Archiving MPEG2 HD to H.264 HD

[Avisynth_challenged]

Hi everyone. I've been thinking recently about how to streamline a growing collection of MPEG2 HD content recorded OTA. 90% of that content is film-based, telecined to 1080i or 720p, and the rest is non-film/true video, 1920x1080@29.97i or 1280x720@59.94p.

The bitrates of these MPEG2 HD sources are fairly low, typically around 13-15Mbps. The filesize of these sources tend to be around 6-8GB/hr.

I'm needing to archive some favorites, so I thought I'd get some thoughts from the community here.

As I see it, my choices are:


1. Do nothing, just continue to accumilate files and buy additional hard disk storage as needed.

2. Convert MPEG2 HD sources to MPEG2 SD and archive to hard disk or DVD.

3. Take the MPEG2 sources and author them to Blu-ray, AVCHD, or mkv and write them to various media (hard disk, Blu-ray, AVCHD-DVD, AVCHD-SDHC).

4. Convert MPEG2 HD to H.264 HD, then author to Blu-ray, AVCHD, or mkv and write them to various media (hard disk, Blu-ray, AVCHD-DVD, AVCHD-SDHC).


Number 1 is do-able, but I'd like to explore alternatives. Number 2 is fairly easy and quick to do (for me), but I do not wish to lose the HD quality. Number 3 seems like it would be easy to do, and no loss of HD. And Number 4 seems the most labor intensive and time consuming, but would give me the opportunity to do improvements to the MPEG2 sources such as inverse telecine and deblocking.

I've been turning the issue in my head for several weeks, and experimenting with x264. If I do decide to do conversion to H.264, I'll probably upgrade my computer for encoding. But I haven't fully made up my mind as to whether or not H.264 is the way to go for archiving MPEG2 HD sources, so I'd like to hear what others here think of the issue. By the way, my initial test conversion from MPEG2 to H.264 did not yield any improvement in compression. However, I used x264 settings to create a H.264 stream strictly for Blu-ray compatibility - and it looked as good as the original source. So I suppose I could improve compression (and encoding speed) by using other settings, but would have to sacrifice quality and/or Blu-ray compatibility.

Trying to decide... is it worth it? I'd really appreciate any feedback here. Thanks :)

[Guest]

With proper settings it would be reasonable to expect a 50% reduction in file size. It's only for you to decide if the large amount of labor needed justifies that. With the availability now of cheap multi-TB drives, my choice would be not to transcode.

[laserfan]

My take:

1. The easiest (do nothing), but I wonder if you are backed-up?

2. No, lotsa time, and loss of HD

3. Move MPEG2 to BD disc, easy to do but just a little pricey @ about $1.50 per 25Gb disc

4. Major time investment, converting and burning your programs to BD-format on DVD-5/9 and/or BD-25/50

I'm inclined to #4, but then I'm retired and have lotsa time & computing power. You at least ought to get started, perhaps with #3, to make certain your "favorites" aren't lost in some sort of data disaster.

P.S. you ought to be able to compress OTA MPEG2HD to a quarter of its original size; at least, you should be happy with a couple hours on a "BD-5" disc using x264...

[Blue_MiSfit]

I'd definitely say keep it, unless you just want something to do :)

Those bitrates are low enough. Heck, when I rip BluRay discs they come out around that bitrate sometimes.

Definitely don't author bluray discs. You'd want to use really good media, which is really expensive. I made the mistake of doing this with captured content in the SD-only era, and now lots of my DVD-R discs are not readable.

If anything, transcode to H.264 using x264's crf mode, plus VBV for level 4. I would then just archive this on hard drives. You can definitely get a reduction in bitrate without taking ages or requiring a two pass encode. You will also get practically transparent results. Plus... if your sources are malformed - i.e. hard telecine, blocking etc, you can clean these up in avisynth beforehand ;)

If you're considering that, get a Core i7 for sure. The speed will be hungrily appreciated by x264 when encoding 1080p!

~MiSfit

[Avisynth_challenged]

Thanks for the replies everyone. I'm basically leaning towards transcoding only a few programs with x264 for archival, and just using VideoRedo to trim the rest with no transcoding from native MPEG2.

If anything, transcode to H.264 using x264's crf mode, plus VBV for level 4. I would then just archive this on hard drives... If you're considering that, get a Core i7 for sure. The speed will be hungrily appreciated by x264 when encoding 1080p!

Could you advise if i7 LGA1156 or LGA1366 is the better choice here? Thank you very much :)

[Blue_MiSfit]

The 1156 is probably the way to go, unless you need any of the features that come with 1366, like tons of RAM etc...

Definitely get one of the i7's with hyperthreading. It gives you a ~25% boost in x264.

~MiSfit

[Avisynth_challenged]

Thanks for the quick response.

Definitely get one of the i7's with hyperthreading. It gives you a ~25% boost in x264.

I thought I read somewhere in this forum that running multiple threads in x264 has some detrimental effect(s) on PQ. Is this true, and are they negligible versus the performance boost? Thanks again for the feedback.

[nm]

I thought I read somewhere in this forum that running multiple threads in x264 has some detrimental effect(s) on PQ. Is this true, and are they negligible versus the performance boost?
The effect is very negligible with the number of threads needed on an i7. No need to worry about it unless you're already using placebo-level settings.

[Blue_MiSfit]

Correct. The quality impact is bigger with sliced threads, which was the old threading method (brought back to life for low latency mode).

Frame based threading (default) performs much better, and doesn't impact quality very much, though it does add a lot of latency. For regular desktop encoding, this doesn't matter _at all_.

The performance boost is almost linear scaling to more than 8 cores. In other words, the performance boost is EPIC. Use threads.

BTW, this has nothing to do with hyperthreading. If you don't use threads, then you only utilize one core. This is fail :)

~MiSfit

[wlee15]

I would also add that in terms of x264 encoding performance AMD Athlon II X4 and Phenom II X6 processors offer excellent value. The rest of the AMD lineup not so much.

[raceviper13]

I transcode all (1080i or 720p) OTA HD to 720p 30/25 or 24 fps using crf 24 and tune ssim. I'll see anywhere from 1/10th to 1/5th the size of the original depending on the level of camera movement.