view liszt.cpp @ 693:b1723ae7675e

begin work on sampling API

This is motivated by the need to be able to sample with arbitrary feature data
(e.g. from a feature file) against a database, for the JNMR "collections" paper
revisions or possible ISMIR paper revisions.  That bit doesn't work yet, but
the C-ified version of the current functionality (sample db x db and
sample key x db) works to the level of anecdotal tests.

The general approach is to mirror the _query_spec() API, where a whole heap
of knobs and twiddles are available to the user.  Unlike in the _query_spec()
API, not quite all of the knobs make sense (and even fewer are actually
implemented), but the basic idea is the same.

I pity the poor chump who will have to document all this.

extern "C" {
#include "audioDB_API.h"
}
#include "audioDB-internals.h"

adb_liszt_results_t *audiodb_liszt(adb_t *adb) {
  uint32_t nfiles = adb->header->numFiles;
  adb_liszt_results_t *results;
  results = (adb_liszt_results_t *) calloc(sizeof(adb_liszt_results_t),1);
  results->nresults = nfiles;
  if(nfiles > 0) {
    results->entries = (adb_track_entry_t *) malloc(nfiles * sizeof(adb_track_entry_t));
  }
  for(uint32_t k = 0; k < nfiles; k++) {
    results->entries[k].nvectors = (*adb->track_lengths)[k];
    results->entries[k].key = audiodb_index_key(adb, k);
  }
  return results;
}

int audiodb_liszt_free_results(adb_t *adb, adb_liszt_results_t *results) {
  free(results->entries);
  free(results);
  return 0;
}