Ottenere informazioni generali da un flusso web audio-video con le risorse del API di VLC

Con le risorse del API di VLC è possibile ottenere alcune informazioni generali di un video trasmesso da una web-TV.

Mostriamo un esempio pratico:

Library "libvlc:5.6.1"

Public Struct video_track_t
  i_height As Integer
  i_width As Integer
  i_sar_num As Integer
  i_sar_den As Integer
  i_frame_rate_num As Integer
  i_frame_rate_den As Integer
  i_orientation As Integer
  i_projection As Integer
  f_yaw As Single
  f_pitch As Single
  f_roll As Single
  f_field_of_view As Single
  i_multiview As Byte
End Struct

' libvlc_instance_t * libvlc_new (int argc, const char *const *argv)
' Create And initialize a libvlc instance.
Private Extern libvlc_new(argc As Integer, argv As String[]) As Pointer

' libvlc_media_t * libvlc_media_new_location (libvlc_instance_t *p_instance, const char *psz_mrl)
' Create a media with a certain given media resource location.
Private Extern libvlc_media_new_location(p_instance As Pointer, psz_mrl As String) As Pointer

' libvlc_media_player_t * libvlc_media_player_new_from_media (libvlc_media_t *p_md)
' Create a Media Player object from a Media.
Private Extern libvlc_media_player_new_from_media(p_md As Pointer) As Pointer

' char* libvlc_media_get_meta (libvlc_media_t * p_md, libvlc_meta_t e_meta)
' Read the meta of the media.
Private Extern libvlc_media_get_meta(p_md As Pointer, e_meta As Integer) As String

' int libvlc_media_player_play (libvlc_media_player_t * p_mi)
' Play the video file.
Private Extern libvlc_media_player_play(p_mi As Pointer) As Integer

' unsigned libvlc_media_tracks_get (libvlc_media_t * p_md, libvlc_media_track_t *** tracks)
' Get media descriptor's elementary streams description.
Private Extern libvlc_media_tracks_get(p_md As Pointer, tracks As Pointer) As Integer

' const char * libvlc_media_get_codec_description (libvlc_track_type_t i_type, uint32_t i_codec)
' Get codec description from media elementary stream.
Private Extern libvlc_media_get_codec_description(i_type As Integer, i_codec As Integer) As String

' void libvlc_media_release (libvlc_media_t *p_md)
' Decrement the reference count of a media descriptor object.
Private Extern libvlc_media_release(p_md As Pointer)

' void libvlc_media_player_release (libvlc_media_player_t * p_mi)
' Release a media_player after use Decrement the reference count of a media player object.le risorse del API di
Private Extern libvlc_media_player_release(p_mi As Pointer)

' libvlc_release (libvlc_instance_t * p_instance)
' Decrement the reference count of a libvlc instance, and destroy it if it reaches zero.
Private Extern libvlc_release(p_instance As Pointer)