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TICKET ARCHIVE -> Quality of Audio After Importing In Imovie
gerard karelse - May 27, 2005 - 8:16 am
I am struggling to get a good audio quality. After importing from a DV camcorder (Canon XM1) or from my JVC DV deck there is something like a digital hickup in the sound. I cannot get rid of it, although I changed both in the Canon and in the JVC to 16 bits audio (my first guess about the origin of the problem) Not all my footage is handicaped this way, most stuff is allright. In this particular case I made a copy on my deck from a Video DVD (no copy rights) to import 3 minutes in my iMovie project. I work with iMovie 5, Tiger on a new Powerbook G4.
I am certainly not an expert but also not a beginner as far as audio/video is concerned and Mac (studied the missing manual about iMovie and iDVD).
I don't want to consider for the time being to import(ripp) the Video TS files directly and convert them into iMovie format if you understand my English.
looking forward to get your response, Gerard Karelse, the Netherlands.
I
I am certainly not an expert but also not a beginner as far as audio/video is concerned and Mac (studied the missing manual about iMovie and iDVD).
I don't want to consider for the time being to import(ripp) the Video TS files directly and convert them into iMovie format if you understand my English.
looking forward to get your response, Gerard Karelse, the Netherlands.
I
Drumhum - May 27, 2005 - 11:58 am
Hi Gerard,
I'm Tom and I will try and help you. Thanks for using Macosx.com.
To help I need to know where the audio problem is occuring.
After you copied the DVD to you JVC deck, what was the audio quality like from the deck. Can you just have a listen via headphones direct from the JVC? Is the sound good at this stage?
How are you connecting the equipment - eg is the dvd to JVC via scart, phonos etc?
I take it the JVC is connected to your mac via firewire.
Can you give more details as to what the sound is like? Could it be the sound is recorded too loud and you are hearing digital clipping? If this is the case you may find the sound from the JVC is better than the Mac as some playback systems can mask clipping better than others. Even so you should be able to detect if anything is wrong on the JVC deck.
have a think and get back to me.
Regards
Tom
--------
gerard karelse - May 29, 2005 - 1:05 pm
Tom, thanks for your assistance. I will try to fill you in about the details.
First of all: the sound on the DV tape (the copy) is excellent. I made the copy from the DVD player on my JVC DV deck with a firewire interface. After importing it to iMovie and playing it back I hear a kind of hickup. The problem is how to describe it, because I am not familiar with the digital audio problems. For one thing: it occurs not constantly but intermittent. It could be clipping (but I didn't change anything as far as volume is concerned) it could be also a result of a sync problem, anyway it is typical a digital conversion problem as far as I can judge. I experienced the same problems with some of my video stuff which originated from a DV tape I made from an old analogue tape (the conversion was also made with my JVC double deck e.g the DV tape was a copy of on old analogue or Hi8 tape)
The tape I made with my JVC deck I did put in my Canon to import the tape into iMovie (because my JVC deck is not in the same place where I do my editing.
Thanks in advance, Gerard.
First of all: the sound on the DV tape (the copy) is excellent. I made the copy from the DVD player on my JVC DV deck with a firewire interface. After importing it to iMovie and playing it back I hear a kind of hickup. The problem is how to describe it, because I am not familiar with the digital audio problems. For one thing: it occurs not constantly but intermittent. It could be clipping (but I didn't change anything as far as volume is concerned) it could be also a result of a sync problem, anyway it is typical a digital conversion problem as far as I can judge. I experienced the same problems with some of my video stuff which originated from a DV tape I made from an old analogue tape (the conversion was also made with my JVC double deck e.g the DV tape was a copy of on old analogue or Hi8 tape)
The tape I made with my JVC deck I did put in my Canon to import the tape into iMovie (because my JVC deck is not in the same place where I do my editing.
Thanks in advance, Gerard.
Drumhum - May 29, 2005 - 2:13 pm
Hi gerard,
To summarize your problem, it seems you have a perfect recording on DV tape which plays back perfectly. When you capture the footage in imovie you get an audio glitch of some sort.
