yading@11: /*
yading@11:  * Ogg bitstream support
yading@11:  * Luca Barbato <lu_zero@gentoo.org>
yading@11:  * Based on tcvp implementation
yading@11:  */
yading@11: 
yading@11: /*
yading@11:     Copyright (C) 2005  Michael Ahlberg, Måns Rullgård
yading@11: 
yading@11:     Permission is hereby granted, free of charge, to any person
yading@11:     obtaining a copy of this software and associated documentation
yading@11:     files (the "Software"), to deal in the Software without
yading@11:     restriction, including without limitation the rights to use, copy,
yading@11:     modify, merge, publish, distribute, sublicense, and/or sell copies
yading@11:     of the Software, and to permit persons to whom the Software is
yading@11:     furnished to do so, subject to the following conditions:
yading@11: 
yading@11:     The above copyright notice and this permission notice shall be
yading@11:     included in all copies or substantial portions of the Software.
yading@11: 
yading@11:     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
yading@11:     EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
yading@11:     MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
yading@11:     NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
yading@11:     HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
yading@11:     WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
yading@11:     OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
yading@11:     DEALINGS IN THE SOFTWARE.
yading@11:  */
yading@11: 
yading@11: #include <stdio.h>
yading@11: #include "libavutil/avassert.h"
yading@11: #include "oggdec.h"
yading@11: #include "avformat.h"
yading@11: #include "internal.h"
yading@11: #include "vorbiscomment.h"
yading@11: 
yading@11: #define MAX_PAGE_SIZE 65307
yading@11: #define DECODER_BUFFER_SIZE MAX_PAGE_SIZE
yading@11: 
yading@11: static const struct ogg_codec * const ogg_codecs[] = {
yading@11:     &ff_skeleton_codec,
yading@11:     &ff_dirac_codec,
yading@11:     &ff_speex_codec,
yading@11:     &ff_vorbis_codec,
yading@11:     &ff_theora_codec,
yading@11:     &ff_flac_codec,
yading@11:     &ff_celt_codec,
yading@11:     &ff_opus_codec,
yading@11:     &ff_old_dirac_codec,
yading@11:     &ff_old_flac_codec,
yading@11:     &ff_ogm_video_codec,
yading@11:     &ff_ogm_audio_codec,
yading@11:     &ff_ogm_text_codec,
yading@11:     &ff_ogm_old_codec,
yading@11:     NULL
yading@11: };
yading@11: 
yading@11: static int64_t ogg_calc_pts(AVFormatContext *s, int idx, int64_t *dts);
yading@11: static int ogg_new_stream(AVFormatContext *s, uint32_t serial);
yading@11: 
yading@11: //FIXME We could avoid some structure duplication
yading@11: static int ogg_save(AVFormatContext *s)
yading@11: {
yading@11:     struct ogg *ogg = s->priv_data;
yading@11:     struct ogg_state *ost =
yading@11:         av_malloc(sizeof(*ost) + (ogg->nstreams - 1) * sizeof(*ogg->streams));
yading@11:     int i;
yading@11:     ost->pos      = avio_tell(s->pb);
yading@11:     ost->curidx   = ogg->curidx;
yading@11:     ost->next     = ogg->state;
yading@11:     ost->nstreams = ogg->nstreams;
yading@11:     memcpy(ost->streams, ogg->streams, ogg->nstreams * sizeof(*ogg->streams));
yading@11: 
yading@11:     for (i = 0; i < ogg->nstreams; i++) {
yading@11:         struct ogg_stream *os = ogg->streams + i;
yading@11:         os->buf = av_mallocz(os->bufsize + FF_INPUT_BUFFER_PADDING_SIZE);
yading@11:         memcpy(os->buf, ost->streams[i].buf, os->bufpos);
yading@11:     }
yading@11: 
yading@11:     ogg->state = ost;
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int ogg_restore(AVFormatContext *s, int discard)
yading@11: {
yading@11:     struct ogg *ogg = s->priv_data;
yading@11:     AVIOContext *bc = s->pb;
yading@11:     struct ogg_state *ost = ogg->state;
yading@11:     int i;
yading@11: 
yading@11:     if (!ost)
yading@11:         return 0;
yading@11: 
yading@11:     ogg->state = ost->next;
yading@11: 
yading@11:     if (!discard) {
yading@11:         struct ogg_stream *old_streams = ogg->streams;
yading@11: 
yading@11:         for (i = 0; i < ogg->nstreams; i++)
