Similar code works very well for me:
class CContext
{
public:
int OnDataRequested(uint8_t* p, int n)
{
}
int64_t OnSeekRequested(int64_t offset, int whence)
{
}
};
static int file_open(URLContext *h, const char *filename, int flags)
{
CContext* pContext = <static variable where CContext is temporarily
stored>;
h->priv_data = (void*) pContext;
return 0;
}
static int file_read(URLContext *h, unsigned char *buf, int size)
{
CContext* p = (CContext*) h->priv_data;
return p->OnDataRequested(buf, size);
}
static int file_write(URLContext *h, unsigned char *buf, int size)
{
return 0;
}
static int64_t file_seek(URLContext *h, int64_t pos, int whence)
{
CContext* p = (CContext*) h->priv_data;
return p->OnSeekRequested(pos, whence);
}
static int file_close(URLContext *h)
{
return 0;
}
static int file_get_handle(URLContext *h)
{
return (intptr_t) h->priv_data;
}
On Wed, Jun 9, 2010 at 4:00 PM, Mark Kenna
<[email protected]> wrote:
> Hi All
>
> I have a problem whilst implementing a custom URLProtocol for use with
> av_open_input_file(...). I am trying to use the protocol so that a custom
> url_read method will receive data from a callback which the user can supply
> from the calling application. To illustrate, I have the following methods
> for the url_open and url_read (which are both static member functions of an
> unmanaged C++ class)
>
> int BufferProtocol::BufferOpen(URLContext *h, const char *pseudofilename,
> int flags)
> {
> //setup the buffer
> BUFFER *buffer = new BUFFER();
> buffer->buflen = BUFFERLENGTH;
> buffer->offset = 0;
> buffer->buf = new unsigned char[BUFFERLENGTH];
> memset(buffer->buf, 0, BUFFERLENGTH);
>
>
> //assign the URLContext's private data to be the buffer
> h->priv_data = buffer;
>
> return 1;
> }
>
> int BufferProtocol::BufferRead(URLContext *h, unsigned char *buf, int size)
> {
> BUFFER *buffer = (BUFFER*)h->priv_data;
>
> int amountRead = 1024;
> unsigned char* data = HELP_HERE_PLEASE
> ...
> ...
>
> }
>
> So in the above Read method I want to invoke a callback which will prompt
> for a certain number of bytes and return the received data (which can be put
> into *buf). I understand how this would work with a typical callback but I
> have one more problem - because I am using Class members for the URLProtocol
> they have to be static, also the application that is going to use this will
> probably call av_open_input_file(...) more than once (for multiple input
> buffer sources) and because the methods are all static I will not be able to
> tell which buffer the callback refers to. This is kind of confusing to
> describe and I hope that my point is clear enough to understand.
>
> Thanks,
> Mark.
>
> _______________________________________________
> libav-user mailing list
> [email protected]
> https://lists.mplayerhq.hu/mailman/listinfo/libav-user
>
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