H264/MP4 Seek Problem

Cyberpro60 · 13th May 2011, 12:55

Over the last few weeks I have been bugged by an apparently new problem with .MP4 files which I haven't been able to resolve in spite of not inconsiderable research and effort:

Basically my problem is that some of my newer H264/.MP4 movies seem to play and seek perfectly whereas others will play perfectly but will fall over immediately upon encountering a seek request.

When I say "fall over" this could mean anything from a total player freeze/crash to several minutes of delay whilst the player moves slowly to the desired frames and starts playing again. This delay can be as long as 15 minutes for a longer, movie length, HD video file.

Note: It doesn't seem to matter what player I am using either as VLC, MPlayer, MPC all seem to have this same "seek" problem.

My research has determined the following:

1. If I mux my source .H264/AAC files into an .MKV container then all these videos will BOTH play and seek perfectly in all players - so this seems to be a "container problem"!

2. If I mux or remux into .MP4 format using either MeGui, AviDemux, Yamb etc I end up with a video that plays but which won't seek.

3. I have even re-encoded my source videos using a variety of H264 front ends but all these videos will not seek properly when played in .MP4 format but will work perfectly when muxed to .MKV format.

4. I have "remuxed" my videos with a range of muxing software but this has not resolved this issue.

5. These exact same problems arise on a range of other computers that I have tested so this is not a "machine specific" issue. Ego, this is some inherent problem with these specific MP4 files.

6. I note that I do not seem to be having any of these problems with MP4 files encoded several months ago. All the problem videos are fairly recent (ie within the last three or four months)

I would be grateful if anybody can throw any light on this issue and suggest a fix or workaround.

13th May 2011, 12:55	#1 \| Link
Cyberpro60 Registered User Join Date: Dec 2006 Posts: 40	H264/MP4 Seek Problem Over the last few weeks I have been bugged by an apparently new problem with .MP4 files which I haven't been able to resolve in spite of not inconsiderable research and effort: Basically my problem is that some of my newer H264/.MP4 movies seem to play and seek perfectly whereas others will play perfectly but will fall over immediately upon encountering a seek request. When I say "fall over" this could mean anything from a total player freeze/crash to several minutes of delay whilst the player moves slowly to the desired frames and starts playing again. This delay can be as long as 15 minutes for a longer, movie length, HD video file. Note: It doesn't seem to matter what player I am using either as VLC, MPlayer, MPC all seem to have this same "seek" problem. My research has determined the following: 1. If I mux my source .H264/AAC files into an .MKV container then all these videos will BOTH play and seek perfectly in all players - so this seems to be a "container problem"! 2. If I mux or remux into .MP4 format using either MeGui, AviDemux, Yamb etc I end up with a video that plays but which won't seek. 3. I have even re-encoded my source videos using a variety of H264 front ends but all these videos will not seek properly when played in .MP4 format but will work perfectly when muxed to .MKV format. 4. I have "remuxed" my videos with a range of muxing software but this has not resolved this issue. 5. These exact same problems arise on a range of other computers that I have tested so this is not a "machine specific" issue. Ego, this is some inherent problem with these specific MP4 files. 6. I note that I do not seem to be having any of these problems with MP4 files encoded several months ago. All the problem videos are fairly recent (ie within the last three or four months) I would be grateful if anybody can throw any light on this issue and suggest a fix or workaround.