MP4 Export Audio Problems

[Sonic]

Hi,

I have been playing with VideoStudio Pro X5 for editing MP4 videos in 1080p/30fps generated by a GoPro HD Hero 2 for a few weeks but can't seem to get exporting the project files back to MP4 without lots of audio distortion.

I am importing the gopro MP4 files directly into VideoStudio, adding some overlays etc but nothing relating to audio (i.e not additional background music) then exporting to MP4.

The audio in the original video is absolutely fine, but in the exported MP4 file from VideoStudio it is very garbled, sounding like multiple layers of compression.

Mediainfo tells me that the original MP4 file has the following audio properties:

Code: Select all

Audio
ID                                       : 2
Format                                   : AAC
Format/Info                              : Advanced Audio Codec
Format profile                           : LC
Codec ID                                 : 40
Duration                                 : 11mn 2s
Bit rate mode                            : Constant
Bit rate                                 : 128 Kbps
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 32.0 KHz
Compression mode                         : Lossy
Delay relative to video                  : 33ms
Stream size                              : 10.1 MiB (1%)
Title                                    : GoPro AAC
Language                                 : English
Encoded date                             : UTC 2012-11-24 10:12:12
Tagged date                              : UTC 2012-11-24 10:12:12

The MP4 video that i have exported (36s test from the original) has the following:

Code: Select all

Audio
ID                                       : 2
Format                                   : AAC
Format/Info                              : Advanced Audio Codec
Format profile                           : LC
Codec ID                                 : 40
Duration                                 : 36s 0ms
Bit rate mode                            : Constant
Bit rate                                 : 128 Kbps
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 32.0 KHz
Compression mode                         : Lossy
Stream size                              : 564 KiB (1%)
Language                                 : English
Encoded date                             : UTC 2012-11-26 16:13:27
Tagged date                              : UTC 2012-11-26 16:13:27

I have tried exporting just the audio in every M4A AAC format ranging from 32khz/96kbps all the way up to 48khz/256kbps with everything in-between just to be sure - all have lots of distortion and sound awful.

If i export to WAV then the audio is fine.

If i try to export "same as first video clip" then the export gets about 10% through then fails. The exported video plays the first few seconds, then errors.

Any ideas about what i'm doing wrong? Any help is very much appreciated.

Cheers,

Andy

[Ken Berry]

AFAIK, no one else has reported audio problems with GoPro footage, though quite a few people had difficulty with the video itself and with VS X4 rather than the current X5. Anyway, FWIW have a look at this sticky thread towards the top of this forum: http://forum.corel.com/EN/viewtopic.php ... 01#p222801 As I say, it relates to the whole GoPro mp4 format, rather than the audio channel. And I am not sure if the new .dll mentioned there will work with X5, though I guess it should do not harm.

Also FWIW, I am personally rather interested in this question as I just yesterday pre-ordered the new Black model Hero 3 which will be released this Friday. I think that one uses h.264 AVCHD mpeg-4 -- though I confess I don't know if the Hero 2 uses the same format or its own separate mp4 format.

[Sonic]

Hi,

Thanks for the reply.

I had read that thread, but not followed the instructions to replace the dll file as i'm not using X4 and dont have a problem importing MP4, rather exporting.

Ive just looked back though the files that i exported a few weeks ago from my laptop, all have the same distortion.

I've tested with Windows Movie Maker and it is absolutely fine exporting to MP4 - so appears to be a VideoStudio problem.

I've also tested on both my desktop and laptop,... same result. VideoStudio seems to cause distortions in any exported MP4 file regardless of what audio encoding i use.

[Ken Berry]

Have you tried exporting it to AVCHD format, with Dolby audio or straight LPCM?

[Sonic]

Just tried, LPCM doesn't work, but it seems fine with dolby

Only thing is that it drops the frame-rate to 25fps rather than 30.

[Ken Berry]

Are you living by any chance in a PAL country? I also understood -- but could be wrong -- that the Hero 2 could be set to either PAL or NTSC...