If you always use your camera to play footage into your computer then I feel it would be wise to try your JVC deck. Sometimes a DV tape can play fine in one machine and not in another. Cameras are not good units for playback - all engineering will be focused on recording not payback. This is particularly the case for cheap or domestic cameras.
Whatever you use to feed the footage to the computer try listening to the audio with headphones from the playback machine (ie NOT via the computer). This way if you hear a glitch then you know it is being caused during capture and not some file-writing issue on your computer.
If an audio glitch occurs then try capturing again just around the point of the problem (say 1 minute of footage where the glitch occured at 30sec). Does the glitch happen again at the same place?
Try a different firewire cable. Some do not work well! Make sure it is good quality.
Make sure your camera is powered by mains, not battery. I have seen this to cause problems.
If we can rule out the camera or JVC deck as being at fault then we must look to the computer. Typical reasons for bad capture for any video application is hard drive space and RAM. You must have plenty of hard drive space for video. I consider a disk drive to be "full" when there is 10% space left - eg 10GB left on a 100GB drive. This gives breathing room for the system. Video apps need LOTS of RAM. I would recommend at least 1GB.
Make sure no other application on your computer is running when you capture - especially applications that do things in the background such as Virus checking software, email apps, disk-checking apps etc
Are you using the laptop's internal disk drive? If so, if possible try using an external firewire disk. If you are using an external firewire disk then try disconnecting it and capturing to the internal drive.
In summary, the main test should be:
Make sure your computer is running no other software, is disconnected from any network or internet and has plenty of hard disk space. Capture the footage while listening on headphones which are connected to the playback machine. Note exactly where a glitch occurs (if it does) so that you can try and capture around that spot later.
There are still other things to consider but have a think about these points first and let me know how you get on.
Sorry if I'm rambling a little but there is a lot to consider!
Regards
Tom
To summarize your problem, it seems you have a perfect recording on DV tape which plays back perfectly. When you capture the footage in imovie you get an audio glitch of some sort.
If you always use your camera to play footage into your computer then I feel it would be wise to try your JVC deck. Sometimes a DV tape can play fine in one machine and not in another. Cameras are not good units for playback - all engineering will be focused on recording not payback. This is particularly the case for cheap or domestic cameras.
Whatever you use to feed the footage to the computer try listening to the audio with headphones from the playback machine (ie NOT via the computer). This way if you hear a glitch then you know it is being caused during capture and not some file-writing issue on your computer.
If an audio glitch occurs then try capturing again just around the point of the problem (say 1 minute of footage where the glitch occured at 30sec). Does the glitch happen again at the same place?
Try a different firewire cable. Some do not work well! Make sure it is good quality.
Make sure your camera is powered by mains, not battery. I have seen this to cause problems.
If we can rule out the camera or JVC deck as being at fault then we must look to the computer. Typical reasons for bad capture for any video application is hard drive space and RAM. You must have plenty of hard drive space for video. I consider a disk drive to be "full" when there is 10% space left - eg 10GB left on a 100GB drive. This gives breathing room for the system. Video apps need LOTS of RAM. I would recommend at least 1GB.
Make sure no other application on your computer is running when you capture - especially applications that do things in the background such as Virus checking software, email apps, disk-checking apps etc
Are you using the laptop's internal disk drive? If so, if possible try using an external firewire disk. If you are using an external firewire disk then try disconnecting it and capturing to the internal drive.
In summary, the main test should be:
Make sure your computer is running no other software, is disconnected from any network or internet and has plenty of hard disk space. Capture the footage while listening on headphones which are connected to the playback machine. Note exactly where a glitch occurs (if it does) so that you can try and capture around that spot later.
There are still other things to consider but have a think about these points first and let me know how you get on.
Sorry if I'm rambling a little but there is a lot to consider!
Regards
Tom
gerard karelse - May 29, 2005 - 2:39 pm
Hi Tom,
Your summary is OK.
I guess my camera is not the source, because it is doing fine with other material and besides it was an expensive machine (Canon XM1).
For sure I will try to import directly from my JVC, may be it makes a difference. It will take some time, because I have to move my equipment.
