seeking in stb_vorbis (Dougall Johnson)

test program for seeking (stb)
pull/163/merge
Sean Barrett 2015-08-30 19:29:35 -07:00
parent c9859afcf9
commit ebb54fd7a3
4 changed files with 446 additions and 285 deletions

View File

@ -15,18 +15,20 @@
//
// Limitations:
//
// - seeking not supported except manually via PUSHDATA api
// - floor 0 not supported (used in old ogg vorbis files pre-2004)
// - lossless sample-truncation at beginning ignored
// - cannot concatenate multiple vorbis streams
// - sample positions are 32-bit, limiting seekable 192Khz
// files to around 6 hours (Ogg supports 64-bit)
//
// Feature contributors:
// Dougall Johnson (sample-exact seeking)
//
// Bugfix/warning contributors:
// Terje Mathisen Niklas Frykholm Andy Hill
// Casey Muratori John Bolton Gargaj
// Laurent Gomila Marc LeBlanc Ronny Chevalier
// Bernhard Wodo Evan Balster "alxprd"@github
// Bernhard Wodo Evan Balster "alxprd"@github
// Tom Beaumont Ingo Leitgeb Nicolas Guillemot
// (If you reported a bug but do not appear in this list, it is because
// someone else reported the bug before you. There were too many of you to
@ -259,7 +261,6 @@ extern stb_vorbis * stb_vorbis_open_file_section(FILE *f, int close_handle_on_cl
extern int stb_vorbis_seek_frame(stb_vorbis *f, unsigned int sample_number);
extern int stb_vorbis_seek(stb_vorbis *f, unsigned int sample_number);
// NOT WORKING YET
// these functions seek in the Vorbis file to (approximately) 'sample_number'.
// after calling seek_frame(), the next call to get_frame_*() will include
// the specified sample. after calling stb_vorbis_seek(), the next call to
@ -268,8 +269,7 @@ extern int stb_vorbis_seek(stb_vorbis *f, unsigned int sample_number);
// you can also use seek_frame().
extern void stb_vorbis_seek_start(stb_vorbis *f);
// this function is equivalent to stb_vorbis_seek(f,0), but it
// actually works
// this function is equivalent to stb_vorbis_seek(f,0)
extern unsigned int stb_vorbis_stream_length_in_samples(stb_vorbis *f);
extern float stb_vorbis_stream_length_in_seconds(stb_vorbis *f);
@ -714,8 +714,6 @@ typedef struct
typedef struct
{
uint32 page_start, page_end;
uint32 after_previous_page_start;
uint32 first_decoded_sample;
uint32 last_decoded_sample;
} ProbedPage;
@ -1423,8 +1421,6 @@ static int start_page_no_capturepattern(vorb *f)
len += 27 + f->segment_count;
p.page_start = f->first_audio_page_offset;
p.page_end = p.page_start + len;
p.after_previous_page_start = p.page_start;
p.first_decoded_sample = 0;
p.last_decoded_sample = loc0;
f->p_first = p;
}
@ -4470,7 +4466,7 @@ static uint32 vorbis_find_page(stb_vorbis *f, uint32 *end, uint32 *last)
int n;
if (f->eof) return 0;
n = get8(f);
if (n == 0x4f) { // page header
if (n == 0x4f) { // page header candidate
unsigned int retry_loc = stb_vorbis_get_file_offset(f);
int i;
// check if we're off the end of a file_section stream
@ -4534,37 +4530,30 @@ static uint32 vorbis_find_page(stb_vorbis *f, uint32 *end, uint32 *last)
}
}
// seek is implemented with 'interpolation search'--this is like
// binary search, but we use the data values to estimate the likely
// location of the data item (plus a bit of a bias so when the
// estimation is wrong we don't waste overly much time)
#define SAMPLE_unknown 0xffffffff
// seeking is implemented with a binary search, which narrows down the range to
// 64K, before using a linear search (because finding the synchronization
// pattern can be expensive, and the chance we'd find the end page again is
// relatively high for small ranges)
//
// two initial interpolation-style probes are used at the start of the search
// to try to bound either side of the binary search sensibly, while still
// working in O(log n) time if they fail.
