extracting sound and video and putting them back together can I do this and how
#1
Posted 27 March 2007 - 10:08 AM
I have no idea how to do that and whether toast will do it, or quicktime, or what other program I would need, and to what format I should write it too. This is really pushing the envelope.
#2
Posted 27 March 2007 - 01:31 PM
Now if you clicked the burn button or chose Save as Disc Image Toast would multiplex the audio and video together in the video DVD's VOB files.
Putting audio and video together is called multiplexing. As for audio being out of sync with video that can be due to a large number of variables.
What kind of audio does your project have?
#3
Posted 27 March 2007 - 05:58 PM
Most disturbing. Should I use streamclip and export to an ac3? But how do I align the two so it is in synch.
#4
Posted 27 March 2007 - 09:31 PM
Most disturbing. Should I use streamclip and export to an ac3? But how do I align the two so it is in synch.
I'd still like to know what kind of audio was in the original video. If you drag the source VOB to Streamclip and choose Show Stream Info from the File menu. How does it describe the audio? For that matter, how does it describe the video?
You've been through a nightmare with all this and it shouldn't have been anywhere near this hard. You even mentioned the need to repair time code breaks. I'm wondering what was used to create the original DVD and what were the audio and video specs.
#5
Posted 28 March 2007 - 06:14 AM
So this is what I have now that is out of synch:
Video Tracks:
224 MPEG-2, 720 × 480, 4:3, 29.97 fps, 6.50 Mbps, upper field first
Audio Tracks:
128 AC3 2/0, 48 kHz, 224 kbps
This is what the mpeg streamclip created from the orginal is :
Duration: 3:14:03
Data Size: 4.22 GB
Bit Rate: 3.11 Mbps
Video Tracks:
224 MPEG-2, 720 × 576, 4:3, 25 fps, 6.50 Mbps, upper field first
Audio Tracks:
128 AC3 2/0, 48 kHz, 224 kbps
This is what the orginal I have is: But remember orginal did not play continously and had some pauses even on computer. I thought the breaks in timecode would fix that. And indeed the mpeg created by streamclip does play well and all is in synch.
Duration: 0:00:03
Data Size: 394.42 MB
Bit Rate: 861.63 Mbps (?)
Video Tracks:
224 MPEG-2, 720 × 576, 4:3, 25 fps, 6.50 Mbps, upper field first
Audio Tracks:
128 AC3 2/0, 48 kHz, 224 kbps
So that is it. Except I might mention that I am having problems with my quicktime, It is not producing any sound on my computer, but vlc is. I think it is just a problem with qt but I can not find it, although that might make it impossible for me to use that to synch tracks. And synching tracks sounds incrediably difficult.
#6
Posted 28 March 2007 - 06:36 AM
Duration: 0:25:10
Data Size: 1008.28 MB
Bit Rate: 5.60 Mbps
#7
Posted 28 March 2007 - 11:48 AM
Here are its details from streamclip:
Type: MPEG elementary stream
Duration: 3:14:04
Data Size: 8.17 GB
Bit Rate: 6.02 Mbps
Video Tracks:
224 MPEG-2, 720 × 480, 4:3, 29.97 fps, 6.50 Mbps, upper field first
Audio Tracks:
Notice the difference in data size and the size of the file listed in finder.
I wonder if I change the extension to mp2 it will turn into an audio file?
I am thinking of using streamclip to demux the .toast file to an ac3, and then using that and the converted items m2v file (because that one plays steady) and putting them together somehow. But I can not let toast just do it, or it will be out of synch. I also need to cut out the first vob, and part of the next, as they are relics of a menu which does not work. I imagine that then I would have to cut part of the audio, also.
To accomplish all this I am going to need room. I have an external drive which was DOS and the file structure seems to have been lost to the point where OSX can not read it. ( Seems to be a recurring problem with usb devices) There is data on it that I want, but I want to finish this nightmare.
So I am anxious to hear your advice, before I continue.
