2 * Ogg bitstream support
3 * Luca Barbato <lu_zero@gentoo.org>
4 * Based on tcvp implementation
8 Copyright (C) 2005 Michael Ahlberg, Måns Rullgård
10 Permission is hereby granted, free of charge, to any person
11 obtaining a copy of this software and associated documentation
12 files (the "Software"), to deal in the Software without
13 restriction, including without limitation the rights to use, copy,
14 modify, merge, publish, distribute, sublicense, and/or sell copies
15 of the Software, and to permit persons to whom the Software is
16 furnished to do so, subject to the following conditions:
18 The above copyright notice and this permission notice shall be
19 included in all copies or substantial portions of the Software.
21 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
22 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
23 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
24 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
25 HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
26 WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
27 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
28 DEALINGS IN THE SOFTWARE.
32 #include "libavutil/avassert.h"
33 #include "libavutil/intreadwrite.h"
34 #include "avio_internal.h"
38 #include "vorbiscomment.h"
40 #define MAX_PAGE_SIZE 65307
41 #define DECODER_BUFFER_SIZE MAX_PAGE_SIZE
43 static const struct ogg_codec * const ogg_codecs[] = {
63 static int64_t ogg_calc_pts(AVFormatContext *s, int idx, int64_t *dts);
64 static int ogg_new_stream(AVFormatContext *s, uint32_t serial);
65 static int ogg_restore(AVFormatContext *s);
67 static void free_stream(AVFormatContext *s, int i)
69 struct ogg *ogg = s->priv_data;
70 struct ogg_stream *stream = &ogg->streams[i];
72 av_freep(&stream->buf);
74 stream->codec->cleanup) {
75 stream->codec->cleanup(s, i);
78 av_freep(&stream->private);
79 av_freep(&stream->new_metadata);
82 //FIXME We could avoid some structure duplication
83 static int ogg_save(AVFormatContext *s)
85 struct ogg *ogg = s->priv_data;
86 struct ogg_state *ost =
87 av_malloc(sizeof(*ost) + (ogg->nstreams - 1) * sizeof(*ogg->streams));
92 return AVERROR(ENOMEM);
94 ost->pos = avio_tell(s->pb);
95 ost->curidx = ogg->curidx;
96 ost->next = ogg->state;
97 ost->nstreams = ogg->nstreams;
98 memcpy(ost->streams, ogg->streams, ogg->nstreams * sizeof(*ogg->streams));
100 for (i = 0; i < ogg->nstreams; i++) {
101 struct ogg_stream *os = ogg->streams + i;
102 os->buf = av_mallocz(os->bufsize + AV_INPUT_BUFFER_PADDING_SIZE);
104 memcpy(os->buf, ost->streams[i].buf, os->bufpos);
106 ret = AVERROR(ENOMEM);
107 os->new_metadata = NULL;
108 os->new_metadata_size = 0;
119 static int ogg_restore(AVFormatContext *s)
121 struct ogg *ogg = s->priv_data;
122 AVIOContext *bc = s->pb;
123 struct ogg_state *ost = ogg->state;
129 ogg->state = ost->next;
131 for (i = 0; i < ogg->nstreams; i++) {
132 struct ogg_stream *stream = &ogg->streams[i];
133 av_freep(&stream->buf);
134 av_freep(&stream->new_metadata);
136 if (i >= ost->nstreams || !ost->streams[i].private) {
141 avio_seek(bc, ost->pos, SEEK_SET);
143 ogg->curidx = ost->curidx;
144 ogg->nstreams = ost->nstreams;
145 if ((err = av_reallocp_array(&ogg->streams, ogg->nstreams,
146 sizeof(*ogg->streams))) < 0) {
150 memcpy(ogg->streams, ost->streams,
151 ost->nstreams * sizeof(*ogg->streams));
158 static int ogg_reset(AVFormatContext *s)
160 struct ogg *ogg = s->priv_data;
162 int64_t start_pos = avio_tell(s->pb);
164 for (i = 0; i < ogg->nstreams; i++) {
165 struct ogg_stream *os = ogg->streams + i;
170 os->lastpts = AV_NOPTS_VALUE;
171 os->lastdts = AV_NOPTS_VALUE;
178 if (start_pos <= s->internal->data_offset) {
181 os->start_trimming = 0;
182 os->end_trimming = 0;
183 av_freep(&os->new_metadata);
184 os->new_metadata_size = 0;
193 static const struct ogg_codec *ogg_find_codec(uint8_t *buf, int size)
197 for (i = 0; ogg_codecs[i]; i++)
198 if (size >= ogg_codecs[i]->magicsize &&
199 !memcmp(buf, ogg_codecs[i]->magic, ogg_codecs[i]->magicsize))
200 return ogg_codecs[i];
206 * Replace the current stream with a new one. This is a typical webradio
207 * situation where a new audio stream spawn (identified with a new serial) and
208 * must replace the previous one (track switch).