// ogg vorbis, in its insane infinite wisdom, only provides
// information about the sample at the END of the page.
// therefore we COULD have the data we need in the current
// page, and not know it. we could just use the end location
// as our only knowledge for bounds, seek back, and eventually
// the binary search finds it. or we can try to be smart and
// not waste time trying to locate more pages. we try to be
// smart, since this data is already in memory anyway, so
// doing needless I/O would be crazy!
static int vorbis_analyze_page(stb_vorbis *f, ProbedPage *z)
static int get_seek_page_info(stb_vorbis *f, ProbedPage *z)
{
uint8 header[27], lacing[255];
uint8 packet_type[255];
int num_packet, packet_start;
int i,len;
uint32 samples;
// record where the page starts
z->page_start = stb_vorbis_get_file_offset(f);
// parse the header
getn(f, header, 27);
assert(header[0] == 'O' && header[1] == 'g' && header[2] == 'g' && header[3] == 'S');
if (header[0] != 'O' || header[1] != 'g' || header[2] != 'g' || header[3] != 'S')
return 0;
getn(f, lacing, header[26]);
// determine the length of the payload
@ -4576,304 +4565,265 @@ static int vorbis_analyze_page(stb_vorbis *f, ProbedPage *z)
z->page_end = z->page_start + 27 + header[26] + len;
// read the last-decoded sample out of the data
z->last_decoded_sample = header[6] + (header[7] << 8) + (header[8] << 16) + (header[9] << 16);
if (header[5] & 4) {
// if this is the last page, it's not possible to work
// backwards to figure out the first sample! whoops! fuck.
z->first_decoded_sample = SAMPLE_unknown;
set_file_offset(f, z->page_start);
return 1;
}
// scan through the frames to determine the sample-count of each one...
// our goal is the sample # of the first fully-decoded sample on the
// page, which is the first decoded sample of the 2nd packet
num_packet=0;
packet_start = ((header[5] & 1) == 0);
for (i=0; i < header[26]; ++i) {
if (packet_start) {
uint8 n,b;
if (lacing[i] == 0) goto bail; // trying to read from zero-length packet
n = get8(f);
// if bottom bit is non-zero, we've got corruption
if (n & 1) goto bail;
n >>= 1;
b = ilog(f->mode_count-1);
n &= (1 << b)-1;
if (n >= f->mode_count) goto bail;
packet_type[num_packet++] = f->mode_config[n].blockflag;
skip(f, lacing[i]-1);
} else
skip(f, lacing[i]);
packet_start = (lacing[i] < 255);
}
// now that we know the sizes of all the pages, we can start determining
// how much sample data there is.
samples = 0;
// for the last packet, we step by its whole length, because the definition
// is that we encoded the end sample loc of the 'last packet completed',
// where 'completed' refers to packets being split, and we are left to guess
// what 'end sample loc' means. we assume it means ignoring the fact that
// the last half of the data is useless without windowing against the next
// packet... (so it's not REALLY complete in that sense)
if (num_packet > 1)
samples += f->blocksize[packet_type[num_packet-1]];
for (i=num_packet-2; i >= 1; --i) {
// now, for this packet, how many samples do we have that
// do not overlap the following packet?
if (packet_type[i] == 1)
if (packet_type[i+1] == 1)
samples += f->blocksize_1 >> 1;
else
samples += ((f->blocksize_1 - f->blocksize_0) >> 2) + (f->blocksize_0 >> 1);
else
samples += f->blocksize_0 >> 1;
}
// now, at this point, we've rewound to the very beginning of the
// _second_ packet. if we entirely discard the first packet after
// a seek, this will be exactly the right sample number. HOWEVER!
// we can't as easily compute this number for the LAST page. The
// only way to get the sample offset of the LAST page is to use
// the end loc from the previous page. But what that returns us
// is _exactly_ the place where we get our first non-overlapped
// sample. (I think. Stupid spec for being ambiguous.) So for
// consistency it's better to do that here, too. However, that
// will then require us to NOT discard all of the first frame we
// decode, in some cases, which means an even weirder frame size
// and extra code. what a fucking pain.
