splitmux: Rewrite buffer collection and scheduling

Majorly change the way that splitmuxsink collects
incoming data and sends it to the output, so that it
makes all decisions about when / where to split files
on the input side.

Use separate queues for each stream, so they can be
grown individually and kept as small as possible.

This removes raciness I observed where sometimes
some data would end up put in a different output file
over multiple runs with the same input.

Also fixes hangs with input queues getting full
and causing muxing to stall out.

gst/multifile/gstsplitmuxsink.h

@@ -24,26 +24,39 @@
 #include <gst/pbutils/pbutils.h>
 
 G_BEGIN_DECLS
-
 #define GST_TYPE_SPLITMUX_SINK               (gst_splitmux_sink_get_type())
 #define GST_SPLITMUX_SINK(obj)               (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_SPLITMUX_SINK,GstSplitMuxSink))
 #define GST_SPLITMUX_SINK_CLASS(klass)       (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_SPLITMUX_SINK,GstSplitMuxSinkClass))
 #define GST_IS_SPLITMUX_SINK(obj)            (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_SPLITMUX_SINK))
 #define GST_IS_SPLITMUX_SINK_CLASS(klass)    (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_SPLITMUX_SINK))
-
 typedef struct _GstSplitMuxSink GstSplitMuxSink;
 typedef struct _GstSplitMuxSinkClass GstSplitMuxSinkClass;
 
-GType gst_splitmux_sink_get_type(void);
+GType gst_splitmux_sink_get_type (void);
 gboolean register_splitmuxsink (GstPlugin * plugin);
 
-typedef enum _SplitMuxState {
-  SPLITMUX_STATE_STOPPED,
-  SPLITMUX_STATE_COLLECTING_GOP_START,
-  SPLITMUX_STATE_WAITING_GOP_COMPLETE,
-  SPLITMUX_STATE_ENDING_FILE,
-  SPLITMUX_STATE_START_NEXT_FRAGMENT,
-} SplitMuxState;
+typedef enum _SplitMuxInputState
+{
+  SPLITMUX_INPUT_STATE_STOPPED,
+  SPLITMUX_INPUT_STATE_COLLECTING_GOP_START,    /* Waiting for the next ref ctx keyframe */
+  SPLITMUX_INPUT_STATE_WAITING_GOP_COLLECT,     /* Waiting for all streams to collect GOP */
+  SPLITMUX_INPUT_STATE_FINISHING_UP             /* Got EOS from reference ctx, send everything */
+} SplitMuxInputState;
+
+typedef enum _SplitMuxOutputState
+{
+  SPLITMUX_OUTPUT_STATE_STOPPED,
+  SPLITMUX_OUTPUT_STATE_AWAITING_COMMAND,       /* Waiting first command packet from input */
+  SPLITMUX_OUTPUT_STATE_OUTPUT_GOP,     /* Outputting a collected GOP */
+  SPLITMUX_OUTPUT_STATE_ENDING_FILE,    /* Finishing the current fragment */
+  SPLITMUX_OUTPUT_STATE_START_NEXT_FILE /* Restarting after ENDING_FILE */
+} SplitMuxOutputState;
+
+typedef struct _SplitMuxOutputCommand
+{
+  gboolean start_new_fragment;  /* Whether to start a new fragment before advancing output ts */
+  GstClockTimeDiff max_output_ts;       /* Set the limit to stop GOP output */
+} SplitMuxOutputCommand;
 
 typedef struct _MqStreamBuf
 {
@@ -59,6 +72,7 @@ typedef struct _MqStreamCtx
 
   GstSplitMuxSink *splitmux;
 
+  guint q_overrun_id;
   guint sink_pad_block_id;
   guint src_pad_block_id;
 
@@ -67,6 +81,7 @@ typedef struct _MqStreamCtx
   gboolean flushing;
   gboolean in_eos;
   gboolean out_eos;
+  gboolean need_unblock;
 
   GstSegment in_segment;
   GstSegment out_segment;
@@ -74,26 +89,24 @@ typedef struct _MqStreamCtx
   GstClockTimeDiff in_running_time;
   GstClockTimeDiff out_running_time;
 
-  guint64 in_bytes;
-
+  GstElement *q;
   GQueue queued_bufs;
 
   GstPad *sinkpad;
   GstPad *srcpad;
 
-  gboolean out_blocked;
-
   GstBuffer *cur_buffer;
   GstEvent *pending_gap;
 } MqStreamCtx;
 
-struct _GstSplitMuxSink {
+struct _GstSplitMuxSink
+{
   GstBin parent;
 
   GMutex lock;
-  GCond data_cond;
+  GCond input_cond;
+  GCond output_cond;
 
-  SplitMuxState state;
   gdouble mux_overhead;
 
   GstClockTime threshold_time;
@@ -101,9 +114,6 @@ struct _GstSplitMuxSink {
   guint max_files;
   gboolean send_keyframe_requests;
 
-  guint mq_max_buffers;
-
-  GstElement *mq;
   GstElement *muxer;
   GstElement *sink;
 
@@ -112,25 +122,39 @@ struct _GstSplitMuxSink {
   GstElement *provided_sink;
   GstElement *active_sink;
 
+  gboolean ready_for_output;
+
   gchar *location;
   guint fragment_id;
 
   GList *contexts;
 
-  MqStreamCtx *reference_ctx;
-  guint queued_gops;
+  SplitMuxInputState input_state;
   GstClockTimeDiff max_in_running_time;
+  /* Number of bytes sent to the
+   * current fragment */
+  guint64 fragment_total_bytes;
+  /* Number of bytes we've collected into
+   * the GOP that's being collected */
+  guint64 gop_total_bytes;
+  /* Start time of the current fragment */
+  GstClockTimeDiff fragment_start_time;
+  /* Start time of the current GOP */
+  GstClockTimeDiff gop_start_time;
+
+  GQueue out_cmd_q;             /* Queue of commands for output thread */
+
+  SplitMuxOutputState output_state;
   GstClockTimeDiff max_out_running_time;
+  GstClockTimeDiff next_max_out_running_time;
 
   GstClockTimeDiff muxed_out_time;
   guint64 muxed_out_bytes;
-  gboolean have_muxed_something;
-  gboolean update_mux_start_time;
 
-  GstClockTimeDiff mux_start_time;
-  guint64 mux_start_bytes;
+  MqStreamCtx *reference_ctx;
+  /* Count of queued keyframes in the reference ctx */
+  guint queued_keyframes;
 
-  gboolean opening_first_fragment;
   gboolean switching_fragment;
 
   gboolean have_video;
@@ -139,10 +163,10 @@ struct _GstSplitMuxSink {
   gboolean async_pending;
 };
 
-struct _GstSplitMuxSinkClass {
+struct _GstSplitMuxSinkClass
+{
   GstBinClass parent_class;
 };
 
 G_END_DECLS
-
 #endif /* __GST_SPLITMUXSINK_H__ */