libvlc: Add a new more extensible struct libvlc_media_track_t

Due to the way this struct is allocated, it can be extended later
without breaking ABI.
Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>

include/vlc/libvlc_media.h

@@ -170,6 +170,52 @@ typedef struct libvlc_media_track_info_t
 } libvlc_media_track_info_t;
 
 
+typedef struct libvlc_audio_track_t
+{
+    unsigned    i_channels;
+    unsigned    i_rate;
+} libvlc_audio_track_t;
+
+typedef struct libvlc_video_track_t
+{
+    unsigned    i_height;
+    unsigned    i_width;
+    unsigned    i_sar_num;
+    unsigned    i_sar_den;
+    unsigned    i_frame_rate_num;
+    unsigned    i_frame_rate_den;
+} libvlc_video_track_t;
+
+typedef struct libvlc_subtitle_track_t
+{
+    char *psz_encoding;
+} libvlc_subtitle_track_t;
+
+typedef struct libvlc_media_track_t
+{
+    /* Codec fourcc */
+    uint32_t    i_codec;
+    uint32_t    i_original_fourcc;
+    int         i_id;
+    libvlc_track_type_t i_type;
+
+    /* Codec specific */
+    int         i_profile;
+    int         i_level;
+
+    union {
+        libvlc_audio_track_t *audio;
+        libvlc_video_track_t *video;
+        libvlc_subtitle_track_t *subtitle;
+    };
+
+    unsigned int i_bitrate;
+    char *psz_language;
+    char *psz_description;
+
+} libvlc_media_track_t;
+
+
 /**
  * Create a media with a certain given media resource location,
  * for instance a valid URL.
@@ -503,16 +549,51 @@ LIBVLC_API void *libvlc_media_get_user_data( libvlc_media_t *p_md );
  * before calling this function.
  * Not doing this will result in an empty array.
  *
+ * \deprecated Use libvlc_media_tracks_get instead
+ *
  * \param p_md media descriptor object
  * \param tracks address to store an allocated array of Elementary Streams
  *        descriptions (must be freed by the caller) [OUT]
  *
  * \return the number of Elementary Streams
  */
-LIBVLC_API
+LIBVLC_DEPRECATED LIBVLC_API
 int libvlc_media_get_tracks_info( libvlc_media_t *p_md,
                                   libvlc_media_track_info_t **tracks );
 
+/**
+ * Get media descriptor's elementary streams description
+ *
+ * Note, you need to call libvlc_media_parse() or play the media at least once
+ * before calling this function.
+ * Not doing this will result in an empty array.
+ *
+ * \version LibVLC 2.1.0 and later.
+ *
+ * \param p_md media descriptor object
+ * \param tracks address to store an allocated array of Elementary Streams
+ *        descriptions (must be freed with libvlc_media_tracks_release
+          by the caller) [OUT]
+ *
+ * \return the number of Elementary Streams
+ */
+LIBVLC_API
+int libvlc_media_tracks_get( libvlc_media_t *p_md,
+                             libvlc_media_track_t ***tracks );
+
+
+/**
+ * Release media descriptor's elementary streams description array
+ *
+ * \version LibVLC 2.1.0 and later.
+ *
+ * \param p_tracks tracks info array to release
+ * \param i_count number of elements in the array
+ */
+LIBVLC_API
+void libvlc_media_tracks_release( libvlc_media_track_t **p_tracks,
+                                  int i_count );
+
 /** @}*/
 
 # ifdef __cplusplus

lib/libvlc.sym

@@ -168,6 +168,8 @@ libvlc_media_set_meta
 libvlc_media_set_state
 libvlc_media_set_user_data
 libvlc_media_subitems
+libvlc_media_tracks_get
+libvlc_media_tracks_release
 libvlc_new
 libvlc_playlist_play
 libvlc_release