// we're going to discard the first packet if we
// start the seek here, so we don't care about it. (we could actually
// do better; if the first packet is long, and the previous packet
// is short, there's actually data in the first half of the first
// packet that doesn't need discarding... but not worth paying the
// effort of tracking that of that here and in the seeking logic)
// except crap, if we infer it from the _previous_ packet's end
// location, we DO need to use that definition... and we HAVE to
// infer the start loc of the LAST packet from the previous packet's
// end location. fuck you, ogg vorbis.
z->first_decoded_sample = z->last_decoded_sample - samples;
z->last_decoded_sample = header[6] + (header[7] << 8) + (header[8] << 16) + (header[9] << 24);
// restore file state to where we were
set_file_offset(f, z->page_start);
return 1;
}
// rarely used function to seek back to the preceeding page while finding the
// start of a packet
static int go_to_page_before(stb_vorbis *f, unsigned int limit_offset)
{
unsigned int previous_safe, end;
// now we want to seek back 64K from the limit
if (limit_offset >= 65536 && limit_offset-65536 >= f->first_audio_page_offset)
previous_safe = limit_offset - 65536;
else
previous_safe = f->first_audio_page_offset;
set_file_offset(f, previous_safe);
while (vorbis_find_page(f, &end, NULL)) {
if (end >= limit_offset && stb_vorbis_get_file_offset(f) < limit_offset)
return 1;
set_file_offset(f, end);
}
// restore file state to where we were
bail:
set_file_offset(f, z->page_start);
return 0;
}
static int vorbis_seek_frame_from_page(stb_vorbis *f, uint32 page_start, uint32 first_sample, uint32 target_sample, int fine)
// implements the search logic for finding a page and starting decoding. if
// the function succeeds, current_loc_valid will be true and current_loc will
// be less than or equal to the provided sample number (the closer the
// better).
static int seek_to_sample_coarse(stb_vorbis *f, uint32 sample_number)
{
int left_start, left_end, right_start, right_end, mode,i;
int frame=0;
uint32 frame_start;
int frames_to_skip, data_to_skip;
ProbedPage left, right, mid;
int i, start_seg_with_known_loc, end_pos, page_start;
uint32 delta, stream_length, padding;
double offset, bytes_per_sample;
int probe = 0;
// first_sample is the sample # of the first sample that doesn't
// overlap the previous page... note that this requires us to
// _partially_ discard the first packet! bleh.
set_file_offset(f, page_start);
// find the last page and validate the target sample
stream_length = stb_vorbis_stream_length_in_samples(f);
if (stream_length == 0) return error(f, VORBIS_seek_without_length);
if (sample_number > stream_length) return error(f, VORBIS_seek_invalid);
f->next_seg = -1; // force page resync
// this is the maximum difference between the window-center (which is the
// actual granule position value), and the right-start (which the spec
// indicates should be the granule position (give or take one)).
padding = ((f->blocksize_1 - f->blocksize_0) >> 2);
if (sample_number < padding)
sample_number = 0;
else
sample_number -= padding;
frame_start = first_sample;
// frame start is where the previous packet's last decoded sample
// was, which corresponds to left_end... EXCEPT if the previous
// packet was long and this packet is short? Probably a bug here.
