making act segmenter

1 files changed, 853 insertions, 0 deletions

diff --git a/ffmpeg/libavformat/oggdec.c b/ffmpeg/libavformat/oggdec.c
new file mode 100644
index 0000000..fdb5e96
--- /dev/null
+++ b/ffmpeg/libavformat/oggdec.c
@@ -0,0 +1,853 @@
+/*
+ * Ogg bitstream support
+ * Luca Barbato <lu_zero@gentoo.org>
+ * Based on tcvp implementation
+ */
+
+/*
+    Copyright (C) 2005  Michael Ahlberg, Måns Rullgård
+
+    Permission is hereby granted, free of charge, to any person
+    obtaining a copy of this software and associated documentation
+    files (the "Software"), to deal in the Software without
+    restriction, including without limitation the rights to use, copy,
+    modify, merge, publish, distribute, sublicense, and/or sell copies
+    of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be
+    included in all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+    NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+    HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+    WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+    DEALINGS IN THE SOFTWARE.
+ */
+
+#include <stdio.h>
+#include "libavutil/avassert.h"
+#include "oggdec.h"
+#include "avformat.h"
+#include "internal.h"
+#include "vorbiscomment.h"
+
+#define MAX_PAGE_SIZE 65307
+#define DECODER_BUFFER_SIZE MAX_PAGE_SIZE
+
+static const struct ogg_codec * const ogg_codecs[] = {
+    &ff_skeleton_codec,
+    &ff_dirac_codec,
+    &ff_speex_codec,
+    &ff_vorbis_codec,
+    &ff_theora_codec,
+    &ff_flac_codec,
+    &ff_celt_codec,
+    &ff_opus_codec,
+    &ff_old_dirac_codec,
+    &ff_old_flac_codec,
+    &ff_ogm_video_codec,
+    &ff_ogm_audio_codec,
+    &ff_ogm_text_codec,
+    &ff_ogm_old_codec,
+    NULL
+};
+
+static int64_t ogg_calc_pts(AVFormatContext *s, int idx, int64_t *dts);
+static int ogg_new_stream(AVFormatContext *s, uint32_t serial);
+
+//FIXME We could avoid some structure duplication
+static int ogg_save(AVFormatContext *s)
+{
+    struct ogg *ogg = s->priv_data;
+    struct ogg_state *ost =
+        av_malloc(sizeof(*ost) + (ogg->nstreams - 1) * sizeof(*ogg->streams));
+    int i;
+    ost->pos      = avio_tell(s->pb);
+    ost->curidx   = ogg->curidx;
+    ost->next     = ogg->state;
+    ost->nstreams = ogg->nstreams;
+    memcpy(ost->streams, ogg->streams, ogg->nstreams * sizeof(*ogg->streams));
+
+    for (i = 0; i < ogg->nstreams; i++) {
+        struct ogg_stream *os = ogg->streams + i;
+        os->buf = av_mallocz(os->bufsize + FF_INPUT_BUFFER_PADDING_SIZE);
+        memcpy(os->buf, ost->streams[i].buf, os->bufpos);
+    }
+
+    ogg->state = ost;
+
+    return 0;
+}
+
+static int ogg_restore(AVFormatContext *s, int discard)
+{
+    struct ogg *ogg = s->priv_data;
+    AVIOContext *bc = s->pb;
+    struct ogg_state *ost = ogg->state;
+    int i;
+
+    if (!ost)
+        return 0;
+
+    ogg->state = ost->next;
+
+    if (!discard) {
+        struct ogg_stream *old_streams = ogg->streams;
+
+        for (i = 0; i < ogg->nstreams; i++)
+            av_free(ogg->streams[i].buf);
+
+        avio_seek(bc, ost->pos, SEEK_SET);
+        ogg->page_pos = -1;
+        ogg->curidx   = ost->curidx;
+        ogg->nstreams = ost->nstreams;
+        ogg->streams  = av_realloc(ogg->streams,
+                                   ogg->nstreams * sizeof(*ogg->streams));
+
+        if (ogg->streams) {
+            memcpy(ogg->streams, ost->streams,
+                   ost->nstreams * sizeof(*ogg->streams));
+        } else {
+            av_free(old_streams);
+            ogg->nstreams = 0;
+        }
+    }
+
+    av_free(ost);
+
+    return 0;
+}
+
