vdr/device.c
Klaus Schmidinger 9f91980146 Version 1.1.27
- The CAM is now accessed only if the current channel actually has a non-zero Ca
  value, and CAM access is completely suppressed during replay, which avoids
  problems in case the CAM is attached to the primary DVB device.
- The "Left" and "Right" buttons now set the cursor to the first or last list item
  even if the list consist only of a single page, like, for instance, the Main menu
  (thanks to Oliver Endriss).
- Made the log message "OSD window width must be a multiple of 4..." a debug message
  instead of an error message, so it can be avoided by using a log level less than 3.
- Updated Greek language texts (thanks to Dimitrios Dimitrakos).
- Fixed faulty behaviour of the "Mute" key in case the channel display is visible
  (thanks to Florian Bartels for reporting this one and Sascha Volkenandt for
  helping to fix it).
- Modified LOF handling to allow for C-band reception (thanks to Malcolm Caldwell).
- Added some missing cAudio handling calls (thanks to Werner Fink).
- Replaced the 'for' loops in StripAudioPackets() with memset() calls (thanks to
  Werner Fink).
- Further increased the timeout until an index file is considerd no longer to be
  written.
- Fixed a crash in case the index file can't be accessed any more during replay
  (thanks to Stefan Huelswitt for reporting this one).
- Fixed displaying messages in the status line in case they exceed the OSD width
  (thanks to Gerhard Steiner for reporting this one).
- Avoiding high CPU load in case the connection to LIRC gets lost (thanks to
  Ludwig Nussel).
- Fixed handling repeat function with LIRC (thanks to Ludwig Nussel).
- Fixed handling min/max borders when entering integer values (thanks to Andy
  Grobb for reporting this one).
- Implemented a "resume ID" which allows several users to each have their own
  resume.vdr files (thanks to Martin Hammerschmid). This parameter can be set in
  the "Setup/Replay" menu (see MANUAL for details).
- Now using 'libdtv' version 0.0.5 (thanks to Rolf Hakenes for the new version
  and Stefan Huelswitt for adapting VDR to it).
- If no device with an MPEG decoder can be found at startup, the first device
  is now used as primary device (just to have some device).
- Adjusted some Premiere channels in 'channels.conf' (thanks to Thomas Koch).
- Updated 'channels.conf.cable' (thanks to Stefan Hußfeldt).
- The 'epg.data' file is now read after all plugins have been started (thanks
  to Sascha Volkenandt).
- The LIRC remote control no longer tries to learn keys if it can't connect to
  the LIRC daemon (thanks to Ludwig Nussel for reporting this one). The same
  applies to the RCU remote control in case of errors during startup.
- Fixed handling of Ca parameters with values <= MAXDEVICES, which don't indicate
  an actual encrypted channel (thanks to Stefan Huelswitt for reporting this one).
2003-04-13 18:00:00 +02:00

819 lines
21 KiB
C

/*
* device.c: The basic device interface
*
* See the main source file 'vdr.c' for copyright information and
* how to reach the author.