210 static int ogg_replace_stream(AVFormatContext *s, uint32_t serial, char *magic,
213 struct ogg *ogg = s->priv_data;
214 struct ogg_stream *os;
215 const struct ogg_codec *codec;
218 if (ogg->nstreams != 1) {
219 avpriv_report_missing_feature(s, "Changing stream parameters in multistream ogg");
220 return AVERROR_PATCHWELCOME;
223 /* Check for codecs */
224 codec = ogg_find_codec(magic, 8);
225 if (!codec && !probing) {
226 av_log(s, AV_LOG_ERROR, "Cannot identify new stream\n");
227 return AVERROR_INVALIDDATA;
230 /* We only have a single stream anyway, so if there's a new stream with
231 * a different codec just replace it */
232 os = &ogg->streams[0];
238 os->start_trimming = 0;
239 os->end_trimming = 0;
241 /* Chained files have extradata as a new packet */
242 if (codec == &ff_opus_codec)
248 static int ogg_new_stream(AVFormatContext *s, uint32_t serial)
250 struct ogg *ogg = s->priv_data;
251 int idx = ogg->nstreams;
253 struct ogg_stream *os;
257 av_log(s, AV_LOG_ERROR, "New streams are not supposed to be added "
258 "in between Ogg context save/restore operations.\n");
262 /* Allocate and init a new Ogg Stream */
263 if (av_size_mult(ogg->nstreams + 1, sizeof(*ogg->streams), &size) < 0 ||
264 !(os = av_realloc(ogg->streams, size)))
265 return AVERROR(ENOMEM);
267 os = ogg->streams + idx;
268 memset(os, 0, sizeof(*os));
270 os->bufsize = DECODER_BUFFER_SIZE;
271 os->buf = av_malloc(os->bufsize + AV_INPUT_BUFFER_PADDING_SIZE);
273 os->start_granule = OGG_NOGRANULE_VALUE;
275 return AVERROR(ENOMEM);
277 /* Create the associated AVStream */
278 st = avformat_new_stream(s, NULL);
281 return AVERROR(ENOMEM);
284 avpriv_set_pts_info(st, 64, 1, 1000000);
290 static int data_packets_seen(const struct ogg *ogg)
294 for (i = 0; i < ogg->nstreams; i++)
295 if (ogg->streams[i].got_data)
300 static int buf_realloc(struct ogg_stream *os, int size)
302 /* Even if invalid guarantee there's enough memory to read the page */
303 if (os->bufsize - os->bufpos < size) {
304 uint8_t *nb = av_realloc(os->buf, 2*os->bufsize + AV_INPUT_BUFFER_PADDING_SIZE);
306 return AVERROR(ENOMEM);
314 static int ogg_read_page(AVFormatContext *s, int *sid, int probing)
316 AVIOContext *bc = s->pb;
317 struct ogg *ogg = s->priv_data;
318 struct ogg_stream *os;
323 uint32_t crc, crc_tmp;
325 int64_t version, page_pos;
328 uint8_t segments[255];
329 uint8_t *readout_buf;
332 ret = avio_read(bc, sync, 4);
334 return ret < 0 ? ret : AVERROR_EOF;
339 if (sync[sp & 3] == 'O' &&
340 sync[(sp + 1) & 3] == 'g' &&
341 sync[(sp + 2) & 3] == 'g' && sync[(sp + 3) & 3] == 'S')
344 if(!i && (bc->seekable & AVIO_SEEKABLE_NORMAL) && ogg->page_pos > 0) {
346 avio_seek(bc, ogg->page_pos+4, SEEK_SET);
356 } while (i++ < MAX_PAGE_SIZE);
358 if (i >= MAX_PAGE_SIZE) {
