dashdemux: reworked the API to retrieve fragment timestamp, fragment duration and media presentation duration

This was necessary to support variable-duration Fragments.

in the new API:
- gst_mpd_client_get_current_position returns the timestamp of the NEXT fragment to download;
- gst_mpd_client_get_next_fragment_duration returns the duration of the next fragment to download;
- gst_mpd_client_get_media_presentation_duration returns the mediaPresentationDuration from the MPD file;

also there is a new internal parser function:
- gst_mpd_client_get_segment_duration extracts the constant segment duration from the MPD file
(only used when there is no SegmentTimeline syntax element in the current representation)

In gst_mpd_client_get_next_fragment, we set the timestamp/duration of the fragment just downloaded
copying the values from the corresponding GstMediaSegment.

TODO: rework SEEKING to support seeking across different Periods.
This commit is contained in:
Gianluca Gennari 2012-10-24 16:30:01 +02:00 committed by Thiago Santos
parent dc5d7d258e
commit 9387365fc9
3 changed files with 82 additions and 62 deletions

View file

@ -507,6 +507,7 @@ gst_dash_demux_src_event (GstPad * pad, GstEvent * event)
GST_MPD_CLIENT_LOCK (demux->client);
stream = gst_mpdparser_get_active_stream_by_index (demux->client, 0);
/* FIXME: support seeking across periods */
current_pos = 0;
target_pos = (GstClockTime) start;
for (walk = stream->segments; walk; walk = walk->next) {
@ -551,6 +552,7 @@ gst_dash_demux_src_event (GstPad * pad, GstEvent * event)
GST_MPD_CLIENT_LOCK (demux->client);
GST_DEBUG_OBJECT (demux, "Seeking to sequence %d", current_sequence);
/* FIXME: support seeking across periods */
stream_idx = 0;
/* Update the current sequence on all streams */
while (stream_idx < nb_active_stream) {
@ -562,7 +564,7 @@ gst_dash_demux_src_event (GstPad * pad, GstEvent * event)
stream_idx++;
}
/* Calculate offset in the next fragment */
gst_mpd_client_get_current_position (demux->client, &demux->position);
demux->position = gst_mpd_client_get_current_position (demux->client);
demux->position_shift = start - demux->position;
demux->need_segment = TRUE;
GST_MPD_CLIENT_UNLOCK (demux->client);
@ -685,7 +687,7 @@ gst_dash_demux_sink_event (GstPad * pad, GstEvent * event)
return FALSE;
/* Send duration message */
if (!gst_mpd_client_is_live (demux->client)) {
GstClockTime duration = gst_mpd_client_get_duration (demux->client);
GstClockTime duration = gst_mpd_client_get_media_presentation_duration (demux->client);
if (duration != GST_CLOCK_TIME_NONE) {
GST_DEBUG_OBJECT (demux, "Sending duration message : %" GST_TIME_FORMAT,
@ -731,7 +733,7 @@ gst_dash_demux_src_query (GstPad * pad, GstQuery * query)
gst_query_parse_duration (query, &fmt, NULL);
if (fmt == GST_FORMAT_TIME) {
duration = gst_mpd_client_get_duration (dashdemux->client);
duration = gst_mpd_client_get_media_presentation_duration (dashdemux->client);
if (GST_CLOCK_TIME_IS_VALID (duration) && duration > 0) {
gst_query_set_duration (query, GST_FORMAT_TIME, duration);
ret = TRUE;
@ -752,7 +754,7 @@ gst_dash_demux_src_query (GstPad * pad, GstQuery * query)
if (fmt == GST_FORMAT_TIME) {
GstClockTime duration;
duration = gst_mpd_client_get_duration (dashdemux->client);
duration = gst_mpd_client_get_media_presentation_duration (dashdemux->client);
if (GST_CLOCK_TIME_IS_VALID (duration) && duration > 0)
stop = duration;
@ -1151,7 +1153,7 @@ gst_dash_demux_download_loop (GstDashDemux * demux)
* buffering time */
GstClockTime target_buffering_time =
demux->min_buffering_time +
gst_mpd_client_get_target_duration (demux->client);
gst_mpd_client_get_next_fragment_duration (demux->client);
if (demux->max_buffering_time > target_buffering_time)
target_buffering_time = demux->max_buffering_time;
if (!demux->end_of_manifest

