Problem with captured video - plays back too fast

[Killer37]

I've just got this program again via TrialPay as I want to record a live stream, that I'm pretty sure only runs in RTMP. The website in question is http://www.livestream.com/ and i'm planning to capture a live stream for an hour on Friday. To be best prepared I thought I'd test it out with some of their other videos, assuming they will be streamed in the same way. RMC captures them ok, but obviously since i'm just testing, I stop capturing after a minute and save. RMC says the file was only partly captured, which I assume is fine.

Now the problem comes with the outputted FLV file. It plays fine in the Applian FLV player, but in an other player everything runs twice as fast, so the video is too fast and the audio garbled.

I've also tried converting the video to various formats using the inbuilt option, and whilst the outputted video now has correct speed audio, the video is still running in fast forward.

So, what is the reason for that, and how can I fix it? Is it because i'm cutting off the live broadcast, and when i actually capture a stream until it stops itself i'll be ok?

Thanks.

[carlobee]

i've never tried cutting off a live broadcast either. what other FLV players did you use by the way?

http://storeyourpicture.com/images/signature_videoStreaming.jpg

[Killer37]

VLC Media Player and another one that I forget the name of, but it came with another stream capture program I tried.

I think what i'll do is try and record another live stream and just leave it going until it finishes.

[Edgarc]

I experienced pretty much the same phenomenon.
I captured a stream (probably RTMP) of a live webcast to the end (over an hour), then did the standard save (as FLV). [Some error appeared after the save, but the file seemed OK so I didn't make note of it.]
I converted this to MP4 for iPod viewing, and when opened in VLC, the video track played twice as fast as the audio, with the video going blank half-way through while the audio played on.
Later I tried playing the original FLV, and found the same phenomenon, but strangely, after trying to tweak some playback parameters, the video still plays back at 2x normal speed but now the audio lasts only as long as the video but sounds very choppy (like fast forwarding through an MP3 during playback, with half the audio being skipped over). I tried other players, and while all play the video at 2x normal speed, some play the audio at normal speed (i.e. lasting 2x as long as the video) while others "squeeze" the audio to match the video duration, with the choppy playback effect.
The saved FLV frame rate is 20 fps, but the original stream was almost certainly only 10 fps.
Is there some way to reset the frame rate to 10 fps without otherwise altering the video? Thanks for any insights anyone can provide.

[Edgarc]

Continuing from above:
In another thread, I found the error message that came up when the captured stream was being saved as FLV.
For details, see the thread entitled:
''RMC closes when downloading live videos. Error: Sorry, could only download a partial RTMP stream''
The error for me (experienced on 3 separate stream captures -- all with same results as described in my above post) was pretty much similar, although I did not save the details.
Thanks.

[Edgarc]

As an experiment, I demuxed the FLV using FLV_Extract to rip out the audio track, then played the original FLV using VLC (which permits on-the-fly adjustment of playback speed) while playing the audio separately using QuickTime Player. The audio played back normally, and to keep the video in sync, I had to adjust it to somewhere between 54% and 57% of its "normal" speed.

So if there is some way to get the video track slowed while maintaining the normal audio track playback speed, and mux it all back together again, it should play fine.
Wish I knew how to do that...

[Edgarc]

Pardon the tiny increments in information...
I tried playing the original FLV using FLVPlayer, and to my astonishment, it played with audio and video in PERFECT sync! VLC and other players always fail with the file...
However, when I use replay converter to try to get an MP4 for my iPod, the video is after all shortened (speeded up) severely, while the audio just plays at the normal speed.
So since I cannot use FLVPlayer on my iPod (or my pre-Intel Mac), the problem remains...

Now I'm thinking that I may have to play the file with FLVPlayer, use Replay Video Capture to grab from the screen, then convert the result of that...talk about roundabout transcoding....

Any suggestions will be appreciated!

[stream-recorder.com]

Pardon the tiny increments in information...
I tried playing the original FLV using FLVPlayer, and to my astonishment, it played with audio and video in PERFECT sync! VLC and other players always fail with the file...
However, when I use replay converter to try to get an MP4 for my iPod, the video is after all shortened (speeded up) severely, while the audio just plays at the normal speed.
So since I cannot use FLVPlayer on my iPod (or my pre-Intel Mac), the problem remains...
Try to extract audio and video with freeware FLV Extract and mux them into MP4 with freeware mp4box GUI. This is fast and doesn't need any conversion, but since not only MPEG-4 video codec can be used in an .FLV container, you may have problems playing some videos on your iPod.

[Edgarc]

Thank you, stream-recorder.com, for that advice. I used MP4Box, and the resulting MP4 file is a big improvement. Now the video and audio seem to be about the same speed, but they are out of sync a little, with the video maybe 1.5 sec ahead of the audio. Using VLC, I can use the Track Synchronization tool to shift the video 1.500 sec later.
So the next task: how to get the original file properly in sync so I don't have to manually tweak it in VLC at each playback -- any ideas here?
(Maybe MP4Box has such a function, but I can't find any documentation.)

I am grateful for help here!

Thank you

[Edgarc]

Oops, I forgot to mention that I did not use MP4Box directly, but via YAMB, and the documentation I cannot find is documentation for YAMB. (I actually have not looked at the MP4Box documentation.)
Sorry for any confusion.

Thanks for your help!

[stream-recorder.com]

Using the delay in mp4box:

-delay trackID=TIME : sets track start-time offset, specified in milliseconds.

Adding a 1500 ms delay to the first track in input.mp4:


MP4Box -delay 1=1500 input.mp4

or

MP4Box -delay 1=1500 input.mp4 -out output.mp4


Yamb should be able to do that as well :) See the properties of the track that needs to be delayed.

[Edgarc]

Thanks much! I will give it a try next chance.
Best,
Edgar

[conchchowder]

Tasha, from Aplian, posted a link to this page but there is no Applian solution...no, "We're working on it" or anything. The program should simply "work" without having to download an(other) program(s) to make THIS one work.
Not good, Applian.