#8
Posted 28 March 2007 - 04:28 PM
But I doubt it will be in sync. My guess is that something about needing those time code breaks fixed in Streamclip made it so the video and audio were not the same length after Toast did the transcoding to NTSC. I'm just guessing, though.
By the way, QuickTime can't play AC3 audio without a special codec so your experience with it playing no audio is normal.
I really don't know what to suggest to you. One option is to trash it all and go back to the source. Have Streamclip repair timecode breaks and also use Streamclip to cut the video at some place near the middle. The idea is to create two DVDs. Then export the first half of the video using the Demux to M2V and AC3 setting. You know how to work with Toast from those exports. Because the file will be less than 2 hours long it will fit a single-layer disc at Toast's default encoding settings. After getting the first disc finished, go back to Streamclip and do the same thing for the second half of the video. Hopefully this attempt will produce audio that is in sync.
Now you'll tell me the whole thing must be on a single disc. But this too is possible after you've created the two disc images with the first and second parts.
Or you can just buy a DVD player that converts PAL to NTSC on the fly while it plays your source disc on your TV and forget you ever wanted to do this.
#9
Posted 28 March 2007 - 04:38 PM
Is there something I can use to make the audio fit the video?
Where can I get what I need to make quicktime play ac3 and what is it that I am looking for?
#10
Posted 28 March 2007 - 04:56 PM
Is there something I can use to make the audio fit the video?
Where can I get what I need to make quicktime play ac3 and what is it that I am looking for?
Give this Codec a try for playing back the AC3 audio.
There's nothing that will put the audio back in sync. That's because both the video and audio are compressed so there is no way to adjust the length of one or the other. There is some interesting info about sync issues Here.
#11
Posted 29 March 2007 - 06:17 AM
What sound could I use that streamclip would create and quicktime can use? aiff?
You are right the sound file from mpeg is much larger than the m2v from converted items, in terms of duration. Pretty much hopeless, but I have not stopped trying yet.
CAn't I uncompress them and change them to match?
#12
Posted 30 March 2007 - 06:56 AM
What sound could I use that streamclip would create and quicktime can use? aiff?
You are right the sound file from mpeg is much larger than the m2v from converted items, in terms of duration. Pretty much hopeless, but I have not stopped trying yet.
CAn't I uncompress them and change them to match?
You're right. Adding that codec doesn't enable AC3 playback in QuickTime. I thought it would. I never use QuickTime to play those because VLC does the job.
I've fooled around trying to get audio and video in sync and I never succeeded.
So I've struck out on both your requests for how to play AC3 audio in QuickTime and how to correct an audio sync issue after re-encoding the video.
#13
Posted 02 April 2007 - 08:15 AM
I have been away for a few days, and so I have not had the chance to thank you for all the help you have given me so far. I do appreciate it and it is valuable. I am fooling around with the files and will let you know if I have any success.
If you find something, please let me know.
#14
Posted 15 April 2007 - 03:37 PM
Hi, I don't want to confuse the process, but I am having similar trouble. Tsantee posted a link about audio-synch problems (http://miraizon.com/...faq.html#3sync), and that seems to have explained what my problem is, but I'm wondering if any of you know how to solve it.
I've got a PAL source with AC3 audio, and I want to burn an NTSC dvd with it. I ran the file through FFmpegx, and I was able to get audio when I burned the .mpv file, but it was out of synch. Any suggestions?
Am I going about this all wrong?
Thanks in advance!
-uli
#15
Posted 15 April 2007 - 10:03 PM
Hi, I don't want to confuse the process, but I am having similar trouble. Tsantee posted a link about audio-synch problems (http://miraizon.com/...faq.html#3sync), and that seems to have explained what my problem is, but I'm wondering if any of you know how to solve it.
I've got a PAL source with AC3 audio, and I want to burn an NTSC dvd with it. I ran the file through FFmpegx, and I was able to get audio when I burned the .mpv file, but it was out of synch. Any suggestions?
Am I going about this all wrong?
Thanks in advance!
-uli
Have you also tried using Toast to convert the PAL to NTSC instead of using FFmpegx?

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