yading@11:             av_free(ogg->streams[i].buf);
yading@11: 
yading@11:         avio_seek(bc, ost->pos, SEEK_SET);
yading@11:         ogg->page_pos = -1;
yading@11:         ogg->curidx   = ost->curidx;
yading@11:         ogg->nstreams = ost->nstreams;
yading@11:         ogg->streams  = av_realloc(ogg->streams,
yading@11:                                    ogg->nstreams * sizeof(*ogg->streams));
yading@11: 
yading@11:         if (ogg->streams) {
yading@11:             memcpy(ogg->streams, ost->streams,
yading@11:                    ost->nstreams * sizeof(*ogg->streams));
yading@11:         } else {
yading@11:             av_free(old_streams);
yading@11:             ogg->nstreams = 0;
yading@11:         }
yading@11:     }
yading@11: 
yading@11:     av_free(ost);
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int ogg_reset(AVFormatContext *s)
yading@11: {
yading@11:     struct ogg *ogg = s->priv_data;
yading@11:     int i;
yading@11:     int64_t start_pos = avio_tell(s->pb);
yading@11: 
yading@11:     for (i = 0; i < ogg->nstreams; i++) {
yading@11:         struct ogg_stream *os = ogg->streams + i;
yading@11:         os->bufpos     = 0;
yading@11:         os->pstart     = 0;
yading@11:         os->psize      = 0;
yading@11:         os->granule    = -1;
yading@11:         os->lastpts    = AV_NOPTS_VALUE;
yading@11:         os->lastdts    = AV_NOPTS_VALUE;
yading@11:         os->sync_pos   = -1;
yading@11:         os->page_pos   = 0;
yading@11:         os->nsegs      = 0;
yading@11:         os->segp       = 0;
yading@11:         os->incomplete = 0;
yading@11:         os->got_data = 0;
yading@11:         if (start_pos <= s->data_offset) {
yading@11:             os->lastpts = 0;
yading@11:         }
yading@11:     }
yading@11: 
yading@11:     ogg->page_pos = -1;
yading@11:     ogg->curidx = -1;
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static const struct ogg_codec *ogg_find_codec(uint8_t *buf, int size)
yading@11: {
yading@11:     int i;
yading@11: 
yading@11:     for (i = 0; ogg_codecs[i]; i++)
yading@11:         if (size >= ogg_codecs[i]->magicsize &&
yading@11:             !memcmp(buf, ogg_codecs[i]->magic, ogg_codecs[i]->magicsize))
yading@11:             return ogg_codecs[i];
yading@11: 
yading@11:     return NULL;
yading@11: }
yading@11: 
yading@11: /**
yading@11:  * Replace the current stream with a new one. This is a typical webradio
yading@11:  * situation where a new audio stream spawn (identified with a new serial) and
yading@11:  * must replace the previous one (track switch).
yading@11:  */
yading@11: static int ogg_replace_stream(AVFormatContext *s, uint32_t serial, int nsegs)
yading@11: {
yading@11:     struct ogg *ogg = s->priv_data;
yading@11:     struct ogg_stream *os;
yading@11:     const struct ogg_codec *codec;
yading@11:     int i = 0;
yading@11: 
yading@11:     if (s->pb->seekable) {
yading@11:         uint8_t magic[8];
yading@11:         int64_t pos = avio_tell(s->pb);
yading@11:         avio_skip(s->pb, nsegs);
yading@11:         avio_read(s->pb, magic, sizeof(magic));
yading@11:         avio_seek(s->pb, pos, SEEK_SET);
yading@11:         codec = ogg_find_codec(magic, sizeof(magic));
yading@11:         if (!codec) {
yading@11:             av_log(s, AV_LOG_ERROR, "Cannot identify new stream\n");
yading@11:             return AVERROR_INVALIDDATA;
yading@11:         }
yading@11:         for (i = 0; i < ogg->nstreams; i++) {
yading@11:             if (ogg->streams[i].codec == codec)
yading@11:                 break;
yading@11:         }
yading@11:         if (i >= ogg->nstreams)
yading@11:             return ogg_new_stream(s, serial);
yading@11:     } else if (ogg->nstreams != 1) {
yading@11:         avpriv_report_missing_feature(s, "Changing stream parameters in multistream ogg");
yading@11:         return AVERROR_PATCHWELCOME;
yading@11:     }
yading@11: 
yading@11:     os = &ogg->streams[i];
yading@11: 
yading@11:     os->serial  = serial;
yading@11:     return i;
yading@11: 
yading@11: #if 0
yading@11:     buf     = os->buf;
yading@11:     bufsize = os->bufsize;
yading@11:     codec   = os->codec;
