stream: add start time reporting

Will be needed to override the demuxer's start time reporting. We could
be lazy and special-case it since the result is always 0 for the streams
that care, but doing it properly is better.

stream/cache2.c

@@ -300,6 +300,7 @@ static int cache_execute_control(cache_vars_t *s) {
       double_res = s->control_double_arg;
     case STREAM_CTRL_GET_CURRENT_TIME:
     case STREAM_CTRL_GET_ASPECT_RATIO:
+    case STREAM_CTRL_GET_START_TIME:
       s->control_res = s->stream->control(s->stream, s->control, &double_res);
       s->control_double_arg = double_res;
       break;
@@ -663,6 +664,7 @@ int cache_do_control(stream_t *stream, int cmd, void *arg) {
     case STREAM_CTRL_GET_ANGLE:
     case STREAM_CTRL_GET_SIZE:
     case STREAM_CTRL_MANAGES_TIMELINE:
+    case STREAM_CTRL_GET_START_TIME:
     case -2:
       s->control = cmd;
       break;
@@ -695,6 +697,7 @@ int cache_do_control(stream_t *stream, int cmd, void *arg) {
     case STREAM_CTRL_GET_TIME_LENGTH:
     case STREAM_CTRL_GET_CURRENT_TIME:
     case STREAM_CTRL_GET_ASPECT_RATIO:
+    case STREAM_CTRL_GET_START_TIME:
       *(double *)arg = s->control_double_arg;
       break;
     case STREAM_CTRL_GET_NUM_TITLES:

stream/stream.h

@@ -103,6 +103,7 @@
 #define STREAM_CTRL_RECONNECT 18
 // DVD/Bluray, signal general support for GET_CURRENT_TIME etc.
 #define STREAM_CTRL_MANAGES_TIMELINE 19
+#define STREAM_CTRL_GET_START_TIME 20
 
 struct stream_lang_req {
     int type;     // STREAM_AUDIO, STREAM_SUB

stream/stream_dvd.c

@@ -624,6 +624,11 @@ static int control(stream_t *stream,int cmd,void* arg)
             *((double *)arg) = (double) mp_get_titleset_length(d->vts_file, d->tt_srpt, d->cur_title-1)/1000.0;
             return 1;
         }
+        case STREAM_CTRL_GET_START_TIME:
+        {
+            *((double *)arg) = 0;
+            return 1;
+        }
         case STREAM_CTRL_GET_NUM_TITLES:
         {
             *((unsigned int *)arg) = d->vmg_file->tt_srpt->nr_of_srpts;