codec.h

来自「gaca源码」· C头文件 代码 · 共 230 行

/*
 *			GPAC - Multimedia Framework C SDK
 *
 *			Copyright (c) Jean Le Feuvre 2000-2005 
 *					All rights reserved
 *
 *  This file is part of GPAC / modules interfaces
 *
 *  GPAC is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation; either version 2, or (at your option)
 *  any later version.
 *   
 *  GPAC is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Lesser General Public License for more details.
 *   
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. 
 *
 */



#ifndef _GF_MODULE_CODEC_H_
#define _GF_MODULE_CODEC_H_


#include <gpac/module.h>

#ifdef __cplusplus
extern "C" {
#endif

/*multimedia processing levels*/
enum
{
	/*normal, full processing*/
	GF_CODEC_LEVEL_NORMAL,
	/*codec is late, should scale down processing*/
	GF_CODEC_LEVEL_LATE,
	/*codec is very late, should turn off post-processing, even drop*/
	GF_CODEC_LEVEL_VERY_LATE,
	/*input frames are already late before decoding*/
	GF_CODEC_LEVEL_DROP,
	/*this is a special level indicating that a seek is happening (decode but no dispatch)
	it is set dynamically*/
	GF_CODEC_LEVEL_SEEK
};

/*the structure for capabilities*/
typedef struct 
{
	/*cap code cf below*/
	u16 CapCode;
	union {
		u32 valueInt;
		Float valueFloat;
	} cap;
} GF_CodecCapability;


/*
			all codecs capabilities
*/

enum
{
	/*size of a single composition unit */
	GF_CODEC_OUTPUT_SIZE =	0x01,
	/*resilency: if packets are lost within an AU, resilience means the AU won't be discarded and the codec
	will try to decode */
	GF_CODEC_RESILIENT,
	/*critical level of composition memory - if below, media management for the object */
	GF_CODEC_BUFFER_MIN,
	/*maximum size in CU of composition memory */
	GF_CODEC_BUFFER_MAX,
	/*flags that all AUs should be discarded till next RAP (needed in case RAPs are not carried by the transport
	protocol */
	GF_CODEC_WAIT_RAP,
	/*number of padding bytes needed - if the decoder needs padding input cannot be pulled and data is duplicated*/
	GF_CODEC_PADDING_BYTES,
	/*codecs can be threaded at will - by default a single thread is used for all decoders and priority is handled
	by the app, but a codec can configure itself to run in a dedicated thread*/
	GF_CODEC_WANTS_THREAD,

	/*video width and height and horizontal pitch (in YV12 we assume half Y pitch for U and V planes) */
	GF_CODEC_WIDTH,
	GF_CODEC_HEIGHT,
	GF_CODEC_STRIDE,
	GF_CODEC_FPS,
	/*Pixel Aspect Ratio, expressed as (par.num<<16) | par.den*/
	GF_CODEC_PAR,
	/*video color mode - color modes are defined in constants.h*/
	GF_CODEC_PIXEL_FORMAT,
	/*isgnal decoder performs frame re-ordering in temporal scalability*/
	GF_CODEC_REORDER,
	
	/*Audio sample rate*/
	GF_CODEC_SAMPLERATE,
	/*Audio num channels*/
	GF_CODEC_NB_CHAN,
	/*Audio bps*/
	GF_CODEC_BITS_PER_SAMPLE,
	/*audio frame format*/
	GF_CODEC_CHANNEL_CONFIG,
	/*this is only used for audio in case transport mapping relies on sampleRate (RTP)
	gets the CU duration in samplerate unit (type: int) */
	GF_CODEC_CU_DURATION,

	/*This is only called on scene decoders to signal that potential overlay scene should be 
	showed (cap.valueINT=1) or hidden (cap.valueINT=0). Currently only used with SetCap*/
	GF_CODEC_SHOW_SCENE,
	/*This is only called on scene decoders, GetCap only. If the decoder may continue modifying the scene once the last AU is recieved,
	it must set cap.valueINT to 1 (typically, text stream decoder will hold the scene for a given duration
	after the last AU). Otherwise the decoder will be stoped and ask to remove any extra scene being displayed*/
	GF_CODEC_MEDIA_NOT_OVER,
};


	/* Generic interface used by both media decoders and scene decoders
@AttachStream:
	Add a Stream to the codec. If DependsOnESID is NULL, the stream is a base layer
	UpStream means that the decoder should send feedback on this channel. 
	WARNING: Feedback format is not standardized by MPEG
	the same API is used for both encoder and decoder (decSpecInfo is ignored
	for an encoder) 
@DetachStream:
	Remove stream
@GetCapabilities:
	Get the desired capability given its code
@SetCapabilities
	Set the desired capability given its code if possible
	if the codec does not support the request capability, return GF_NOT_SUPPORTED
@CanHandleStream
	Can module handle this codec? Return 0 if No and !0 otherwise
	decoderSpecificInfo is provided for MPEG4 audio/visual where a bunch of codecs are defined 
	with same objectType
@GetDecoderName
	returns codec name - only called once the stream is successfully attached
@privateStack
	user defined.
*/