yading@11: 
yading@11:     if (!ogg->state || ogg->state->streams[i].private != os->private)
yading@11:         av_freep(&ogg->streams[i].private);
yading@11: 
yading@11:     /* Set Ogg stream settings similar to what is done in ogg_new_stream(). We
yading@11:      * also re-use the ogg_stream allocated buffer */
yading@11:     memset(os, 0, sizeof(*os));
yading@11:     os->serial  = serial;
yading@11:     os->bufsize = bufsize;
yading@11:     os->buf     = buf;
yading@11:     os->header  = -1;
yading@11:     os->codec   = codec;
yading@11: 
yading@11:     return i;
yading@11: #endif
yading@11: }
yading@11: 
yading@11: static int ogg_new_stream(AVFormatContext *s, uint32_t serial)
yading@11: {
yading@11:     struct ogg *ogg = s->priv_data;
yading@11:     int idx         = ogg->nstreams;
yading@11:     AVStream *st;
yading@11:     struct ogg_stream *os;
yading@11:     size_t size;
yading@11: 
yading@11:     if (ogg->state) {
yading@11:         av_log(s, AV_LOG_ERROR, "New streams are not supposed to be added "
yading@11:                "in between Ogg context save/restore operations.\n");
yading@11:         return AVERROR_BUG;
yading@11:     }
yading@11: 
yading@11:     /* Allocate and init a new Ogg Stream */
yading@11:     if (av_size_mult(ogg->nstreams + 1, sizeof(*ogg->streams), &size) < 0 ||
yading@11:         !(os = av_realloc(ogg->streams, size)))
yading@11:         return AVERROR(ENOMEM);
yading@11:     ogg->streams = os;
yading@11:     os           = ogg->streams + idx;
yading@11:     memset(os, 0, sizeof(*os));
yading@11:     os->serial        = serial;
yading@11:     os->bufsize       = DECODER_BUFFER_SIZE;
yading@11:     os->buf           = av_malloc(os->bufsize + FF_INPUT_BUFFER_PADDING_SIZE);
yading@11:     os->header        = -1;
yading@11:     os->start_granule = OGG_NOGRANULE_VALUE;
yading@11:     if (!os->buf)
yading@11:         return AVERROR(ENOMEM);
yading@11: 
yading@11:     /* Create the associated AVStream */
yading@11:     st = avformat_new_stream(s, NULL);
yading@11:     if (!st) {
yading@11:         av_freep(&os->buf);
yading@11:         return AVERROR(ENOMEM);
yading@11:     }
yading@11:     st->id = idx;
yading@11:     avpriv_set_pts_info(st, 64, 1, 1000000);
yading@11: 
yading@11:     ogg->nstreams++;
yading@11:     return idx;
yading@11: }
yading@11: 
yading@11: static int ogg_new_buf(struct ogg *ogg, int idx)
yading@11: {
yading@11:     struct ogg_stream *os = ogg->streams + idx;
yading@11:     uint8_t *nb = av_malloc(os->bufsize + FF_INPUT_BUFFER_PADDING_SIZE);
yading@11:     int size = os->bufpos - os->pstart;
yading@11: 
yading@11:     if (os->buf) {
yading@11:         memcpy(nb, os->buf + os->pstart, size);
yading@11:         av_free(os->buf);
yading@11:     }
yading@11: 
yading@11:     os->buf    = nb;
yading@11:     os->bufpos = size;
yading@11:     os->pstart = 0;
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int data_packets_seen(const struct ogg *ogg)
yading@11: {
yading@11:     int i;
yading@11: 
yading@11:     for (i = 0; i < ogg->nstreams; i++)
yading@11:         if (ogg->streams[i].got_data)
yading@11:             return 1;
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int ogg_read_page(AVFormatContext *s, int *sid)
yading@11: {
yading@11:     AVIOContext *bc = s->pb;
yading@11:     struct ogg *ogg = s->priv_data;
yading@11:     struct ogg_stream *os;
yading@11:     int ret, i = 0;
yading@11:     int flags, nsegs;
yading@11:     uint64_t gp;
yading@11:     uint32_t serial;
yading@11:     int size, idx;
yading@11:     uint8_t sync[4];
yading@11:     int sp = 0;
yading@11: 
yading@11:     ret = avio_read(bc, sync, 4);
yading@11:     if (ret < 4)
yading@11:         return ret < 0 ? ret : AVERROR_EOF;
yading@11: 
yading@11:     do {
yading@11:         int c;
yading@11: 
yading@11:         if (sync[sp & 3] == 'O' &&
yading@11:             sync[(sp + 1) & 3] == 'g' &&
yading@11:             sync[(sp + 2) & 3] == 'g' && sync[(sp + 3) & 3] == 'S')
yading@11:             break;
yading@11: 
yading@11:         if(!i && bc->seekable && ogg->page_pos > 0) {
yading@11:             memset(sync, 0, 4);
