Today, I put my first program onto my empeg. It's called "hello world" and you can guess what it does.

I also put my second program onto it. It's a bit more useful. It's designed to answer the question everybody asks you: how much music is there on your empeg? It only works on single-drive machines at present, but I include source so you can see how to fix that.

To use, just install it on $PATH in your player (e.g. in /empeg/bin) and run it with no arguments to see how long it would take to play your root playlist, or with a list of FIDs to measure those.

Here's the code (binary is attached):

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <linux/limits.h>



#define FID_ROOTPLAYLIST 0x100



#define FIDS_DIR         "/drive0/fids"

#define FIDS_FILE0_FORMAT FIDS_DIR"/%x0"

#define FIDS_FILE1_FORMAT FIDS_DIR"/%x1"



#define LINESZ 512



#define TYPE_TUNE     1

#define TYPE_PLAYLIST 2



#if 0

#define DEBUG0(s) fprintf(stderr, s);

#define DEBUG1(s, x) fprintf(stderr, s, x);

#endif



int measure_item(int playlist);

int measure_playlist(int playlist);





int main(int argc, char **argv) {

  

  int playlist;

  int duration;                 /* in milliseconds */

  int total = 0;

  int i;

  char *numend;



  if (argc <= 1) {

    /* argument not supplied - measure root playlist */

    total = duration = measure_item(FID_ROOTPLAYLIST);

    printf("Root playlist: %d.%03d", duration/1000, duration%1000);

  } else {

    for (i = 1;  i < argc;  i++) {

      /* Parse argument as hexadecimal FID */

      playlist = (int)strtol(argv[ i], &numend, 16);

      if (*numend) {

        fprintf(stderr, "%s: Unrecognised argument %s\n", argv[ 0], argv[ i]);

        fprintf(stderr, "Usage: %s [ fid...]\n", argv[ 0]);

        exit(EXIT_FAILURE);

      }

      total += duration = measure_item(playlist);

      printf("Playlist %5x: %d.%03d\n", playlist, duration/1000, duration%1000);

    }

    printf("Total: %d.%03d", total/1000, total%1000);

  }

  

  if (duration > 60000) {

    int hours, minutes, seconds, millis;

    millis = total % 1000;

    total /= 1000;

    seconds = total % 60;

    minutes = total / 60 % 60;

    hours = total / 3600;

    

    printf(" (");

    if (hours)

      printf("%dh", hours);

    if (minutes)

      printf("%dm", minutes);

    printf("%ds", seconds);

    printf(")");

  }

  printf("\n");

  

  return EXIT_SUCCESS;



}





/* Returns length of playlist or tune, in milliseconds. */

int measure_item(int playlist) {

  char filename[ PATH_MAX+1];

  char line[ LINESZ+1];

  int duration = 0;

  int type = 0;

  FILE *f;



  /* First, read the *1 file - is it a tune or a playlist? */

  sprintf(filename, FIDS_FILE1_FORMAT, playlist/16);

 

  /*DEBUG1("Opening %s\n", filename);*/

  f = fopen(filename, "r");

  if (f == NULL) {

    perror(filename);

    exit(EXIT_FAILURE);

  }



  while (fgets(line, LINESZ, f)) {

    if (!strcmp(line, "type=tune\n")) {

      type = TYPE_TUNE;

    } else if (!strcmp(line, "type=playlist\n")) {

      type = TYPE_PLAYLIST;

    } else if (!strncmp(line, "duration=", 9)) {

      duration = (int)strtol(line+9, NULL, 10);

    }

  }

  

  if (ferror(f)) {

    /* fgets failed, not at EOF */

    perror(filename);

    fclose(f);

    exit(EXIT_FAILURE);

  }



  if (fclose(f)) {

    perror(filename);

    exit(EXIT_FAILURE);

  }



  switch (type) {

  case TYPE_TUNE:

    return duration;



  case TYPE_PLAYLIST:

    return measure_playlist(playlist);

    

  default:

    fprintf(stderr, "No type for %s", filename);

    exit(EXIT_FAILURE);

  }

}





int measure_playlist(int playlist) {

  char filename[ PATH_MAX+1];

  int fid;

  int duration = 0;

  FILE *f;



  /* First, read the *0 file - this holds the child pointers. */

  sprintf(filename, FIDS_FILE0_FORMAT, playlist/16);

  

  f = fopen(filename, "rb");

  if (f == NULL) {

    perror(filename);

    exit(EXIT_FAILURE);

  }



  while (1 == fread(&fid, 4, 1, f)) {    

    duration += measure_item(fid);

  }

  

  if (ferror(f)){

    /* fread failed */

    perror(filename);

    fclose(f);

    exit(EXIT_FAILURE);

  }



  if (fclose(f)) {

    perror(filename);

    exit(EXIT_FAILURE);

  }



  return duration;

}

--
Toby Speight

How to install this program on empeg? Using serial link!?

Upload the binary using zmodem - I'm assuming that anyone wanting this already knows how to get a shell on the empeg...

--
Toby Speight

Kewl, although I do have to say at this point that, in v2.0, both Emplode and the player will give you this information too.

http://empeg.comms.net/php/showthreaded.php?Cat=&Board=wishlist&Number=33565&page=&view=&sb=&o=

Peter

That's great - I did this mainly for my own amusement, and thought I'd share the code. If I were to do it properly, I'd read the database instead of grinding the discs reading fids/*1...

BTW, has anyone reverse-engineered the DB? I can imagine some cool uses...

--
Toby Speight

has anyone reverse-engineered the DB

Well, I hope no-one's gone to the bother of reverse-engineering it... all the code to parse it is in the GPL'd emptool sources. (The emptool/emplode protocol just grabs the entire file, pipes it over the connection, and parses it at the PC end.)

Peter

Peter wrote:

> Well, I hope no-one's gone to the bother of reverse-engineering it... all the code to parse it is in the GPL'd emptool sources.

I should have looked - I assumed that it was built on the player.

--
Toby Speight

It is -- it's built on the player during a sync. But it's parsed in emplode/emptool during a dowload from the player.



Roger - not necessarily speaking for empeg

Cool, just looked into emptool source... This has potential...

Frank van Gestel

In reply to:

---

Cool, just looked into emptool source... This has potential...

---

Ut oh, Roger now you've done it ...

Cheers,
Hans

Mk2 - Blue & Red - 080000431