I have for sure enough hard drive space. I use an external drive which has more then 200 Gb available. Also I will try another firewire cable, this also will take some time (shopping). Also no other applications are running while I am importing footage. I will also listen to the plauback machine while I am importing as you suggested and I will figure out if the glitch will occur at the same place by importing it once more around the spot of the glitch (or whatever it is (-:
I let you know, thanks a lot for your fast response. I am not desperate only suicidal (-:
Gerard.
Your summary is OK.
I guess my camera is not the source, because it is doing fine with other material and besides it was an expensive machine (Canon XM1).
For sure I will try to import directly from my JVC, may be it makes a difference. It will take some time, because I have to move my equipment.
I have for sure enough hard drive space. I use an external drive which has more then 200 Gb available. Also I will try another firewire cable, this also will take some time (shopping). Also no other applications are running while I am importing footage. I will also listen to the plauback machine while I am importing as you suggested and I will figure out if the glitch will occur at the same place by importing it once more around the spot of the glitch (or whatever it is (-:
I let you know, thanks a lot for your fast response. I am not desperate only suicidal (-:
Gerard.
gerard karelse - May 30, 2005 - 3:15 pm
Hi Tom,
I am still very eager to find the origin of my audio problem, but meanwhile I managed to import a particular piece of a professionally made DVD into my iMovie project.
(After studying internet sources of course)
I made of copy of the DVD with versiontracker (freeware) on my harddisk and then I made a conversion to MPEG4 with Handbrake (also freeware). Funny, because the developer of this sophisticated piece of software mentioned that his software is not suitable for make 'imports' to iMovie.
I will inform you about the results of the experiments you suggested. Please understand that, now that I can continue with my iMovie project this has not a top priority anymore.
regards, Gerard.
I am still very eager to find the origin of my audio problem, but meanwhile I managed to import a particular piece of a professionally made DVD into my iMovie project.
(After studying internet sources of course)
I made of copy of the DVD with versiontracker (freeware) on my harddisk and then I made a conversion to MPEG4 with Handbrake (also freeware). Funny, because the developer of this sophisticated piece of software mentioned that his software is not suitable for make 'imports' to iMovie.
I will inform you about the results of the experiments you suggested. Please understand that, now that I can continue with my iMovie project this has not a top priority anymore.
regards, Gerard.
Drumhum - May 30, 2005 - 4:51 pm
gerard,
Glad you are back on track with your work.
for the record, iMovie is quite happy importing MPEG 4, However imovie will convert this to the DV codec (that you have set in preferences). It would improve picture quality if you could avoid the MPEG 4 conversion and encode mpeg2 to dv.
Just a thought. ;-)
regards
Tom
Glad you are back on track with your work.
for the record, iMovie is quite happy importing MPEG 4, However imovie will convert this to the DV codec (that you have set in preferences). It would improve picture quality if you could avoid the MPEG 4 conversion and encode mpeg2 to dv.
Just a thought. ;-)
regards
Tom
gerard karelse - May 31, 2005 - 6:50 am
Hi Tom
This is very interesting! Can you tell me how to avoid MPEG4. This Handbrake utility has only two options as far as I can see: AVI and MPEG4.
AVI doesn't work.
regards, Gerard.
This is very interesting! Can you tell me how to avoid MPEG4. This Handbrake utility has only two options as far as I can see: AVI and MPEG4.
AVI doesn't work.
regards, Gerard.
Drumhum - May 31, 2005 - 12:16 pm
Hi Gerard,
I'm not familiar with Handbreak myself but after a little look on versiontracker I see its soul function is to rip DVD to MPEG4. To go to DV from DVD you will obviously need different software to Handbreak.
After more snooping on versiontracker.com and found this:
http://www.kaisakura.com/fortytwovx.php
might be useful. it looks like you can convert to quicktime (and therefore the DV codec). I think it's shareware.
I've never used this software though.
If you do further searches on google etc I'm sure you'll find other useful stuff.
