Replay sound after it is ended

[Pap]

Greetings VideoLAN community,
being a fan of VLC player for years now, I decided to use libVLC for developing multimedia applications. Note that I am only interested on sound playback for now. Compared to other APIs, I found libVLC to be much easier to use. I am also developing Fortran 2003/2008 bindings for libVLC, which work pretty well.

However, I have a problem concerning sound replay; specifically, I can initialize a libvlc_media_player_t struct, with libvlc_media_player_new_from_media(), which is played as expected with libvlc_media_player_play(). Once the sound is "ended" (as verified with libvlc_media_player_get_state()), I cannot replay the sound. Any further call of libvlc_media_player_play() produces no sound at all. The only way I found to replay a sound once it is ended is to call libvlc_media_player_stop() first, then call libvlc_media_player_play(), in which case the sound is replayed. I am probably missing something important here, as I don't see why I should stop a sound that is already ended in order to replay it.

The problem is irrelevant to said Fortran bindings, as it appears in C/C++ programs as well. It is also irrelevant to the operating system, as it appears in both Debian Linux 64-bit, and Windows 7 (32-bit) applications. I am using libVLC 2.1.2 (Rincewind).

[Jean-Baptiste Kempf]

This is weird. Please share your logs.

[Pap]

The following simple program demonstrates the problem:

Code: Select all

#include <iostream> #include <vlc/vlc.h> int main(void) { libvlc_instance_t *vlc_instance; libvlc_media_t *media; libvlc_media_player_t *player; char ch; vlc_instance = libvlc_new(0, NULL); media = libvlc_media_new_path(vlc_instance,"sample.ogg"); player = libvlc_media_player_new_from_media(media); libvlc_media_release(media); libvlc_media_player_play(player); // Play the sound. std::cin>>ch; // This is to delay program execution until the sound is "ended". std::cout<<"Media player state: "<<libvlc_media_player_get_state(player) <<std::endl; // libvlc_media_player_stop(player); libvlc_media_player_play(player); // Try to replay the sound. std::cin>>ch; libvlc_media_player_release(player); libvlc_release(vlc_instance); return 0; }

The media player is played normally with the first call of libvlc_media_player_play(), while the program is waiting for a character to be entered by the user (with std::cin>>ch). I wait for the sound to be played, then I enter a character to continue. The call of libvlc_media_player_get_state() is there to ensure the sound is "ended". Indeed, reported state is 6, which, according to libvlc_state_t documentation, corresponds to "ENDED". Now, the second call of libvlc_media_player_play() produces no sound at all. The only way to hear the sound again is to uncomment the call of libvlc_media_player_stop() in the above code. So, it seems I cannot replay a media player, even if it's ended, unless I stop the media player first. This is weird, and I think I might be missing something important here.

Note that I have similar issues with other functions such as libvlc_audio_set_volume() and libvlc_audio_set_channel(), which won't work as expected. For example, libvlc_audio_set_volume() doesn't change the volume unless I stop the media player first.