*
* $Id: device.c 1.39 2003/04/12 11:51:04 kls Exp $
*/
#include "device.h"
#include <errno.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include "audio.h"
#include "channels.h"
#include "eit.h"
#include "i18n.h"
#include "player.h"
#include "receiver.h"
#include "status.h"
#include "transfer.h"
// --- cDevice ---------------------------------------------------------------
// The default priority for non-primary devices:
#define DEFAULTPRIORITY -2
// The maximum time we wait before assuming that a recorded video data stream
// is broken:
#define MAXBROKENTIMEOUT 30 // seconds
int cDevice::numDevices = 0;
int cDevice::useDevice = 0;
int cDevice::nextCardIndex = 0;
int cDevice::currentChannel = 0;
cDevice *cDevice::device[MAXDEVICES] = { NULL };
cDevice *cDevice::primaryDevice = NULL;
cDevice::cDevice(void)
{
cardIndex = nextCardIndex++;
SetVideoFormat(Setup.VideoFormat);
active = false;
mute = false;
volume = Setup.CurrentVolume;
ciHandler = NULL;
player = NULL;
playerDetached = false;
for (int i = 0; i < MAXRECEIVERS; i++)
receiver[i] = NULL;
if (numDevices < MAXDEVICES) {
device[numDevices++] = this;
SetCaCaps(cardIndex);
}
else
esyslog("ERROR: too many devices!");
}
cDevice::~cDevice()
{
Detach(player);
for (int i = 0; i < MAXRECEIVERS; i++)
Detach(receiver[i]);
delete ciHandler;
}
void cDevice::SetUseDevice(int n)
{
if (n < MAXDEVICES)
useDevice |= (1 << n);
}
int cDevice::NextCardIndex(int n)
{
if (n > 0) {
nextCardIndex += n;
if (nextCardIndex >= MAXDEVICES)
esyslog("ERROR: nextCardIndex too big (%d)", nextCardIndex);
}
else if (n < 0)
esyslog("ERROR: illegal value in IncCardIndex(%d)", n);
return nextCardIndex;
}
int cDevice::DeviceNumber(void) const
{
for (int i = 0; i < numDevices; i++) {
if (device[i] == this)
return i;
}
return -1;
}
void cDevice::MakePrimaryDevice(bool On)
{
}
bool cDevice::SetPrimaryDevice(int n)
{
n--;
if (0 <= n && n < numDevices && device[n]) {
isyslog("setting primary device to %d", n + 1);
if (primaryDevice)
primaryDevice->MakePrimaryDevice(false);
primaryDevice = device[n];
primaryDevice->MakePrimaryDevice(true);
return true;
}
esyslog("ERROR: invalid primary device number: %d", n + 1);
return false;
}
bool cDevice::HasDecoder(void) const
{
return false;
}
bool cDevice::PlayerDetached(void)
{
bool result = playerDetached;
playerDetached = false;
return result;
}
cOsdBase *cDevice::NewOsd(int x, int y)
{
return NULL;
}
cSpuDecoder *cDevice::GetSpuDecoder(void)
{
return NULL;
}
cDevice *cDevice::GetDevice(int Index)
{
return (0 <= Index && Index < numDevices) ? device[Index] : NULL;
}
cDevice *cDevice::GetDevice(const cChannel *Channel, int Priority, bool *NeedsDetachReceivers)
{
cDevice *d = NULL;
for (int i = 0; i < numDevices; i++) {
bool ndr;
if (device[i]->ProvidesChannel(Channel, Priority, &ndr) // this device is basicly able to do the job
&& (!d // we don't have a device yet, or...
|| (device[i]->Receiving() && !ndr) // ...this one is already receiving and allows additional receivers, or...
|| !d->Receiving() // ...the one we have is not receiving...
&& (device[i]->Priority() < d->Priority() // ...this one has an even lower Priority, or...
|| device[i]->Priority() == d->Priority() // ...same Priority...
&& device[i]->ProvidesCa(Channel->Ca()) < d->ProvidesCa(Channel->Ca()) // ...but this one provides fewer Ca values
)
)
) {
d = device[i];
if (NeedsDetachReceivers)
*NeedsDetachReceivers = ndr;
}
}
/*XXX+ too complex with multiple recordings per device
if (!d && Ca > MAXDEVICES) {
// We didn't find one the easy way, so now we have to try harder:
int ShiftLevel = -1;
for (int i = 0; i < numDevices; i++) {
if (Provides[i]) { // this device is basicly able to do the job, but for some reason we didn't get it above
int sl = device[i]->CanShift(Ca, Priority); // asks this device to shift its job to another device
if (sl >= 0 && (ShiftLevel < 0 || sl < ShiftLevel)) {
d = device[i]; // found one that can be shifted with the fewest number of subsequent shifts
ShiftLevel = sl;
}
}
}
}
XXX*/
return d;
}
void cDevice::SetCaCaps(int Index)
{
for (int d = 0; d < numDevices; d++) {
if (Index < 0 || Index == device[d]->CardIndex()) {
for (int i = 0; i < MAXCACAPS; i++)
device[d]->caCaps[i] = Setup.CaCaps[device[d]->CardIndex()][i];
}
}
}
void cDevice::Shutdown(void)
{
