Howto go to code "case pmRepeat:" in play()-fn of

[tejpratap]

when using the Dataplayer class for playing a file, it works fine. But still there is a problem when I want to use the 'Mode' - property of the class wherein I am setting the mode as "Player.Mode(DataPlayer::pmRepeat)". after setting the mode like above in the host program, when I execute it , the "play"-function of the Dataplayer never reaches to the line:

switch (FMode) :

so that case 'pmRepeat' can be executed. I observed that it is because value of 'residual' is always 0 in the line :

if(residual)
{
.......
}

because the gcount() method returns the same value which was assigned to the variable 'residual' during the start of the play() -function of the Dataplayer class in each call to play()-fn till my playback-file is read and played back completely.

Please tell me how to reach to the line of code :

case pmRepeat:

so that I can use this property of the Mode of the Dataplyer.

[csmith]

The use of residual for the EOF test is incorrect, this is a bug in the code. Instead we should be using feof() to detect the EOF condition there. In addition the EOF test is moved to be right after the read(). I also set FPlayed to 0 in the repeat test to avoid increasing that number indefinitely.

Note - if you have included packet headers in your playback file, do not use pmZero mode. The zeroed header makes an illegal packet.

[tejpratap]

Dear Sir,
I have tried to incorporate the provided code into the file DataPlayer_Mb.cpp which I included in the application project and then built the project. But, I am receiving the following errors:

---------------------------------------------------------------------------------
[C++ Error] DataPlayer_Mb.cpp(191): E2034 Cannot convert '_STL::ifstream' to 'FILE *'
[C++ Error] DataPlayer_Mb.cpp(191): E2342 Type mismatch in parameter '__stream' (wanted 'FILE *', got '_STL::ifstream')
[C++ Error] DataPlayer_Mb.cpp(195): E2288 Pointer to structure required on left side of -> or ->*
[C++ Error] DataPlayer_Mb.cpp(209): E2034 Cannot convert '_STL::ifstream' to 'FILE *'
[C++ Error] DataPlayer_Mb.cpp(209): E2342 Type mismatch in parameter '__stream' (wanted 'FILE *', got '_STL::ifstream')
-----------------------------------------------------------------------------------

Then I tried to put this code in the following way:

====================================================

size_t DataPlayer::Play(int * data, size_t size)
{
if (!FOpened || !FEnabled || !size || !mFile)
return 0;

std::streamsize residual = size*sizeof(int);
char * dst = reinterpret_cast<char *>(data);

while (residual)
{
// size_t read = fread(dst, 1, residual, mFile);
mFile.read(dst, residual);

// Handle EOF condition
// if (feof(mFile))

if(mFile.eof())
{
switch (FMode)
{
case pmStop:
return (size*sizeof(int)-residual)/sizeof(int);

case pmRepeat:
mFile.seekg(0,std::ios::beg);
FPlayed = 0;
/*
fseek(mFile, 0, SEEK_SET);
FPlayed = 0;
*/
break;

case pmZero:
memset(dst, 0, residual);
return size;
}
}

// residual -= read;
residual -= mFile.gcount();
// dst += read;
dst += mFile.gcount();
// FPlayed += read;
FPlayed += mFile.gcount();
}

return size;
}

=====================================================

1) Am I correct in doing so to implement your new code?

2) When I debug the code, I find that the program returns at the following line itself inside the play() function:

size_t DataPlayer::Play(int * data, size_t size)
{
if (!FOpened || !FEnabled || !size || !mFile)
return 0;

because, FOpened=false and mFile shows NULL in watch.

Why is it so, when the file was successfully opened which I can see when the program was executing inside Player.start() before calling play() ?

With regards
tej pratap

[csmith]

If Start() could not open the file, you could get this condition. Otherwise, the only way I see that this could occur is if you had called Stop() before Play(). This will close the file and reset FOpened.

[tejpratap]

Dear sir,
My playback code earlier was working ok except for the situations of
playback when I wanted to use the line of code " switch (FMode) :" for cases of 'case pmZero: ' and 'case pmRepeat: '. But I was not able to reach to the line of code " switch (FMode) :" as I have written in my first mail under this topic. Then as suggested by you, I replaced the play() code only keeping the other parts of the playback code same. Hence, there is no question of calling Stop() before Play(). Also, I have not changed the Start() code or a call to this . Start() is working fine now also as earlier as can be monitored through 'Watch'. Then Why I am getting the errors ?

with regards
tej pratap

[csmith]

If Start() is setting those variables, something has to be changing them before you call Play(), or they would be in the proper state. If this is not happening in Stop(), then you may have to debug to see where this data is getting overwritten improperly.

Alternatively, you could look at the more recent Malibu releases, which have rewritten this class (primarily to accommodate other OSes).