static GstFlowReturn
mpegts_base_scan (MpegTSBase * base)
{
GstFlowReturn ret = GST_FLOW_OK;
GstBuffer *buf = NULL;
guint i;
gboolean done = FALSE;
MpegTSPacketizerPacketReturn pret;
gint64 tmpval;
gint64 upstream_size, seek_pos, reverse_limit;
GstFormat format;
guint initial_pcr_seen;
GST_DEBUG ("Scanning for initial sync point");
/* Find initial sync point and at least 5 PCR values */
for (i = 0; i < 20 && !done; i++) {
GST_DEBUG ("Grabbing %d => %d", i * 65536, (i + 1) * 65536);
ret = gst_pad_pull_range (base->sinkpad, i * 65536, 65536, &buf);
if (G_UNLIKELY (ret == GST_FLOW_EOS))
break;
if (G_UNLIKELY (ret != GST_FLOW_OK))
goto beach;
/* Push to packetizer */
mpegts_packetizer_push (base->packetizer, buf);
buf = NULL;
if (mpegts_packetizer_has_packets (base->packetizer)) {
if (base->seek_offset == -1) {
/* Mark the initial sync point and remember the packetsize */
base->seek_offset = base->packetizer->offset;
GST_DEBUG ("Sync point is now %" G_GUINT64_FORMAT, base->seek_offset);
base->packetsize = base->packetizer->packet_size;
}
while (1) {
/* Eat up all packets */
pret = mpegts_packetizer_process_next_packet (base->packetizer);
if (pret == PACKET_NEED_MORE)
break;
if (pret != PACKET_BAD && base->packetizer->nb_seen_offsets >= 5) {
GST_DEBUG ("Got enough initial PCR");
done = TRUE;
break;
}
}
}
}
initial_pcr_seen = base->packetizer->nb_seen_offsets;
if (G_UNLIKELY (initial_pcr_seen == 0))
goto no_initial_pcr;
GST_DEBUG ("Seen %d initial PCR", initial_pcr_seen);
/* Now send data from the end */
/* Get the size of upstream */
format = GST_FORMAT_BYTES;
if (!gst_pad_peer_query_duration (base->sinkpad, format, &tmpval))
goto beach;
upstream_size = tmpval;
/* The scanning takes place on the last 2048kB. Considering PCR should
* be present at least every 100ms, this should cope with streams
* up to 160Mbit/s */
reverse_limit = MAX (0, upstream_size - 2097152);
/* Find last PCR value, searching backwards by chunks of 300 MPEG-ts packets */
for (seek_pos = MAX (0, upstream_size - 56400);
seek_pos >= reverse_limit; seek_pos -= 56400) {
mpegts_packetizer_clear (base->packetizer);
GST_DEBUG ("Grabbing %" G_GUINT64_FORMAT " => %" G_GUINT64_FORMAT, seek_pos,
seek_pos + 56400);
ret = gst_pad_pull_range (base->sinkpad, seek_pos, 56400, &buf);
if (G_UNLIKELY (ret == GST_FLOW_EOS))
break;
if (G_UNLIKELY (ret != GST_FLOW_OK))
goto beach;
/* Push to packetizer */
mpegts_packetizer_push (base->packetizer, buf);
buf = NULL;
if (mpegts_packetizer_has_packets (base->packetizer)) {
pret = PACKET_OK;
/* Eat up all packets, really try to get last PCR(s) */
while (pret != PACKET_NEED_MORE)
pret = mpegts_packetizer_process_next_packet (base->packetizer);
if (base->packetizer->nb_seen_offsets > initial_pcr_seen) {
GST_DEBUG ("Got last PCR(s) (total seen:%d)",
base->packetizer->nb_seen_offsets);
break;
}
}
}
beach:
mpegts_packetizer_clear (base->packetizer);
return ret;
no_initial_pcr:
mpegts_packetizer_clear (base->packetizer);
GST_WARNING_OBJECT (base, "Couldn't find any PCR within the first %d bytes",
10 * 65536);
return GST_FLOW_ERROR;
}
static GstFlowReturn
mpegts_base_scan (MpegTSBase * base)
{
GstFlowReturn ret = GST_FLOW_OK;
GstBuffer *buf = NULL;
guint i;
gboolean done = FALSE;
MpegTSPacketizerPacketReturn pret;
gint64 tmpval;
guint64 upstream_size, seek_pos;
GstFormat format;
guint initial_pcr_seen;
GST_DEBUG ("Scanning for initial sync point");
/* Find initial sync point and at least 5 PCR values */
for (i = 0; i < 10 && !done; i++) {
GST_DEBUG ("Grabbing %d => %d", i * 65536, 65536);
ret = gst_pad_pull_range (base->sinkpad, i * 65536, 65536, &buf);
if (G_UNLIKELY (ret != GST_FLOW_OK))
goto beach;
/* Push to packetizer */
mpegts_packetizer_push (base->packetizer, buf);
buf = NULL;
if (mpegts_packetizer_has_packets (base->packetizer)) {
if (base->seek_offset == -1) {
/* Mark the initial sync point and remember the packetsize */
base->seek_offset = base->packetizer->offset;
GST_DEBUG ("Sync point is now %" G_GUINT64_FORMAT, base->seek_offset);
base->packetsize = base->packetizer->packet_size;
}
while (1) {
/* Eat up all packets */
pret = mpegts_packetizer_process_next_packet (base->packetizer);
if (pret == PACKET_NEED_MORE)
break;
if (pret != PACKET_BAD &&
mpegts_packetizer_get_seen_pcr (base->packetizer) >= 5) {
GST_DEBUG ("Got enough initial PCR");
done = TRUE;
break;
}
}
}
}
initial_pcr_seen = mpegts_packetizer_get_seen_pcr (base->packetizer);
if (G_UNLIKELY (initial_pcr_seen == 0))
goto no_initial_pcr;
GST_DEBUG ("Seen %d initial PCR", initial_pcr_seen);
/* Now send data from the end */
mpegts_packetizer_clear (base->packetizer);
/* Get the size of upstream */
format = GST_FORMAT_BYTES;
if (!gst_pad_peer_query_duration (base->sinkpad, format, &tmpval))
goto beach;
upstream_size = tmpval;
done = FALSE;
/* Find last PCR value */
for (seek_pos = MAX (0, upstream_size - 655360);
seek_pos < upstream_size && !done; seek_pos += 65536) {
GST_DEBUG ("Grabbing %" G_GUINT64_FORMAT " => %d", seek_pos, 65536);
ret = gst_pad_pull_range (base->sinkpad, seek_pos, 65536, &buf);
if (G_UNLIKELY (ret != GST_FLOW_OK))
goto beach;
/* Push to packetizer */
mpegts_packetizer_push (base->packetizer, buf);
buf = NULL;
if (mpegts_packetizer_has_packets (base->packetizer)) {
while (1) {
/* Eat up all packets */
pret = mpegts_packetizer_process_next_packet (base->packetizer);
if (pret == PACKET_NEED_MORE)
break;
if (pret != PACKET_BAD &&
mpegts_packetizer_get_seen_pcr (base->packetizer) >
initial_pcr_seen) {
GST_DEBUG ("Got last PCR");
done = TRUE;
break;
}
}
}
}
beach:
mpegts_packetizer_clear (base->packetizer);
return ret;
no_initial_pcr:
mpegts_packetizer_clear (base->packetizer);
GST_WARNING_OBJECT (base, "Couldn't find any PCR within the first %d bytes",
10 * 65536);
return GST_FLOW_ERROR;
}