yading@11:             avio_seek(bc, ogg->page_pos+4, SEEK_SET);
yading@11:             ogg->page_pos = -1;
yading@11:         }
yading@11: 
yading@11:         c = avio_r8(bc);
yading@11: 
yading@11:         if (url_feof(bc))
yading@11:             return AVERROR_EOF;
yading@11: 
yading@11:         sync[sp++ & 3] = c;
yading@11:     } while (i++ < MAX_PAGE_SIZE);
yading@11: 
yading@11:     if (i >= MAX_PAGE_SIZE) {
yading@11:         av_log(s, AV_LOG_INFO, "cannot find sync word\n");
yading@11:         return AVERROR_INVALIDDATA;
yading@11:     }
yading@11: 
yading@11:     if (avio_r8(bc) != 0) {      /* version */
yading@11:         av_log (s, AV_LOG_ERROR, "ogg page, unsupported version\n");
yading@11:         return AVERROR_INVALIDDATA;
yading@11:     }
yading@11: 
yading@11:     flags  = avio_r8(bc);
yading@11:     gp     = avio_rl64(bc);
yading@11:     serial = avio_rl32(bc);
yading@11:     avio_skip(bc, 8); /* seq, crc */
yading@11:     nsegs  = avio_r8(bc);
yading@11: 
yading@11:     idx = ogg_find_stream(ogg, serial);
yading@11:     if (idx < 0) {
yading@11:         if (data_packets_seen(ogg))
yading@11:             idx = ogg_replace_stream(s, serial, nsegs);
yading@11:         else
yading@11:             idx = ogg_new_stream(s, serial);
yading@11: 
yading@11:         if (idx < 0) {
yading@11:             av_log(s, AV_LOG_ERROR, "failed to create or replace stream\n");
yading@11:             return idx;
yading@11:         }
yading@11:     }
yading@11: 
yading@11:     os = ogg->streams + idx;
yading@11:     ogg->page_pos =
yading@11:     os->page_pos = avio_tell(bc) - 27;
yading@11: 
yading@11:     if (os->psize > 0)
yading@11:         ogg_new_buf(ogg, idx);
yading@11: 
yading@11:     ret = avio_read(bc, os->segments, nsegs);
yading@11:     if (ret < nsegs)
yading@11:         return ret < 0 ? ret : AVERROR_EOF;
yading@11: 
yading@11:     os->nsegs = nsegs;
yading@11:     os->segp  = 0;
yading@11: 
yading@11:     size = 0;
yading@11:     for (i = 0; i < nsegs; i++)
yading@11:         size += os->segments[i];
yading@11: 
yading@11:     if (!(flags & OGG_FLAG_BOS))
yading@11:         os->got_data = 1;
yading@11: 
yading@11:     if (flags & OGG_FLAG_CONT || os->incomplete) {
yading@11:         if (!os->psize) {
yading@11:             // If this is the very first segment we started
yading@11:             // playback in the middle of a continuation packet.
yading@11:             // Discard it since we missed the start of it.
yading@11:             while (os->segp < os->nsegs) {
yading@11:                 int seg = os->segments[os->segp++];
yading@11:                 os->pstart += seg;
yading@11:                 if (seg < 255)
yading@11:                     break;
yading@11:             }
yading@11:             os->sync_pos = os->page_pos;
yading@11:         }
yading@11:     } else {
yading@11:         os->psize    = 0;
yading@11:         os->sync_pos = os->page_pos;
yading@11:     }
yading@11: 
yading@11:     if (os->bufsize - os->bufpos < size) {
yading@11:         uint8_t *nb = av_malloc((os->bufsize *= 2) + FF_INPUT_BUFFER_PADDING_SIZE);
yading@11:         if (!nb)
yading@11:             return AVERROR(ENOMEM);
yading@11:         memcpy(nb, os->buf, os->bufpos);
yading@11:         av_free(os->buf);
yading@11:         os->buf = nb;
yading@11:     }
yading@11: 
yading@11:     ret = avio_read(bc, os->buf + os->bufpos, size);
yading@11:     if (ret < size)
yading@11:         return ret < 0 ? ret : AVERROR_EOF;
yading@11: 
yading@11:     os->bufpos += size;
yading@11:     os->granule = gp;
yading@11:     os->flags   = flags;
yading@11: 
yading@11:     memset(os->buf + os->bufpos, 0, FF_INPUT_BUFFER_PADDING_SIZE);
yading@11:     if (sid)
yading@11:         *sid = idx;
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: /**
yading@11:  * @brief find the next Ogg packet
yading@11:  * @param *sid is set to the stream for the packet or -1 if there is
yading@11:  *             no matching stream, in that case assume all other return
yading@11:  *             values to be uninitialized.
yading@11:  * @return negative value on error or EOF.
