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Community Feedback: Finding a good balance between size, quality and conversion time.

Apr 28, 2014 at 4:34 PM
I hope this is the right place to post a question like this. If not, please correct me.

I'm super new to the world of HTPC and all that it encompasses, so please use that filter when reading this & formulating a response.

I stood up a basic HTPC quite a while ago now that met our immediate needs and so far am quite pleased with it. Its a Windows 8.1 machine with a Ceton InfiniTV card and we rely on Windows Media Center with storage on a Synology NAS via iSCSI LUN. (Although that will change soon to a UNC path directly to the NAS vs UNC path to a share of an iSCSI LUN on a machine.) While doing some maintenance recently, I discovered that a typical hour-long show in WTV format is roughly 7GB. As a result, I have something like 3TB+ of media, which is about 449 WTV files (e.g.: 181 some odd episodes of Seinfeld, a couple dozen episodes of several shows, a handful of moves - like 6).

Because I'm sort of 'in a rush' to accomplish a specific task revolving the home network, I'm using what I believe is called the MKV Unprocessed profile. The 'conversion' process is super quick, but I'm still left with a massive file that's just maybe 130MB smaller than the original. Sure, I could remove commercials - and I want to once I get around the subtitle timing shift issue - but I doubt that's going to bring this down substantially. (Meaning, I don't expect the removal of commercials to result in a 3-4GB file.)

So, I need a little help and am reaching out to seasoned AV/HTPC & MCEBuddy folks on how they get their videos into 'acceptable' formats, which I realize is a very broad and generic statement.

Now, I'm not some super AV expert, but I do know that I like, prefer & want good quality videos. I'd like the keep the same level of quality as it was broadcast in because I think the picture quality is darn good. (e.g.: If I start with a 1080p WTV file, I'd like to have a 1080p file at the end, not 720) It would be great to get those file sizes down, but I don't want to do so at the expense of quality.

For starters, I think I need a little help re-adjusting my expectations:
  1. I'm hoping to cut the file sizes in half, maybe more like the 1-2GB range, without sacrificing [too much] quality. I just don't want to go from ultra crystal clear 4K quality to 1993 VHS quality. (Obvious exaggeration)
  2. I'm looking for a process that won't take half a day to convert a file. I did a test run once and found it took somewhere between 4 & 6.5 hours to convert a single file. That to me was ages too long, especially when I have so many files files to convert. (We're talking 93-94 days of converting non-stop round the clock at 5 hours per video!)
Remember, I'm speaking with zero understanding about video files or video container formats. Its a little difficult for me to understand (conceptually) why it takes long to convert, and why files are so huge.

My objective here is to get some feedback / advice from the community on conversion processes that
  • maximize quality
  • retain captions / subtitles (requirement for our home)
  • retain multi-channel audio (e.g.: if it was broadcast in 5.1 even though I only have 2.1 currently)
  • produce [significantly] smaller file sizes
  • convert as quickly as possible
I'm hoping for responses that include things like what your conversion process looks like and what settings you find work best.

Lastly, some information about the systems available for conversion:
  • HP ML150G6 Windows 8.1, 1xE5504, 10GB RAM, GT 610
  • Dell XPS 720 Windows 7, Q6700, 8GB RAM, dual GTX 560Ti 448 core edition
  • Dell OptiPlex 960 Windows 7, Q9400, generic video card but I could pull one of the GTX 560 from the above system.
​Bonus Questions:
  1. Is there a hardware configuration that greatly helps to reduce conversion times? (e.g.: X core processor, X video card(s), X video driver, X RAM, SSD etc.; or specifically Intel video cards over nvidia/ATI cards, desktop grade X core processors versus server grade processors etc.)
  2. Do conversion times go down exponentially the more cores you have (e.g.: 4xcores = 4 hours, 8xcores = 2 hours) or the more processors you have (e.g.: 1x4core = 4 hours, 2x4core = 1 hour)
    (We're assuming here that the same profile and video file is being used for each test.)
Looking for as much advice & constructive criticism as possible!
Apr 28, 2014 at 5:08 PM
Try this for starters.

Also there was a similar thread earlier this month on the forum. See if you can track it down.
Your best bet is to get a system with Intel QuickSync support which will drastically cut down your encoding time.

Marked as answer by rboy1 on 5/4/2014 at 9:57 AM
Apr 28, 2014 at 6:53 PM

From a container perspective your best 2 options would be MP4 and MKV (note that MCEBuddy by default uses AAC for MP4 and AC3 for MKV), you may need to customize the profile if you want to change the default audio codecs.

A HD video should take about 45 min to 60 min to process and hour's worth of video with a Normal profile. That can be reduced to 15-20 min with hardware encoding.
You can keep the video at 1080p to get pretty good quality and increase the quality slides if you want to keep a higher bitrate. Both support multi channel audio, ensure you select the option for multi channel audio in your conversion task

Conversion times do not go down exponentially in my own testing, it's more linear. However they do down exponentially with processor architecture (pentium v/s iCore). Ofcourse Intel QuickSync chipsets are the best way to speed up encoding. See the GPU encoding thread for more details,
Marked as answer by rboy1 on 5/4/2014 at 9:57 AM