Changing MXF Timecode without transcoding

[tar...@gmail.com]

Hi there,

I have a ton of MXF files with a bad starting timecode and I need to change these. I'm not sure but it seems that the start timecode is just a metadata in the file.

I have tried a command like that :

ffmbc -i mymxf.mxf -timecode 00:00:00:00 -vcodec copy -acodec copy out.mxf

but it seems to be slow (I have dropped to 13 frames per second doing that on my local file system).

I was wondering if ffmbc (or any other tool) can change the start timecode directly in the file so it take less time.

Thanks for your answer.

[Baptiste Coudurier]

Hi,

FFmbc cannot do that. The -vcodec copy will work and it's pretty fast here.

--
Baptiste COUDURIER
Key fingerprint 8D77134D20CC9220201FC5DB0AC9325C5C1ABAAA
FFmpeg maintainer http://www.ffmpeg.org

[tar...@gmail.com]

Thanks for your answer Baptiste.

I'm trying to do it with a transcode.

I've tried several commands but I'm not able to copy all the audio streams from the original file to the new target. I've tried mapping and using -newaudio but any audio track that is not the first one won't be copied according to the output mapping of ffmbc.

Am I missing any important stuff ?

My input file is a MXF xdcamhd422 op1a with 8 audio channels and I need to still have these streams in the output.

I've tried things like :

ffmbc -i input.mxf -timecode 00:00:00:00 -acodec copy -vcodec copy out.mxf

ffmbc -i input.mxf -timecode 00:00:00:00 -acodec copy -vcodec copy -map 0 out.mxf

and some lines with manual mapping (with map_audio_channel and map) combined with -newaudio and everytime I get a new audio stream that is not a copy but a reencoding according to output mapping. 

[Baptiste Coudurier]

Hi,

On 4/18/12 7:27 AM, tar...@gmail.com wrote:
> Thanks for your answer Baptiste.
>
> I'm trying to do it with a transcode.
>
> I've tried several commands but I'm not able to copy all the audio streams
> from the original file to the new target. I've tried mapping and using
> -newaudio but any audio track that is not the first one won't be copied
> according to the output mapping of ffmbc.
>
> Am I missing any important stuff ?
>
> My input file is a MXF xdcamhd422 op1a with 8 audio channels and I need to
> still have these streams in the output.
>
> I've tried things like :
> ffmbc -i input.mxf -timecode 00:00:00:00 -acodec copy -vcodec copy out.mxf
> ffmbc -i input.mxf -timecode 00:00:00:00 -acodec copy -vcodec copy -map 0
> out.mxf
>
> and some lines with manual mapping (with map_audio_channel and map)
> combined with -newaudio and everytime I get a new audio stream that is not
> a copy but a reencoding according to output mapping.

Something like this:

ffmbc -i input.mxf -timecode 00:00:00:00 -acodec copy -vcodec copy out.mxf

-acodec copy -newaudio -acodec copy -newaudio -acodec copy -newaudio -acodec copy -newaudio
-acodec copy -newaudio -acodec copy -newaudio -acodec copy -newaudio

(yes it's a bit convoluted)