Need help searching for bytes in an InputStream. I need to look for id3v2 frames and headers in mp3 files. I am disgusted with the existing id3 libs (they aint that bad but just annoys me somehow). :(emo):
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Need help searching for bytes in an InputStream. I need to look for id3v2 frames and headers in mp3 files. I am disgusted with the existing id3 libs (they aint that bad but just annoys me somehow). :(emo):
Can you define what bytes you are looking for and what problems you are having?Quote:
Need help searching for bytes
Well, the bytes i'm lookin for is the id3v2 frame headers like the hex representation of "APIC" frame header or "TIT2" etc. Actually i dont have any problem, i just dont how to do !
Moved from Advanced Java.Quote:
Originally Posted by Evanxtreme
db
Can you post an array containing the bytes you are looking for?Quote:
i dont have any problem, i just dont how to do
What is the hex representation of "APIC" ? Why in hex? A byte has two hex digits.
Well that would come from any mp3 file as inputstream. And hex reprentation of "APIC" means char "A" would be represented by "0x41" , "C" by "0x44", "I" by "0x49" etc. This is because i'm gonna work with *binary* data (not chars).
Do those four 'characters' take up four bytes? If so, do all those byte values represent valid ASCII code characters? (still they're bytes).Quote:
Originally Posted by Evanxtreme
kind regards,
Jos
Yup! They're four bytes and they are ascii
If all those bytes represent valid ASCII characters (in single bytes) you can transform your byte stream to a char stream and fiddle diddle with Strings (there are many more methods available for Strings, e.g. regular expression matching etc.)Quote:
Originally Posted by Evanxtreme
kind regards,
Jos
Oh yeah! But i gotta work with other bytes such as 0x03 0x02 etc. Which i think can't workaround by casting to string :@ and also as an addon Q. How do i trim off (that is, remove) a portion within a file ? Hope its not off-topic ;) .
Byte values 0x02 and 0x03 are valid ASCII values (aamof all bytes in the range 0x00 - 0x7f are valid ASCII values) so they make excellent characters; you probably can't print them but they are valid chars nevertheless ...Quote:
Originally Posted by Evanxtreme
kind regards,
Jo
but how do i check that the stream has those bytes ? is there any way to cast hex to string ?
thanks
One way to get hex into a String is to use the escape sequence:
String str = "\u0003";
Do you have an example of hex values you want to create a String from?
Oh nice! I've been using 'very long' steps to get strings from hex, and here is the hex "0x41 0x50 0x49 0x43" and "0xff 0xd8" (i think they aint valid ascii but i want to check them too!) and the code you showed seem to be for unicode char, how do i do that for hex ?
Did you try any of those values?
Code:String str = "\u0041\u0042\u0043\u00ff\u00d8";
System.out.println("str=" + str + "<"); // str=ABCÿØ<
Oh thank you all ! I got it now, thanks again, do this forum have a "problem solved" button ?
Edit the first post, click 'Go Advanced' and select the prefix.Quote:
Originally Posted by Evanxtreme
This time round, I'm doing it for you.
db