yading@11:  */
yading@11: static int ogg_packet(AVFormatContext *s, int *sid, int *dstart, int *dsize,
yading@11:                       int64_t *fpos)
yading@11: {
yading@11:     struct ogg *ogg = s->priv_data;
yading@11:     int idx, i, ret;
yading@11:     struct ogg_stream *os;
yading@11:     int complete = 0;
yading@11:     int segp     = 0, psize = 0;
yading@11: 
yading@11:     av_dlog(s, "ogg_packet: curidx=%i\n", ogg->curidx);
yading@11:     if (sid)
yading@11:         *sid = -1;
yading@11: 
yading@11:     do {
yading@11:         idx = ogg->curidx;
yading@11: 
yading@11:         while (idx < 0) {
yading@11:             ret = ogg_read_page(s, &idx);
yading@11:             if (ret < 0)
yading@11:                 return ret;
yading@11:         }
yading@11: 
yading@11:         os = ogg->streams + idx;
yading@11: 
yading@11:         av_dlog(s, "ogg_packet: idx=%d pstart=%d psize=%d segp=%d nsegs=%d\n",
yading@11:                 idx, os->pstart, os->psize, os->segp, os->nsegs);
yading@11: 
yading@11:         if (!os->codec) {
yading@11:             if (os->header < 0) {
yading@11:                 os->codec = ogg_find_codec(os->buf, os->bufpos);
yading@11:                 if (!os->codec) {
yading@11:                     av_log(s, AV_LOG_WARNING, "Codec not found\n");
yading@11:                     os->header = 0;
yading@11:                     return 0;
yading@11:                 }
yading@11:             } else {
yading@11:                 return 0;
yading@11:             }
yading@11:         }
yading@11: 
yading@11:         segp  = os->segp;
yading@11:         psize = os->psize;
yading@11: 
yading@11:         while (os->segp < os->nsegs) {
yading@11:             int ss = os->segments[os->segp++];
yading@11:             os->psize += ss;
yading@11:             if (ss < 255) {
yading@11:                 complete = 1;
yading@11:                 break;
yading@11:             }
yading@11:         }
yading@11: 
yading@11:         if (!complete && os->segp == os->nsegs) {
yading@11:             ogg->curidx    = -1;
yading@11:             // Do not set incomplete for empty packets.
yading@11:             // Together with the code in ogg_read_page
yading@11:             // that discards all continuation of empty packets
yading@11:             // we would get an infinite loop.
yading@11:             os->incomplete = !!os->psize;
yading@11:         }
yading@11:     } while (!complete);
yading@11: 
yading@11: 
yading@11:     if (os->granule == -1)
yading@11:         av_log(s, AV_LOG_WARNING,
yading@11:                "Page at %"PRId64" is missing granule\n",
yading@11:                os->page_pos);
yading@11: 
yading@11:     ogg->curidx    = idx;
yading@11:     os->incomplete = 0;
yading@11: 
yading@11:     if (os->header) {
yading@11:         os->header = os->codec->header(s, idx);
yading@11:         if (!os->header) {
yading@11:             os->segp  = segp;
yading@11:             os->psize = psize;
yading@11: 
yading@11:             // We have reached the first non-header packet in this stream.
yading@11:             // Unfortunately more header packets may still follow for others,
yading@11:             // but if we continue with header parsing we may lose data packets.
yading@11:             ogg->headers = 1;
yading@11: 
yading@11:             // Update the header state for all streams and
yading@11:             // compute the data_offset.
