Question regarding this library

[hwen3]

Hi Lars,

Thanks for this amazing and light library. However, I am currently running into problems with parsing some mp3 files. For these files the library spits out garbage strings, any thoughts as to what could be causing this?

Thank you, Jim

[antontriola]

Jim, I'm running into similar issue, I think I can fix it pretty easily (it's a unicode string parsing thing), I'll post back with a fix if I succeed.

[antontriola]

OK, here's the fix. This works whether the content is ascii or unicode.

• Open the file: frame.c
• Copy the following code to frame.c right after the #includes:

char* uni2text(unsigned char *binbuf, int len)
{
    unsigned char *b;       //must be unsigned
    char *p;                //scratch ptr
    static char cbuf[4096]; //examp: feel free to malloc instead
    int i;                  //counter

    memset(cbuf,0,sizeof(cbuf)); //zero, required

    for(b=binbuf, p=cbuf, i=0; i<len; i++, b++)
    {
        if(*b==0||*b==1||*b==0xff||*b==0xfe) 
            continue;
        else
            *p++=*b;
    } 
    return cbuf;
}

Now, scroll down to parse_text_frame_content(), add one line as shown:

ID3v2_frame_text_content* parse_text_frame_content(ID3v2_frame* frame)
{
    if(frame == NULL)
    {
        return NULL;
    }

    ID3v2_frame_text_content* content = new_text_content(frame->size);
    content->encoding = frame->data[0];
    content->size = frame->size - ID3_FRAME_ENCODING;
    memcpy(content->data, frame->data + ID3_FRAME_ENCODING, content->size);

    //add this line:
    content->data=uni2text(content->data, content->size);

return content;
}

• Re-compile your lib.
• Re-compile your app.

The parsing function will now read ascii or unicode and insure content->data is ascii. NOTE: you may want to do this to parse_comment_frame_content(), as well, or any other parsing functions that may potentially return unicode text.

Cheers, Tony

[hwen3]

Oh, sorry, forgot to close the issue. It was like you said an issue with unicode encoding in the id3 metadata. Since I want to minimize changes to the library I use, I simply used ICU library to decode the data if it was utf-16 encoded.

[Jonatas4ndrade]

OK, here's the fix. This works whether the content is ascii or unicode.

• Open the file: frame.c
• Copy the following code to frame.c right after the #includes:

char* uni2text(unsigned char *binbuf, int len)
{
    unsigned char *b;       //must be unsigned
    char *p;                //scratch ptr
    static char cbuf[4096]; //examp: feel free to malloc instead
    int i;                  //counter

    memset(cbuf,0,sizeof(cbuf)); //zero, required

    for(b=binbuf, p=cbuf, i=0; i<len; i++, b++)
    {
        if(*b==0||*b==1||*b==0xff||*b==0xfe) 
            continue;
        else
            *p++=*b;
    } 
    return cbuf;
}

Now, scroll down to parse_text_frame_content(), add one line as shown:

ID3v2_frame_text_content* parse_text_frame_content(ID3v2_frame* frame)
{
    if(frame == NULL)
    {
        return NULL;
    }

    ID3v2_frame_text_content* content = new_text_content(frame->size);
    content->encoding = frame->data[0];
    content->size = frame->size - ID3_FRAME_ENCODING;
    memcpy(content->data, frame->data + ID3_FRAME_ENCODING, content->size);

    //add this line:
    content->data=uni2text(content->data, content->size);

return content;
}

• Re-compile your lib.
• Re-compile your app.

The parsing function will now read ascii or unicode and insure content->data is ascii. NOTE: you may want to do this to parse_comment_frame_content(), as well, or any other parsing functions that may potentially return unicode text.

Cheers, Tony

Thanks man, solved my problem as well. Maybe open a pull request to incorporate the fix?