left = f->p_first;
while (left.last_decoded_sample == ~0U) {
// (untested) the first page does not have a 'last_decoded_sample'
set_file_offset(f, left.page_end);
if (!get_seek_page_info(f, &left)) goto error;
}
right = f->p_last;
assert(right.last_decoded_sample != ~0U);
// now, we can start decoding frames... we'll only FAKE decode them,
// until we find the frame that contains our sample; then we'll rewind,
// and try again
for (;;) {
int start;
// starting from the start is handled differently
if (sample_number <= left.last_decoded_sample) {
stb_vorbis_seek_start(f);
return 1;
}
if (!vorbis_decode_initial(f, &left_start, &left_end, &right_start, &right_end, &mode))
return error(f, VORBIS_seek_failed);
while (left.page_end != right.page_start) {
assert(left.page_end < right.page_start);
// search range in bytes
delta = right.page_start - left.page_end;
if (delta <= 65536) {
// there's only 64K left to search - handle it linearly
set_file_offset(f, left.page_end);
} else {
if (probe < 2) {
if (probe == 0) {
// first probe (interpolate)
double data_bytes = right.page_end - left.page_start;
bytes_per_sample = data_bytes / right.last_decoded_sample;
offset = left.page_start + bytes_per_sample * (sample_number - left.last_decoded_sample);
} else {
// second probe (try to bound the other side)
double error = ((double) sample_number - mid.last_decoded_sample) * bytes_per_sample;
if (error >= 0 && error < 8000) error = 8000;
if (error < 0 && error > -8000) error = -8000;
offset += error * 2;
}
if (frame == 0)
start = left_end;
else
start = left_start;
// ensure the offset is valid
if (offset < left.page_end)
offset = left.page_end;
if (offset > right.page_start - 65536)
offset = right.page_start - 65536;
// the window starts at left_start; the last valid sample we generate
// before the next frame's window start is right_start-1
if (target_sample < frame_start + right_start-start)
set_file_offset(f, (unsigned int) offset);
} else {
// binary search for large ranges (offset by 32K to ensure
// we don't hit the right page)
set_file_offset(f, left.page_end + (delta / 2) - 32768);
}
if (!vorbis_find_page(f, NULL, NULL)) goto error;
}
for (;;) {
if (!get_seek_page_info(f, &mid)) goto error;
if (mid.last_decoded_sample != ~0U) break;
// (untested) no frames end on this page
set_file_offset(f, mid.page_end);
assert(mid.page_start < right.page_start);
}
// if we've just found the last page again then we're in a tricky file,
// and we're close enough.
if (mid.page_start == right.page_start)
break;
flush_packet(f);
if (f->eof)
return error(f, VORBIS_seek_failed);
if (sample_number < mid.last_decoded_sample)
right = mid;
else
left = mid;
frame_start += right_start - start;
++frame;
}
// ok, at this point, the sample we want is contained in frame #'frame'
// to decode frame #'frame' normally, we have to decode the
// previous frame first... but if it's the FIRST frame of the page
// we can't. if it's the first frame, it means it falls in the part
// of the first frame that doesn't overlap either of the other frames.
// so, if we have to handle that case for the first frame, we might
// as well handle it for all of them, so:
if (target_sample > frame_start + (left_end - left_start)) {
// so what we want to do is go ahead and just immediately decode
// this frame, but then make it so the next get_frame_float() uses
// this already-decoded data? or do we want to go ahead and rewind,
// and leave a flag saying to skip the first N data? let's do that
frames_to_skip = frame; // if this is frame #1, skip 1 frame (#0)
data_to_skip = left_end - left_start;
} else {
// otherwise, we want to skip frames 0, 1, 2, ... frame-2
// (which means frame-2+1 total frames) then decode frame-1,
// then leave frame pending
frames_to_skip = frame - 1;
assert(frames_to_skip >= 0);
data_to_skip = -1;
++probe;
}
// seek back to start of the last packet
page_start = left.page_start;
set_file_offset(f, page_start);
f->next_seg = - 1; // force page resync
if (!start_page(f)) return error(f, VORBIS_seek_failed);
end_pos = f->end_seg_with_known_loc;
assert(end_pos >= 0);
for (i=0; i < frames_to_skip; ++i) {
maybe_start_packet(f);
flush_packet(f);
for (;;) {
for (i = end_pos; i > 0; --i)
if (f->segments[i-1] != 255)
break;
start_seg_with_known_loc = i;
if (start_seg_with_known_loc > 0 || !(f->page_flag & PAGEFLAG_continued_packet))
break;
// (untested) the final packet begins on an earlier page
if (!go_to_page_before(f, page_start))
goto error;
page_start = stb_vorbis_get_file_offset(f);
if (!start_page(f)) goto error;
end_pos = f->segment_count - 1;
}
if (data_to_skip >= 0) {
int i,j,n = f->blocksize_0 >> 1;
f->discard_samples_deferred = data_to_skip;
for (i=0; i < f->channels; ++i)
for (j=0; j < n; ++j)
f->previous_window[i][j] = 0;
f->previous_length = n;
frame_start += data_to_skip;
} else {
f->previous_length = 0;
vorbis_pump_first_frame(f);
}
// prepare to start decoding
f->current_loc_valid = FALSE;
f->last_seg = FALSE;
f->valid_bits = 0;
f->packet_bytes = 0;
f->bytes_in_seg = 0;
f->previous_length = 0;
f->next_seg = start_seg_with_known_loc;
// at this point, the NEXT decoded frame will generate the desired sample
if (fine) {
// so if we're doing sample accurate streaming, we want to go ahead and decode it!