yading@11:             if (!s->data_offset)
yading@11:                 s->data_offset = os->sync_pos;
yading@11: 
yading@11:             for (i = 0; i < ogg->nstreams; i++) {
yading@11:                 struct ogg_stream *cur_os = ogg->streams + i;
yading@11: 
yading@11:                 // if we have a partial non-header packet, its start is
yading@11:                 // obviously at or after the data start
yading@11:                 if (cur_os->incomplete)
yading@11:                     s->data_offset = FFMIN(s->data_offset, cur_os->sync_pos);
yading@11:             }
yading@11:         } else {
yading@11:             os->nb_header++;
yading@11:             os->pstart += os->psize;
yading@11:             os->psize   = 0;
yading@11:         }
yading@11:     } else {
yading@11:         os->pflags    = 0;
yading@11:         os->pduration = 0;
yading@11:         if (os->codec && os->codec->packet)
yading@11:             os->codec->packet(s, idx);
yading@11:         if (sid)
yading@11:             *sid = idx;
yading@11:         if (dstart)
yading@11:             *dstart = os->pstart;
yading@11:         if (dsize)
yading@11:             *dsize = os->psize;
yading@11:         if (fpos)
yading@11:             *fpos = os->sync_pos;
yading@11:         os->pstart  += os->psize;
yading@11:         os->psize    = 0;
yading@11:         if(os->pstart == os->bufpos)
yading@11:             os->bufpos = os->pstart = 0;
yading@11:         os->sync_pos = os->page_pos;
yading@11:     }
yading@11: 
yading@11:     // determine whether there are more complete packets in this page
yading@11:     // if not, the page's granule will apply to this packet
yading@11:     os->page_end = 1;
yading@11:     for (i = os->segp; i < os->nsegs; i++)
yading@11:         if (os->segments[i] < 255) {
yading@11:             os->page_end = 0;
yading@11:             break;
yading@11:         }
yading@11: 
yading@11:     if (os->segp == os->nsegs)
yading@11:         ogg->curidx = -1;
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int ogg_get_length(AVFormatContext *s)
yading@11: {
yading@11:     struct ogg *ogg = s->priv_data;
yading@11:     int i;
yading@11:     int64_t size, end;
yading@11:     int streams_left=0;
yading@11: 
yading@11:     if (!s->pb->seekable)
yading@11:         return 0;
yading@11: 
yading@11: // already set
yading@11:     if (s->duration != AV_NOPTS_VALUE)
yading@11:         return 0;
yading@11: 
yading@11:     size = avio_size(s->pb);
yading@11:     if (size < 0)
yading@11:         return 0;
yading@11:     end = size > MAX_PAGE_SIZE ? size - MAX_PAGE_SIZE : 0;
yading@11: 
yading@11:     ogg_save(s);
yading@11:     avio_seek(s->pb, end, SEEK_SET);
yading@11:     ogg->page_pos = -1;
yading@11: 
yading@11:     while (!ogg_read_page(s, &i)) {
yading@11:         if (ogg->streams[i].granule != -1 && ogg->streams[i].granule != 0 &&
yading@11:             ogg->streams[i].codec) {
yading@11:             s->streams[i]->duration =
yading@11:                 ogg_gptopts(s, i, ogg->streams[i].granule, NULL);
yading@11:             if (s->streams[i]->start_time != AV_NOPTS_VALUE) {
yading@11:                 s->streams[i]->duration -= s->streams[i]->start_time;
yading@11:                 streams_left-= (ogg->streams[i].got_start==-1);
yading@11:                 ogg->streams[i].got_start= 1;
yading@11:             } else if(!ogg->streams[i].got_start) {
yading@11:                 ogg->streams[i].got_start= -1;
yading@11:                 streams_left++;
yading@11:             }
yading@11:         }
yading@11:     }
yading@11: 
yading@11:     ogg_restore(s, 0);
yading@11: 
yading@11:     ogg_save (s);
yading@11:     avio_seek (s->pb, s->data_offset, SEEK_SET);
yading@11:     ogg_reset(s);
yading@11:     while (streams_left > 0 && !ogg_packet(s, &i, NULL, NULL, NULL)) {
yading@11:         int64_t pts;
yading@11:         if (i < 0) continue;
yading@11:         pts = ogg_calc_pts(s, i, NULL);
yading@11:         if (pts != AV_NOPTS_VALUE && s->streams[i]->start_time == AV_NOPTS_VALUE && !ogg->streams[i].got_start) {
yading@11:             s->streams[i]->duration -= pts;
yading@11:             ogg->streams[i].got_start= 1;
yading@11:             streams_left--;
yading@11:         }else if(s->streams[i]->start_time != AV_NOPTS_VALUE && !ogg->streams[i].got_start) {
yading@11:             ogg->streams[i].got_start= 1;
yading@11:             streams_left--;
yading@11:         }
yading@11:     }
yading@11:     ogg_restore (s, 0);
