[vlc-devel] [PATCH] libvlc: add function to get track id from video setup callback.

[Jerome Forissier]

This commit adds a new function to the media player interface:
libvlc_video_format_cb_get_track_id(), which may be called form the
video setup callback (libvlc_video_format_cb). It returns the ID of
the track for which the video decoder thread is creating the video
output. It is useful e.g., when playing an MP4 file with several
streams.
---
 include/vlc/libvlc_media_player.h | 8 ++++++++
 include/vlc_es.h                  | 2 ++
 lib/libvlc.sym                    | 1 +
 lib/media_player.c                | 8 ++++++++
 modules/video_output/vmem.c       | 3 +++
 src/input/decoder.c               | 1 +
 6 files changed, 23 insertions(+)

diff --git a/include/vlc/libvlc_media_player.h b/include/vlc/libvlc_media_player.h
index fb91f59..75e7577 100644
--- a/include/vlc/libvlc_media_player.h
+++ b/include/vlc/libvlc_media_player.h
@@ -393,6 +393,14 @@ void libvlc_video_set_format_callbacks( libvlc_media_player_t *mp,
                                         libvlc_video_cleanup_cb cleanup );
 
 /**
+ * Return the track ID of the video stream for which @ref libvlc_video_format_cb
+ * is being called. This function is valid only when called from the setup
+ * callback.
+ */
+LIBVLC_API
+int libvlc_video_format_cb_get_track_id( void **opaque );
+
+/**
  * Set the NSView handler where the media player should render its video output.
  *
  * Use the vout called "macosx".
diff --git a/include/vlc_es.h b/include/vlc_es.h
index 38d63da..536883e 100644
--- a/include/vlc_es.h
+++ b/include/vlc_es.h
@@ -202,6 +202,8 @@ struct video_format_t
     int i_rbshift, i_lbshift;
     video_palette_t *p_palette;              /**< video palette from demuxer */
     video_orientation_t orientation;                /**< picture orientation */
+
+    int i_dec_es_id;                  /**< elementary stream ID from decoder */
 };
 
 /**
diff --git a/lib/libvlc.sym b/lib/libvlc.sym
index fdfd164..f24ad30 100644
--- a/lib/libvlc.sym
+++ b/lib/libvlc.sym
@@ -199,6 +199,7 @@ libvlc_toggle_fullscreen
 libvlc_toggle_teletext
 libvlc_track_description_release
 libvlc_track_description_list_release
+libvlc_video_format_cb_get_track_id
 libvlc_video_get_adjust_float
 libvlc_video_get_adjust_int
 libvlc_video_get_aspect_ratio
diff --git a/lib/media_player.c b/lib/media_player.c
index 868aefe..54c7cd1 100644
--- a/lib/media_player.c
+++ b/lib/media_player.c
@@ -861,6 +861,14 @@ void libvlc_video_set_format_callbacks( libvlc_media_player_t *mp,
     var_SetAddress( mp, "vmem-cleanup", cleanup );
 }
 
+/**************************************************************************
+ * Get track id from opaque pointer passed to libvlc_video_format_cb.
+ **************************************************************************/
+int libvlc_video_format_cb_get_track_id( void **opaque )
+{
+    return *(int *)(opaque + 1);
+}
+
 void libvlc_video_set_format( libvlc_media_player_t *mp, const char *chroma,
                               unsigned width, unsigned height, unsigned pitch )
 {
diff --git a/modules/video_output/vmem.c b/modules/video_output/vmem.c
index 2575f75..8acfcb1 100644
--- a/modules/video_output/vmem.c
+++ b/modules/video_output/vmem.c
@@ -92,6 +92,8 @@ struct vout_display_sys_t {
     unsigned        count;
 
     void *opaque;
+    int  track_id; /* Keep at (int *)(opaque + 1) --
+                      see libvlc_video_format_cb_get_track_id() */
     void *(*lock)(void *sys, void **plane);
     void (*unlock)(void *sys, void *id, void *const *plane);
     void (*display)(void *sys, void *id);
@@ -136,6 +138,7 @@ static int Open(vlc_object_t *object)
     sys->display = var_InheritAddress(vd, "vmem-display");
     sys->cleanup = var_InheritAddress(vd, "vmem-cleanup");
     sys->opaque = var_InheritAddress(vd, "vmem-data");
+    sys->track_id = vd->fmt.i_dec_es_id;
     sys->pool = NULL;
 
     /* Define the video format */
diff --git a/src/input/decoder.c b/src/input/decoder.c
index 46129fc..892a3c7 100644
--- a/src/input/decoder.c
+++ b/src/input/decoder.c
@@ -2060,6 +2060,7 @@ static picture_t *vout_new_buffer( decoder_t *p_dec )
 
         video_format_t fmt = p_dec->fmt_out.video;
         fmt.i_chroma = p_dec->fmt_out.i_codec;
+        fmt.i_dec_es_id = p_dec->fmt_in.i_id;
         p_owner->video = fmt;
 
         if( vlc_fourcc_IsYUV( fmt.i_chroma ) )
-- 
1.8.1.5