool InitDevice();

	void ProcessAudio();

protected:
	int					m_audioDevice;
	u_int16_t			m_maxPasses;
	Timestamp			m_audioStartTimestamp;
	u_int8_t*			m_pcmFrameBuffer;
	u_int32_t			m_pcmFrameSize;
};

class CAudioCapabilities {
public:
	CAudioCapabilities(char* deviceName) {
		m_deviceName = stralloc(deviceName);
		m_canOpen = false;
		m_numSamplingRates = 0;

		ProbeDevice();
	}

	~CAudioCapabilities() {
		free(m_deviceName);
	}

	inline bool IsValid() {
		return m_canOpen;
	}

public:
	char*		m_deviceName; 
	bool		m_canOpen;

	// N.B. the rest of the fields are only valid 
	// if m_canOpen is true

	char*		m_driverName; 

	u_int16_t	m_numSamplingRates;
	u_int32_t	m_samplingRates[16];

protected:
	bool ProbeDevice(void);
};

#endif /* __AUDIO_OSS_SOURCE_H__ */