Decoding H.264 and remuxing

[theherecy]

This seems like it could have been answered before but I can't seem to find the answer regardless!

If I am taking a blu ray and decoding the H.264 video (which is lossy), and then remuxing it back into an m2ts container, is this bit perfect, i.e identical to the source?

Thanks!

[Guest]

If I am taking a blu ray and decoding the H.264 video (which is lossy), and then remuxing it back into an m2ts container, is this bit perfect, i.e identical to the source? It depends on how you recompress the video for muxing after you have decoded it. As the recompression is almost certainly going to be lossy, the result will not be bit perfect to the original stream.

If you simply demux the video and then remux it, then you can have no further loss.

[theherecy]

I don't believe I am compressing it at all, I am only taking the video, audio and main subtitle track (through eac3to) and leaving all other material behind.

From there I am using tsmuxer with no compression options enabled and remuxing it into a blu ray structure.

So that should be a "perfect" copy of the video/audio?

[Guest]

As I said, if you simply demux the elementary streams and remux them, then they are not altered. Why bother with all that if you started with an M2TS anyway? Demux from M2TS and remux to M2TS...what is the point"?

And if you are simply extracting and remuxing then why did you say "If I am taking a blu ray and decoding the H.264 video..."? Do you know what "decoding" means? Finally, your first post did not mention audio, but the same answer applies.

[theherecy]

I apologise if I have mixed up my terminology, eac3to utilises decoders and requests the use of 3rd party decoders such as arcsoft's for what I thought was the decoding process.

So many articles instruct you to use the arcsoft decoder for the best results, in which case surely you aren't actually using those decoders then?!

Also when using tsmuxer it says its decoding : http://imgdump.nl/hosted/1abf997de2b02a22b1f03ac5ebf93233.jpg

My aim was to take my collection onto hard disk but to minimise the redundant audio/subtitles whilst preserving full quality.

Thanks for taking the time to answer my questions!

[Guest]

Moving to Newbies.

Anyway, your first post's question has been answered. Regarding your new question, one option is to use BDRB to backup while removing unneeded stuff.

[Blue_MiSfit]

You're decoding audio (and likely re-encoding it into something else), while just remuxing the video. There should be no difference between the original video and remuxed video. At least, not in the actual picture data. It's conceivable that some of the header / SEI messages might be changed, but not the picture.

Keep this in mind :)

[theherecy]

Strange as the only audio paramater I have specified is the language:

A_DTS, "F:\DEMUX\Audio_4_English.DTS", lang=eng

[nixo]

It's no wonder you're confused; tsMuxer doesn't decode audio at all, it's just a muxer/demuxer. It would probably be better if it said 'reading DTS-HD stream' or similar and not 'decoding'. Don't worry about it.

--
Nikolaj

[theherecy]

It's no wonder you're confused; tsMuxer doesn't decode audio at all, it's just a muxer/demuxer. It would probably be better if it said 'reading DTS-HD stream' or similar and not 'decoding'. Don't worry about it.

--
Nikolaj

I was hoping that was the case. It's concerning they call it decoding though... Any thoughts why that is?

[nixo]

I can only speculate that something got jumbled in the translation and nobody really cared enough to bring it to the attention of physic (http://forum.doom9.org/member.php?u=212885). He/she posts here now, so you could ask.

--
Nikolaj