I hope that helps a little!
regards
Tom
I'm not familiar with Handbreak myself but after a little look on versiontracker I see its soul function is to rip DVD to MPEG4. To go to DV from DVD you will obviously need different software to Handbreak.
After more snooping on versiontracker.com and found this:
http://www.kaisakura.com/fortytwovx.php
might be useful. it looks like you can convert to quicktime (and therefore the DV codec). I think it's shareware.
I've never used this software though.
If you do further searches on google etc I'm sure you'll find other useful stuff.
I hope that helps a little!
regards
Tom
gerard karelse - Jun 1, 2005 - 12:25 pm
Hi Tom,
You are a genius. I never figured out that could be the solution. The first experiment I did was succesful: I did import the footage from the tape with my JVC deck into my iMovie project and the audio quality is OK now. Although I am disapointed in my Canon XM1 camera and I have to carry around my JVC deck in the future to import footage into my Powerbook I thank you a lot!
I will also buy the software you suggested.
best regards, Gerard (NL).
You are a genius. I never figured out that could be the solution. The first experiment I did was succesful: I did import the footage from the tape with my JVC deck into my iMovie project and the audio quality is OK now. Although I am disapointed in my Canon XM1 camera and I have to carry around my JVC deck in the future to import footage into my Powerbook I thank you a lot!
I will also buy the software you suggested.
best regards, Gerard (NL).
Drumhum - Jun 1, 2005 - 12:56 pm
Gerard,
genius eh? Flattery will get you everywhere!
Glad we've identified the problem.
Don't be too disappointed with your camera. You will find the same problems with cameras costing 10 times more than yours!
Also bare in mind that using the camera as a playback/edit machine is not good for the camera. It is nowhere near as robust as a dedicated DV deck. A quick way of wearing out your camera is to use it as a playback machine!
Glad to be of service
All the best
Tom
genius eh? Flattery will get you everywhere!
Glad we've identified the problem.
Don't be too disappointed with your camera. You will find the same problems with cameras costing 10 times more than yours!
Also bare in mind that using the camera as a playback/edit machine is not good for the camera. It is nowhere near as robust as a dedicated DV deck. A quick way of wearing out your camera is to use it as a playback machine!
Glad to be of service
All the best
Tom
gerard karelse - Jun 1, 2005 - 3:22 pm
Hi Tom,
One last question if it all possible. You know a lot more then I do.
Do you know an efficient way to filter or eliminate the lower frequencies from some parts in my iMovie project.(I forgot to enable the windshield and now I have 'rumble' from the wind in the microphone.) May be I can transfer the piece to Quicktime and use the audio freq. analyzer, save it and import it back into my iMovie project. I am curious about your suggestions, about the steps I have to take without sacrificing picture quality.
regards, Gerard.
One last question if it all possible. You know a lot more then I do.
Do you know an efficient way to filter or eliminate the lower frequencies from some parts in my iMovie project.(I forgot to enable the windshield and now I have 'rumble' from the wind in the microphone.) May be I can transfer the piece to Quicktime and use the audio freq. analyzer, save it and import it back into my iMovie project. I am curious about your suggestions, about the steps I have to take without sacrificing picture quality.
regards, Gerard.
Drumhum - Jun 1, 2005 - 6:23 pm
hi Gerard,
Firstly I must admit to not being a big iMovie user. I have access to more pro end systems so as cool as imovie is I just don't use it much. As far as I am aware you can't do much with audio other than cutting, trimming, volume etc so if you need to do more advanced editing, such as cutting out unwanted bass then you will have to take the audio out of iMovie and edit it in another application. Just as you suggested you could use quicktime to do this. Use the a/v controls (from the "Window" menu) to turn down the bass and then save it as a "self contained" file. I'm not sure what you mean by the "audio freq. analyzer" - perhaps you can explain for me.
Quicktime is still rather limiting though and a basic audio editing app would be better. It would be worth looking on google for shareware stuff (eg "audio editor Mac")
Another quick fix would be to use Garage band. there are better controls for audio here than in imovie. There is even a control to specifically reduce bass called "bass reduction". I've just had a play with it and I think this would sort you out perfectly!
