How do you reduce video size without reducing [visual] quality?

[The Stig]

As topic title.

I suspect many of my anime are visually fine, but the sound quality is unbelievably high. I wish to reduce the file size to an acceptable amount but not reduce the visual quality.

For example, coalgirls encode their stuff with FLAC which is where the bulk comes from I think. I will probably never in my life own equipment capable of taking full advantage of this. I wish to re-encode the whole file to an acceptable file size standard and not lose any visual quality and to a mp3 (or equivalent, I can't tell the difference) or something where it's more manageable.

Sorry in advance if I hurt anyone's feelings. I understand some must have the top of the range encode. But my budget does not allow this. Maybe in another life/universe.

[Stromgarde]

Use VirtualDub, direct stream copy for video, encode the audio to AAC or something else that is more sensible.

Edit: Handbrake is also good for this, and has a better interface.

[Niya]

Tried around with some of my anime treasures.
An episode encoded by Elysium (720p, video H264, audio FLAC) with a total size of 535MB contains a FLAC track that's about 153MB.
An episode encoded by Chihiro (720p, video H264, audio AAC) with a total size of 166MB contains an AAC track that's about 19MB.

Those are pretty much the extremes of both ends in my 720p collection: Elysium (and coalgirls) go for maximum quality with acceptable file size, and groups like Chihiro aim for minimal size with still good quality.
The H264 codec has so many screws to tune, you'd have a hard time getting similar video quality as you currently have with a re-encode since each new encode automatically means quality loss.

One thing you could do would be to extract the FLAC tracks, re-encode them to AAC/MP3, and then re-mux them into the video. That would reduce the file size by 100+MB without touching video quality. https://mkvtoolnix.download/

Or, simply look for another release of the anime by another group that used a smaller file size target.

Should you really want to fiddle with muxing/re-encoding, these are the track details from both video tracks:
Elysium

Spoiler: show

Format : AVC
Format/Info : Advanced Video Codec
Format profile : [email protected]
Format settings, CABAC : Yes
Format settings, ReFrames : 4 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 26mn 50s
Width : 1 280 pixels
Height : 720 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 23.976 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Writing library : x264 core 114 r1900 60ef1f8
Encoding settings : cabac=1 / ref=4 / deblock=1:0:0 / analyse=0x3:0x133 / me=umh / subme=9 / psy=1 / psy_rd=0.80:0.00 / mixed_ref=1 / me_range=24 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=0 / chroma_qp_offset=-2 / threads=6 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / constrained_intra=0 / bframes=6 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=1 / weightp=2 / keyint=250 / keyint_min=23 / scenecut=40 / intra_refresh=0 / rc_lookahead=60 / rc=crf / mbtree=1 / crf=18.0 / qcomp=0.60 / qpmin=0 / qpmax=51 / qpstep=4 / ip_ratio=1.40 / aq=1:1.10

Chihiro

Spoiler: show

Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4
Format settings, CABAC : Yes
Format settings, ReFrames : 6 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 21mn 9s
Nominal bit rate : 971 Kbps
Width : 1 280 pixels
Height : 720 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 23.976 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.044
Writing library : x264 core 67 r1139M 1024283
Encoding settings : cabac=1 / ref=6 / deblock=1:1:1 / analyse=0x3:0x133 / me=umh / subme=9 / psy_rd=0.0:0.0 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / chroma_qp_offset=0 / threads=3 / nr=0 / decimate=1 / mbaff=0 / bframes=8 / b_pyramid=1 / b_adapt=2 / b_bias=0 / direct=3 / wpredb=1 / keyint=250 / keyint_min=25 / scenecut=40 / rc=2pass / bitrate=971 / ratetol=1.0 / qcomp=0.60 / qpmin=10 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / ip_ratio=1.40 / pb_ratio=1.30 / aq=1:1.00

@Strom I looked into Handbreak too and wanted to suggest it, but it seems it doesn't offer a "stream copy" option for the video track, it always wants to re-encode.

[Stromgarde]

@Strom I looked into Handbreak too and wanted to suggest it, but it seems it doesn't offer a "stream copy" option for the video track, it always wants to re-encode.

Ah, that's a shame. Good old VirtualDub will get the job done then. See the following link for help regarding batch conversion:
http://www.animemusicvideos.org/guid...pp-vdub.html#5

[Gryffes]

Avidemux will do the job copying source vid and re-encoding audio.

https://sourceforge.net/projects/avidemux/

[The Stig]

Nice guys!!

I'm mkvtoolnix muxing my videos first, as I actually downloaded 2 copies (1 HQ 1 LQ), I'll join them up for now.

I'll fiddle with virtualdub/avidemux after/later on my other files. This is working great.

edit: this is really handy, I have a cantonese copy of some of my anime, I can mux them all together and save more space! Just need to be careful on the audio timings on some.

[Prothescar]

Going to second the guy who said Handbrake. Easy to use, highly configurable, does a great job at reencoding and compressing video without quality loss if you set it up right.

[The Stig]

Thanks, I shoved handbreak through one of my 7.5gb files (was a movie) and it reduced it to 2.7 something.

Don't notice any difference. I can settle with this for stuff I can't reduce reliably.

On a series I really care about I'll acquire the best quality I can find.