if (target_sample != frame_start) {
int n;
stb_vorbis_get_frame_float(f, &n, NULL);
assert(target_sample > frame_start);
assert(f->channel_buffer_start + (int) (target_sample-frame_start) < f->channel_buffer_end);
f->channel_buffer_start += (target_sample - frame_start);
}
}
for (i = 0; i < start_seg_with_known_loc; i++)
skip(f, f->segments[i]);
return 0;
// start decoding (optimizable - this frame is generally discarded)
vorbis_pump_first_frame(f);
return 1;
error:
// try to restore the file to a valid state
stb_vorbis_seek_start(f);
return error(f, VORBIS_seek_failed);
}
static int vorbis_seek_base(stb_vorbis *f, unsigned int sample_number, int fine)
// the same as vorbis_decode_initial, but without advancing
static int peek_decode_initial(vorb *f, int *p_left_start, int *p_left_end, int *p_right_start, int *p_right_end, int *mode)
{
ProbedPage p[2],q;
if (IS_PUSH_MODE(f)) return error(f, VORBIS_invalid_api_mixing);
int bits_read, bytes_read;
// do we know the location of the last page?
if (f->p_last.page_start == 0) {
uint32 z = stb_vorbis_stream_length_in_samples(f);
if (z == 0) return error(f, VORBIS_cant_find_last_page);
}
p[0] = f->p_first;
p[1] = f->p_last;
if (sample_number >= f->p_last.last_decoded_sample)
sample_number = f->p_last.last_decoded_sample-1;
if (sample_number < f->p_first.last_decoded_sample) {
vorbis_seek_frame_from_page(f, p[0].page_start, 0, sample_number, fine);
if (!vorbis_decode_initial(f, p_left_start, p_left_end, p_right_start, p_right_end, mode))
return 0;
} else {
int attempts=0;
while (p[0].page_end < p[1].page_start) {
uint32 probe;
uint32 start_offset, end_offset;
uint32 start_sample, end_sample;
// copy these into local variables so we can tweak them
// if any are unknown
start_offset = p[0].page_end;
end_offset = p[1].after_previous_page_start; // an address known to seek to page p[1]
start_sample = p[0].last_decoded_sample;
end_sample = p[1].last_decoded_sample;
// either 1 or 2 bytes were read, figure out which so we can rewind
bits_read = 1 + ilog(f->mode_count-1);
if (f->mode_config[*mode].blockflag)
bits_read += 2;
bytes_read = (bits_read + 7) / 8;
// currently there is no such tweaking logic needed/possible?
if (start_sample == SAMPLE_unknown || end_sample == SAMPLE_unknown)
return error(f, VORBIS_seek_failed);
f->bytes_in_seg += bytes_read;
f->packet_bytes -= bytes_read;
skip(f, -bytes_read);
if (f->next_seg == -1)
f->next_seg = f->segment_count - 1;
else
f->next_seg--;
f->valid_bits = 0;
// now we want to lerp between these for the target samples...
// step 1: we need to bias towards the page start...
if (start_offset + 4000 < end_offset)
end_offset -= 4000;
// now compute an interpolated search loc
probe = start_offset + (int) floor((float) (end_offset - start_offset) / (end_sample - start_sample) * (sample_number - start_sample));
// next we need to bias towards binary search...
