Feed data from a user-supplied callback to an AVFifoBuffer.
@param f AVFifoBuffer to write to
@param src data source; non-const since it may be used as a
modifiable context by the function defined in func
@param size number of bytes to write
@param func generic write function; the first parameter is src,
the second is dest_buf, the third is dest_buf_size.
func must return the number of bytes written to dest_buf, or <= 0 to
indicate no more data available to write.
If func is NULL, src is interpreted as a simple byte array for source data.
@return the number of bytes written to the FIFO
Feed data from a user-supplied callback to an AVFifoBuffer. @param f AVFifoBuffer to write to @param src data source; non-const since it may be used as a modifiable context by the function defined in func @param size number of bytes to write @param func generic write function; the first parameter is src, the second is dest_buf, the third is dest_buf_size. func must return the number of bytes written to dest_buf, or <= 0 to indicate no more data available to write. If func is NULL, src is interpreted as a simple byte array for source data. @return the number of bytes written to the FIFO