+static int ogg_reset(AVFormatContext *s)
+{
+    struct ogg *ogg = s->priv_data;
+    int i;
+    int64_t start_pos = avio_tell(s->pb);
+
+    for (i = 0; i < ogg->nstreams; i++) {
+        struct ogg_stream *os = ogg->streams + i;
+        os->bufpos     = 0;
+        os->pstart     = 0;
+        os->psize      = 0;
+        os->granule    = -1;
+        os->lastpts    = AV_NOPTS_VALUE;
+        os->lastdts    = AV_NOPTS_VALUE;
+        os->sync_pos   = -1;
+        os->page_pos   = 0;
+        os->nsegs      = 0;
+        os->segp       = 0;
+        os->incomplete = 0;
+        os->got_data = 0;
+        if (start_pos <= s->data_offset) {
+            os->lastpts = 0;
+        }
+    }
+
+    ogg->page_pos = -1;
+    ogg->curidx = -1;
+
+    return 0;
+}
+
+static const struct ogg_codec *ogg_find_codec(uint8_t *buf, int size)
+{
+    int i;
+
+    for (i = 0; ogg_codecs[i]; i++)
+        if (size >= ogg_codecs[i]->magicsize &&
+            !memcmp(buf, ogg_codecs[i]->magic, ogg_codecs[i]->magicsize))
+            return ogg_codecs[i];
+
+    return NULL;
+}
+
+/**
+ * Replace the current stream with a new one. This is a typical webradio
+ * situation where a new audio stream spawn (identified with a new serial) and
+ * must replace the previous one (track switch).
+ */
+static int ogg_replace_stream(AVFormatContext *s, uint32_t serial, int nsegs)
+{
+    struct ogg *ogg = s->priv_data;
+    struct ogg_stream *os;
+    const struct ogg_codec *codec;
+    int i = 0;
+
+    if (s->pb->seekable) {
+        uint8_t magic[8];
+        int64_t pos = avio_tell(s->pb);
+        avio_skip(s->pb, nsegs);
+        avio_read(s->pb, magic, sizeof(magic));
+        avio_seek(s->pb, pos, SEEK_SET);
+        codec = ogg_find_codec(magic, sizeof(magic));
+        if (!codec) {
+            av_log(s, AV_LOG_ERROR, "Cannot identify new stream\n");
+            return AVERROR_INVALIDDATA;
+        }
+        for (i = 0; i < ogg->nstreams; i++) {
+            if (ogg->streams[i].codec == codec)
+                break;
+        }
+        if (i >= ogg->nstreams)
+            return ogg_new_stream(s, serial);
+    } else if (ogg->nstreams != 1) {
+        avpriv_report_missing_feature(s, "Changing stream parameters in multistream ogg");
+        return AVERROR_PATCHWELCOME;
+    }
+
+    os = &ogg->streams[i];
+
+    os->serial  = serial;
+    return i;
+
+#if 0
+    buf     = os->buf;
+    bufsize = os->bufsize;
+    codec   = os->codec;
+
+    if (!ogg->state || ogg->state->streams[i].private != os->private)
+        av_freep(&ogg->streams[i].private);
+
+    /* Set Ogg stream settings similar to what is done in ogg_new_stream(). We
+     * also re-use the ogg_stream allocated buffer */
+    memset(os, 0, sizeof(*os));
+    os->serial  = serial;
+    os->bufsize = bufsize;
+    os->buf     = buf;
+    os->header  = -1;
+    os->codec   = codec;
+
+    return i;
+#endif
+}
+
+static int ogg_new_stream(AVFormatContext *s, uint32_t serial)
+{
+    struct ogg *ogg = s->priv_data;
+    int idx         = ogg->nstreams;
+    AVStream *st;
+    struct ogg_stream *os;
+    size_t size;
+
+    if (ogg->state) {
+        av_log(s, AV_LOG_ERROR, "New streams are not supposed to be added "
+               "in between Ogg context save/restore operations.\n");
+        return AVERROR_BUG;
+    }
+
+    /* Allocate and init a new Ogg Stream */
+    if (av_size_mult(ogg->nstreams + 1, sizeof(*ogg->streams), &size) < 0 ||
+        !(os = av_realloc(ogg->streams, size)))
+        return AVERROR(ENOMEM);
+    ogg->streams = os;
+    os           = ogg->streams + idx;
+    memset(os, 0, sizeof(*os));