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int ogg_read_close(AVFormatContext *s)
yading@11: {
yading@11:     struct ogg *ogg = s->priv_data;
yading@11:     int i;
yading@11: 
yading@11:     for (i = 0; i < ogg->nstreams; i++) {
yading@11:         av_free(ogg->streams[i].buf);
yading@11:         if (ogg->streams[i].codec &&
yading@11:             ogg->streams[i].codec->cleanup) {
yading@11:             ogg->streams[i].codec->cleanup(s, i);
yading@11:         }
yading@11:         av_free(ogg->streams[i].private);
yading@11:     }
yading@11:     av_free(ogg->streams);
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int ogg_read_header(AVFormatContext *s)
yading@11: {
yading@11:     struct ogg *ogg = s->priv_data;
yading@11:     int ret, i;
yading@11: 
yading@11:     ogg->curidx = -1;
yading@11: 
yading@11:     //linear headers seek from start
yading@11:     do {
yading@11:         ret = ogg_packet(s, NULL, NULL, NULL, NULL);
yading@11:         if (ret < 0) {
yading@11:             ogg_read_close(s);
yading@11:             return ret;
yading@11:         }
yading@11:     } while (!ogg->headers);
yading@11:     av_dlog(s, "found headers\n");
yading@11: 
yading@11:     for (i = 0; i < ogg->nstreams; i++) {
yading@11:         struct ogg_stream *os = ogg->streams + i;
yading@11: 
yading@11:         if (ogg->streams[i].header < 0) {
yading@11:             av_log(s, AV_LOG_ERROR, "Header parsing failed for stream %d\n", i);
yading@11:             ogg->streams[i].codec = NULL;
yading@11:         } else if (os->codec && os->nb_header < os->codec->nb_header) {
yading@11:             av_log(s, AV_LOG_WARNING, "Number of headers (%d) mismatch for stream %d\n", os->nb_header, i);
yading@11:         }
yading@11:         if (os->start_granule != OGG_NOGRANULE_VALUE)
yading@11:             os->lastpts = s->streams[i]->start_time =
yading@11:                 ogg_gptopts(s, i, os->start_granule, NULL);
yading@11:     }
yading@11: 
yading@11:     //linear granulepos seek from end
yading@11:     ogg_get_length(s);
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int64_t ogg_calc_pts(AVFormatContext *s, int idx, int64_t *dts)
yading@11: {
yading@11:     struct ogg *ogg       = s->priv_data;
yading@11:     struct ogg_stream *os = ogg->streams + idx;
yading@11:     int64_t pts           = AV_NOPTS_VALUE;
yading@11: 
yading@11:     if (dts)
yading@11:         *dts = AV_NOPTS_VALUE;
yading@11: 
yading@11:     if (os->lastpts != AV_NOPTS_VALUE) {
yading@11:         pts         = os->lastpts;
yading@11:         os->lastpts = AV_NOPTS_VALUE;
yading@11:     }
yading@11:     if (os->lastdts != AV_NOPTS_VALUE) {
yading@11:         if (dts)
yading@11:             *dts = os->lastdts;
yading@11:         os->lastdts = AV_NOPTS_VALUE;
yading@11:     }
yading@11:     if (os->page_end) {
yading@11:         if (os->granule != -1LL) {
yading@11:             if (os->codec && os->codec->granule_is_start)
yading@11:                 pts = ogg_gptopts(s, idx, os->granule, dts);
yading@11:             else
yading@11:                 os->lastpts = ogg_gptopts(s, idx, os->granule, &os->lastdts);
yading@11:             os->granule = -1LL;
yading@11:         }
yading@11:     }
yading@11:     return pts;
yading@11: }
yading@11: 
yading@11: static void ogg_validate_keyframe(AVFormatContext *s, int idx, int pstart, int psize)
yading@11: {
yading@11:     struct ogg *ogg = s->priv_data;
yading@11:     struct ogg_stream *os = ogg->streams + idx;
yading@11:     if (psize && s->streams[idx]->codec->codec_id == AV_CODEC_ID_THEORA) {
yading@11:         if (!!(os->pflags & AV_PKT_FLAG_KEY) != !(os->buf[pstart] & 0x40)) {
yading@11:             os->pflags ^= AV_PKT_FLAG_KEY;
yading@11:             av_log(s, AV_LOG_WARNING, "Broken file, %skeyframe not correctly marked.\n",
yading@11:                    (os->pflags & AV_PKT_FLAG_KEY) ? "" : "non-");
yading@11:         }
yading@11:     }
yading@11: }
yading@11: 
yading@11: static int ogg_read_packet(AVFormatContext *s, AVPacket *pkt)
yading@11: {
yading@11:     struct ogg *ogg;
yading@11:     struct ogg_stream *os;
yading@11:     int idx, ret;
yading@11:     int pstart, psize;
yading@11:     int64_t fpos, pts, dts;
yading@11: 
yading@11:     if (s->io_repositioned) {
yading@11:         ogg_reset(s);
yading@11:         s->io_repositioned = 0;
yading@11:     }
yading@11: 
yading@11:     //Get an ogg packet
yading@11: retry:
yading@11:     do {
yading@11:         ret = ogg_packet(s, &idx, &pstart, &psize, &fpos);
yading@11:         if (ret < 0)
yading@11:             return ret;