for (int i = 0; i < numDevices; i++) {
delete device[i];
device[i] = NULL;
}
primaryDevice = NULL;
}
bool cDevice::GrabImage(const char *FileName, bool Jpeg, int Quality, int SizeX, int SizeY)
{
return false;
}
void cDevice::SetVideoFormat(bool VideoFormat16_9)
{
}
//#define PRINTPIDS(s) { char b[500]; char *q = b; q += sprintf(q, "%d %s ", CardIndex(), s); for (int i = 0; i < MAXPIDHANDLES; i++) q += sprintf(q, " %s%4d %d", i == ptOther ? "* " : "", pidHandles[i].pid, pidHandles[i].used); dsyslog(b); }
#define PRINTPIDS(s)
bool cDevice::HasPid(int Pid) const
{
for (int i = 0; i < MAXPIDHANDLES; i++) {
if (pidHandles[i].pid == Pid)
return true;
}
return false;
}
bool cDevice::AddPid(int Pid, ePidType PidType)
{
if (Pid) {
int n = -1;
int a = -1;
for (int i = 0; i < MAXPIDHANDLES; i++) {
if (pidHandles[i].pid == Pid)
n = i;
else if (a < 0 && i >= ptOther && !pidHandles[i].used)
a = i;
}
if (n >= 0) {
// The Pid is already in use
if (++pidHandles[n].used == 2 && n <= ptTeletext) {
// It's a special PID that may have to be switched into "tap" mode
PRINTPIDS("A");
return SetPid(&pidHandles[n], n, true);
}
PRINTPIDS("a");
return true;
}
else if (PidType < ptOther) {
// The Pid is not yet in use and it is a special one
n = PidType;
}
else if (a >= 0) {
// The Pid is not yet in use and we have a free slot
n = a;
}
else
esyslog("ERROR: no free slot for PID %d", Pid);
if (n >= 0) {
pidHandles[n].pid = Pid;
pidHandles[n].used = 1;
PRINTPIDS("C");
return SetPid(&pidHandles[n], n, true);
}
}
return true;
}
void cDevice::DelPid(int Pid)
{
if (Pid) {
for (int i = 0; i < MAXPIDHANDLES; i++) {
if (pidHandles[i].pid == Pid) {
PRINTPIDS("D");
if (--pidHandles[i].used < 2) {
SetPid(&pidHandles[i], i, false);
if (pidHandles[i].used == 0) {
pidHandles[i].handle = -1;
pidHandles[i].pid = 0;
}
}
PRINTPIDS("E");
}
}
}
}
bool cDevice::SetPid(cPidHandle *Handle, int Type, bool On)
{
return false;
}
bool cDevice::ProvidesSource(int Source) const
{
return false;
}
bool cDevice::ProvidesChannel(const cChannel *Channel, int Priority, bool *NeedsDetachReceivers) const
{
return false;
}
bool cDevice::SwitchChannel(const cChannel *Channel, bool LiveView)
{
if (LiveView)
isyslog("switching to channel %d", Channel->Number());
for (int i = 3; i--;) {
switch (SetChannel(Channel, LiveView)) {
case scrOk: return true;
case scrNotAvailable: if (Interface)
Interface->Error(tr("Channel not available!"));
return false;
case scrNoTransfer: if (Interface)
Interface->Error(tr("Can't start Transfer Mode!"));
return false;
case scrFailed: break; // loop will retry
}
esyslog("retrying");
}
return false;
}
bool cDevice::SwitchChannel(int Direction)
{
bool result = false;
Direction = sgn(Direction);
if (Direction) {
int n = CurrentChannel() + Direction;
int first = n;
cChannel *channel;
while ((channel = Channels.GetByNumber(n, Direction)) != NULL) {
// try only channels which are currently available
if (PrimaryDevice()->ProvidesChannel(channel, Setup.PrimaryLimit) || PrimaryDevice()->CanReplay() && GetDevice(channel, 0))
break;
n = channel->Number() + Direction;
}
if (channel) {
int d = n - first;
if (abs(d) == 1)
dsyslog("skipped channel %d", first);
else if (d)
dsyslog("skipped channels %d..%d", first, n - sgn(d));
if (PrimaryDevice()->SwitchChannel(channel, true))
result = true;
}
else if (n != first && Interface)
Interface->Error(tr("Channel not available!"));
}
return result;
}
eSetChannelResult cDevice::SetChannel(const cChannel *Channel, bool LiveView)
{
if (LiveView)
StopReplay();
// If this card can't receive this channel, we must not actually switch
// the channel here, because that would irritate the driver when we
// start replaying in Transfer Mode immediately after switching the channel:
bool NeedsTransferMode = (LiveView && IsPrimaryDevice() && !ProvidesChannel(Channel, Setup.PrimaryLimit));
eSetChannelResult Result = scrOk;
// If this DVB card can't receive this channel, let's see if we can
// use the card that actually can receive it and transfer data from there:
if (NeedsTransferMode) {
cDevice *CaDevice = GetDevice(Channel, 0);
if (CaDevice && CanReplay()) {
cStatus::MsgChannelSwitch(this, 0); // only report status if we are actually going to switch the channel
if (CaDevice->SetChannel(Channel, false) == scrOk) // calling SetChannel() directly, not SwitchChannel()!