359 av_log(s, AV_LOG_INFO, "cannot find sync word\n");
360 return AVERROR_INVALIDDATA;
363 /* 0x4fa9b05f = av_crc(AV_CRC_32_IEEE, 0x0, "OggS", 4) */
364 ffio_init_checksum(bc, ff_crc04C11DB7_update, 0x4fa9b05f);
366 /* To rewind if checksum is bad/check magic on switches - this is the max packet size */
367 ffio_ensure_seekback(bc, MAX_PAGE_SIZE);
368 start_pos = avio_tell(bc);
370 version = avio_r8(bc);
373 serial = avio_rl32(bc);
374 avio_skip(bc, 4); /* seq */
376 crc_tmp = ffio_get_checksum(bc);
378 crc_tmp = ff_crc04C11DB7_update(crc_tmp, (uint8_t[4]){0}, 4);
379 ffio_init_checksum(bc, ff_crc04C11DB7_update, crc_tmp);
382 page_pos = avio_tell(bc) - 27;
384 ret = avio_read(bc, segments, nsegs);
386 return ret < 0 ? ret : AVERROR_EOF;
388 for (i = 0; i < nsegs; i++)
391 idx = ogg_find_stream(ogg, serial);
393 os = ogg->streams + idx;
395 ret = buf_realloc(os, size);
399 readout_buf = os->buf + os->bufpos;
401 readout_buf = av_malloc(size);
404 ret = avio_read(bc, readout_buf, size);
407 av_free(readout_buf);
408 return ret < 0 ? ret : AVERROR_EOF;
411 if (crc ^ ffio_get_checksum(bc)) {
412 av_log(s, AV_LOG_ERROR, "CRC mismatch!\n");
414 av_free(readout_buf);
415 avio_seek(bc, start_pos, SEEK_SET);
419 /* Since we're almost sure its a valid packet, checking the version after
420 * the checksum lets the demuxer be more tolerant */
422 av_log(s, AV_LOG_ERROR, "Invalid Ogg vers!\n");
424 av_free(readout_buf);
425 avio_seek(bc, start_pos, SEEK_SET);
429 /* CRC is correct so we can be 99% sure there's an actual change here */
431 if (data_packets_seen(ogg))
432 idx = ogg_replace_stream(s, serial, readout_buf, probing);
434 idx = ogg_new_stream(s, serial);
437 av_log(s, AV_LOG_ERROR, "failed to create or replace stream\n");
438 av_free(readout_buf);
442 os = ogg->streams + idx;
444 ret = buf_realloc(os, size);
446 av_free(readout_buf);
450 memcpy(os->buf + os->bufpos, readout_buf, size);
451 av_free(readout_buf);
454 ogg->page_pos = page_pos;
455 os->page_pos = page_pos;
458 os->got_data = !(flags & OGG_FLAG_BOS);
462 memcpy(os->segments, segments, nsegs);
463 memset(os->buf + os->bufpos, 0, AV_INPUT_BUFFER_PADDING_SIZE);
465 if (flags & OGG_FLAG_CONT || os->incomplete) {
467 // If this is the very first segment we started
468 // playback in the middle of a continuation packet.
469 // Discard it since we missed the start of it.
470 while (os->segp < os->nsegs) {
471 int seg = os->segments[os->segp++];
476 os->sync_pos = os->page_pos;
480 os->sync_pos = os->page_pos;
483 /* This function is always called with sid != NULL */
490 * @brief find the next Ogg packet
491 * @param *sid is set to the stream for the packet or -1 if there is
492 * no matching stream, in that case assume all other return
493 * values to be uninitialized.
494 * @return negative value on error or EOF.