+    os->serial        = serial;
+    os->bufsize       = DECODER_BUFFER_SIZE;
+    os->buf           = av_malloc(os->bufsize + FF_INPUT_BUFFER_PADDING_SIZE);
+    os->header        = -1;
+    os->start_granule = OGG_NOGRANULE_VALUE;
+    if (!os->buf)
+        return AVERROR(ENOMEM);
+
+    /* Create the associated AVStream */
+    st = avformat_new_stream(s, NULL);
+    if (!st) {
+        av_freep(&os->buf);
+        return AVERROR(ENOMEM);
+    }
+    st->id = idx;
+    avpriv_set_pts_info(st, 64, 1, 1000000);
+
+    ogg->nstreams++;
+    return idx;
+}
+
+static int ogg_new_buf(struct ogg *ogg, int idx)
+{
+    struct ogg_stream *os = ogg->streams + idx;
+    uint8_t *nb = av_malloc(os->bufsize + FF_INPUT_BUFFER_PADDING_SIZE);
+    int size = os->bufpos - os->pstart;
+
+    if (os->buf) {
+        memcpy(nb, os->buf + os->pstart, size);
+        av_free(os->buf);
+    }
+
+    os->buf    = nb;
+    os->bufpos = size;
+    os->pstart = 0;
+
+    return 0;
+}
+
+static int data_packets_seen(const struct ogg *ogg)
+{
+    int i;
+
+    for (i = 0; i < ogg->nstreams; i++)
+        if (ogg->streams[i].got_data)
+            return 1;
+    return 0;
+}
+
+static int ogg_read_page(AVFormatContext *s, int *sid)
+{
+    AVIOContext *bc = s->pb;
+    struct ogg *ogg = s->priv_data;
+    struct ogg_stream *os;
+    int ret, i = 0;
+    int flags, nsegs;
+    uint64_t gp;
+    uint32_t serial;
+    int size, idx;
+    uint8_t sync[4];
+    int sp = 0;
+
+    ret = avio_read(bc, sync, 4);
+    if (ret < 4)
+        return ret < 0 ? ret : AVERROR_EOF;
+
+    do {
+        int c;
+
+        if (sync[sp & 3] == 'O' &&
+            sync[(sp + 1) & 3] == 'g' &&
+            sync[(sp + 2) & 3] == 'g' && sync[(sp + 3) & 3] == 'S')
+            break;
+
+        if(!i && bc->seekable && ogg->page_pos > 0) {
+            memset(sync, 0, 4);
+            avio_seek(bc, ogg->page_pos+4, SEEK_SET);
+            ogg->page_pos = -1;
+        }
+
+        c = avio_r8(bc);
+
+        if (url_feof(bc))
+            return AVERROR_EOF;
+
+        sync[sp++ & 3] = c;
+    } while (i++ < MAX_PAGE_SIZE);
+
+    if (i >= MAX_PAGE_SIZE) {
+        av_log(s, AV_LOG_INFO, "cannot find sync word\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    if (avio_r8(bc) != 0) {      /* version */
+        av_log (s, AV_LOG_ERROR, "ogg page, unsupported version\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    flags  = avio_r8(bc);
+    gp     = avio_rl64(bc);
+    serial = avio_rl32(bc);
+    avio_skip(bc, 8); /* seq, crc */
+    nsegs  = avio_r8(bc);
+
+    idx = ogg_find_stream(ogg, serial);
+    if (idx < 0) {
+        if (data_packets_seen(ogg))
+            idx = ogg_replace_stream(s, serial, nsegs);
+        else
+            idx = ogg_new_stream(s, serial);
+
+        if (idx < 0) {
+            av_log(s, AV_LOG_ERROR, "failed to create or replace stream\n");
+            return idx;
+        }
+    }
+
+    os = ogg->streams + idx;
+    ogg->page_pos =
+    os->page_pos = avio_tell(bc) - 27;
+
+    if (os->psize > 0)
+        ogg_new_buf(ogg, idx);
+
+    ret = avio_read(bc, os->segments, nsegs);
+    if (ret < nsegs)
+        return ret < 0 ? ret : AVERROR_EOF;
+
+    os->nsegs = nsegs;
+    os->segp  = 0;
+
+    size = 0;
+    for (i = 0; i < nsegs; i++)
+        size += os->segments[i];
+
+    if (!(flags & OGG_FLAG_BOS))
+        os->got_data = 1;
+
+    if (flags & OGG_FLAG_CONT || os->incomplete) {
+        if (!os->psize) {
+            // If this is the very first segment we started
+            // playback in the middle of a continuation packet.
