GNOME Bugzilla – Bug 340804
fast forward and resume playback ability
Last modified: 2009-02-03 13:38:16 UTC
Hey, there are two features i would really like to see. I am not sure if these are gstreamer or application related, though. anyways, the ability to fast forward and rewind in movie files and dvds. you know like changing the speed of the playback to 2x, 4x, 8x up to about 16x the original speed. same for rewinding. the second thing is the abilitly to resume playback of a dvd at the position I stopped it and maybe closed the player application. i remember powerDVD under Windows being able to do that. are these achievable requests? i would surely appreciate it. thank you for your awesome efforts with gstreamer so far :) it's really a great project :) regards, clast
Sure, this is all doable, the design in GStreamer accommodates that at least to some extent. Fast forward can be done by sending a seek event with a 'rate' parameter > 1.0. Whether this works/is honoured depends on the elements involved. Not all elements support this properly at the moment, but those that don't should be fairly easy to fix. Fast backward playback is a bit trickier. Theoretically one should be able to do the same as above just with a negative 'rate' parameter < -1.0. In practice, there is not a single element supporting this yet though (AFAIK). This document might also be of interest: http://webcvs.freedesktop.org/gstreamer/gstreamer/docs/design/part-trickmodes.txt?view=markup Resuming playback of a dvd/film where you stopped earlier is something that should be (and can easily be) done on the application side, not in GStreamer.
thanks for your quick response. i would really like to help out here, but unfortunately, i have no clue how gstreamer works. i just have some basic C coding skills. I might forward my second request to the totem developers, though. thanks Clemens
I believe Wim (as always ;) ) has a patch for backwards playback for WAV files, as the easiest starting case. There isn't any others yet, but it's definitely on the cards. Fast forward works to some extent, in that you can request it, and it will try and play faster, but it still tries to decode every frame and saturates the cpu, because the mechanisms aren't implemented in many decoders to compensate by skipping frames. As for saving and reloading, that's easy enough for plain files - the application just needs to remember the filename and the current position. It's a little trickier than __tim suggests for DVD, because there's no mechanism to store the DVD virtual machine state, which you need in order to do a full resume later.
concerning dvds: wouldn't it be enough to remember the Titel and the current position for that titel? and when you start the application again it just needs to jump the appropriate titel and time, doesn't it? i guess, once you umount the dvd it gets even trickier. but as I said, i actually don't know anything about this kinda stuff ;)
No, that's not enough info if you want to start replaying with the language track and subtitles they've picked, plus any special playback state like the 'White Rabbit' mode of the matrix dvd.
Since 0.10.<small number> we have rate support in seeking. As for resume-playback ability ... it seems to be an application-side issue. Maybe Jan has more info about this. Otherwise this bug should be closed.
Closing this bug, since it's overly generic and hence IMHO not useful to keep around. The design should accommodate the features asked for, and for specific feature/implementation request it's better to open separate bugs for the specific component in question.