id3dump.c

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/*
    id3dump: Print ID3 tags of files, scanned using libmpg123.
 
    This is example code only sensible to be considered in the public domain.
    Initially written by Thomas Orgis.
*/
 
#include "mpg123.h"
#include <string.h>
#include "stdio.h"
#include "sys/types.h"
 
void safe_print(char* name, char *data, size_t size)
{
    char safe[31];
    if(size>30) return;
 
    memcpy(safe, data, size);
    safe[size] = 0;
    printf("%s: %s\n", name, safe);
}
 
void print_v1(mpg123_id3v1 *v1)
{
    safe_print("Title",   v1->title,   sizeof(v1->title));
    safe_print("Artist",  v1->artist,  sizeof(v1->artist));
    safe_print("Album",   v1->album,   sizeof(v1->album));
    safe_print("Year",    v1->year,    sizeof(v1->year));
    safe_print("Comment", v1->comment, sizeof(v1->comment));
    printf("Genre: %i", v1->genre);
}
 
void print_lines(const char* prefix, mpg123_string *inlines)
{
    size_t i;
    int hadcr = 0, hadlf = 0;
    char *lines = NULL;
    char *line  = NULL;
    size_t len = 0;
 
    if(inlines != NULL && inlines->fill)
    {
        lines = inlines->p;
        len   = inlines->fill;
    }
    else return;
 
    line = lines;
    for(i=0; i<len; ++i)
    {
        if(lines[i] == '\n' || lines[i] == '\r' || lines[i] == 0)
        {
            char save = lines[i]; /* saving, changing, restoring a byte in the data */
            if(save == '\n') ++hadlf;
            if(save == '\r') ++hadcr;
            if((hadcr || hadlf) && hadlf % 2 == 0 && hadcr % 2 == 0) line = "";
 
            if(line)
            {
                lines[i] = 0;
                printf("%s%s\n", prefix, line);
                line = NULL;
                lines[i] = save;
            }
        }
        else
        {
            hadlf = hadcr = 0;
            if(line == NULL) line = lines+i;
        }
    }
}
 
void print_v2(mpg123_id3v2 *v2)
{
    print_lines("Title: ",   v2->title);
    print_lines("Artist: ",  v2->artist);
    print_lines("Album: ",   v2->album);
    print_lines("Year: ",    v2->year);
    print_lines("Comment: ", v2->comment);
    print_lines("Genre: ",   v2->genre);
}
 
void print_raw_v2(mpg123_id3v2 *v2)
{
    size_t i;
    for(i=0; i<v2->texts; ++i)
    {
        char id[5];
        char lang[4];
        memcpy(id, v2->text[i].id, 4);
        id[4] = 0;
        memcpy(lang, v2->text[i].lang, 3);
        lang[3] = 0;
        if(v2->text[i].description.fill)
        printf("%s language(%s) description(%s)\n", id, lang, v2->text[i].description.p);
        else printf("%s language(%s)\n", id, lang);
 
        print_lines(" ", &v2->text[i].text);
    }
    for(i=0; i<v2->extras; ++i)
    {
        char id[5];
        memcpy(id, v2->extra[i].id, 4);
        id[4] = 0;
        printf( "%s description(%s)\n",
                id,
                v2->extra[i].description.fill ? v2->extra[i].description.p : "" );
        print_lines(" ", &v2->extra[i].text);
    }
    for(i=0; i<v2->comments; ++i)
    {
        char id[5];
        char lang[4];
        memcpy(id, v2->comment_list[i].id, 4);
        id[4] = 0;
        memcpy(lang, v2->comment_list[i].lang, 3);
        lang[3] = 0;
        printf( "%s description(%s) language(%s): \n",
                id,
                v2->comment_list[i].description.fill ? v2->comment_list[i].description.p : "",
                lang );
        print_lines(" ", &v2->comment_list[i].text);
    }
}
 
int main(int argc, char **argv)
{
    int i;
    mpg123_handle* m;
    if(argc < 2)
    {
        fprintf(stderr, "\nI will print some ID3 tag fields of MPEG audio files.\n");
        fprintf(stderr, "\nUsage: %s <mpeg audio file list>\n\n", argv[0]);
        return -1;
    }
#if MPG123_API_VERSION < 46
    // Newer versions of the library don't need that anymore, but it is safe
    // to have the no-op call present for compatibility with old versions.
    mpg123_init();
#endif
    m = mpg123_new(NULL, NULL);
 
    for(i=1; i < argc; ++i)
    {
        mpg123_id3v1 *v1;
        mpg123_id3v2 *v2;
        int meta;
        if(mpg123_open(m, argv[i]) != MPG123_OK)
        {
            fprintf(stderr, "Cannot open %s: %s\n", argv[i], mpg123_strerror(m));
            continue;
        }
        mpg123_scan(m);
        meta = mpg123_meta_check(m);
        if(meta & MPG123_ID3 && mpg123_id3(m, &v1, &v2) == MPG123_OK)
        {
            printf("Tag data on %s:\n", argv[i]);
            printf("\n====      ID3v1       ====\n");
            if(v1 != NULL) print_v1(v1);
 
            printf("\n====      ID3v2       ====\n");
            if(v2 != NULL) print_v2(v2);
 
            printf("\n==== ID3v2 Raw frames ====\n");
            if(v2 != NULL) print_raw_v2(v2);
        }
        else printf("Nothing found for %s.\n", argv[i]);
 
        mpg123_close(m);
    }
    mpg123_delete(m);
    return 0;
}