+            // Discard it since we missed the start of it.
+            while (os->segp < os->nsegs) {
+                int seg = os->segments[os->segp++];
+                os->pstart += seg;
+                if (seg < 255)
+                    break;
+            }
+            os->sync_pos = os->page_pos;
+        }
+    } else {
+        os->psize    = 0;
+        os->sync_pos = os->page_pos;
+    }
+
+    if (os->bufsize - os->bufpos < size) {
+        uint8_t *nb = av_malloc((os->bufsize *= 2) + FF_INPUT_BUFFER_PADDING_SIZE);
+        if (!nb)
+            return AVERROR(ENOMEM);
+        memcpy(nb, os->buf, os->bufpos);
+        av_free(os->buf);
+        os->buf = nb;
+    }
+
+    ret = avio_read(bc, os->buf + os->bufpos, size);
+    if (ret < size)
+        return ret < 0 ? ret : AVERROR_EOF;
+
+    os->bufpos += size;
+    os->granule = gp;
+    os->flags   = flags;
+
+    memset(os->buf + os->bufpos, 0, FF_INPUT_BUFFER_PADDING_SIZE);
+    if (sid)
+        *sid = idx;
+
+    return 0;
+}
+
+/**
+ * @brief find the next Ogg packet
+ * @param *sid is set to the stream for the packet or -1 if there is
+ *             no matching stream, in that case assume all other return
+ *             values to be uninitialized.
+ * @return negative value on error or EOF.
+ */
+static int ogg_packet(AVFormatContext *s, int *sid, int *dstart, int *dsize,
+                      int64_t *fpos)
+{
+    struct ogg *ogg = s->priv_data;
+    int idx, i, ret;
+    struct ogg_stream *os;
+    int complete = 0;
+    int segp     = 0, psize = 0;
+
+    av_dlog(s, "ogg_packet: curidx=%i\n", ogg->curidx);
+    if (sid)
+        *sid = -1;
+
+    do {
+        idx = ogg->curidx;
+
+        while (idx < 0) {
+            ret = ogg_read_page(s, &idx);
+            if (ret < 0)
+                return ret;
+        }
+
+        os = ogg->streams + idx;
+
+        av_dlog(s, "ogg_packet: idx=%d pstart=%d psize=%d segp=%d nsegs=%d\n",
+                idx, os->pstart, os->psize, os->segp, os->nsegs);
+
+        if (!os->codec) {
+            if (os->header < 0) {
+                os->codec = ogg_find_codec(os->buf, os->bufpos);
+                if (!os->codec) {
+                    av_log(s, AV_LOG_WARNING, "Codec not found\n");
+                    os->header = 0;
+                    return 0;
+                }
+            } else {
+                return 0;
+            }
+        }
+
+        segp  = os->segp;
+        psize = os->psize;
+
+        while (os->segp < os->nsegs) {
+            int ss = os->segments[os->segp++];
+            os->psize += ss;
+            if (ss < 255) {
+                complete = 1;
+                break;
+            }
+        }
+
+        if (!complete && os->segp == os->nsegs) {
+            ogg->curidx    = -1;
+            // Do not set incomplete for empty packets.
+            // Together with the code in ogg_read_page
+            // that discards all continuation of empty packets
+            // we would get an infinite loop.
+            os->incomplete = !!os->psize;
+        }
+    } while (!complete);
+
+
+    if (os->granule == -1)
+        av_log(s, AV_LOG_WARNING,
+               "Page at %"PRId64" is missing granule\n",
+               os->page_pos);
+
+    ogg->curidx    = idx;
+    os->incomplete = 0;
+
+    if (os->header) {
+        os->header = os->codec->header(s, idx);
+        if (!os->header) {
+            os->segp  = segp;
+            os->psize = psize;
+
+            // We have reached the first non-header packet in this stream.
