demux: remove tracking of number of forward buffered packets

In ancient times, the number of packets was used to limit excessive
read-ahead. This was completely replaced by tracking the size in bytes.
The number of packets was used in debugging output only.

In one case (packet got demuxed and is added to a queue), only log
whether there were packets on this stream before. (Unknown whether it's
useful.)

In another case (queue overflow), actually count the number of packets.
It's vaguely useful, and the message with the number of packets is shown
only once after a seek reset, so it doesn't matter whether it's slow.

1 files changed, 10 insertions, 14 deletions

diff --git a/demux/demux.c b/demux/demux.c
index 7c340fdd4b..f0512e5859 100644
--- a/demux/demux.c
+++ b/demux/demux.c
@@ -333,7 +333,6 @@ struct demux_stream {
     double last_br_ts;      // timestamp of last packet bitrate was calculated
     size_t last_br_bytes;   // summed packet sizes since last bitrate calculation
     double bitrate;
-    size_t fw_packs;        // number of packets in buffer (forward)
     size_t fw_bytes;        // total bytes of packets in buffer (forward)
     struct demux_packet *reader_head;   // points at current decoder position
     bool skip_to_keyframe;
@@ -415,7 +414,6 @@ static void check_queue_consistency(struct demux_internal *in)
             assert(queue->range == range);
 
             size_t fw_bytes = 0;
-            size_t fw_packs = 0;
             bool is_forward = false;
             bool kf_found = false;
             bool npt_found = false;
@@ -429,7 +427,6 @@ static void check_queue_consistency(struct demux_internal *in)
                 total_bytes += bytes;
                 if (is_forward) {
                     fw_bytes += bytes;
-                    fw_packs += 1;
                     assert(range == in->current_range);
                     assert(queue->ds->queue == queue);
                 }
@@ -458,9 +455,8 @@ static void check_queue_consistency(struct demux_internal *in)
 
             if (range == in->current_range) {
                 assert(queue->ds->fw_bytes == fw_bytes);
-                assert(queue->ds->fw_packs == fw_packs);
             } else {
-                assert(fw_bytes == 0 && fw_packs == 0);
+                assert(fw_bytes == 0);
             }
 
             if (queue->keyframe_latest)
@@ -530,12 +526,10 @@ static void mp_packet_tags_make_writable(struct mp_packet_tags **tags)
 
 static void recompute_buffers(struct demux_stream *ds)
 {
-    ds->fw_packs = 0;
     ds->fw_bytes = 0;
 
     for (struct demux_packet *dp = ds->reader_head; dp; dp = dp->next) {
         ds->fw_bytes += demux_packet_estimate_total_size(dp);
-        ds->fw_packs++;
     }
 }
 
@@ -631,7 +625,7 @@ broken:
     range->seek_start = range->seek_end = MP_NOPTS_VALUE;
 }
 
-// Remove queue->head from the queue. Does not update in->fw_bytes/in->fw_packs.
+// Remove queue->head from the queue. Does not update in->fw_bytes.
 static void remove_head_packet(struct demux_queue *queue)
 {
     struct demux_packet *dp = queue->head;
@@ -728,7 +722,6 @@ static void ds_clear_reader_queue_state(struct demux_stream *ds)
     ds->in->fw_bytes -= ds->fw_bytes;
     ds->reader_head = NULL;
     ds->fw_bytes = 0;
-    ds->fw_packs = 0;
     ds->eof = false;
     ds->need_wakeup = true;
 }
@@ -1811,7 +1804,6 @@ static void add_packet_locked(struct sh_stream *stream, demux_packet_t *dp)
     size_t bytes = demux_packet_estimate_total_size(dp);
     in->total_bytes += bytes;
     if (ds->reader_head) {
-        ds->fw_packs++;
         ds->fw_bytes += bytes;
         in->fw_bytes += bytes;
     }
@@ -1841,9 +1833,10 @@ static void add_packet_locked(struct sh_stream *stream, demux_packet_t *dp)
     if (ds->base_ts == MP_NOPTS_VALUE)
         ds->base_ts = queue->last_ts;
 
+    const char *num_pkts = queue->head == queue->tail ? "1" : ">1";
     MP_TRACE(in, "append packet to %s: size=%d pts=%f dts=%f pos=%"PRIi64" "
-             "[num=%zd size=%zd]\n", stream_type_name(stream->type),
-             dp->len, dp->pts, dp->dts, dp->pos, ds->fw_packs, ds->fw_bytes);
+             "[num=%s size=%zd]\n", stream_type_name(stream->type),
+             dp->len, dp->pts, dp->dts, dp->pos, num_pkts, ds->fw_bytes);
 
     adjust_seek_range_on_packet(ds, dp);
 
@@ -1950,9 +1943,13 @@ static bool read_packet(struct demux_internal *in)
             for (int n = 0; n < in->num_streams; n++) {
                 struct demux_stream *ds = in->streams[n]->ds;
                 if (ds->selected) {
+                    size_t num_pkts = 0;
+                    for (struct demux_packet *dp = ds->reader_head;
+                         dp; dp = dp->next)
+                        num_pkts++;
                     MP_WARN(in, "  %s/%d: %zd packets, %zd bytes%s%s\n",
                             stream_type_name(ds->type), n,
-                            ds->fw_packs, ds->fw_bytes,
+                            num_pkts, ds->fw_bytes,
                             ds->eager ? "" : " (lazy)",
                             ds->refreshing ? " (refreshing)" : "");
                 }
@@ -2201,7 +2198,6 @@ static struct demux_packet *advance_reader_head(struct demux_stream *ds)
     ds->reader_head = pkt->next;
 
     // Update cached packet queue state.
-    ds->fw_packs--;
     size_t bytes = demux_packet_estimate_total_size(pkt);
     ds->fw_bytes -= bytes;
     ds->in->fw_bytes -= bytes;