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Best 5.1 sound settings when creating MP4 w/Handbrake

jjwunderjjwunder Members Posts: 1

I am just getting started with encoding content for streaming.   I'm using MakeMKV to RIP to harddrive and Handbrake to encode file for streaming.   Is this the correct process?   My interest is mainly in DVD and BD concerts that are in DTS and/or Dolby 5.1.

 

I tried several Handbrake Audio Codec settings during encode, and listened to the streamed content on either new Vizio TV or new Sony BD player,  trying either DLNA server or Plex server.   Audio playback is usually 2 channel, sometimes 5.1 or even sometimes absent, depending on settings during encode.   It frequently sounds a little "watery" like cell phone audio.   I presume this is due to compression.  

There are so many different combinations of audio settings which makes this pretty confusing to a newbie :)   The audio from the Vizio TV is fed to the surround system via digital optical cable.   The disks sound excellent and are 5.1 when played directly on BD player instead of streamed.

 

I would appreciate some recommended settings to achieve best possible audio, as close to the actual DVD/BD itself.  I am willing to use the required amount of disk space.

 

Thanks for your help!

 

John

 

 

Comments

  • jmckeejmckee Members, Plex Pass, Plex Ninja Posts: 5,065 Plex Ninja

    A lot of it will depend on what you like. When I was actually converting audio I would have 2 tracks  (I now actually just leave the highest quality audio track in the file and let Plex trancode on the fly to my devices)  

    First Track(5.1):

    AC3, Bitrate 640/448, Mix Down None

    Second Track(Stereo):

    AAC, Bitrate 128, Mix Down Stereo

    I would add the 2nd track for devices that couldn't handle AC3 surround track. While I would lose surround sound, I would still be able to switch to a track that would work so I could still watch my video.

  • jetlagpicturesjetlagpictures Members Posts: 1

    I feel like i've spent an eternity refining my Handbrake settings which evolve with the price of storage dropping. I used to keep the DTS (1500 kbps) track thinking it was necessary but as I wanted to keep file sizes ~3-5 Gb sometimes the video stream was ending up around the same bitrate which made no sense. So now for all movies I do AC3 640 kbps 5.1 channels. It sounds great and I dont have a high end enough sound system to discern it from the DTS. 

  • dancefmlivedancefmlive Members Posts: 4 ✭✭

    @jetlagpictures May i ask, Why encode at 640 if you encode this high sound will be massive in size so,... coming from a guy....hay i dont know much about sound quality but WAV uncompressed would be smaller than 3-5gb's wouldn't it, i mean, i work at a radio station and studio 640k is not even been heard as of yet mp3 is only 320k so why not do that and save space... Just saying correct me please if im wrong

  • tasadar2tasadar2 Members, Plex Pass Posts: 2 Plex Pass

    @dancefmlive 640Kbs is still quite compressed in comparison to an uncompressed WAV. Remember that 5.1 is 6 channels, which means if was encoded with 320Kbs, it each channel would be effectively ~53Kbs. So keeping this up at 448 or above is a good idea. To do a little math, assuming the audio is 48KHz at 16bit with 6 channels, 120 minutes of uncompressed PCM would be ~3.86GB. While the same compressed to 640Kbs would be ~562.5MB.

    In response to the OP, I typically find that the settings @jmckee suggested work well. One thing to add would be to check if there are any tracks that already exist in the source with the desired channels and bitrate, and if so, use a Passthru option to avoid re-encoding.

  • HackissHackiss Members Posts: 1

    @jmckee said:
    A lot of it will depend on what you like. When I was actually converting audio I would have 2 tracks  (I now actually just leave the highest quality audio track in the file and let Plex trancode on the fly to my devices)  

    First Track(5.1):

    AC3, Bitrate 640/448, Mix Down None

    Second Track(Stereo):

    AAC, Bitrate 128, Mix Down Stereo

    I would add the 2nd track for devices that couldn't handle AC3 surround track. While I would lose surround sound, I would still be able to switch to a track that would work so I could still watch my video.

    How do you choose "Mix Down None"?

  • jmckeejmckee Members, Plex Pass, Plex Ninja Posts: 5,065 Plex Ninja

    I normally do it from the command line using ffmpeg which normally just have either a -acodec copy or -c:a copy the first option will just copy all audio streams, the second option allows you to specify specific audio streams.

    For handbrake I just downloaded the latest version to see what is, but it should be this setting (they have an auto pass-through and a separate one for each codec, but I normally match up the codecs just to be safe) :

  • tom80Htom80H Members, Plex Pass Posts: 2,272 Plex Pass

    @jmckee said:
    For handbrake I just downloaded the latest version to see what is, but it should be this setting (they have an auto pass-through and a separate one for each codec, but I normally match up the codecs just to be safe) :

    Correct.
    @Hackiss:the Pass-through options mean that Handbrake won’t touch the audio but keeps it as-is. For streaming purposes this should work with any AC3 ar AAC tracks

  • bjs59bjs59 Members, Plex Pass Posts: 10 Plex Pass
    edited February 11

    Like most I also do two audio tracks (mainly to stop Plex from transcoding on the fly)... I have one AC3 track that is set to Passthru... The second one I transcode and mix down to AAC Stereo Dolby Pro-Logic II... Works and sounds great!!!

  • winspiritwinspirit Members Posts: 24 ✭✭
    edited February 14

    Just a little question:
    Why using AC3 for the 5.1 track and not AAC 5.1 Channels? I've read everywhere that AAC codec is far better than AC3 and use less bitrate...

  • tom80Htom80H Members, Plex Pass Posts: 2,272 Plex Pass

    there's 2 factors:
    1. compatibility
    2. quality loss

    AC3 is widely supported by players/receivers. AAC in its surround configuration is getting more support but is still far behind in my experience. So while basically all players with surround support will play AC3 5.1, not all of them will do the same for 6-channel AAC.

    Both formats are lossy, which means they're compressed by at least in parts cutting stuff away (e.g. frequencies outside the usual hearing bandwidth). They're already compressed when you get them on your DVD/Blu-Ray. Quality won't improve if you compress the compressed format -- as many DVDs/Blu-Rays already include an AC3 track, you can re-use it as-is instead of transcoding it again.

    So while your argument is not wrong (AAC is a more modern standard which can achieve the same quality at a lower bitrate), you need to consider that you're not starting from a flawless source.

  • winspiritwinspirit Members Posts: 24 ✭✭

    Absolutely right. First rule is to avoid re-compressing with lossy format. Use Passthru if you can.

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