496 static int ogg_packet(AVFormatContext *s, int *sid, int *dstart, int *dsize,
499 struct ogg *ogg = s->priv_data;
501 struct ogg_stream *os;
503 int segp = 0, psize = 0;
505 av_log(s, AV_LOG_TRACE, "ogg_packet: curidx=%i\n", ogg->curidx);
513 ret = ogg_read_page(s, &idx, 0);
518 os = ogg->streams + idx;
520 av_log(s, AV_LOG_TRACE, "ogg_packet: idx=%d pstart=%d psize=%d segp=%d nsegs=%d\n",
521 idx, os->pstart, os->psize, os->segp, os->nsegs);
524 if (os->header < 0) {
525 os->codec = ogg_find_codec(os->buf, os->bufpos);
527 av_log(s, AV_LOG_WARNING, "Codec not found\n");
539 while (os->segp < os->nsegs) {
540 int ss = os->segments[os->segp++];
548 if (!complete && os->segp == os->nsegs) {
550 // Do not set incomplete for empty packets.
551 // Together with the code in ogg_read_page
552 // that discards all continuation of empty packets
553 // we would get an infinite loop.
554 os->incomplete = !!os->psize;
559 if (os->granule == -1)
560 av_log(s, AV_LOG_WARNING,
561 "Page at %"PRId64" is missing granule\n",
568 if ((ret = os->codec->header(s, idx)) < 0) {
569 av_log(s, AV_LOG_ERROR, "Header processing failed: %s\n", av_err2str(ret));
577 // We have reached the first non-header packet in this stream.
578 // Unfortunately more header packets may still follow for others,
579 // but if we continue with header parsing we may lose data packets.
582 // Update the header state for all streams and
583 // compute the data_offset.
584 if (!s->internal->data_offset)
585 s->internal->data_offset = os->sync_pos;
587 for (i = 0; i < ogg->nstreams; i++) {
588 struct ogg_stream *cur_os = ogg->streams + i;
590 // if we have a partial non-header packet, its start is
591 // obviously at or after the data start
592 if (cur_os->incomplete)
593 s->internal->data_offset = FFMIN(s->internal->data_offset, cur_os->sync_pos);
597 os->pstart += os->psize;
603 if (os->codec && os->codec->packet) {
604 if ((ret = os->codec->packet(s, idx)) < 0) {
605 av_log(s, AV_LOG_ERROR, "Packet processing failed: %s\n", av_err2str(ret));
612 *dstart = os->pstart;
616 *fpos = os->sync_pos;
617 os->pstart += os->psize;
619 if(os->pstart == os->bufpos)
620 os->bufpos = os->pstart = 0;
621 os->sync_pos = os->page_pos;
624 // determine whether there are more complete packets in this page
625 // if not, the page's granule will apply to this packet
627 for (i = os->segp; i < os->nsegs; i++)
628 if (os->segments[i] < 255) {
633 if (os->segp == os->nsegs)
639 static int ogg_get_length(AVFormatContext *s)
641 struct ogg *ogg = s->priv_data;
646 if (!(s->pb->seekable & AVIO_SEEKABLE_NORMAL))
650 if (s->duration != AV_NOPTS_VALUE)
653 size = avio_size(s->pb);
656 end = size > MAX_PAGE_SIZE ? size - MAX_PAGE_SIZE : 0;
661 avio_seek(s->pb, end, SEEK_SET);
664 while (!ogg_read_page(s, &i, 1)) {
665 if (ogg->streams[i].granule != -1 && ogg->streams[i].granule != 0 &&
666 ogg->streams[i].codec) {
667 s->streams[i]->duration =
668 ogg_gptopts(s, i, ogg->streams[i].granule, NULL);
669 if (s->streams[i]->start_time != AV_NOPTS_VALUE) {
670 s->streams[i]->duration -= s->streams[i]->start_time;
671 streams_left-= (ogg->streams[i].got_start==-1);
672 ogg->streams[i].got_start= 1;
673 } else if(!ogg->streams[i].got_start) {