yading@11:     } while (idx < 0 || !s->streams[idx]);
yading@11: 
yading@11:     ogg = s->priv_data;
yading@11:     os  = ogg->streams + idx;
yading@11: 
yading@11:     // pflags might not be set until after this
yading@11:     pts = ogg_calc_pts(s, idx, &dts);
yading@11:     ogg_validate_keyframe(s, idx, pstart, psize);
yading@11: 
yading@11:     if (os->keyframe_seek && !(os->pflags & AV_PKT_FLAG_KEY))
yading@11:         goto retry;
yading@11:     os->keyframe_seek = 0;
yading@11: 
yading@11:     //Alloc a pkt
yading@11:     ret = av_new_packet(pkt, psize);
yading@11:     if (ret < 0)
yading@11:         return ret;
yading@11:     pkt->stream_index = idx;
yading@11:     memcpy(pkt->data, os->buf + pstart, psize);
yading@11: 
yading@11:     pkt->pts      = pts;
yading@11:     pkt->dts      = dts;
yading@11:     pkt->flags    = os->pflags;
yading@11:     pkt->duration = os->pduration;
yading@11:     pkt->pos      = fpos;
yading@11: 
yading@11:     return psize;
yading@11: }
yading@11: 
yading@11: static int64_t ogg_read_timestamp(AVFormatContext *s, int stream_index,
yading@11:                                   int64_t *pos_arg, int64_t pos_limit)
yading@11: {
yading@11:     struct ogg *ogg = s->priv_data;
yading@11:     AVIOContext *bc = s->pb;
yading@11:     int64_t pts     = AV_NOPTS_VALUE;
yading@11:     int64_t keypos  = -1;
yading@11:     int i;
yading@11:     int pstart, psize;
yading@11:     avio_seek(bc, *pos_arg, SEEK_SET);
yading@11:     ogg_reset(s);
yading@11: 
yading@11:     while (   avio_tell(bc) <= pos_limit
yading@11:            && !ogg_packet(s, &i, &pstart, &psize, pos_arg)) {
yading@11:         if (i == stream_index) {
yading@11:             struct ogg_stream *os = ogg->streams + stream_index;
yading@11:             pts = ogg_calc_pts(s, i, NULL);
yading@11:             ogg_validate_keyframe(s, i, pstart, psize);
yading@11:             if (os->pflags & AV_PKT_FLAG_KEY) {
yading@11:                 keypos = *pos_arg;
yading@11:             } else if (os->keyframe_seek) {
yading@11:                 // if we had a previous keyframe but no pts for it,
yading@11:                 // return that keyframe with this pts value.
yading@11:                 if (keypos >= 0)
yading@11:                     *pos_arg = keypos;
yading@11:                 else
yading@11:                     pts = AV_NOPTS_VALUE;
yading@11:             }
yading@11:         }
yading@11:         if (pts != AV_NOPTS_VALUE)
yading@11:             break;
yading@11:     }
yading@11:     ogg_reset(s);
yading@11:     return pts;
yading@11: }
yading@11: 
yading@11: static int ogg_read_seek(AVFormatContext *s, int stream_index,
yading@11:                          int64_t timestamp, int flags)
yading@11: {
yading@11:     struct ogg *ogg       = s->priv_data;
yading@11:     struct ogg_stream *os = ogg->streams + stream_index;
yading@11:     int ret;
yading@11: 
yading@11:     av_assert0(stream_index < ogg->nstreams);
yading@11:     // Ensure everything is reset even when seeking via
yading@11:     // the generated index.
yading@11:     ogg_reset(s);
yading@11: 
yading@11:     // Try seeking to a keyframe first. If this fails (very possible),
yading@11:     // av_seek_frame will fall back to ignoring keyframes
yading@11:     if (s->streams[stream_index]->codec->codec_type == AVMEDIA_TYPE_VIDEO
yading@11:         && !(flags & AVSEEK_FLAG_ANY))
yading@11:         os->keyframe_seek = 1;
yading@11: 
yading@11:     ret = ff_seek_frame_binary(s, stream_index, timestamp, flags);
yading@11:     os  = ogg->streams + stream_index;
yading@11:     if (ret < 0)
yading@11:         os->keyframe_seek = 0;
yading@11:     return ret;
yading@11: }
yading@11: 
yading@11: static int ogg_probe(AVProbeData *p)
yading@11: {
yading@11:     if (!memcmp("OggS", p->buf, 5) && p->buf[5] <= 0x7)
yading@11:         return AVPROBE_SCORE_MAX;
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: AVInputFormat ff_ogg_demuxer = {
yading@11:     .name           = "ogg",
yading@11:     .long_name      = NULL_IF_CONFIG_SMALL("Ogg"),
yading@11:     .priv_data_size = sizeof(struct ogg),
yading@11:     .read_probe     = ogg_probe,
yading@11:     .read_header    = ogg_read_header,
yading@11:     .read_packet    = ogg_read_packet,
yading@11:     .read_close     = ogg_read_close,
yading@11:     .read_seek      = ogg_read_seek,
yading@11:     .read_timestamp = ogg_read_timestamp,
yading@11:     .extensions     = "ogg",
yading@11:     .flags          = AVFMT_GENERIC_INDEX | AVFMT_TS_DISCONT,
yading@11: };