In R5D1, Mythburn took only 30-40 minutes to turn out a full DVD - start to finish! Wow.

Addition:

That time INCLUDED re-encoding two 4GB mpeg files to fit on a single layer DVD-R disc!!

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KnoppMyth R5.5, Asus A8N-VM CSM (nvidia 6150 onboard video), AMD Athlon 64 dual-core 4200+, two 1GB sticks DDR 400, HD-3000 HDTV card, PVR-150 card, Iguanaworks RS-232 IR receiver/transmitter, Pioneer DVR-110 DVD burner

FWIW - The MythBurn author is one of two main people who collaborated on MythArchive, which uses many of the same components. Where parts have been replaced it seems to have been done mainly for reliability. MythArchive also includes somewhat more flexible and sophisticated peprocessing. If there's a slow down it's small enough that I've never noticed it.

Your not really comparing like for like. MythArchive does a lot more to ensure the DVDs it creates are fully DVD compatible so if a file doesn't have a DVD compliant resolution for example it will re-encode it so it does. MythBurn would never re-encode so it would often create DVDs that wouldn't play properly in standalone players.

If the files are already DVD compliant or you tell MythArchive to not re-encode then it is just as fast as MythBurn was. Thats because as tjc said it uses the same tools to do most of the work.

I think you may be confusing re-encoding with requantizing they aren't the same. MythArchive can also optionally requantize the files if they are to large to fit on a DVD if that is what you want.

Huh. I've never heard of requantization before and I'm not new to mpeg video recording and editing. Transcoding, encoding and re-encoding are familiar terms, but requantization is a new one.

1. So, if requantization isn't re-encoding the video file, how does it reduce the size of the mpeg file? Some sort of file compression - like a zip file?

2. How do we switch off the re-encoding and switch on requantizing?
The only video alteration controls I saw in Mytharchive were the Video Profiles that you chose for each of your video files. I've been choosing SP to get 2 hours of video on a single layer dvd-r. When I do this for two 4GB files, Mytharchive shows that the final disc will be about 4GB.

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KnoppMyth R5.5, Asus A8N-VM CSM (nvidia 6150 onboard video), AMD Athlon 64 dual-core 4200+, two 1GB sticks DDR 400, HD-3000 HDTV card, PVR-150 card, Iguanaworks RS-232 IR receiver/transmitter, Pioneer DVR-110 DVD burner

The requantization is done by tcrequant which is part of the transcode package. It somehow manipuates the quantization matrixes in mpeg2 files. Googling for tcrequant didn't turn up much info on exactly how it works I do know its isn't re-encoding as I would call it.


If you have tcrequant installed and you have told MythArchive where to find it in the settings then it should just use it if it thinks the DVD is too big to fit.

I used "locate tcrequant" and found "/usr/bin/tcrequant" and no other hits.

I'm not sure where in the Mytharchive setup I point it to tcrequant.

I read on the Mythtv wiki that Mytharchive forces a re-encoding of mpeg files if they are not 100% compliant with the dvd standard.
http://www.mythtv.org/wiki/index.php/Mytharchive

One of my local digital tv stations has been transmitting the newly remastered Star Treks out at a resolution of 705x480. This comes in via my HD-3000 card. The DVD standard uses a resolution of 720x480, so I guess that forces Mytharchive to re-encode any show I get from this TV channel to convert the resolution to 720x480. I don't think I can replace re-encoding with requantization when using Mytharchive.

Sound correct?

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KnoppMyth R5.5, Asus A8N-VM CSM (nvidia 6150 onboard video), AMD Athlon 64 dual-core 4200+, two 1GB sticks DDR 400, HD-3000 HDTV card, PVR-150 card, Iguanaworks RS-232 IR receiver/transmitter, Pioneer DVR-110 DVD burner

The tcrequant setting is on the last page of MythArchive's settings. You just need to make sure it isn't blank and that it's set to a sane value. Since it looks like tcrequant is in your normal PATH you can just set it to 'tcrequant'.

It's true that MythArchive always tries to do the right thing by default but you can always override it. All you need to do is select 'Don't Re-encode' on the last page of the 'Create DVD' wizard. If you add more than one file you'll have to do that for each file. The DVD will be created as normal except there will be no re-encoding done. After all the pre-processing is done the script will check all the file sizes to make sure they will all fit on the size of DVD you selected. If they don't then tcrequant will be run on each video file to reduce the size.

Talking about this has reminded me of something I meant to do ages ago and that was to revise the value used to estimate how much space to allow for the overhead when the streams are re-muxed

I found that during the configuration screens for the DVD creation, if you tell Mytharchive not to re-encode the video files (even if the total amount of data you intend to burn exceeds the size of your 4.3GB dvd-r) it will use the requantize method of resizing the mpeg files. If you choose to use one of the re-encoding profiles, such as SP, or EP, it will use the re-encoding method of resizing the mpeg files.

I tried both re-encode and re-quantize.
* The re-encoding process literally took hours and the output is the DVD-compliant 720x480 resolution but it looks bad - blocky video.
* The re-quantize process took less than an hour and the output looks much better - cleaner video. The only downside here is that the ouput video may be a non-DVD-compliant resolution, which some DVD players might have troubles with.

It looks Mytharchive does not have the "delete DVD folders" control any more, so your temp directory can end up with quite a lot of data sitting in it at the end of the DVD creation/burn process. Mine had about 12GB in it, as I recall - which I manually deleted to get the disc space back.

Good luck!
Eric

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KnoppMyth R5.5, Asus A8N-VM CSM (nvidia 6150 onboard video), AMD Athlon 64 dual-core 4200+, two 1GB sticks DDR 400, HD-3000 HDTV card, PVR-150 card, Iguanaworks RS-232 IR receiver/transmitter, Pioneer DVR-110 DVD burner