lib/media.c

@@ -734,3 +734,116 @@ libvlc_media_get_tracks_info( libvlc_media_t *p_md, libvlc_media_track_info_t **
     vlc_mutex_unlock( &p_input_item->lock );
     return i_es;
 }
+
+int
+libvlc_media_tracks_get( libvlc_media_t *p_md, libvlc_media_track_t *** pp_es )
+{
+    assert( p_md );
+
+    input_item_t *p_input_item = p_md->p_input_item;
+    vlc_mutex_lock( &p_input_item->lock );
+
+    const int i_es = p_input_item->i_es;
+    *pp_es = (i_es > 0) ? calloc( i_es, sizeof(**pp_es) ) : NULL;
+
+    if( !*pp_es ) /* no ES, or OOM */
+    {
+        vlc_mutex_unlock( &p_input_item->lock );
+        return 0;
+    }
+
+    /* Fill array */
+    for( int i = 0; i < i_es; i++ )
+    {
+        libvlc_media_track_t *p_mes = calloc( 1, sizeof(*p_mes) );
+        if ( p_mes )
+        {
+            p_mes->audio = malloc( __MAX(__MAX(sizeof(*p_mes->audio),
+                                               sizeof(*p_mes->video)),
+                                               sizeof(*p_mes->subtitle)) );
+        }
+        if ( !p_mes || !p_mes->audio )
+        {
+            libvlc_media_tracks_release( *pp_es, i_es );
+            *pp_es = NULL;
+            return 0;
+        }
+        (*pp_es)[i] = p_mes;
+
+        const es_format_t *p_es = p_input_item->es[i];
+
+        p_mes->i_codec = p_es->i_codec;
+        p_mes->i_original_fourcc = p_es->i_original_fourcc;
+        p_mes->i_id = p_es->i_id;
+
+        p_mes->i_profile = p_es->i_profile;
+        p_mes->i_level = p_es->i_level;
+
+        p_mes->i_bitrate = p_es->i_bitrate;
+        p_mes->psz_language = p_es->psz_language != NULL ? strdup(p_es->psz_language) : NULL;
+        p_mes->psz_description = p_es->psz_description != NULL ? strdup(p_es->psz_description) : NULL;
+
+        switch(p_es->i_cat)
+        {
+        case UNKNOWN_ES:
+        default:
+            p_mes->i_type = libvlc_track_unknown;
+            break;
+        case VIDEO_ES:
+            p_mes->i_type = libvlc_track_video;
+            p_mes->video->i_height = p_es->video.i_height;
+            p_mes->video->i_width = p_es->video.i_width;
+            p_mes->video->i_sar_num = p_es->video.i_sar_num;
+            p_mes->video->i_sar_den = p_es->video.i_sar_den;
+            p_mes->video->i_frame_rate_num = p_es->video.i_frame_rate;
+            p_mes->video->i_frame_rate_den = p_es->video.i_frame_rate_base;
+            break;
+        case AUDIO_ES:
+            p_mes->i_type = libvlc_track_audio;
+            p_mes->audio->i_channels = p_es->audio.i_channels;
+            p_mes->audio->i_rate = p_es->audio.i_rate;
+            break;
+        case SPU_ES:
+            p_mes->i_type = libvlc_track_text;
+            p_mes->subtitle->psz_encoding = p_es->subs.psz_encoding != NULL ?
+                                            strdup(p_es->subs.psz_encoding) : NULL;
+            break;
+        }
+    }
+
+    vlc_mutex_unlock( &p_input_item->lock );
+    return i_es;
+}
+
+
+/**************************************************************************
+ * Release media descriptor's elementary streams description array
+ **************************************************************************/
+void libvlc_media_tracks_release( libvlc_media_track_t **p_tracks, int i_count )
+{
+    if( !p_tracks )
+        return;
+    for( int i = 0; i < i_count; ++i )
+    {
+        if ( !p_tracks[i] )
+            continue;
+        free( p_tracks[i]->psz_language );
+        free( p_tracks[i]->psz_description );
+        switch( p_tracks[i]->i_type )
+        {
+        case libvlc_track_audio:
+            break;
+        case libvlc_track_video:
+            break;
+        case libvlc_track_text:
+            free( p_tracks[i]->subtitle->psz_encoding );
+            break;
+        case libvlc_track_unknown:
+        default:
+            break;
+        }
+        free( p_tracks[i]->audio );
+        free( p_tracks[i] );
+    }
+    free( p_tracks );
+}