Problème de conversion

[MAX92 91]

Bonjour,

J'ai une erreur lors d'une conversion mais je ne sais pas pourquoi. Quand j'essaie de convertir un enregistrement *.ts dans le profil "TV", cela ne fonctionne pas si je mets Quality à Original ou 8Mbps. Par contre, en 4Mbps c'est bon. Pourriez vous me dire pourquoi ? 

ffmpeg-transcode-2eb6f4a2-841b-4fc3-996b-af218bbf1a12_1.txt embyserver.txt

[Carlo 4560]

Hi, that ffmpeg log was stopped as it's showing a quit command received.

[MAX92 91]

Yes dor the last test 4Mbps I stopped it. But the 2 first don't work.

[Carlo 4560]

Can you post an ffmpeg log file when it doesn't work and not quit/ended?

Thanks

[MAX92 91]

Here it is. I don't know why you don't see in the previous ffmepg log.

I try to convert in profil "TV" quality "Original"

ffmpeg-remux-f4cf26db-1bf6-4e7d-b23a-3286e68b51ae_1.txt

[Carlo 4560]

Hi, this is a remux and not even a transcode but ffmpeg is getting failures trying to read parts of the file.

That would usually indicate a bad media file that should likely be replaced.

[MAX92 91]

But if I convert it in "mobile" profil, no problem.

[Carlo 4560]

That's interesting.  Could you do that for this same exact media and upload that ffmpeg log please?

[MAX92 91]

here it is. THe same file converted with mobile "profil". I can do in TV 4Mbps too.

ffmpeg-remux-a992dde6-2eab-4b6f-a5a5-ecaf5d84ac20_1.txt

Edited July 6, 2021 by MAX92

[Carlo 4560]

Thanks appreciate you doing this.

We'll take a look and try to reproduce.

[Carlo 4560]

Hi, would it be possible to upload this file so I could use it for testing?

[MAX92 91]

Voilà

https://we.tl/t-sZyriyujPq 

[Carlo 4560]

Thanks got it.  Would you mind showing me a screen shot of how you were converting this when it fails?

[MAX92 91]

[Carlo 4560]

I can reproduce exactly as you said.  Mobile works, TV doesn't

@softworkz Can you take a look at this please.

[softworkz 5066]

@MAX92 - the video stream in the recording does not include DTS timestamps (only PTS). This is pretty unusual and the reason why conversion to MKV fails. MKV and MP4 containers have different requirements, that why it fails in one case but not in the other.

Where did you get this recording from?

Does the problem exist only with that specific file or with all recordings...

•   from a specific channel (or multiple specific channels)?
•   from all channels?

[MAX92 91]

@softworkzThe recording is from HDHomeRun and EMBY.

The problem is not with all recordings. I will say allways from the same channels. Remember the conversion always works in 4Mbps.

[softworkz 5066]

17 minutes ago, MAX92 said:

@softworkzThe recording is from HDHomeRun and EMBY.

The problem is not with all recordings. I will say allways from the same channels. Remember the conversion always works in 4Mbps.

Yes, that's expected, when you choose 4Mbps (or any other lower quality), the video will get transcoded (re-encoded). The process of re-encoding adds DTS timestamps to the video stream, and then there's no problem anymore to convert to MKV.

[softworkz 5066]

When choosing "original quality", the video stream is "re-muxed", which means that it is left unchanged and only embedded into the target container (e.g. mkv, mp4).

ffmpeg has a number of flags and options for dealing with and manipulating various timestamp values, but the problem is that these get only in effect when a stream is decoded and re-encoded (=transcoded) but not when remuxing.

I need to think about this a little more, but right now I don't see any other solution for this, than either enforce transcoding the video or simply using mp4 containers instead of mkv.

[MAX92 91]

@softworkzThanks. Last thing, doesn't work too with 8Mbps.

[softworkz 5066]

17 minutes ago, MAX92 said:

@softworkzThanks.

You're welcome!

17 minutes ago, MAX92 said:

Last thing, doesn't work too with 8Mbps.

The recording has a total bitrate of about 4.6 Mbps:

 

That means that it won't transcode when you are setting 8 Mbps because it's already lower than 8, but it will transcode when setting 4 because it is greater than 4.