View file

@ -83,6 +83,7 @@ static gchar *gst_mpdparser_get_initializationURL (GstURLType *InitializationURL
static gchar *gst_mpdparser_build_URL_from_template (const gchar *url_template, const gchar *id, guint number, guint bandwidth, guint time);
static gboolean gst_mpd_client_add_media_segment (GstActiveStream *stream, GstSegmentURLNode *url_node, guint number, guint start, GstClockTime start_time, GstClockTime duration);
static const gchar *gst_mpdparser_mimetype_to_caps (const gchar * mimeType);
static GstClockTime gst_mpd_client_get_segment_duration (GstMpdClient * client);
/* Adaptation Set */
static GstAdaptationSetNode *gst_mpdparser_get_first_adapt_set_with_mimeType (GList *AdaptationSets, const gchar *mimeType);
@ -2331,6 +2332,40 @@ gst_mpdparser_parse_baseURL (GstMpdClient * client)
return ret;
}
static GstClockTime
gst_mpd_client_get_segment_duration (GstMpdClient * client)
{
GstActiveStream *stream;
GstStreamPeriod *stream_period;
GstMultSegmentBaseType *base = NULL;
GstClockTime duration;
guint timescale;
stream = gst_mpdparser_get_active_stream_by_index (client, client->stream_idx);
g_return_val_if_fail (stream != NULL, GST_CLOCK_TIME_NONE);
stream_period = gst_mpdparser_get_stream_period (client);
g_return_val_if_fail (stream_period != NULL, GST_CLOCK_TIME_NONE);
if (stream->cur_segment_list) {
base = stream->cur_segment_list->MultSegBaseType;
} else if (stream->cur_seg_template) {
base = stream->cur_seg_template->MultSegBaseType;
}
if (base == NULL || base->SegBaseType == NULL) {
/* this may happen when we have a single segment */
duration = stream_period->duration;
} else {
duration = base->duration * GST_SECOND;
timescale = base->SegBaseType->timescale;
if (timescale > 1)
duration /= timescale;
}
return duration;
}
/*****************************/
/******* API functions *******/
/*****************************/
@ -2504,7 +2539,10 @@ gst_mpd_client_setup_representation (GstMpdClient * client, GstActiveStream *str
g_return_val_if_fail (stream_period->period != NULL, FALSE);
PeriodStart = stream_period->start;
PeriodEnd = stream_period->start + stream_period->duration;
if (GST_CLOCK_TIME_IS_VALID (stream_period->duration))
PeriodEnd = stream_period->start + stream_period->duration;
else
PeriodEnd = GST_CLOCK_TIME_NONE;
GST_LOG ("Building segment list for Period from %" GST_TIME_FORMAT " to %"
GST_TIME_FORMAT, GST_TIME_ARGS (PeriodStart), GST_TIME_ARGS (PeriodEnd));
@ -2573,7 +2611,9 @@ gst_mpd_client_setup_representation (GstMpdClient * client, GstActiveStream *str
}
}
} else {
duration = gst_mpd_client_get_target_duration (client);
duration = gst_mpd_client_get_segment_duration (client);
if (!GST_CLOCK_TIME_IS_VALID (duration))
return FALSE;
while (SegmentURL) {
if (!gst_mpd_client_add_media_segment (stream, SegmentURL->data, i, 0, start_time, duration)) {
@ -2638,7 +2678,9 @@ gst_mpd_client_setup_representation (GstMpdClient * client, GstActiveStream *str
}
}
} else {
duration = gst_mpd_client_get_target_duration (client);
duration = gst_mpd_client_get_segment_duration (client);
if (!GST_CLOCK_TIME_IS_VALID (duration) || !GST_CLOCK_TIME_IS_VALID (PeriodEnd))
return FALSE;
while (PeriodStart + start_time < PeriodEnd) {
if (!gst_mpd_client_add_media_segment (stream, NULL, i, 0, start_time, duration)) {
@ -2653,7 +2695,7 @@ gst_mpd_client_setup_representation (GstMpdClient * client, GstActiveStream *str
/* check duration of last segment */
last_media_segment = g_list_last (stream->segments)->data;
if (last_media_segment) {
if (last_media_segment && GST_CLOCK_TIME_IS_VALID (PeriodEnd)) {
if (last_media_segment->start_time + last_media_segment->duration > PeriodEnd) {
last_media_segment->duration = PeriodEnd - last_media_segment->start_time;
GST_LOG ("Fixed duration of last segment: %" GST_TIME_FORMAT, GST_TIME_ARGS (last_media_segment->duration));
@ -2908,12 +2950,9 @@ gst_mpd_client_get_next_fragment (GstMpdClient * client,
stream->cur_representation->id, currentChunk->number, stream->cur_representation->bandwidth, currentChunk->start);
}
gst_mpd_client_get_current_position (client, timestamp);
*duration = gst_mpd_client_get_target_duration (client);
//*timestamp = currentChunk->start_time;
//*duration = currentChunk->duration;
*timestamp = currentChunk->start_time;
*duration = currentChunk->duration;
*discontinuity = stream->segment_idx != currentChunk->number;
stream->segment_idx += 1;
if (mediaURL == NULL) {
/* single segment with URL encoded in the baseURL syntax element */
*uri = g_strdup (gst_mpdparser_get_baseURL (client));
@ -2923,6 +2962,7 @@ gst_mpd_client_get_next_fragment (GstMpdClient * client,
} else {
*uri = mediaURL;
}
stream->segment_idx += 1;
GST_MPD_CLIENT_UNLOCK (client);
GST_DEBUG ("Loading chunk with URL %s", *uri);
@ -2965,24 +3005,37 @@ gst_mpd_client_get_next_header (GstMpdClient * client, const gchar **uri, guint
return *uri == NULL ? FALSE : TRUE;
}
void
gst_mpd_client_get_current_position (GstMpdClient * client,
GstClockTime * timestamp)
GstClockTime
gst_mpd_client_get_current_position (GstMpdClient * client)
{
GstActiveStream *stream;
GstClockTime duration;
*timestamp = GST_CLOCK_TIME_NONE;
GstMediaSegment *media_segment;
stream = g_list_nth_data (client->active_streams, client->stream_idx);
g_return_if_fail (stream != NULL);
g_return_val_if_fail (stream != NULL, GST_CLOCK_TIME_NONE);
duration = gst_mpd_client_get_target_duration (client);
*timestamp = duration == GST_CLOCK_TIME_NONE ? GST_CLOCK_TIME_NONE : stream->segment_idx * duration;
media_segment = g_list_nth_data (stream->segments, stream->segment_idx);
g_return_val_if_fail (media_segment != NULL, GST_CLOCK_TIME_NONE);
return media_segment->start_time;
}
GstClockTime
gst_mpd_client_get_duration (GstMpdClient * client)
gst_mpd_client_get_next_fragment_duration (GstMpdClient * client)
{
GstActiveStream *stream;
GstMediaSegment *media_segment;
stream = g_list_nth_data (client->active_streams, client->stream_idx);
g_return_val_if_fail (stream != NULL, 0);
media_segment = g_list_nth_data (stream->segments, stream->segment_idx);
return media_segment == NULL ? 0 : media_segment->duration;
}
GstClockTime
gst_mpd_client_get_media_presentation_duration (GstMpdClient * client)
{
GstClockTime duration;
@ -3000,41 +3053,6 @@ gst_mpd_client_get_duration (GstMpdClient * client)
return duration;
}
GstClockTime
gst_mpd_client_get_target_duration (GstMpdClient * client)
{
GstActiveStream *stream;
GstStreamPeriod *stream_period;
GstMultSegmentBaseType *base = NULL;
GstClockTime duration;
guint timescale;
stream = gst_mpdparser_get_active_stream_by_index (client, client->stream_idx);
g_return_val_if_fail (stream != NULL, GST_CLOCK_TIME_NONE);
stream_period = gst_mpdparser_get_stream_period (client);
g_return_val_if_fail (stream_period != NULL, GST_CLOCK_TIME_NONE);
if (stream->cur_segment_list) {
base = stream->cur_segment_list->MultSegBaseType;
} else if (stream->cur_seg_template) {
base = stream->cur_seg_template->MultSegBaseType;
}
if (base == NULL || base->SegBaseType == NULL) {
/* this may happen when we have a single segment */
/* TODO: support SegmentTimeline */
duration = stream_period->duration;
} else {
duration = base->duration * GST_SECOND;
timescale = base->SegBaseType->timescale;
if (timescale > 1)
duration /= timescale;
}
return duration;
}
gboolean
gst_mpd_client_get_next_period (GstMpdClient *client)
{