cControl::Launch(new cTransferControl(CaDevice, Channel->Vpid(), Channel->Apid1(), Channel->Apid2(), Channel->Dpid1(), Channel->Dpid2()));//XXX+
else
Result = scrNoTransfer;
}
else
Result = scrNotAvailable;
}
else {
cStatus::MsgChannelSwitch(this, 0); // only report status if we are actually going to switch the channel
if (!SetChannelDevice(Channel, LiveView))
Result = scrFailed;
}
if (Result == scrOk) {
if (LiveView && IsPrimaryDevice()) {
cSIProcessor::SetCurrentChannelID(Channel->GetChannelID());
currentChannel = Channel->Number();
}
cStatus::MsgChannelSwitch(this, Channel->Number()); // only report status if channel switch successfull
}
return Result;
}
bool cDevice::SetChannelDevice(const cChannel *Channel, bool LiveView)
{
return false;
}
void cDevice::SetVolumeDevice(int Volume)
{
}
int cDevice::NumAudioTracksDevice(void) const
{
return 0;
}
const char **cDevice::GetAudioTracksDevice(int *CurrentTrack) const
{
return NULL;
}
void cDevice::SetAudioTrackDevice(int Index)
{
}
bool cDevice::ToggleMute(void)
{
int OldVolume = volume;
mute = !mute;
//XXX why is it necessary to use different sequences???
if (mute) {
SetVolume(0, mute);
Audios.MuteAudio(mute); // Mute external audio after analog audio
}
else {
Audios.MuteAudio(mute); // Enable external audio before analog audio
SetVolume(0, mute);
}
volume = OldVolume;
return mute;
}
void cDevice::SetVolume(int Volume, bool Absolute)
{
volume = min(max(Absolute ? Volume : volume + Volume, 0), MAXVOLUME);
SetVolumeDevice(volume);
cStatus::MsgSetVolume(volume, Absolute);
if (volume > 0) {
mute = false;
Audios.MuteAudio(mute);
}
}
int cDevice::NumAudioTracks(void) const
{
return player ? player->NumAudioTracks() : NumAudioTracksDevice();
}
const char **cDevice::GetAudioTracks(int *CurrentTrack) const
{
return player ? player->GetAudioTracks(CurrentTrack) : GetAudioTracksDevice(CurrentTrack);
}
void cDevice::SetAudioTrack(int Index)
{
if (player)
player->SetAudioTrack(Index);
else
SetAudioTrackDevice(Index);
}
bool cDevice::CanReplay(void) const
{
return HasDecoder();
}
bool cDevice::SetPlayMode(ePlayMode PlayMode)
{
return false;
}
void cDevice::TrickSpeed(int Speed)
{
}
void cDevice::Clear(void)
{
Audios.ClearAudio();
}
void cDevice::Play(void)
{
Audios.MuteAudio(mute);
}
void cDevice::Freeze(void)
{
Audios.MuteAudio(true);
}
void cDevice::Mute(void)
{
Audios.MuteAudio(true);
}
void cDevice::StillPicture(const uchar *Data, int Length)
{
}
bool cDevice::Replaying(void) const
{
return player != NULL;
}
bool cDevice::AttachPlayer(cPlayer *Player)
{
if (CanReplay()) {
if (player)
Detach(player);
player = Player;
player->device = this;
SetPlayMode(player->playMode);
player->Activate(true);
return true;
}
return false;
}
void cDevice::Detach(cPlayer *Player)
{
if (Player && player == Player) {
player->Activate(false);
player->device = NULL;
player = NULL;
SetPlayMode(pmNone);
playerDetached = true;
Audios.ClearAudio();
}
}
void cDevice::StopReplay(void)
{
if (player) {
Detach(player);
if (IsPrimaryDevice())
cControl::Shutdown();
}
}
bool cDevice::Poll(cPoller &Poller, int TimeoutMs)
{
return false;
}
int cDevice::PlayVideo(const uchar *Data, int Length)
{
return -1;
}