+            // Unfortunately more header packets may still follow for others,
+            // but if we continue with header parsing we may lose data packets.
+            ogg->headers = 1;
+
+            // Update the header state for all streams and
+            // compute the data_offset.
+            if (!s->data_offset)
+                s->data_offset = os->sync_pos;
+
+            for (i = 0; i < ogg->nstreams; i++) {
+                struct ogg_stream *cur_os = ogg->streams + i;
+
+                // if we have a partial non-header packet, its start is
+                // obviously at or after the data start
+                if (cur_os->incomplete)
+                    s->data_offset = FFMIN(s->data_offset, cur_os->sync_pos);
+            }
+        } else {
+            os->nb_header++;
+            os->pstart += os->psize;
+            os->psize   = 0;
+        }
+    } else {
+        os->pflags    = 0;
+        os->pduration = 0;
+        if (os->codec && os->codec->packet)
+            os->codec->packet(s, idx);
+        if (sid)
+            *sid = idx;
+        if (dstart)
+            *dstart = os->pstart;
+        if (dsize)
+            *dsize = os->psize;
+        if (fpos)
+            *fpos = os->sync_pos;
+        os->pstart  += os->psize;
+        os->psize    = 0;
+        if(os->pstart == os->bufpos)
+            os->bufpos = os->pstart = 0;
+        os->sync_pos = os->page_pos;
+    }
+
+    // determine whether there are more complete packets in this page
+    // if not, the page's granule will apply to this packet
+    os->page_end = 1;
+    for (i = os->segp; i < os->nsegs; i++)
+        if (os->segments[i] < 255) {
+            os->page_end = 0;
+            break;
+        }
+
+    if (os->segp == os->nsegs)
+        ogg->curidx = -1;
+
+    return 0;
+}
+
+static int ogg_get_length(AVFormatContext *s)
+{
+    struct ogg *ogg = s->priv_data;
+    int i;
+    int64_t size, end;
+    int streams_left=0;
+
+    if (!s->pb->seekable)
+        return 0;
+
+// already set
+    if (s->duration != AV_NOPTS_VALUE)
+        return 0;
+
+    size = avio_size(s->pb);
+    if (size < 0)
+        return 0;
+    end = size > MAX_PAGE_SIZE ? size - MAX_PAGE_SIZE : 0;
+
+    ogg_save(s);
+    avio_seek(s->pb, end, SEEK_SET);
+    ogg->page_pos = -1;
+
+    while (!ogg_read_page(s, &i)) {
+        if (ogg->streams[i].granule != -1 && ogg->streams[i].granule != 0 &&
+            ogg->streams[i].codec) {
+            s->streams[i]->duration =
+                ogg_gptopts(s, i, ogg->streams[i].granule, NULL);
+            if (s->streams[i]->start_time != AV_NOPTS_VALUE) {
+                s->streams[i]->duration -= s->streams[i]->start_time;
+                streams_left-= (ogg->streams[i].got_start==-1);
+                ogg->streams[i].got_start= 1;
+            } else if(!ogg->streams[i].got_start) {
+                ogg->streams[i].got_start= -1;
+                streams_left++;
+            }
+        }
+    }
+
+    ogg_restore(s, 0);
+
+    ogg_save (s);
+    avio_seek (s->pb, s->data_offset, SEEK_SET);
+    ogg_reset(s);
+    while (streams_left > 0 && !ogg_packet(s, &i, NULL, NULL, NULL)) {
+        int64_t pts;
+        if (i < 0) continue;
+        pts = ogg_calc_pts(s, i, NULL);
+        if (pts != AV_NOPTS_VALUE && s->streams[i]->start_time == AV_NOPTS_VALUE && !ogg->streams[i].got_start) {
+            s->streams[i]->duration -= pts;
+            ogg->streams[i].got_start= 1;
+            streams_left--;
