Mystery? No audio in MP4 unless render twice

[brouillette]

From my VSP (a 35 minutes photos+videos travel movie) I rendered (=share) into a MP4 output video (MPEG-4 AVC 1080-30p 15M).

Resulting successful video plays well but has no audio. I reloaded VSX10 but still no audio.

I thought VSX10 did not have the necessary codecs but then discovered that if I open a NEW VSP and insert the "no audio MP4", and render again in the same output format , then the MP4 has now the audio part ???

So VSX10 has obviously the necessary codecs but does anyone know why I have to render twice to get the audio ?

[Ken Berry]

Does the 'no audio' video play with audio in another video player e.g. VLC Player?

[brouillette]

...hum...! ...strange...it does have audio on VLC player...but no audio on "Windows 10 Film & TV" player, no audio on "PowerDVD 14", no audio on 2 Panasonic HDTVs (USB input in Media Player) and no audio on one Samsung HDTV, unless I render twice as mentioned previously ?

[Ken Berry]

With the no audio video in the timeline, when you right click on it, does Properties show any audio?

[brouillette]

Yes it does show in Properties, under the Details tab, 192kbps-stereo-48000kHz.

I did further testing to be sure. I reloaded again VSX10. I rendered my VSP to MP4-30p again. Audio is present in some cases (...VLC...) and no audio in other cases (HDTVs...). Everything is corrected when I render again using the "no audio video" in the timeline (audio in all cases).

I decided to try another profile by rendering my VSP into a MP4-60p (Share>MPEG-4>XAVC S MP4 HD (1920 x 1080 60p 20Mbps). Audio is perfect everywhere the first time I render.

Is it a glitch in the MP4-30p profile ? Anyway I can correct it by rendering twice for MP4-30p, and MP4-60p works fine first time around.

I don't know how to pass this on to Corel Technical Support (maybe you do) so that they check their profile . If there is a glitch, it can be corrected in the next VSX10 update and not repeated in VSX11. If not a glitch, then mystery remains...!!!

Thanks Ken !

[lata]

Hi
As Film & TV, Media Player and 2 Pana TV’s have problems I doubt it is just Corels profile rather than the video file itself?
If you pass this to Corel Support they will probably ask for a sample, so are you able to upload an original video to a sharing site, provide a share link on your post.
From Video Studio - Help menu CorelSupport

One thing you could try is renaming the MP4 video file to use .Mov as its file extension then try editing in Video Studio.

[brouillette]

Yes Trevor, there is no problem for me to upload thru Google Drive the video with "no audio on HDTVs unless I render twice" (4 Gb ). I will contact Corel Support and see what they say.

Thanks !

Guy

[brouillette]

[SOLVED]
For your info, I contacted Corel Tech Support : they told me to delete all the temp files from my computer and reset my VideoStudio to its default settings.

I did render my VSP project after the VS Reset and audio is fine now.

Thank you all for your input in trying to solve my problem !

Guy

[lata]

Hi Guy

Thanks for the update, something to keep in mind, happy you have it working