void cDevice::PlayAudio(const uchar *Data, int Length)
{
Audios.PlayAudio(Data, Length);
}
int cDevice::Ca(void) const
{
int ca = 0;
for (int i = 0; i < MAXRECEIVERS; i++) {
if (receiver[i] && (ca = receiver[i]->ca) != 0)
break; // all receivers have the same ca
}
return ca;
}
int cDevice::Priority(void) const
{
int priority = IsPrimaryDevice() ? Setup.PrimaryLimit - 1 : DEFAULTPRIORITY;
for (int i = 0; i < MAXRECEIVERS; i++) {
if (receiver[i])
priority = max(receiver[i]->priority, priority);
}
return priority;
}
int cDevice::CanShift(int Ca, int Priority, int UsedCards) const
{
return -1;//XXX+ too complex with multiple recordings per device
// Test whether a receiver on this device can be shifted to another one
// in order to perform a new receiving with the given Ca and Priority on this device:
int ShiftLevel = -1; // default means this device can't be shifted
if (UsedCards & (1 << CardIndex()) != 0)
return ShiftLevel; // otherwise we would get into a loop
if (Receiving()) {
if (ProvidesCa(Ca) // this device provides the requested Ca
&& (Ca != this->Ca() // the requested Ca is different from the one currently used...
|| Priority > this->Priority())) { // ...or the request comes from a higher priority
cDevice *d = NULL;
int Provides[MAXDEVICES];
UsedCards |= (1 << CardIndex());
for (int i = 0; i < numDevices; i++) {
if ((Provides[i] = device[i]->ProvidesCa(this->Ca())) != 0) { // this device is basicly able to do the job
if (device[i] != this) { // it is not _this_ device
int sl = device[i]->CanShift(this->Ca(), Priority, UsedCards); // this is the original Priority!
if (sl >= 0 && (ShiftLevel < 0 || sl < ShiftLevel)) {
d = device[i];
ShiftLevel = sl;
}
}
}
}
if (ShiftLevel >= 0)
ShiftLevel++; // adds the device's own shift
}
}
else if (Priority > this->Priority())
ShiftLevel = 0; // no shifting necessary, this device can do the job
return ShiftLevel;
}
int cDevice::ProvidesCa(int Ca) const
{
if (Ca == CardIndex() + 1)
return 1; // exactly _this_ card was requested
if (Ca && Ca <= MAXDEVICES)
return 0; // a specific card was requested, but not _this_ one
int result = Ca ? 0 : 1; // by default every card can provide FTA
int others = Ca ? 1 : 0;
for (int i = 0; i < MAXCACAPS; i++) {
if (caCaps[i]) {
if (caCaps[i] == Ca)
result = 1;
else
others++;
}
}
return result ? result + others : 0;
}
bool cDevice::Receiving(bool CheckAny) const
{
for (int i = 0; i < MAXRECEIVERS; i++) {
if (receiver[i] && (CheckAny || receiver[i]->priority >= 0)) // cReceiver with priority < 0 doesn't count
return true;
}
return false;
}
void cDevice::Action(void)
{
dsyslog("receiver thread started on device %d (pid=%d)", CardIndex() + 1, getpid());
if (OpenDvr()) {
time_t t = time(NULL);
active = true;
for (; active;) {
// Read data from the DVR device:
uchar *b = NULL;
if (GetTSPacket(b)) {
if (b) {
int Pid = (((uint16_t)b[1] & PID_MASK_HI) << 8) | b[2];
// Distribute the packet to all attached receivers:
Lock();
for (int i = 0; i < MAXRECEIVERS; i++) {
if (receiver[i] && receiver[i]->WantsPid(Pid))
receiver[i]->Receive(b, TS_SIZE);
}
Unlock();
t = time(NULL);
}
}
else
break;
//XXX+ put this into the recorder??? or give the receiver a flag whether it wants this?
