sub: preload external text subtitles

If a subtitle is external, read it completely and add all subtitle
events in advance when the subtitle track is selected. This is done
for text subtitles only. (Note that subreader.c and subtitles loaded
with libass are different and don't have anything to do with this
commit.)

2 files changed, 38 insertions, 1 deletions

diff --git a/demux/demux.c b/demux/demux.c
index d9b41e2c99..23c4a28706 100644
--- a/demux/demux.c
+++ b/demux/demux.c
@@ -40,7 +40,8 @@
 
 #include "audio/format.h"
 
-#include "libavcodec/avcodec.h"
+#include <libavcodec/avcodec.h>
+
 #if MP_INPUT_BUFFER_PADDING_SIZE < FF_INPUT_BUFFER_PADDING_SIZE
 #error MP_INPUT_BUFFER_PADDING_SIZE is too small!
 #endif
@@ -183,6 +184,41 @@ void free_demux_packet(struct demux_packet *dp)
     talloc_free(dp);
 }
 
+static int destroy_avpacket(void *pkt)
+{
+    av_free_packet(pkt);
+    return 0;
+}
+
+struct demux_packet *demux_copy_packet(struct demux_packet *dp)
+{
+    struct demux_packet *new = NULL;
+    // No av_copy_packet() in Libav
+#if LIBAVCODEC_VERSION_MICRO >= 100
+    if (dp->avpacket) {
+        assert(dp->buffer == dp->avpacket->data);
+        assert(dp->len == dp->avpacket->size);
+        AVPacket *newavp = talloc_zero(NULL, AVPacket);
+        talloc_set_destructor(newavp, destroy_avpacket);
+        av_init_packet(newavp);
+        if (av_copy_packet(newavp, dp->avpacket) < 0)
+            abort();
+        new = new_demux_packet_fromdata(newavp->data, newavp->size);
+        new->avpacket = newavp;
+    }
+#endif
+    if (!new) {
+        new = new_demux_packet(dp->len);
+        memcpy(new->buffer, dp->buffer, new->len);
+    }
+    new->pts = dp->pts;
+    new->duration = dp->duration;
+    new->stream_pts = dp->stream_pts;
+    new->pos = dp->pos;
+    new->keyframe = dp->keyframe;
+    return new;
+}
+
 static void free_demuxer_stream(struct demux_stream *ds)
 {
     ds_free_packs(ds);
diff --git a/demux/demux.h b/demux/demux.h
index 9ec6d0c6f0..a82fbea91a 100644
--- a/demux/demux.h
+++ b/demux/demux.h
@@ -291,6 +291,7 @@ struct demux_packet *new_demux_packet_fromdata(void *data, size_t len);
 struct demux_packet *new_demux_packet_from(void *data, size_t len);
 void resize_demux_packet(struct demux_packet *dp, size_t len);
 void free_demux_packet(struct demux_packet *dp);
+struct demux_packet *demux_copy_packet(struct demux_packet *dp);
 
 #ifndef SIZE_MAX
 #define SIZE_MAX ((size_t)-1)