ffmpeg2.8: add OpenPHT patches

1 files changed, 47 insertions, 0 deletions

diff --git a/abs/extra/ffmpeg2.8/ffmpeg-Speed_up_wtv_index_creation.patch b/abs/extra/ffmpeg2.8/ffmpeg-Speed_up_wtv_index_creation.patch
new file mode 100644
index 0000000..d829898
--- /dev/null
+++ b/abs/extra/ffmpeg2.8/ffmpeg-Speed_up_wtv_index_creation.patch
@@ -0,0 +1,47 @@
+commit 0e7427498cb1131671f6fe9d054245ae7e5a36f5
+Author: popcornmix <popcornmix@gmail.com>
+Date:   Tue Mar 25 19:43:07 2014 +0000
+
+    [ffmpeg] Speed up wtv index creation
+
+    The index creation is O(N^2) with number of entries (typically thousands).
+    On a Pi this can take more than 60 seconds to execute for a recording of a few hours.
+
+    By replacing with an O(N) loop, this takes virtually zero time
+
+diff --git a/libavformat/wtvdec.c b/libavformat/wtvdec.c
+index e423370..70898bd 100644
+--- a/libavformat/wtvdec.c
++++ b/libavformat/wtvdec.c
+@@ -980,21 +980,23 @@ static int read_header(AVFormatContext *s)
+                 pb = wtvfile_open(s, root, root_size, ff_timeline_table_0_entries_Events_le16);
+                 if (pb) {
+                     int i;
++                    AVIndexEntry *e = wtv->index_entries;
++                    AVIndexEntry *e_end = wtv->index_entries + wtv->nb_index_entries - 1;
++                    uint64_t last_position = 0;
+                     while (1) {
+                         uint64_t frame_nb = avio_rl64(pb);
+                         uint64_t position = avio_rl64(pb);
++                        while (frame_nb > e->size && e <= e_end) {
++                           e->pos = last_position;
++                           e++;
++                        }
+                         if (avio_feof(pb))
+                             break;
+-                        for (i = wtv->nb_index_entries - 1; i >= 0; i--) {
+-                            AVIndexEntry *e = wtv->index_entries + i;
+-                            if (frame_nb > e->size)
+-                                break;
+-                            if (position > e->pos)
+-                                e->pos = position;
+-                        }
++                        last_position = position;
+                     }
++                    e_end->pos = last_position;
+                     wtvfile_close(pb);
+-                    st->duration = wtv->index_entries[wtv->nb_index_entries - 1].timestamp;
++                    st->duration = e_end->timestamp;
+                 }
+             }
+         }