remux giving different timescale

[iceborne]

i got an mp4 file which has he-aac in it but wasn't correctly signal for directshow so i went ahead and extracted the avc and raw aac file and then remux them back together using yamb 1.5. the resulting video plays fine but requires more cpu resource to run as i notice. i also notice from yamb extraction info of the files that the timescales are not the same as well as the duration.

this is the info for the original movie file:
* Movie Info *
Timescale 600 - Duration 01:53:58.203
Fragmented File no - 2 track(s)
File Brand isom - version 1
Created: Sat Feb 04 12:29:59 2006

File has root IOD
Scene PL 0xff - Graphics PL 0xff - OD PL 0xff
Visual PL: AVC/H264 Profile (0x15)
Audio PL: AAC Profile @ Level 1 (0x28)
No streams included in root OD

Track # 1 Info - TrackID 1 - TimeScale 2997 - Duration 01:53:58.271
Media Info: Language "und" - Type "vide" - Sub Type "avc1" - 204941 samples
MPEG-4 Config: Visual Stream - ObjectTypeIndication 0x21
AVC/H264 Video - Visual Size 576 x 320 - Profile Unknown @ Level 5.1
Self-synchronized

Track # 2 Info - TrackID 2 - TimeScale 24000 - Duration 01:53:58.058
Media Info: Language "und" - Type "soun" - Sub Type "mp4a" - 160267 samples
MPEG-4 Config: Audio Stream - ObjectTypeIndication 0x67
MPEG-2 Audio AAC LC - 2 Channel(s) - SampleRate 24000
Synchronized on stream 1



and here's the remuxed file:
* Movie Info *
Timescale 600 - Duration 01:53:58.263
Fragmented File no - 2 track(s)
File Brand isom - version 1
Created: Thu Feb 09 08:13:28 2006

File has root IOD
Scene PL 0xff - Graphics PL 0xff - OD PL 0xff
Visual PL: AVC/H264 Profile (0x15)
Audio PL: AAC Profile @ Level 1 (0x28)
No streams included in root OD

Copyrights:
(und) 2005

Track # 1 Info - TrackID 1 - TimeScale 30000 - Duration 01:53:58.264
Media Info: Language "eng" - Type "vide" - Sub Type "avc1" - 204941 samples
MPEG-4 Config: Visual Stream - ObjectTypeIndication 0x21
AVC/H264 Video - Visual Size 576 x 320 - Profile Unknown @ Level 5.1
Self-synchronized

Track # 2 Info - TrackID 2 - TimeScale 24000 - Duration 01:53:58.058
Media Info: Language "eng" - Type "soun" - Sub Type "mp4a" - 160267 samples
MPEG-4 Config: Audio Stream - ObjectTypeIndication 0x67
MPEG-2 Audio AAC LC - 2 Channel(s) - SampleRate 24000 - SBR SampleRate 48000
Synchronized on stream 1

[bond]

1) the timescale can be set as you wish, thats not a problem
2) maybe more cpu is needed as your aac decoder now also decodes the sbr part of he-aac? just a quess
3) no idea why the duration has changed. maybe it wasnt correct in the source mp4? how was it created?

[foxyshadis]

7 thousandths of a second could simply be a rounding error in conversion of the timescale. It's not enough to have chopped the last frame, so maybe it just shortened it. Timescale won't change cpu usange, it's just one division calculation either way.

[iceborne]

thing is i set the timescale to 29.97, not 30.00 for the remuxed file. do you think its a bad mp4box that i have. the source mp4 is from a friend. he said he made it through gknot.

[bond]

you cant make mp4 files through gknot

the timescale is not the framerate. iirc you cant set an individual timescale in mp4box

[iceborne]

my mistake, the source file was confirmed to be made with megui and later muxed it with aac through yamb.