dashdemux: change bitrates based on the stream bitrate

Do not use a global bitrate as the sizes of the fragments matter
when calculating the download rate as the connection setup time is
also being taken into the download duration, a smaller fragment
will have a lower bitrate than a larger one.

This avoids switching the bitrates for streams frequently because
of bitrate mismatches
This commit is contained in:
Thiago Santos 2013-02-05 14:22:51 -03:00
parent 770df6277a
commit 94dcb60127
2 changed files with 28 additions and 17 deletions

View file

@ -231,8 +231,7 @@ static void gst_dash_demux_pause_stream_task (GstDashDemux * demux);
static void gst_dash_demux_resume_stream_task (GstDashDemux * demux);
static void gst_dash_demux_resume_download_task (GstDashDemux * demux);
static gboolean gst_dash_demux_setup_all_streams (GstDashDemux * demux);
static gboolean gst_dash_demux_select_representations (GstDashDemux * demux,
guint64 current_bitrate);
static gboolean gst_dash_demux_select_representations (GstDashDemux * demux);
static gboolean gst_dash_demux_get_next_fragment (GstDashDemux * demux);
static void gst_dash_demux_reset (GstDashDemux * demux, gboolean dispose);
@ -1414,8 +1413,7 @@ gst_dash_demux_download_loop (GstDashDemux * demux)
/* try to switch to another set of representations if needed */
if (gst_dash_demux_all_streams_have_data (demux)) {
gst_dash_demux_select_representations (demux,
demux->bandwidth_usage * demux->dnl_rate);
gst_dash_demux_select_representations (demux);
}
/* fetch the next fragment */
@ -1526,7 +1524,7 @@ gst_dash_demux_prepare_pad_switch (GstDashDemux * demux)
/* gst_dash_demux_select_representations:
*
* Select the most appropriate media representations based on a target
* Select the most appropriate media representations based on current target
* bitrate.
*
* FIXME: all representations are selected against the same bitrate, but
@ -1537,7 +1535,7 @@ gst_dash_demux_prepare_pad_switch (GstDashDemux * demux)
* Returns TRUE if a new set of representations has been selected
*/
static gboolean
gst_dash_demux_select_representations (GstDashDemux * demux, guint64 bitrate)
gst_dash_demux_select_representations (GstDashDemux * demux)
{
GstActiveStream *active_stream = NULL;
GList *rep_list = NULL;
@ -1548,8 +1546,10 @@ gst_dash_demux_select_representations (GstDashDemux * demux, guint64 bitrate)
guint i = 0;
GST_MPD_CLIENT_LOCK (demux->client);
for (iter = demux->streams; iter; iter = g_slist_next (iter)) {
guint64 bitrate;
stream = iter->data;
active_stream =
gst_mpdparser_get_active_stream_by_index (demux->client, stream->index);
@ -1562,6 +1562,9 @@ gst_dash_demux_select_representations (GstDashDemux * demux, guint64 bitrate)
if (!rep_list)
return FALSE;
bitrate = stream->dnl_rate * demux->bandwidth_usage;
GST_DEBUG_OBJECT (demux, "Trying to change to bitrate: %llu", bitrate);
/* get representation index with current max_bandwidth */
new_index =
gst_mpdparser_get_rep_idx_with_max_bandwidth (rep_list, bitrate);
@ -1571,9 +1574,11 @@ gst_dash_demux_select_representations (GstDashDemux * demux, guint64 bitrate)
new_index = gst_mpdparser_get_rep_idx_with_min_bandwidth (rep_list);
if (new_index != active_stream->representation_idx) {
GST_INFO_OBJECT (demux, "Changing representation idx: %d", new_index);
GstRepresentationNode *rep = g_list_nth_data (rep_list, new_index);
GST_INFO_OBJECT (demux, "Changing representation idx: %d %d %u",
stream->index, new_index, rep->bandwidth);
if (gst_mpd_client_setup_representation (demux->client, active_stream,
g_list_nth_data (rep_list, new_index))) {
rep)) {
ret = TRUE;
GST_INFO_OBJECT (demux, "Switching bitrate to %d",
active_stream->cur_representation->bandwidth);
@ -1767,7 +1772,6 @@ gst_dash_demux_get_next_fragment (GstDashDemux * demux)
}
}
g_get_current_time (&start);
/* Get the fragment corresponding to each stream index */
if (selected_stream) {
guint stream_idx = selected_stream->index;
@ -1776,6 +1780,7 @@ gst_dash_demux_get_next_fragment (GstDashDemux * demux)
if (gst_mpd_client_get_next_fragment (demux->client,
stream_idx, &discont, &next_fragment_uri, &duration, &timestamp)) {
g_get_current_time (&start);
GST_INFO_OBJECT (demux, "Next fragment for stream #%i", stream_idx);
GST_INFO_OBJECT (demux,
"Fetching next fragment %s ts:%" GST_TIME_FORMAT " dur:%"
@ -1813,6 +1818,7 @@ gst_dash_demux_get_next_fragment (GstDashDemux * demux)
}
selected_stream->need_header = FALSE;
}
g_get_current_time (&now);
buffer = gst_buffer_make_metadata_writable (buffer);
@ -1837,11 +1843,15 @@ gst_dash_demux_get_next_fragment (GstDashDemux * demux)
/* Wake the download task up */
GST_TASK_SIGNAL (demux->download_task);
g_get_current_time (&now);
diff = (GST_TIMEVAL_TO_TIME (now) - GST_TIMEVAL_TO_TIME (start));
demux->dnl_rate = (size_buffer * 8) / ((double) diff / GST_SECOND);
GST_INFO_OBJECT (demux,
"Download rate = %" PRIu64 " Kbits/s (%" PRIu64 " Ko in %.2f s)",
demux->dnl_rate / 1000, size_buffer / 1024, ((double) diff / GST_SECOND));
if (selected_stream) {
diff = (GST_TIMEVAL_TO_TIME (now) - GST_TIMEVAL_TO_TIME (start));
selected_stream->dnl_rate =
(size_buffer * 8) / ((double) diff / GST_SECOND);
GST_INFO_OBJECT (demux,
"Stream: %d Download rate = %" PRIu64 " Kbits/s (%" PRIu64
" Ko in %.2f s)", selected_stream->index,
selected_stream->dnl_rate / 1000, size_buffer / 1024,
((double) diff / GST_SECOND));
}
return TRUE;
}

View file

@ -92,6 +92,9 @@ struct _GstDashDemuxStream
gboolean has_data_queued;
GstDataQueue *queue;
/* Download rate */
guint64 dnl_rate;
};
/**
@ -137,8 +140,6 @@ struct _GstDashDemux
GstClockTime position;
GstClockTime position_shift;
GstClockTime last_position_shift;
/* Download rate */
guint64 dnl_rate;
};
struct _GstDashDemuxClass