+        }else if(s->streams[i]->start_time != AV_NOPTS_VALUE && !ogg->streams[i].got_start) {
+            ogg->streams[i].got_start= 1;
+            streams_left--;
+        }
+    }
+    ogg_restore (s, 0);
+
+    return 0;
+}
+
+static int ogg_read_close(AVFormatContext *s)
+{
+    struct ogg *ogg = s->priv_data;
+    int i;
+
+    for (i = 0; i < ogg->nstreams; i++) {
+        av_free(ogg->streams[i].buf);
+        if (ogg->streams[i].codec &&
+            ogg->streams[i].codec->cleanup) {
+            ogg->streams[i].codec->cleanup(s, i);
+        }
+        av_free(ogg->streams[i].private);
+    }
+    av_free(ogg->streams);
+    return 0;
+}
+
+static int ogg_read_header(AVFormatContext *s)
+{
+    struct ogg *ogg = s->priv_data;
+    int ret, i;
+
+    ogg->curidx = -1;
+
+    //linear headers seek from start
+    do {
+        ret = ogg_packet(s, NULL, NULL, NULL, NULL);
+        if (ret < 0) {
+            ogg_read_close(s);
+            return ret;
+        }
+    } while (!ogg->headers);
+    av_dlog(s, "found headers\n");
+
+    for (i = 0; i < ogg->nstreams; i++) {
+        struct ogg_stream *os = ogg->streams + i;
+
+        if (ogg->streams[i].header < 0) {
+            av_log(s, AV_LOG_ERROR, "Header parsing failed for stream %d\n", i);
+            ogg->streams[i].codec = NULL;
+        } else if (os->codec && os->nb_header < os->codec->nb_header) {
+            av_log(s, AV_LOG_WARNING, "Number of headers (%d) mismatch for stream %d\n", os->nb_header, i);
+        }
+        if (os->start_granule != OGG_NOGRANULE_VALUE)
+            os->lastpts = s->streams[i]->start_time =
+                ogg_gptopts(s, i, os->start_granule, NULL);
+    }
+
+    //linear granulepos seek from end
+    ogg_get_length(s);
+
+    return 0;
+}
+
+static int64_t ogg_calc_pts(AVFormatContext *s, int idx, int64_t *dts)
+{
+    struct ogg *ogg       = s->priv_data;
+    struct ogg_stream *os = ogg->streams + idx;
+    int64_t pts           = AV_NOPTS_VALUE;
+
+    if (dts)
+        *dts = AV_NOPTS_VALUE;
+
+    if (os->lastpts != AV_NOPTS_VALUE) {
+        pts         = os->lastpts;
+        os->lastpts = AV_NOPTS_VALUE;
+    }
+    if (os->lastdts != AV_NOPTS_VALUE) {
+        if (dts)
+            *dts = os->lastdts;
+        os->lastdts = AV_NOPTS_VALUE;
+    }
+    if (os->page_end) {
+        if (os->granule != -1LL) {
+            if (os->codec && os->codec->granule_is_start)
+                pts = ogg_gptopts(s, idx, os->granule, dts);
+            else
+                os->lastpts = ogg_gptopts(s, idx, os->granule, &os->lastdts);
+            os->granule = -1LL;
+        }
+    }
+    return pts;
+}
+
+static void ogg_validate_keyframe(AVFormatContext *s, int idx, int pstart, int psize)
+{
+    struct ogg *ogg = s->priv_data;
+    struct ogg_stream *os = ogg->streams + idx;
+    if (psize && s->streams[idx]->codec->codec_id == AV_CODEC_ID_THEORA) {
+        if (!!(os->pflags & AV_PKT_FLAG_KEY) != !(os->buf[pstart] & 0x40)) {
+            os->pflags ^= AV_PKT_FLAG_KEY;
+            av_log(s, AV_LOG_WARNING, "Broken file, %skeyframe not correctly marked.\n",
+                   (os->pflags & AV_PKT_FLAG_KEY) ? "" : "non-");
+        }
+    }
+}
+
+static int ogg_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    struct ogg *ogg;
+    struct ogg_stream *os;
+    int idx, ret;
+    int pstart, psize;
+    int64_t fpos, pts, dts;
+
+    //Get an ogg packet
+retry:
+    do {
+        ret = ogg_packet(s, &idx, &pstart, &psize, &fpos);
