Ticket #233 (closed defect: duplicate)
Annoying video delay with multiple VP6/MP3 tracks in a .mov
|Reported by:||Adreitz||Owned by:|
Let's imagine that there is a US cable channel that often plays anime at night during a programming block that I will refer to as "AS". And let's imagine that on AS's web site, they have a streaming video service for episodes of their shows, served by a shockwave interface in .FLV format (VP6/MP3 audio and video). And let's suppose that each episode is broken up into four different files, which I download using Safari's Activity window, use Perian to open in QuickTime Player, assemble them in order in a single movie, and save (without reencoding) as a self-contained .mov file. This file will then have four audio-video track pairs, played one after another with no breaks.
When I open this file in iTunes or QT Player to play at a later time, I notice that at the beginning of each of the four sections of the file there will be a variable-length pause in the video while the audio plays normally. Sometimes it is unnoticeable, and other times the video window will sit blank for eight to ten seconds before showing again (it won't then be out of sync with the audio - it starts playing the video at the proper place). This is annoying, because I then have to rewind and replay the part I missed, and it's a possibility that the initial portion still won't load properly. And since it happens at the beginning of each track change (possibly including the beginning of the file itself), that adds to the annoyance. It would be nice if Perian would start preloading the next track before playback gets to it, to avoid the delay.
Scrubbing through the entire length of the movie will not get all of the sections to load. It seems to require that section to be played for a certain length of time, and afterward that portion will stay loaded even if playback moves to another section. So if I immediately played the file again without closing it, it would play smoothly.
Do any of the developers have a solution to this? Can anyone else reproduce this? I have not verified whether this requires VP6 video, but I suspect it at least requires a video format that QT needs Perian to play.
2x1.8 GHz G4 1.5 GB RAM 10.4.10 QT 7.2 Perian 1.0