[Sonic]

Yes in the UK - but the videos will all be editing and uploaded to youtube and kept for my own entertainment anyway.

Nothing too serious or any kind of broadcasting so not fussed about PAL/NTSC.

[Ken Berry]

Well, if you really want to output in NTSC format i.e. using a frame rate of 29.97 fps, then you can make a Custom template in VS. Go to Settings and select Make Movie Template Manager.

In the dialogue box which appears, click New. Another dialogue will appear. In the top window, click the down arrow and select MPEG Transport Stream as the format. Make sure it is Transport Stream, not just the general MPEG template. Then give the new Template a name e.g. AVCHD_NTSC, and click OK.

Another box labelled Template Options will appear. Click first on the Compression tab. At the very top, in Media Type, select NTSC HDMV. Then further down, in Video Format, select H.264 Video. Then a little further down, tick the AVCHD box. Leave the Audio settings as they are by default Dolby.

Now go back to the General tab. You will see the frame rate is now set at 29.97 fps.

Down below that, you can change the frame size to 1920 x 1080. Then click OK to close that box, then click 'Close' to close the final box. Now in future when you want to make a new video file with those properties, you select Share > Create Video File and in the drop down menu, you will see your new template at the very bottom. So select and use that.

[yipcw]

seems like the problem persists in X7 and X8.5 after 3 years since X6.

I just exported audio only and MP4 (H.264) in AAC (44 or 48kHz, 256kbps) from a .WAV, the spectral graphs show both lose anything above 16kHz. The problem is not there if you use Dolby Digital in M2T container.

graphs at http://users.wfu.edu/yipcw/atg/corel/videostudio/x8.5/

(just to be certain, I did the same thing in Adobe Premiere Pro, AAC 48kHz 320kbps, there is no loss of >16kHz.)

I think it is a bug in the audio export module of VideoStudio.

[Ken Berry]

Unfortunately, I use my Hero 3 Black all the time, and never have any problem at all with the AAC audio, which I also use as the output audio format for my Hero projects. No loss of quality at all. The only significant difference is that I have used the Hero footage in VS X6, X7 and now X8/8.5, and perhaps that makes the difference. With the last two, you now have the option to set the Project Properties to match those of the original footage by ticking, in Preferences > General, the box beside 'Show message when inserting first video clip'. With that ticked, then after doing your editing, you can go to Share and simply choose 'Same As Project Properties' to produce a new video with precisely the same Properties as those of the original, including the audio. And as I say, no loss in audio quality is detectable at all.

[ali]

seems like the problem persists in X7 and X8.5 after 3 years since X6.

I just exported audio only and MP4 (H.264) in AAC (44 or 48kHz, 256kbps) from a .WAV, the spectral graphs show both lose anything above 16kHz. The problem is not there if you use Dolby Digital in M2T container.

graphs at http://users.wfu.edu/yipcw/atg/corel/videostudio/x8.5/

(just to be certain, I did the same thing in Adobe Premiere Pro, AAC 48kHz 320kbps, there is no loss of >16kHz.)

I think it is a bug in the audio export module of VideoStudio.

I have exactly the same problem. I've spent several hours trying out different combinations of input WAV settings (44kHz/48Khz, different bitrates), Project Settings, and MP4 AAC output settings, as well as matching them all (all set to 44kHz or 48kHz and the same bitrate), but still the output mp4 audio is distorted and loses audio data. I also guess this must be a bug or problem with the VS AAC encoder.

I use my Hero 3 Black all the time, and never have any problem at all with the AAC audio, which I also use as the output audio format for my Hero projects. No loss of quality at all.

Since VS supports WAV as the input, I doubt it's designed to only work with GoPro movies. As such, I expect that VS must be working properly without the least of problems with the oldest and the simplest audio input format (WAV) and the most popular web output format (MP4/AAC) today. I hope that the dev support checks and debugs the problem, and comes up with a solution and/or patch rather quickly.