Differenze tra le versioni di "Ottenere la durata di un file Midi con le funzioni esterne del API di VLC"
Da Gambas-it.org - Wikipedia.
Riga 59: | Riga 59: | ||
'''End''' | '''End''' | ||
+ | |||
==Uso della funzione esterna "libvlc_media_player_get_length()"== | ==Uso della funzione esterna "libvlc_media_player_get_length()"== | ||
+ | Si potrà utilizzare anche la funzione "libvlc_media_player_get_length()". L'uso di tale funzione esterna, però, è preferibile nel caso di contestuale esecuzione di un file Midi. | ||
+ | |||
+ | Mostriamo un esempio pratico: | ||
+ | Library "libvlc:5.6.0" | ||
+ | |||
+ | 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_path (libvlc_instance_t *p_instance, const char *path) | ||
+ | ' Create a media for a certain file path. | ||
+ | Private Extern libvlc_media_new_path(p_instance As Pointer, path 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 | ||
+ | |||
+ | ' int libvlc_media_player_play (libvlc_media_player_t * p_mi) | ||
+ | ' Play the audio file. | ||
+ | Private Extern libvlc_media_player_play(p_mi As Pointer) As Integer | ||
+ | |||
+ | ' libvlc_time_t libvlc_media_player_get_length(libvlc_media_player_t *, libvlc_exception_t *) | ||
+ | ' Get the current movie length (in ms). | ||
+ | Private Extern libvlc_media_player_get_length(p_mi As Pointer, l_ex As Pointer) As Integer | ||
+ | |||
+ | ' 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. | ||
+ | Private Extern libvlc_media_player_release(p_mi As Pointer) | ||
+ | |||
+ | ' 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) | ||
+ | |||
+ | ' 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) | ||
+ | |||
+ | |||
+ | '''Public''' Sub Main() | ||
+ | |||
+ | Dim inst, md, mp As Pointer | ||
+ | Dim lg, dd As Integer | ||
+ | Dim tm As Date | ||
+ | |||
+ | inst = libvlc_new(0, Null) | ||
+ | |||
+ | md = libvlc_media_new_path(inst, "/home/ploppo/Musica/MIDI/Fausto Leali - Se Qualcuno Cercasse Di Te.mid") | ||
+ | |||
+ | ' Crea un media player: | ||
+ | mp = libvlc_media_player_new_from_media(md) | ||
+ | |||
+ | libvlc_media_player_play(mp) | ||
+ | |||
+ | Repeat | ||
+ | lg = libvlc_media_player_get_length(mp, 0) | ||
+ | Until lg > 0 | ||
+ | |||
+ | tm = Now | ||
+ | |||
+ | Repeat | ||
+ | dd = DateDiff(tm, Now, gb.Millisecond) | ||
+ | Write "\e[0m\r" & "Durata: " & Str(Time(0, 0, 0, lg)) & | ||
+ | " - \e[31m" & Str(Time(0, 0, 0, dd)) | ||
+ | Until dd >= lg | ||
+ | |||
+ | libvlc_media_player_release(mp) | ||
+ | libvlc_media_release(md) | ||
+ | libvlc_release(inst) | ||
+ | |||
+ | '''End''' | ||
+ | |||
<B><FONT Color=Red size=4>Paragrafo in costruzione !</font></b> | <B><FONT Color=Red size=4>Paragrafo in costruzione !</font></b> |
Versione delle 18:59, 26 giu 2021
Per ottenere la durata di un file Midi con l'API di VLC, è possibile utilizzare due funzioni esterne.
E' necessario avere installata nel sistema e richiamare nel programma Gambas la libreria condivisa: "libvlc.so.5.6.0 ".
Uso della funzione esterna "libvlc_media_get_duration()"
Mostriamo un esempio con il semplice uso della funzione esterna "libvlc_media_get_duration()":
Library "libvlc:5.6.0" Private Enum libvlc_media_parse_local = 0, libvlc_media_parse_network, libvlc_media_fetch_local, libvlc_media_fetch_network = 4, libvlc_media_do_interact = 8 ' 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_path (libvlc_instance_t *p_instance, const char *path) ' Create a media for a certain file path. Private Extern libvlc_media_new_path(p_instance As Pointer, path As String) As Pointer ' int libvlc_media_parse_with_options (libvlc_media_t *p_md, libvlc_media_parse_flag_t parse_flag, int timeout) ' Parse the media asynchronously with options. Private Extern libvlc_media_parse_with_options(p_md As Pointer, parse_flag As Integer, timeout As Integer) As Integer ' libvlc_time_t libvlc_media_get_duration(libvlc_media_t *p_md) ' Get duration (in ms) of media descriptor object item. Private Extern libvlc_media_get_duration(p_md As Pointer) As Long ' 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) ' 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) Public Sub Main() Dim inst, md As Pointer Dim tm As Long inst = libvlc_new(0, Null) md = libvlc_media_new_path(inst, "/percorso/del/file.mid") libvlc_media_parse_with_options(md, libvlc_media_parse_local, 0) Repeat tm = libvlc_media_get_duration(md) Until tm > 0 Print "Durata: "; Time(0, 0, 0, tm) libvlc_media_release(md) libvlc_release(inst) End
Uso della funzione esterna "libvlc_media_player_get_length()"
Si potrà utilizzare anche la funzione "libvlc_media_player_get_length()". L'uso di tale funzione esterna, però, è preferibile nel caso di contestuale esecuzione di un file Midi.
Mostriamo un esempio pratico:
Library "libvlc:5.6.0" 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_path (libvlc_instance_t *p_instance, const char *path) ' Create a media for a certain file path. Private Extern libvlc_media_new_path(p_instance As Pointer, path 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 ' int libvlc_media_player_play (libvlc_media_player_t * p_mi) ' Play the audio file. Private Extern libvlc_media_player_play(p_mi As Pointer) As Integer ' libvlc_time_t libvlc_media_player_get_length(libvlc_media_player_t *, libvlc_exception_t *) ' Get the current movie length (in ms). Private Extern libvlc_media_player_get_length(p_mi As Pointer, l_ex As Pointer) As Integer ' 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. Private Extern libvlc_media_player_release(p_mi As Pointer) ' 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) ' 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) Public Sub Main() Dim inst, md, mp As Pointer Dim lg, dd As Integer Dim tm As Date inst = libvlc_new(0, Null) md = libvlc_media_new_path(inst, "/home/ploppo/Musica/MIDI/Fausto Leali - Se Qualcuno Cercasse Di Te.mid") ' Crea un media player: mp = libvlc_media_player_new_from_media(md) libvlc_media_player_play(mp) Repeat lg = libvlc_media_player_get_length(mp, 0) Until lg > 0 tm = Now Repeat dd = DateDiff(tm, Now, gb.Millisecond) Write "\e[0m\r" & "Durata: " & Str(Time(0, 0, 0, lg)) & " - \e[31m" & Str(Time(0, 0, 0, dd)) Until dd >= lg libvlc_media_player_release(mp) libvlc_media_release(md) libvlc_release(inst) End
Paragrafo in costruzione !