674 ogg->streams[i].got_start= -1;
686 avio_seek (s->pb, s->internal->data_offset, SEEK_SET);
688 while (streams_left > 0 && !ogg_packet(s, &i, NULL, NULL, NULL)) {
691 pts = ogg_calc_pts(s, i, NULL);
692 if (s->streams[i]->duration == AV_NOPTS_VALUE)
694 if (pts != AV_NOPTS_VALUE && s->streams[i]->start_time == AV_NOPTS_VALUE && !ogg->streams[i].got_start) {
695 s->streams[i]->duration -= pts;
696 ogg->streams[i].got_start= 1;
698 }else if(s->streams[i]->start_time != AV_NOPTS_VALUE && !ogg->streams[i].got_start) {
699 ogg->streams[i].got_start= 1;
708 static int ogg_read_close(AVFormatContext *s)
710 struct ogg *ogg = s->priv_data;
713 for (i = 0; i < ogg->nstreams; i++) {
719 av_freep(&ogg->streams);
723 static int ogg_read_header(AVFormatContext *s)
725 struct ogg *ogg = s->priv_data;
730 //linear headers seek from start
732 ret = ogg_packet(s, NULL, NULL, NULL, NULL);
737 } while (!ogg->headers);
738 av_log(s, AV_LOG_TRACE, "found headers\n");
740 for (i = 0; i < ogg->nstreams; i++) {
741 struct ogg_stream *os = ogg->streams + i;
743 if (ogg->streams[i].header < 0) {
744 av_log(s, AV_LOG_ERROR, "Header parsing failed for stream %d\n", i);
745 ogg->streams[i].codec = NULL;
746 av_freep(&ogg->streams[i].private);
747 } else if (os->codec && os->nb_header < os->codec->nb_header) {
748 av_log(s, AV_LOG_WARNING,
749 "Headers mismatch for stream %d: "
750 "expected %d received %d.\n",
751 i, os->codec->nb_header, os->nb_header);
752 if (s->error_recognition & AV_EF_EXPLODE) {
754 return AVERROR_INVALIDDATA;
757 if (os->start_granule != OGG_NOGRANULE_VALUE)
758 os->lastpts = s->streams[i]->start_time =
759 ogg_gptopts(s, i, os->start_granule, NULL);
762 //linear granulepos seek from end
763 ret = ogg_get_length(s);
772 static int64_t ogg_calc_pts(AVFormatContext *s, int idx, int64_t *dts)
774 struct ogg *ogg = s->priv_data;
775 struct ogg_stream *os = ogg->streams + idx;
776 int64_t pts = AV_NOPTS_VALUE;
779 *dts = AV_NOPTS_VALUE;
781 if (os->lastpts != AV_NOPTS_VALUE) {
783 os->lastpts = AV_NOPTS_VALUE;
785 if (os->lastdts != AV_NOPTS_VALUE) {
788 os->lastdts = AV_NOPTS_VALUE;
791 if (os->granule != -1LL) {
792 if (os->codec && os->codec->granule_is_start)
793 pts = ogg_gptopts(s, idx, os->granule, dts);
795 os->lastpts = ogg_gptopts(s, idx, os->granule, &os->lastdts);
802 static void ogg_validate_keyframe(AVFormatContext *s, int idx, int pstart, int psize)
804 struct ogg *ogg = s->priv_data;
805 struct ogg_stream *os = ogg->streams + idx;
808 switch (s->streams[idx]->codecpar->codec_id) {
809 case AV_CODEC_ID_THEORA:
810 invalid = !!(os->pflags & AV_PKT_FLAG_KEY) != !(os->buf[pstart] & 0x40);
812 case AV_CODEC_ID_VP8:
813 invalid = !!(os->pflags & AV_PKT_FLAG_KEY) != !(os->buf[pstart] & 1);
816 os->pflags ^= AV_PKT_FLAG_KEY;
817 av_log(s, AV_LOG_WARNING, "Broken file, %skeyframe not correctly marked.\n",
818 (os->pflags & AV_PKT_FLAG_KEY) ? "" : "non-");
823 static int ogg_read_packet(AVFormatContext *s, AVPacket *pkt)
826 struct ogg_stream *os;
829 int64_t fpos, pts, dts;
831 if (s->io_repositioned) {
833 s->io_repositioned = 0;
839 ret = ogg_packet(s, &idx, &pstart, &psize, &fpos);
842 } while (idx < 0 || !s->streams[idx]);
845 os = ogg->streams + idx;
