[Gambas-user] reading files
Shane
buster6seven at ...626...
Thu Jul 20 12:09:56 CEST 2017
yep can't use structs have to do like tony's code works perfect thanks
again tony
p.s is this your code ?
On 20/07/17 19:56, Gianluigi wrote:
> Right ... and a look here too [0]
>
> Ciao :)
> Gianluigi
>
> [0] http://www.gambas-it.org/smf/index.php?topic=5794.msg41793#msg41793
>
> 2017-07-20 3:15 GMT+02:00 Shane <buster6seven at ...626...>:
>
>> thanks tony sounds like just what i needed i will take a look
>>
>> cheers
>>
>>
>>
>> On 19/07/17 22:34, Tony Morehen wrote:
>>
>>> I've attached an archive containing the code I use to read v1 and v2 MP3
>>> tags and other MP3 info including bitrates (fixed and VBR), sampling rates
>>> and number of channels. v1 tags are pretty staightforward to read if you
>>> don't try to read the structure directly, but by each element of the
>>> structure at a time. Some tips:
>>>
>>> 1) Numeric elements (bytes, bytearrays, shorts, integers, longs) can be
>>> read directly from the stream. ie (4 byte Integer) = Read #Stream As
>>> Integer. Gambas can handle little endian/big endian issues.
>>>
>>> 2) Fixed length strings must be handled in a two stage process. First,
>>> the required string length number of bytes is read into a byte array. This
>>> byte array is then converted to a string. Sample code:
>>>
>>> Dim Bytes As New Byte[StringLength]
>>> Bytes.Read(Stream)
>>> FixedString = Bytes.ToString()
>>>
>>> Note: Bytes.ToString stops the string conversion at the first null or at
>>> the end of the array. Therfore, you don't have to worry about
>>> null-terminated strings.
>>>
>>> v2 tags are more complicated, particularly since the tags can be ascii,
>>> either kind of utf16, or utf8 encoding. The code I sent has been tested
>>> with over 10,000 mp3 files has seems to have no issues.
>>>
>>>
>>> On 2017-07-19 12:33 AM, Shane wrote:
>>>
>>>> thank you Gian i did take a rest and read but alas it did not help
>>>>
>>>> as far as i see it he is saying don't use binary file for fixed length
>>>> strings
>>>>
>>>> but as this is an mp3 file tag witch i have no control i am doomed
>>>>
>>>>
>>>>
>>>> On 18/07/17 19:22, Gianluigi wrote:
>>>>
>>>>> Why do not you take a moment of rest and read what Tobias Boege
>>>>> recommend
>>>>> me in the discussion [0] I told you here [1]?
>>>>>
>>>>> [0]
>>>>> http://gambas.8142.n7.nabble.com/Random-access-files-with-fi
>>>>> xed-length-string-td50880.html
>>>>> [1] http://gambas.8142.n7.nabble.com/vb-code-td59764.html
>>>>>
>>>>> 2017-07-18 9:04 GMT+02:00 Shane <buster6seven at ...626...>:
>>>>>
>>>>> I am very confused from the docs
>>>>>> _Variable_ *= READ* [ *#* _Stream_ ] *AS* _Datatype_
>>>>>>
>>>>>> _Variable_ *= READ* [ *#* _Stream_ *,* ] _Length_
>>>>>>
>>>>>> so wouldn't it be_
>>>>>> _
>>>>>>
>>>>>> IDtag = read #hfile as ID3v1_TAG ?
>>>>>>
>>>>>> with doesn't work by the way
>>>>>>
>>>>>>
>>>>>>
>>>>>> On 18/07/17 12:44, nando_f at ...951... wrote:
>>>>>>
>>>>>> I think
>>>>>>> Read #hfile, IDtag, ID3v1_TAG
>>>>>>> should be
>>>>>>> Read #hfile, IDtag as ID3v1_TAG
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> Open WebMail Project (http://openwebmail.org)
>>>>>>>
>>>>>>>
>>>>>>> ---------- Original Message -----------
>>>>>>> From: Shane <buster6seven at ...626...>
>>>>>>> To: gambas-user at lists.sourceforge.net
>>>>>>> Sent: Tue, 18 Jul 2017 10:50:43 +1000
>>>>>>> Subject: Re: [Gambas-user] reading files
>>>>>>>
>>>>>>> i don't know what i am doing wrong
>>>>>>>
>>>>>>>> Public Struct ID3v1_TAG '(128 bytes)
>>>>>>>> Tag[3] As String 'always TAG
>>>>>>>> Title[30] As String 'title, 30 characters
>>>>>>>> Artist[30] As String 'artist, 30 characters
>>>>>>>> Album[30] As String 'album, 30 characters
>>>>>>>> Year[4] As String 'year, 4 characters
>>>>>>>> Comment[30] As String 'comment, 30 characters (or
>>>>>>>> 28 if
>>>>>>>> track# included)
>>>>>>>> Genre As Byte 'genre, 255 for none defined
>>>>>>>> End Struct
>>>>>>>>
>>>>>>>> Private Sub GetID3v1(File As String)
>>>>>>>> Dim IDtag As ID3v1_TAG
>>>>>>>> Dim hfile As File
>>>>>>>>
>>>>>>>> hfile = Open File For Read
>>>>>>>>
>>>>>>>> '
>>>>>>>> 'read the tag
>>>>>>>> ' seek to end of less tag size
>>>>>>>>
>>>>>>>> Read #hfile, IDtag, ID3v1_TAG
>>>>>>>>
>>>>>>>> here i get IDtag is NULL
>>>>>>>>
>>>>>>>> On 18/07/17 05:05, nando_f at ...951... wrote:
>>>>>>>>
>>>>>>>> Yes it is possible, I do it. here is some code (incomplete)
>>>>>>>>> -Nando (Canada)
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> ' top of class file
>>>>>>>>> Public Struct recstruc
>>>>>>>>> _a as integer
>>>>>>>>> _b as integer
>>>>>>>>> _c as integer
>>>>>>>>> end struct
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> ' a function
>>>>>>>>> public function openAfile(filename as string) as file
>>>>>>>>>
>>>>>>>>> dim hfile as file
>>>>>>>>> dim arec as recstruc
>>>>>>>>>
>>>>>>>>> hfile = open filename for read write create
>>>>>>>>>
>>>>>>>>> with arec 'some values to write.
