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Note: This API doc is automatically generated from the current development version that you can get via Subversion or as a daily snapshot from http://mpg123.org/snapshot. There may be differences (additions) compared to the latest stable release. See NEWS.libmpg123 and the overall NEWS file on libmpg123 versions and important changes between them.
Let me emphasize that the policy for libmpg123 is to always stay backwards compatible -- only additions are planned (and it's not yet planned to change the plans;-).

id3dump.c

Go to the documentation of this file.

/*
        id3dump: Print ID3 tags of files, scanned using libmpg123.

        copyright 2007 by the mpg123 project - free software under the terms of the LGPL 2.1
        see COPYING and AUTHORS files in distribution or http://mpg123.org
        initially written by Thomas Orgis
*/

#include "mpg123.h"
#include <string.h>
#include "stdio.h"
#include "sys/types.h"

/* Helper for v1 printing, get these strings their zero byte. */
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);
}

/* Print out ID3v1 info. */
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);
}

/* Split up a number of lines separated by \n, \r, both or just zero byte
   and print out each line with specified prefix. */
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;
                }
        }
}

/* Print out the named ID3v2  fields. */
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);
}

/* Print out all stored ID3v2 fields with their 4-character IDs. */
void print_raw_v2(mpg123_id3v2 *v2)
{
        size_t i;
        for(i=0; i<v2->texts; ++i)
        {
                char id[5];
                memcpy(id, v2->text[i].id, 4);
                id[4] = 0;
                printf("%s\n", id);
                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;
        }
        mpg123_init();
        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);
        mpg123_exit();
        return 0;
}

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