#define GF_CODEC_BASE_INTERFACE(IFCE_NAME)		\
	GF_DECL_MODULE_INTERFACE	\
	GF_Err (*AttachStream)(IFCE_NAME, u16 ES_ID, unsigned char *decSpecInfo, u32 decSpecInfoSize, u16 DependsOnES_ID, u32 objectTypeIndication, Bool UpStream);\
	GF_Err (*DetachStream)(IFCE_NAME, u16 ES_ID);\
	GF_Err (*GetCapabilities)(IFCE_NAME, GF_CodecCapability *capability);\
	GF_Err (*SetCapabilities)(IFCE_NAME, GF_CodecCapability capability);\
	Bool (*CanHandleStream)(IFCE_NAME, u32 StreamType, u32 ObjectType, unsigned char *decSpecInfo, u32 decSpecInfoSize, u32 PL);\
	const char *(*GetName)(IFCE_NAME);\
	void *privateStack;	\


typedef struct _basedecoder
{
	GF_CODEC_BASE_INTERFACE(struct _basedecoder *)
} GF_BaseDecoder;

/*interface name and version for media decoder */
#define GF_MEDIA_DECODER_INTERFACE		GF_4CC('G', 'M', 'D', 0x01)

/*the media module interface. A media module MUST be implemented in synchronous mode as time 
and resources management is done by the terminal*/
typedef struct _mediadecoder
{
	GF_CODEC_BASE_INTERFACE(struct _basedecoder *)

	/*Process the media data in inAU. 
	@inBuffer, inBufferLength: encoded input data (complete framing of encoded data)
	@ES_ID: stream this data belongs too (scalable object)
	@outBuffer, outBufferLength: allocated data for decoding - if outBufferLength is not enough
		you must set the size in outBufferLength and GF_BUFFER_TOO_SMALL 

	@PaddingBits is the padding at the end of the buffer (some codecs need this info)
	@mmlevel: speed indicator for the decoding - cf above for values*/
	GF_Err (*ProcessData)(struct _mediadecoder *, 
			unsigned char *inBuffer, u32 inBufferLength,
			u16 ES_ID,
			unsigned char *outBuffer, u32 *outBufferLength,
			u8 PaddingBits, u32 mmlevel);
} GF_MediaDecoder;



typedef struct _inline_scene *LPINLINESCENE;

/*interface name and version for scene decoder */
#define GF_SCENE_DECODER_INTERFACE		GF_4CC('G', 'S', 'D', 0x01)

typedef struct _scenedecoder
{
	GF_CODEC_BASE_INTERFACE(struct _basedecoder *)
	
	/*attaches scene to the decoder - a scene may be attached to several decoders of several types
	(BIFS or others scene dec, ressource decoders (OD), etc. 
	is: inline scene owning graph (and not just graph), defined in intern/terminal_dev.h. With inline scene
	the complete terminal is exposed so there's pretty much everything doable in a scene decoder
	@is_scene_root: set to true if this decoder is the root of the scene, false otherwise (either another decoder
	or a re-entrant call, cf below)
	This is called once upon creation of the decoder (several times if re-entrant)
	*/
	GF_Err (*AttachScene)(struct _scenedecoder *, LPINLINESCENE is, Bool is_scene_root);
	/*releases scene. If decoder manages nodes / resources in the scene, THESE MUST BE DESTROYED. 
	May be NULL if decoder doesn't manage nodes but only create them (like BIFS, OD)
	This is called each time the scene is about to be reseted (eg, seek and destroy)
	*/
	GF_Err (*ReleaseScene)(struct _scenedecoder *);
	/*Process the scene data in inAU. 
	@inBuffer, inBufferLength: encoded input data (complete framing of encoded data)
	@ES_ID: stream this data belongs too (scalable object)
	@AU_Time: specifies the current AU time. This is usually unused, however is needed for decoder
	handling the scene graph without input data (cf below). In this case the buffer passed is always NULL and the AU
	time caries the time of the scene (or of the stream object attached to the scene decoder, cf below)
	@mmlevel: speed indicator for the decoding - cf above for values*/
	GF_Err (*ProcessData)(struct _scenedecoder *, unsigned char *inBuffer, u32 inBufferLength,
					u16 ES_ID, u32 AU_Time, u32 mmlevel);

} GF_SceneDecoder;

#ifdef __cplusplus
}
#endif

#endif	/*_GF_MODULE_CODEC_H_*/