>>>>>>>>> ._a = 1
>>>>>>>>> ._b = 22
>>>>>>>>> ._c = 333
>>>>>>>>> end with
>>>>>>>>>
>>>>>>>>> write #hfile, arec as recstruc
>>>>>>>>>
>>>>>>>>> 'if you position the hfile pointer back to zero, you can...
>>>>>>>>> read #hfile, arec as recstruc
>>>>>>>>>
>>>>>>>>> close #hfile
>>>>>>>>>
>>>>>>>>> end
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>> Open WebMail Project (http://openwebmail.org)
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> ---------- Original Message -----------
>>>>>>>>> From: T Lee Davidson <t.lee.davidson at ...626...>
>>>>>>>>> To: gambas-user at lists.sourceforge.net
>>>>>>>>> Sent: Sun, 16 Jul 2017 12:42:35 -0400
>>>>>>>>> Subject: Re: [Gambas-user] reading files
>>>>>>>>>
>>>>>>>>> On 07/16/2017 06:57 AM, Shane wrote:
>>>>>>>>>
>>>>>>>>>> given this example
>>>>>>>>>>> PRIVATE SUB BinaryRead(FilePath AS String)
>>>>>>>>>>> DIM binaryFile AS File
>>>>>>>>>>> DIM i AS Integer
>>>>>>>>>>> DIM b AS Byte
>>>>>>>>>>> DIM s AS Short
>>>>>>>>>>> DIM s1 AS String
>>>>>>>>>>> DIM s2 AS String
>>>>>>>>>>> ' Read binary file
>>>>>>>>>>> binaryFile = OPEN FilePath FOR READ
>>>>>>>>>>> READ #binaryFile, i
>>>>>>>>>>> READ #binaryFile, b
>>>>>>>>>>> READ #binaryFile, s
>>>>>>>>>>> READ #binaryFile, s1
>>>>>>>>>>> READ #binaryFile, s2
>>>>>>>>>>> CLOSE #binaryFile
>>>>>>>>>>> ' Display results
>>>>>>>>>>> PRINT i
>>>>>>>>>>> PRINT b
>>>>>>>>>>> PRINT s
>>>>>>>>>>> PRINT s1
>>>>>>>>>>> PRINT s2
>>>>>>>>>>> END
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> is there a way for gambas to read a struct of all these variables
>>>>>>>>>>> in one read ?
>>>>>>>>>>>
>>>>>>>>>>> You may have hinted at the solution within your question. Have you
>>>>>>>>>>>
>>>>>>>>>> considered
>>>>>>>>>> using a Structure?
>>>>>>>>>>
>>>>>>>>>> http://gambaswiki.org/wiki/lang/read :
>>>>>>>>>> "... reads the stream Stream as binary data whose type is
>>>>>>>>>> specified by
>>>>>>>>>> the
>>>>>>>>>> Datatype argument."
>>>>>>>>>>
>>>>>>>>>> "The returned datatype can be one of the following: NULL, Boolean,
>>>>>>>>>> Byte, Short,
>>>>>>>>>> Integer, Long, Pointer, Single, Float, Date, String, Variant,
>>>>>>>>>> any
>>>>>>>>>> Array,
>>>>>>>>>> Collection or structure."
>>>>>>>>>>
>>>>>>>>>> http://gambaswiki.org/wiki/lang/structdecl
>>>>>>>>>>
>>>>>>>>>> --
>>>>>>>>>> Lee
>>>>>>>>>>
>>>>>>>>>> ------------------------------------------------------------
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>>>>>>>>>>
>>>>>>>>>> ------- End of Original Message -------
>>>>>>>>>
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