mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-07-15 10:48:16 +00:00
hlsdemux: add more comments and document better all the threads involved
This commit is contained in:
Andoni Morales Alastruey
Sebastian Dröge
parent
8a683fc035
commit
3fa4b22149
|
|
@ -338,7 +338,7 @@ gst_hls_demux_sink_event (GstPad * pad, GstEvent * event)
|
|||
GST_BUFFER_SIZE (demux->playlist));
|
||||
gst_buffer_unref (demux->playlist);
|
||||
if (!gst_m3u8_client_update (demux->client, playlist)) {
|
||||
/* In most cases, this will happen when if we set a wrong url in the
|
||||
/* In most cases, this will happen if we set a wrong url in the
|
||||
* source element and we have received the 404 HTML response instead of
|
||||
* the playlist */
|
||||
GST_ELEMENT_ERROR (demux, STREAM, DECODE, ("Invalid playlist."), NULL);
|
||||
|
|
@ -407,14 +407,15 @@ gst_hls_demux_fetcher_chain (GstPad * pad, GstBuffer * buf)
|
|||
/* The source element can be an http source element. In case we get a 404,
|
||||
* the html response will be sent downstream and demux->downloaded_uri
|
||||
* will not be null, which might make us think that the request proceed
|
||||
* successfully. But it it will also post an error message in the bus that
|
||||
* successfully. But it will also post an error message in the bus that
|
||||
* is handled synchronously and that will set demux->fetcher_error to TRUE,
|
||||
* which is used to discard this buffer with the html response. */
|
||||
if (demux->fetcher_error) {
|
||||
goto done;
|
||||
}
|
||||
|
||||
GST_LOG_OBJECT (demux, "Received new buffer in the fecther");
|
||||
GST_LOG_OBJECT (demux, "The uri fetcher received a new buffer of size %lld",
|
||||
GST_BUFFER_SIZE (buf));
|
||||
if (demux->downloaded_uri == NULL)
|
||||
demux->downloaded_uri = buf;
|
||||
else
|
||||
|
|
@ -431,22 +432,31 @@ gst_hls_demux_stop_fetcher (GstHLSDemux * demux, gboolean cancelled)
|
|||
{
|
||||
GstPad *pad;
|
||||
|
||||
/* When the fetcher is stopped while it's downloading, we will get an EOS that
|
||||
* unblocks the fetcher thread and tries to stop it again from that thread.
|
||||
* Here we check if the fetcher as already been stopped before continuing */
|
||||
if (demux->fetcher == NULL || demux->stopping_fetcher)
|
||||
return;
|
||||
|
||||
GST_DEBUG_OBJECT (demux, "Stopping fetcher.");
|
||||
demux->stopping_fetcher = TRUE;
|
||||
/* set the element state to NULL */
|
||||
gst_element_set_state (demux->fetcher, GST_STATE_NULL);
|
||||
/* unlink it from the internal pad */
|
||||
pad = gst_pad_get_peer (demux->fetcherpad);
|
||||
if (pad) {
|
||||
gst_pad_unlink (pad, demux->fetcherpad);
|
||||
gst_object_unref (pad);
|
||||
}
|
||||
/* and finally unref it */
|
||||
gst_object_unref (demux->fetcher);
|
||||
demux->fetcher = NULL;
|
||||
|
||||
/* if we stopped it to cancell a download, free the cached buffer */
|
||||
if (cancelled && demux->downloaded_uri != NULL) {
|
||||
gst_buffer_unref (demux->downloaded_uri);
|
||||
demux->downloaded_uri = NULL;
|
||||
/* signal the fetcher thread that the download has finished/cancelled */
|
||||
g_cond_signal (demux->fetcher_cond);
|
||||
}
|
||||
}
|
||||
|
|
@ -466,13 +476,19 @@ gst_hls_demux_loop (GstHLSDemux * demux)
|
|||
GstBuffer *buf;
|
||||
GstFlowReturn ret;
|
||||
|
||||
/* cache the first fragments if we need it */
|
||||
/* Loop for the source pad task. The task is started when we have
|
||||
* received the main playlist from the source element. It tries first to
|
||||
* cache the first fragments and then it waits until it has more data in the
|
||||
* queue. This task is woken up when we push a new fragment to the queue or
|
||||
* when we reached the end of the playlist */
|
||||
|