// code is a little wonky to allow for full 32-bit unsigned values
if (attempts >= 4) {
uint32 probe2 = start_offset + ((end_offset - start_offset) >> 1);
if (attempts >= 8)
probe = probe2;
else if (probe < probe2)
probe = probe + ((probe2 - probe) >> 1);
else
probe = probe2 + ((probe - probe2) >> 1);
}
++attempts;
set_file_offset(f, probe);
if (!vorbis_find_page(f, NULL, NULL)) return error(f, VORBIS_seek_failed);
if (!vorbis_analyze_page(f, &q)) return error(f, VORBIS_seek_failed);
q.after_previous_page_start = probe;
// it's possible we've just found the last page again
if (q.page_start == p[1].page_start) {
p[1] = q;
continue;
}
if (sample_number < q.last_decoded_sample)
p[1] = q;
else
p[0] = q;
}
if (p[0].last_decoded_sample <= sample_number && sample_number < p[1].last_decoded_sample) {
vorbis_seek_frame_from_page(f, p[1].page_start, p[0].last_decoded_sample, sample_number, fine);
return 0;
}
return error(f, VORBIS_seek_failed);
}
return 1;
}
int stb_vorbis_seek_frame(stb_vorbis *f, unsigned int sample_number)
{
return vorbis_seek_base(f, sample_number, FALSE);
uint32 max_frame_samples;
if (IS_PUSH_MODE(f)) return error(f, VORBIS_invalid_api_mixing);
// fast page-level search
if (!seek_to_sample_coarse(f, sample_number))
return 0;
assert(f->current_loc_valid);
assert(f->current_loc <= sample_number);
// linear search for the relevant packet
max_frame_samples = (f->blocksize_1*3 - f->blocksize_0) >> 2;
while (f->current_loc < sample_number) {
int left_start, left_end, right_start, right_end, mode, frame_samples;
if (!peek_decode_initial(f, &left_start, &left_end, &right_start, &right_end, &mode))
return error(f, VORBIS_seek_failed);
// calculate the number of samples returned by the next frame
frame_samples = right_start - left_start;
if (f->current_loc + frame_samples > sample_number) {
return 1; // the next frame will contain the sample
} else if (f->current_loc + frame_samples + max_frame_samples > sample_number) {
// there's a chance the frame after this could contain the sample
vorbis_pump_first_frame(f);
} else {
// this frame is too early to be relevant
f->current_loc += frame_samples;
f->previous_length = 0;
maybe_start_packet(f);
flush_packet(f);
}
}
// the next frame will start with the sample
assert(f->current_loc == sample_number);
return 1;
}
int stb_vorbis_seek(stb_vorbis *f, unsigned int sample_number)
{
return vorbis_seek_base(f, sample_number, TRUE);
if (!stb_vorbis_seek_frame(f, sample_number))
return 0;
if (sample_number != f->current_loc) {
int n;
uint32 frame_start = f->current_loc;
stb_vorbis_get_frame_float(f, &n, NULL);
assert(sample_number > frame_start);
assert(f->channel_buffer_start + (int) (sample_number-frame_start) <= f->channel_buffer_end);
f->channel_buffer_start += (sample_number - frame_start);
}
return 1;
}
void stb_vorbis_seek_start(stb_vorbis *f)
@ -4954,8 +4904,6 @@ unsigned int stb_vorbis_stream_length_in_samples(stb_vorbis *f)
f->p_last.page_start = last_page_loc;
f->p_last.page_end = end;
f->p_last.last_decoded_sample = lo;
f->p_last.first_decoded_sample = SAMPLE_unknown;
f->p_last.after_previous_page_start = previous_safe;
done:
set_file_offset(f, restore_offset);

View File

@ -63,7 +63,7 @@ Package=<4>
###############################################################################
Project: "resize"=.\resize\resize.dsp - Package Owner=<4>
Project: "resize"=.\resize.dsp - Package Owner=<4>
Package=<5>
{{{
@ -123,6 +123,18 @@ Package=<4>
###############################################################################
Project: "vorbseek"=.\vorbseek\vorbseek.dsp - Package Owner=<4>
Package=<5>
{{{
}}}
Package=<4>
{{{
}}}
###############################################################################
Global:
Package=<5>

105
tests/vorbseek/vorbseek.c Normal file
View File

@ -0,0 +1,105 @@
#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;
}
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);
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;
}

View File

@ -0,0 +1,96 @@
# Microsoft Developer Studio Project File - Name="vorbseek" - Package Owner=<4>
# Microsoft Developer Studio Generated Build File, Format Version 6.00
# ** DO NOT EDIT **
# TARGTYPE "Win32 (x86) Console Application" 0x0103
CFG=vorbseek - Win32 Debug
!MESSAGE This is not a valid makefile. To build this project using NMAKE,
!MESSAGE use the Export Makefile command and run
!MESSAGE
!MESSAGE NMAKE /f "vorbseek.mak".