View file

@ -467,9 +467,9 @@ gboolean gst_mpd_parse (GstMpdClient *client, const gchar *data, gint size);
gboolean gst_mpd_client_setup_media_presentation (GstMpdClient *client);
gboolean gst_mpd_client_setup_streaming (GstMpdClient *client, GstStreamMimeType mimeType, gchar* lang);
gboolean gst_mpd_client_setup_representation (GstMpdClient *client, GstActiveStream *stream, GstRepresentationNode *representation);
void gst_mpd_client_get_current_position (GstMpdClient *client, GstClockTime * timestamp);
GstClockTime gst_mpd_client_get_duration (GstMpdClient *client);
GstClockTime gst_mpd_client_get_target_duration (GstMpdClient *client);
GstClockTime gst_mpd_client_get_current_position (GstMpdClient *client);
GstClockTime gst_mpd_client_get_next_fragment_duration (GstMpdClient * client);
GstClockTime gst_mpd_client_get_media_presentation_duration (GstMpdClient *client);
gboolean gst_mpd_client_get_next_fragment (GstMpdClient *client, guint indexStream, gboolean *discontinuity, gchar **uri, GstClockTime *duration, GstClockTime *timestamp);
gboolean gst_mpd_client_get_next_header (GstMpdClient *client, const gchar **uri, guint stream_idx);
gboolean gst_mpd_client_is_live (GstMpdClient * client);