||||
if (G_UNLIKELY (demux->need_cache)) {
|
||||
gboolean ret;
|
||||
ret = gst_hls_demux_cache_fragments (demux);
|
||||
if (!ret) {
|
||||
goto cache_error;
|
||||
}
|
||||
/* we can start now the updates thread */
|
||||
gst_hls_demux_start_update (demux);
|
||||
GST_INFO_OBJECT (demux, "First fragments cached successfully");
|
||||
}
|
||||
|
|
@ -602,6 +618,12 @@ gst_hls_demux_set_location (GstHLSDemux * demux, const gchar * uri)
|
|||
static gboolean
|
||||
gst_hls_demux_update_thread (GstHLSDemux * demux)
|
||||
{
|
||||
/* Loop for the updates. It's started when the first fragments are cached and
|
||||
* schedules the next update of the playlist (for lives sources) and the next
|
||||
* update of fragments. When a new fragment is downloaded, it compares the
|
||||
* download time with the next scheduled update to check if we can or should
|
||||
* switch to a different bitrate */
|
||||
|
||||
g_mutex_lock (demux->thread_lock);
|
||||
while (TRUE) {
|
||||
/* block until the next scheduled update or the signal to quit this thread */
|
||||
|
|
@ -622,7 +644,7 @@ gst_hls_demux_update_thread (GstHLSDemux * demux)
|
|||
gst_hls_demux_schedule (demux);
|
||||
|
||||
/* if it's a live source and the playlist couldn't be updated, there aren't
|
||||
* more fragments in the playlist so we just wait for the next schedulled
|
||||
* more fragments in the playlist, so we just wait for the next schedulled
|
||||
* update */
|
||||
if (gst_m3u8_client_is_live (demux->client) &&
|
||||
demux->client->update_failed_count > 0) {
|
||||
|
|
@ -655,8 +677,7 @@ gst_hls_demux_start_update (GstHLSDemux * demux)
|
|||
{
|
||||
GError *error;
|
||||
|
||||
/* create a new thread for the updates so that we don't block in the streaming
|
||||
* thread */
|
||||
/* creates a new thread for the updates */
|
||||
demux->updates_thread = g_thread_create (
|
||||
(GThreadFunc) gst_hls_demux_update_thread, demux, TRUE, &error);
|
||||
return (error != NULL);
|
||||
|
|
@ -678,7 +699,7 @@ gst_hls_demux_cache_fragments (GstHLSDemux * demux)
|
|||
}
|
||||
}
|
||||
|
||||
/* If this playlist is a list of playlists, select the first one
|
||||
/* If this playlist is a variant playlist, select the first one
|
||||
* and update it */
|
||||
if (gst_m3u8_client_has_variant_playlist (demux->client)) {
|
||||
GstM3U8 *child = demux->client->main->lists->data;
|
||||
|
|
@ -729,7 +750,7 @@ gst_hls_demux_fetch_location (GstHLSDemux * demux, const gchar * uri)
|
|||
if (ret == GST_STATE_CHANGE_FAILURE)
|
||||
goto state_change_error;
|
||||
|
||||
/* wait until we have fetched the element */
|
||||
/* wait until we have fetched the uri */
|
||||
GST_DEBUG_OBJECT (demux, "Waiting to fetch the URI");
|
||||
g_cond_wait (demux->fetcher_cond, demux->fetcher_lock);
|
||||
|
||||
|
|
@ -858,7 +879,7 @@ gst_hls_demux_switch_playlist (GstHLSDemux * demux)
|
|||
if (diff > limit) {
|
||||
gst_hls_demux_change_playlist (demux, TRUE);
|
||||
} else if (diff < 0) {
|
||||
/* if the client is to slow wait until it has accumulate a certain delay to
|
||||
/* if the client is too slow wait until it has accumulated a certain delay to
|
||||
* switch to a lower bitrate */
|
||||
demux->accumulated_delay -= diff;
|
||||
if (demux->accumulated_delay >= limit) {
|
||||
|
|
@ -891,7 +912,7 @@ gst_hls_demux_get_next_fragment (GstHLSDemux * demux, gboolean retry)
|
|||
return FALSE;
|
||||
|
||||
if (discont) {
|
||||
GST_DEBUG_OBJECT (demux, "Marking fragment has discontinuous");
|
||||
GST_DEBUG_OBJECT (demux, "Marking fragment as discontinuous");
|
||||
GST_BUFFER_FLAG_SET (demux->downloaded_uri, GST_BUFFER_FLAG_DISCONT);
|
||||
}
|
||||
|
||||
|
|
|
|||
Loading…
Reference in a new issue