!MESSAGE
!MESSAGE You can specify a configuration when running NMAKE
!MESSAGE by defining the macro CFG on the command line. For example:
!MESSAGE
!MESSAGE NMAKE /f "vorbseek.mak" CFG="vorbseek - Win32 Debug"
!MESSAGE
!MESSAGE Possible choices for configuration are:
!MESSAGE
!MESSAGE "vorbseek - Win32 Release" (based on "Win32 (x86) Console Application")
!MESSAGE "vorbseek - Win32 Debug" (based on "Win32 (x86) Console Application")
!MESSAGE
# Begin Project
# PROP AllowPerConfigDependencies 0
# PROP Scc_ProjName ""
# PROP Scc_LocalPath ""
CPP=cl.exe
RSC=rc.exe
!IF "$(CFG)" == "vorbseek - Win32 Release"
# PROP BASE Use_MFC 0
# PROP BASE Use_Debug_Libraries 0
# PROP BASE Output_Dir "Release"
# PROP BASE Intermediate_Dir "Release"
# PROP BASE Target_Dir ""
# PROP Use_MFC 0
# PROP Use_Debug_Libraries 0
# PROP Output_Dir "Release"
# PROP Intermediate_Dir "Release"
# PROP Target_Dir ""
# ADD BASE CPP /nologo /W3 /GX /O2 /D "WIN32" /D "NDEBUG" /D "_CONSOLE" /D "_MBCS" /YX /FD /c
# ADD CPP /nologo /W3 /GX /O2 /D "WIN32" /D "NDEBUG" /D "_CONSOLE" /D "_MBCS" /YX /FD /c
# ADD BASE RSC /l 0x409 /d "NDEBUG"
# ADD RSC /l 0x409 /d "NDEBUG"
BSC32=bscmake.exe
# ADD BASE BSC32 /nologo
# ADD BSC32 /nologo
LINK32=link.exe
# ADD BASE LINK32 kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:console /machine:I386
# ADD LINK32 kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:console /machine:I386
!ELSEIF "$(CFG)" == "vorbseek - Win32 Debug"
# PROP BASE Use_MFC 0
# PROP BASE Use_Debug_Libraries 1
# PROP BASE Output_Dir "Debug"
# PROP BASE Intermediate_Dir "Debug"
# PROP BASE Target_Dir ""
# PROP Use_MFC 0
# PROP Use_Debug_Libraries 1
# PROP Output_Dir "Debug"
# PROP Intermediate_Dir "Debug"
# PROP Target_Dir ""
# ADD BASE CPP /nologo /W3 /Gm /GX /ZI /Od /D "WIN32" /D "_DEBUG" /D "_CONSOLE" /D "_MBCS" /YX /FD /GZ /c
# ADD CPP /nologo /W3 /Gm /GX /ZI /Od /D "WIN32" /D "_DEBUG" /D "_CONSOLE" /D "_MBCS" /YX /FD /GZ /c
# ADD BASE RSC /l 0x409 /d "_DEBUG"
# ADD RSC /l 0x409 /d "_DEBUG"
BSC32=bscmake.exe
# ADD BASE BSC32 /nologo
# ADD BSC32 /nologo
LINK32=link.exe
# ADD BASE LINK32 kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:console /debug /machine:I386 /pdbtype:sept
# ADD LINK32 kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:console /debug /machine:I386 /pdbtype:sept
!ENDIF
# Begin Target
# Name "vorbseek - Win32 Release"
# Name "vorbseek - Win32 Debug"
# Begin Group "Source Files"
# PROP Default_Filter "cpp;c;cxx;rc;def;r;odl;idl;hpj;bat"
# End Group
# Begin Group "Header Files"
# PROP Default_Filter "h;hpp;hxx;hm;inl"
# End Group
# Begin Group "Resource Files"
# PROP Default_Filter "ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe"
# End Group
# End Target
# End Project