MP4box getting time incorrect

[dattrax]

Hi,

I have an AVC file encoded with interlacing at 1920x1080i. It is 1:30 in length, but when I mux it with MP4BOX it has a duration of ~3:00

* Movie Info *
Timescale 600 - Duration 00:03:01.545
Fragmented File no - 2 track(s)
File Brand isom - version 1
Created: GMT Wed Aug 02 19:08:25 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 4 (0x2a)
No streams included in root OD

Track # 1 Info - TrackID 1 - TimeScale 29976 - Duration 00:03:01.545
Media Info: Language "Undetermined" - Type "vide" - Sub Type "avc1" - 5442 sampl
es
MPEG-4 Config: Visual Stream - ObjectTypeIndication 0x21
AVC/H264 Video - Visual Size 1920 x 1080 - Profile High @ Level 4.1
Pixel Aspect Ratio 1:1 - Indicated track size 1920 x 1080
Self-synchronized

Track # 2 Info - TrackID 2 - TimeScale 48000 - Duration 00:01:30.773
Media Info: Language "Undetermined" - Type "soun" - Sub Type "mp4a" - 4255 sampl
es
MPEG-4 Config: Audio Stream - ObjectTypeIndication 0x67
MPEG-2 Audio AAC LC - 6 Channel(s) - SampleRate 48000
Synchronized on stream 1

Is this the interlacing that is messing this up?

coreavc can play the .264 file back, but mplayer is unable to as [h264 @ 00B4A3C8]PAFF interlacing is not implemented

Am I using a feature which is currently unsupported?

Cheers

Jim

[foxyshadis]

Mux it with the fps explicitly stated; it's well-documented that mp4box always muxes .264 with 25 fps unless the -fps switch is used. (In this case, looks like 50 fps, likely due to each field being counted as a frame.)

[dattrax]

I was already using the -fps option as you will notice the video rate is 29976. I don't belive that this is the problem as I effectivly doubled the rate to 59.94fps and this is the value that mplayer pulled out when trying the decode.

The durations for both tracks now match, but like I mentioned the fps is now corrupt.

The other issue is that the resulting file will not play with the coreavc directshow decoder, whereas the seperate streams do.

Cheers

Jim

[bond]

whats the framerate of the source video being in sync with the audio?

[dattrax]

The video is 29.976fps and should be ~1:30 in length. You can see that MP4Box from the output is doubling it (probably due to the interlacing)

Cheers

Jim

[bond]

The video is 29.976fps and should be ~1:30 in length. You can see that MP4Box from the output is doubling it (probably due to the interlacing)

Cheers

Jim
might be possible. can you make a bug report in the gpac project bug tracker plz