--- /dev/null
+#include <assert.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#define STB_VORBIS_HEADER_ONLY
+#include "stb_vorbis.c"
+
+#define SAMPLES_TO_TEST 3000
+
+int test_count [5] = { 5000, 3000, 2000, 50000, 50000 };
+int test_spacing[5] = { 1, 111, 3337, 7779, 72717 };
+
+int try_seeking(stb_vorbis *v, unsigned int pos, short *output, unsigned int num_samples)
+{
+ int count;
+ short samples[SAMPLES_TO_TEST*2];
+ assert(pos <= num_samples);
+
+ if (!stb_vorbis_seek(v, pos)) {
+ fprintf(stderr, "Seek to %u returned error from stb_vorbis\n", pos);
+ return 0;
+ }
+
+ count = stb_vorbis_get_samples_short_interleaved(v, 2, samples, SAMPLES_TO_TEST*2);
+
+ if (count > (int) (num_samples - pos)) {
+ fprintf(stderr, "Seek to %u allowed decoding %d samples when only %d should have been valid.\n",
+ pos, count, (int) (num_samples - pos));
+ return 0;
+ }
+
+ if (count < SAMPLES_TO_TEST && count < (int) (num_samples - pos)) {
+ fprintf(stderr, "Seek to %u only decoded %d samples of %d attempted when at least %d should have been valid.\n",
+ pos, count, SAMPLES_TO_TEST, num_samples - pos);
+ return 0;
+ }
+
+ if (0 != memcmp(samples, output + pos*2, count*2)) {
+ int k;
+ for (k=0; k < SAMPLES_TO_TEST*2; ++k) {
+ if (samples[k] != output[k]) {
+ fprintf(stderr, "Seek to %u produced incorrect samples starting at sample %u (short #%d in buffer).\n",
+ pos, pos + (k/2), k);
+ break;
+ }
+ }
+ assert(k != SAMPLES_TO_TEST*2);
+ return 0;
+ }
+
+ return 1;
+}
+
+int main(int argc, char **argv)
+{
+ int num_chan, samprate;
+ int i, j, test, phase;
+ short *output;
+
+ if (argc == 1) {
+ fprintf(stderr, "Usage: vorbseek {vorbisfile} [{vorbisfile]*]\n");
+ fprintf(stderr, "Tests various seek offsets to make sure they're sample exact.\n");
+ return 0;
+ }
+
+ #if 0
+ {
+ // check that outofmem occurs correctly
+ stb_vorbis_alloc va;
+ va.alloc_buffer = malloc(1024*1024);
+ for (i=0; i < 1024*1024; i += 10) {
+ int error=0;
+ stb_vorbis *v;
+ va.alloc_buffer_length_in_bytes = i;
+ v = stb_vorbis_open_filename(argv[1], &error, &va);
+ if (v != NULL)
+ break;
+ printf("Error %d at %d\n", error, i);
+ }
+ }
+ #endif
+
+ for (j=1; j < argc; ++j) {
+ unsigned int successes=0, attempts = 0;
+ unsigned int num_samples = stb_vorbis_decode_filename(argv[j], &num_chan, &samprate, &output);
+
+ break;
+
+ if (num_samples == 0xffffffff) {
+ fprintf(stderr, "Error: couldn't open file or not vorbis file: %s\n", argv[j]);
+ goto fail;
+ }
+
+ if (num_chan != 2) {
+ fprintf(stderr, "vorbseek testing only works with files with 2 channels, %s has %d\n", argv[j], num_chan);
+ goto fail;
+ }
+
+ for (test=0; test < 5; ++test) {
+ int error;
+ stb_vorbis *v = stb_vorbis_open_filename(argv[j], &error, NULL);
+ if (v == NULL) {
+ fprintf(stderr, "Couldn't re-open %s for test #%d\n", argv[j], test);
+ goto fail;
+ }
+ for (phase=0; phase < 3; ++phase) {
+ unsigned int base = phase == 0 ? 0 : phase == 1 ? num_samples - test_count[test]*test_spacing[test] : num_samples/3;
+ for (i=0; i < test_count[test]; ++i) {
+ unsigned int pos = base + i*test_spacing[test];
+ if (pos > num_samples) // this also catches underflows
+ continue;
+ successes += try_seeking(v, pos, output, num_samples);
+ attempts += 1;
+ }
+ }
+ stb_vorbis_close(v);
+ }
+ printf("%d of %d seeks failed in %s (%d samples)\n", attempts-successes, attempts, argv[j], num_samples);
+ free(output);
+ }
+ return 0;
+ fail:
+ return 1;
+}
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