847 // pflags might not be set until after this
848 pts = ogg_calc_pts(s, idx, &dts);
849 ogg_validate_keyframe(s, idx, pstart, psize);
851 if (os->keyframe_seek && !(os->pflags & AV_PKT_FLAG_KEY))
853 os->keyframe_seek = 0;
856 ret = av_new_packet(pkt, psize);
859 pkt->stream_index = idx;
860 memcpy(pkt->data, os->buf + pstart, psize);
864 pkt->flags = os->pflags;
865 pkt->duration = os->pduration;
868 if (os->start_trimming || os->end_trimming) {
869 uint8_t *side_data = av_packet_new_side_data(pkt,
870 AV_PKT_DATA_SKIP_SAMPLES,
873 return AVERROR(ENOMEM);
874 AV_WL32(side_data + 0, os->start_trimming);
875 AV_WL32(side_data + 4, os->end_trimming);
876 os->start_trimming = 0;
877 os->end_trimming = 0;
880 if (os->new_metadata) {
881 uint8_t *side_data = av_packet_new_side_data(pkt,
882 AV_PKT_DATA_METADATA_UPDATE,
883 os->new_metadata_size);
885 return AVERROR(ENOMEM);
887 memcpy(side_data, os->new_metadata, os->new_metadata_size);
888 av_freep(&os->new_metadata);
889 os->new_metadata_size = 0;
895 static int64_t ogg_read_timestamp(AVFormatContext *s, int stream_index,
896 int64_t *pos_arg, int64_t pos_limit)
898 struct ogg *ogg = s->priv_data;
899 AVIOContext *bc = s->pb;
900 int64_t pts = AV_NOPTS_VALUE;
904 avio_seek(bc, *pos_arg, SEEK_SET);
907 while ( avio_tell(bc) <= pos_limit
908 && !ogg_packet(s, &i, &pstart, &psize, pos_arg)) {
909 if (i == stream_index) {
910 struct ogg_stream *os = ogg->streams + stream_index;
911 // Do not trust the last timestamps of an ogm video
912 if ( (os->flags & OGG_FLAG_EOS)
913 && !(os->flags & OGG_FLAG_BOS)
914 && os->codec == &ff_ogm_video_codec)
916 pts = ogg_calc_pts(s, i, NULL);
917 ogg_validate_keyframe(s, i, pstart, psize);
918 if (os->pflags & AV_PKT_FLAG_KEY) {
920 } else if (os->keyframe_seek) {
921 // if we had a previous keyframe but no pts for it,
922 // return that keyframe with this pts value.
926 pts = AV_NOPTS_VALUE;
929 if (pts != AV_NOPTS_VALUE)
936 static int ogg_read_seek(AVFormatContext *s, int stream_index,
937 int64_t timestamp, int flags)
939 struct ogg *ogg = s->priv_data;
940 struct ogg_stream *os = ogg->streams + stream_index;
943 av_assert0(stream_index < ogg->nstreams);
944 // Ensure everything is reset even when seeking via
945 // the generated index.
948 // Try seeking to a keyframe first. If this fails (very possible),
949 // av_seek_frame will fall back to ignoring keyframes
950 if (s->streams[stream_index]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO
951 && !(flags & AVSEEK_FLAG_ANY))
952 os->keyframe_seek = 1;
954 ret = ff_seek_frame_binary(s, stream_index, timestamp, flags);
956 os = ogg->streams + stream_index;
958 os->keyframe_seek = 0;
962 static int ogg_probe(const AVProbeData *p)
964 if (!memcmp("OggS", p->buf, 5) && p->buf[5] <= 0x7)
965 return AVPROBE_SCORE_MAX;
969 AVInputFormat ff_ogg_demuxer = {
971 .long_name = NULL_IF_CONFIG_SMALL("Ogg"),
972 .priv_data_size = sizeof(struct ogg),
973 .read_probe = ogg_probe,
974 .read_header = ogg_read_header,
975 .read_packet = ogg_read_packet,
976 .read_close = ogg_read_close,
977 .read_seek = ogg_read_seek,
978 .read_timestamp = ogg_read_timestamp,
980 .flags = AVFMT_GENERIC_INDEX | AVFMT_TS_DISCONT | AVFMT_NOBINSEARCH,