As for the picture quality suggestion, I presume you are referring to when I was talking about MPEG4 and dvd ripping. I think I may have confused the issue a little. I hadn't realised that iMovie can edit in MPEG4. I thought it would convert any mpeg4 movies to DV first - my mistake! Sorry.
However, whenever a movie is converted to a compressed codec then quality suffers (DV, MPEG1,2,4 are all compressed - in fact most codecs compress the data). Some codecs do not convert to other codecs very well either. I felt that going from Mpeg2 (DVD) to MPEG4 to DV was not the best route for image quality. Skipping MPEG4 and going straight to DV would be better.
Its worth noting though that even if you are editing footage in mpeg4, if you are then outputting to DV tape then you are having that extra conversion again! Ideally if you are outputting to DV then you should be editing in DV. Even a transition can cause a reduction in picture quality as you are re-encoding two DV movie streams - and that extra encode process means reduction in picture quality. Its hard (often impossible) to notice though admittedly!
Don't worry too much about this - if the picture looks ok to you, then all is well. Its a subject important to pro users, broadcasters etc and it is complicated! This is why iMovie is so great as it hides so much of the complicated technology.
I hope this clears things up a bit for you. feel free to get back to me if there is anything else I can do for you.
regards
Tom
Firstly I must admit to not being a big iMovie user. I have access to more pro end systems so as cool as imovie is I just don't use it much. As far as I am aware you can't do much with audio other than cutting, trimming, volume etc so if you need to do more advanced editing, such as cutting out unwanted bass then you will have to take the audio out of iMovie and edit it in another application. Just as you suggested you could use quicktime to do this. Use the a/v controls (from the "Window" menu) to turn down the bass and then save it as a "self contained" file. I'm not sure what you mean by the "audio freq. analyzer" - perhaps you can explain for me.
Quicktime is still rather limiting though and a basic audio editing app would be better. It would be worth looking on google for shareware stuff (eg "audio editor Mac")
Another quick fix would be to use Garage band. there are better controls for audio here than in imovie. There is even a control to specifically reduce bass called "bass reduction". I've just had a play with it and I think this would sort you out perfectly!
As for the picture quality suggestion, I presume you are referring to when I was talking about MPEG4 and dvd ripping. I think I may have confused the issue a little. I hadn't realised that iMovie can edit in MPEG4. I thought it would convert any mpeg4 movies to DV first - my mistake! Sorry.
However, whenever a movie is converted to a compressed codec then quality suffers (DV, MPEG1,2,4 are all compressed - in fact most codecs compress the data). Some codecs do not convert to other codecs very well either. I felt that going from Mpeg2 (DVD) to MPEG4 to DV was not the best route for image quality. Skipping MPEG4 and going straight to DV would be better.
Its worth noting though that even if you are editing footage in mpeg4, if you are then outputting to DV tape then you are having that extra conversion again! Ideally if you are outputting to DV then you should be editing in DV. Even a transition can cause a reduction in picture quality as you are re-encoding two DV movie streams - and that extra encode process means reduction in picture quality. Its hard (often impossible) to notice though admittedly!
Don't worry too much about this - if the picture looks ok to you, then all is well. Its a subject important to pro users, broadcasters etc and it is complicated! This is why iMovie is so great as it hides so much of the complicated technology.
I hope this clears things up a bit for you. feel free to get back to me if there is anything else I can do for you.
regards
Tom
gerard karelse - Jun 2, 2005 - 4:33 am
Hi Tom,
It sure clarifies things for me. I will try to eliminate the bass problems this weekend with the procedures you mentioned and let you know if anything goes wrong.
Audio freq. analyzer I mean the several draw bars you can use to adjust the frequencies higher and lower as you have in for instance Quick Time.
best regards, Gerard.
It sure clarifies things for me. I will try to eliminate the bass problems this weekend with the procedures you mentioned and let you know if anything goes wrong.
Audio freq. analyzer I mean the several draw bars you can use to adjust the frequencies higher and lower as you have in for instance Quick Time.
best regards, Gerard.
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