+        if (ret < 0)
+            return ret;
+    } while (idx < 0 || !s->streams[idx]);
+
+    ogg = s->priv_data;
+    os  = ogg->streams + idx;
+
+    // pflags might not be set until after this
+    pts = ogg_calc_pts(s, idx, &dts);
+    ogg_validate_keyframe(s, idx, pstart, psize);
+
+    if (os->keyframe_seek && !(os->pflags & AV_PKT_FLAG_KEY))
+        goto retry;
+    os->keyframe_seek = 0;
+
+    //Alloc a pkt
+    ret = av_new_packet(pkt, psize);
+    if (ret < 0)
+        return ret;
+    pkt->stream_index = idx;
+    memcpy(pkt->data, os->buf + pstart, psize);
+
+    pkt->pts      = pts;
+    pkt->dts      = dts;
+    pkt->flags    = os->pflags;
+    pkt->duration = os->pduration;
+    pkt->pos      = fpos;
+
+    return psize;
+}
+
+static int64_t ogg_read_timestamp(AVFormatContext *s, int stream_index,
+                                  int64_t *pos_arg, int64_t pos_limit)
+{
+    struct ogg *ogg = s->priv_data;
+    AVIOContext *bc = s->pb;
+    int64_t pts     = AV_NOPTS_VALUE;
+    int64_t keypos  = -1;
+    int i;
+    int pstart, psize;
+    avio_seek(bc, *pos_arg, SEEK_SET);
+    ogg_reset(s);
+
+    while (   avio_tell(bc) <= pos_limit
+           && !ogg_packet(s, &i, &pstart, &psize, pos_arg)) {
+        if (i == stream_index) {
+            struct ogg_stream *os = ogg->streams + stream_index;
+            pts = ogg_calc_pts(s, i, NULL);
+            ogg_validate_keyframe(s, i, pstart, psize);
+            if (os->pflags & AV_PKT_FLAG_KEY) {
+                keypos = *pos_arg;
+            } else if (os->keyframe_seek) {
+                // if we had a previous keyframe but no pts for it,
+                // return that keyframe with this pts value.
+                if (keypos >= 0)
+                    *pos_arg = keypos;
+                else
+                    pts = AV_NOPTS_VALUE;
+            }
+        }
+        if (pts != AV_NOPTS_VALUE)
+            break;
+    }
+    ogg_reset(s);
+    return pts;
+}
+
+static int ogg_read_seek(AVFormatContext *s, int stream_index,
+                         int64_t timestamp, int flags)
+{
+    struct ogg *ogg       = s->priv_data;
+    struct ogg_stream *os = ogg->streams + stream_index;
+    int ret;
+
+    av_assert0(stream_index < ogg->nstreams);
+    // Ensure everything is reset even when seeking via
+    // the generated index.
+    ogg_reset(s);
+
+    // Try seeking to a keyframe first. If this fails (very possible),
+    // av_seek_frame will fall back to ignoring keyframes
+    if (s->streams[stream_index]->codec->codec_type == AVMEDIA_TYPE_VIDEO
+        && !(flags & AVSEEK_FLAG_ANY))
+        os->keyframe_seek = 1;
+
+    ret = ff_seek_frame_binary(s, stream_index, timestamp, flags);
+    os  = ogg->streams + stream_index;
+    if (ret < 0)
+        os->keyframe_seek = 0;
+    return ret;
+}
+
+static int ogg_probe(AVProbeData *p)
+{
+    if (!memcmp("OggS", p->buf, 5) && p->buf[5] <= 0x7)
+        return AVPROBE_SCORE_MAX;
+    return 0;
+}
+
+AVInputFormat ff_ogg_demuxer = {
+    .name           = "ogg",
+    .long_name      = NULL_IF_CONFIG_SMALL("Ogg"),
+    .priv_data_size = sizeof(struct ogg),
+    .read_probe     = ogg_probe,
+    .read_header    = ogg_read_header,
+    .read_packet    = ogg_read_packet,
+    .read_close     = ogg_read_close,
+    .read_seek      = ogg_read_seek,
+    .read_timestamp = ogg_read_timestamp,
+    .extensions     = "ogg",
+    .flags          = AVFMT_GENERIC_INDEX | AVFMT_TS_DISCONT,
+};