src/add-ons/media/media-add-ons/usb_webcam/CamDeframer.h

   1 /*
   2  * Copyright 2004-2008, François Revol, <revol@free.fr>.
   3  * Distributed under the terms of the MIT License.
   4  */
   5 #ifndef _CAM_DEFRAMER_H
   6 #define _CAM_DEFRAMER_H
   7
   8 #include <OS.h>
   9 #include <DataIO.h>
  10 #include <Locker.h>
  11 #include <List.h>
  12 #include "CamFilterInterface.h"
  13 class CamDevice;
  14
  15 #define CAMDEFRAMER_MAX_TAG_LEN 16
  16 #define CAMDEFRAMER_MAX_QUEUED_FRAMES 50
  17
  18 enum {
  19 ST_SYNC, /* waiting for start of frame */
  20 ST_FRAME
  21 };
  22
  23
  24 /* should have a real Frame class someday */
  25 class CamFrame : public BMallocIO {
  26 public:
  27                         CamFrame() : BMallocIO() { fStamp = system_time(); };
  28 virtual         ~CamFrame() {};
  29 bigtime_t                       Stamp() const { return fStamp; };
  30 bigtime_t                       fStamp;
  31 };
  32
  33 class CamDeframer : public CamFilterInterface {
  34 public:
  35                         CamDeframer(CamDevice *device);
  36 virtual         ~CamDeframer();
  37                                         // BPositionIO interface
  38                                         // read from translators/cs transforms
  39 virtual ssize_t         Read(void *buffer, size_t size);
  40 virtual ssize_t         ReadAt(off_t pos, void *buffer, size_t size);
  41 virtual off_t           Seek(off_t position, uint32 seek_mode);
  42 virtual off_t           Position() const;
  43 virtual status_t        SetSize(off_t size);
  44                                         // write from usb transfers
  45 virtual ssize_t         Write(const void *buffer, size_t size);
  46 virtual ssize_t         WriteAt(off_t pos, const void *buffer, size_t size);
  47
  48 virtual status_t        WaitFrame(bigtime_t timeout);
  49 virtual status_t        GetFrame(CamFrame **frame, bigtime_t *stamp); // caller deletes
  50 virtual status_t        DropFrame();
  51
  52 status_t        RegisterSOFTags(const uint8 **tags, int count, size_t len, size_t skip);
  53 status_t        RegisterEOFTags(const uint8 **tags, int count, size_t len, size_t skip);
  54
  55 protected:
  56
  57 int             FindTags(const uint8 *buf, size_t buflen, const uint8 **tags, int tagcount, size_t taglen, size_t skiplen, int *which=NULL);
  58 int             FindSOF(const uint8 *buf, size_t buflen, int *which=NULL);
  59 int             FindEOF(const uint8 *buf, size_t buflen, int *which=NULL);
  60
  61 CamFrame        *AllocFrame();
  62
  63 CamDevice       *fDevice;
  64 size_t  fMinFrameSize;
  65 size_t  fMaxFrameSize;
  66 int     fState;
  67 sem_id  fFrameSem;
  68 BList   fFrames;
  69 BLocker fLocker;
  70 CamFrame        *fCurrentFrame; /* the one we write to*/
  71
  72 /* tags */
  73 const uint8 **fSOFTags;
  74 const uint8 **fEOFTags;
  75 int                     fNumSOFTags;
  76 int                     fNumEOFTags;
  77 size_t          fLenSOFTags;
  78 size_t          fLenEOFTags;
  79 size_t          fSkipSOFTags;
  80 size_t          fSkipEOFTags;
  81
  82
  83
  84 };
  85
  86
  87 #endif /* _CAM_DEFRAMER_H */