ecchh | 19 points
Since people are interested in these encodes, I would like to hold an opinion poll concerning which audio codec should be included with publicly linked FRANKeNCODE releases.
Currently, I upload the releases with Opus audio, which is technically superior than other codecs but also less compatible overall.
AAC audio is the alternative, which is more compatible, but not as effective a codec as Opus at identical bitrates.
TLDR: I'm very happy with Opus on x265 encodes.
However, since you asked:
A key hidden bonus is that Opus allows you to keep 7.1 soundtracks without adding (further) compatability problems: players that play Opus 5.1 also play Opus 7.1, including VLC (which hates AAC 7.1).
If you are going to try AAC (with Apple's encoder, I presume?), I'd suggest either being properly generous with the bitrate (~450kbps) or just going low and using HE-AAC at 192kbps (all rates I'm giving are for 5.1). I've sometimes been surprised to hear artifacts on Tigole's (~350kpbs) AAC LC encodes that weren't present on PSA's HE-AAC versions.
Of course, if you're going high, it may be better to just use the original core Dolby (usually 640kbps) or DTS (occasionally 768kpbs) audio from the source.
For me, taking HE-AAC past 192kbps just doesn't add anything, and I don't feel AAC LC can be fully trusted until I'm over twice that rate. For that huge 200-400kbps range, Opus is a great solution, and playback support is only going to improve.
On x264 encodes, where a huge numbers of dumb players exist, and for 4K x265 where more people have to use hardware players due to PCs that can't keep up, AAC (or Dolby) might be worth having for added compatability.
I'd suggest encoding for quality instead of bitrate.
With music the difference is not always evident, but with movies where many times there's nothing complex to encode with only few portions containing more information, you often get your 640 kbps quality for half the audio filesize.
Since audio VBR is miles simpler than the power required to decode HEVC, there's not really any gain with fixed bitrate and a lot to lose. Fixed might be useful for streaming, but for streaming Opus makes more sense than AAC anyway.
I like Opus but the problem is with people who stream the content. If you watch it on PC/Laptop you got no issues. People who stream usually don't have Opus support.
[-] Blue-Thunder | 2 points
You're doing a fantastic job and anyone who complains I would tell them do shut the fuck up and contribute. Audio transparency is key, and Opus is better than AAC. Personally I would prefer uncompressed audio, but that comes with ridiculous file sizes and I'm not going to be an asshole. If I really want that I can always just fine the track and mux it in :P Thank you for your hard work!
I'm more interested in overall bitrate of the audio. Basically, as long as you're not artificially inflating filesize with TrueHD/DTS at 24 bit / 192 kHz whose only utility is either studio operation (applying an effect a few thousand times) or tricking the consumer to spend more on psychological factors, and not getting into really low bitrates (what's the point of saving 100MB on a 3-15GB encode?) both are equivalent.
Encode 5.1 or 7.1 at quality 4-6 in AAC (thus variable bitrate - with the way movie audio goes you end up with noticeably smaller size and better quality than fixed bitrate) and you get comparable results/filesize as Opus.
Opus strengths is low bitrate / low latency and selecting the best option depending on the bandwidth available at a given time, ideal for the web (i.e. streaming) but of no concern with movies you download then watch. It makes less sense here: unless you encode AAC like a fool there won't be much a difference in quality and size.
Edit: if you look at https://en.wikipedia.org/wiki/Opus_(audio_format)#/media/File:Opus_quality_comparison_colorblind_compatible.svg you'll see that for Stereo from 64kbps upwards the difference between Opus, AAC and Vorbis is extremely marginal; at 128kbps (which is nothing and should really be minimum with video files since the size difference with 64kbps is negligible compared with the impact of video encoding options) and upwards the difference becomes philosophical.
[-] Redditor20121 | -1 points
[-] uwotm8_888 | 12 points | Oct 22 2017 03:24:55
opus imo is great and thanks for your own personal encodes. opus is not even hard to transcode and plays with any device thats not a decade old.
I only use MPC-HC which plays its great
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