if (time(NULL) - t > MAXBROKENTIMEOUT) {
esyslog("ERROR: video data stream broken on device %d", CardIndex() + 1);
cThread::EmergencyExit(true);
t = time(NULL);
}
}
CloseDvr();
}
dsyslog("receiver thread ended on device %d (pid=%d)", CardIndex() + 1, getpid());
}
bool cDevice::OpenDvr(void)
{
return false;
}
void cDevice::CloseDvr(void)
{
}
bool cDevice::GetTSPacket(uchar *&Data)
{
return false;
}
bool cDevice::AttachReceiver(cReceiver *Receiver)
{
if (!Receiver)
return false;
if (Receiver->device == this)
return true;
for (int i = 0; i < MAXRECEIVERS; i++) {
if (!receiver[i]) {
for (int n = 0; n < MAXRECEIVEPIDS; n++)
AddPid(Receiver->pids[n]);//XXX+ retval!
Receiver->Activate(true);
Lock();
Receiver->device = this;
receiver[i] = Receiver;
Unlock();
Start();
return true;
}
}
esyslog("ERROR: no free receiver slot!");
return false;
}
void cDevice::Detach(cReceiver *Receiver)
{
if (!Receiver || Receiver->device != this)
return;
bool receiversLeft = false;
for (int i = 0; i < MAXRECEIVERS; i++) {
if (receiver[i] == Receiver) {
Receiver->Activate(false);
Lock();
receiver[i] = NULL;
Receiver->device = NULL;
Unlock();
for (int n = 0; n < MAXRECEIVEPIDS; n++)
DelPid(Receiver->pids[n]);
}
else if (receiver[i])
receiversLeft = true;
}
if (!receiversLeft) {
active = false;
Cancel(3);
}
}
// --- cTSBuffer -------------------------------------------------------------
cTSBuffer::cTSBuffer(int File, int Size, int CardIndex)
{
f = File;
size = Size / TS_SIZE * TS_SIZE;
cardIndex = CardIndex;
tsRead = tsWrite = 0;
buf = (f >= 0 && size >= TS_SIZE) ? MALLOC(uchar, size + TS_SIZE) : NULL;
// the '+ TS_SIZE' allocates some extra space for handling packets that got split by a buffer roll-over
firstRead = true;
}
cTSBuffer::~cTSBuffer()
{
free(buf);
}
int cTSBuffer::Read(void)
{
if (buf) {
cPoller Poller(f, false);
bool repeat;
int total = 0;
do {
repeat = false;
if (firstRead || Used() > TS_SIZE || Poller.Poll(100)) { // only wait if there's not enough data in the buffer
firstRead = false;
if (tsRead == tsWrite)
tsRead = tsWrite = 0; // keep the maximum buffer space available
if (tsWrite >= size && tsRead > 0)
tsWrite = 0;
int free = tsRead <= tsWrite ? size - tsWrite : tsRead - tsWrite - 1;
if (free > 0) {
int r = read(f, buf + tsWrite, free);
if (r > 0) {
total += r;
tsWrite += r;
if (tsWrite >= size && tsRead > 0) {
tsWrite = 0;
repeat = true; // read again after a boundary roll-over
}
}
}
}
} while (repeat);
return total;
}
return -1;
}
uchar *cTSBuffer::Get(void)
{
if (Used() >= TS_SIZE) {
uchar *p = buf + tsRead;
if (*p != TS_SYNC_BYTE) {
esyslog("ERROR: not sync'ed to TS packet on device %d", cardIndex);
int tsMax = tsRead < tsWrite ? tsWrite : size;
for (int i = tsRead; i < tsMax; i++) {
if (buf[i] == TS_SYNC_BYTE) {
esyslog("ERROR: skipped %d bytes to sync on TS packet on device %d", i - tsRead, cardIndex);
tsRead = i;
return NULL;
}
}
if ((tsRead = tsMax) >= size)
tsRead = 0;
return NULL;
}
if (tsRead + TS_SIZE > size) {
// the packet rolled over the buffer boundary, so let's fetch the rest from the beginning (which MUST be there, since Used() >= TS_SIZE)
int rest = TS_SIZE - (size - tsRead);
memcpy(buf + size, buf, rest);
tsRead = rest;
}
else if ((tsRead += TS_SIZE) >= size)
tsRead = 0;
return p;
}
return NULL;
}