Bluray Audio Format Supported - And what is minimum audio bitrate?

[VideoFanatic]

My videos are h264 so I would like to know what audio formats work with that.

Also what is the minimum audio bitrate supported.

I can't seem to find either of that information on Google.

[videopoo]

https://www.videohelp.com/hd

[VideoFanatic]

Thanks but that doesn't tell me the min bitrate allowed.

[El Heggunte]

ANY audio format may work well with H264, it depends on the chosen container

As for the "minimum bitrate", each format is a case --- which depends on the sampling frequency, the number of channels, and sometimes, also on "how versatile" is the encoding application.

For starters,

http://en.wikipedia.org/wiki/Comparison_of_container_formats

[jman98]

Most audio encoders work on multiples of 32 so 32 Kbps would be the lowest bit rate you could expect from many formats. I would not personally recommend that bit rate, but you could do it. What's your final video format? MKV container? BluRay? MKV supports audio formats such as AAC and MP3 that are not part of the BluRay spec. We can't really answer your question on what audio formats are supported until we know what your final format is. MKV basically supports everything. BluRay does not. IF you're looking for a good quality "pretty much everything can play it" audio format to use, I recommend AC3.

[yoda313]

IF you're looking for a good quality "pretty much everything can play it" audio format to use, I recommend AC3.

If this is surround sound material I would totally agree. But personally I wouldn't go lower than 384kpbs - 256 at the lowest if space is totally an issue edit - this is my personal preference fyi.

If its stereo than you can really go as low as you want. - edit but you may not like the quality at super low levels - you'll just have to test the lower end of the spectrum to see what is tolerable to you personally.

Ac3 may not work on some off brand media players and if this is intended for a portable ipod type device it might not like ac3. AAC or mp3 would be best for a portable video player - edit of course read the manual to know what the specific devices requirements actually are.

These are somewhat generalities but based on personal experiences.

Jman98 is right we need to know what your final destination is before a more definitive answer can be given.

[VideoFanatic]

I am just making Bluray discs for viewing on a Bluray player connected to a TV. They are low quality samples of my work. I figured out that if I lower the bitrate of the audio then I can fit all my stuff on 1 single layer Bluray disc.

I would just like to know what audio format offers the best compression and what is the lowest bitrate I can use to still give a standards compliant Bluray?

[jman98]

Worry about audio bit rates in general is something like getting all excited about saving pennies, yes pennies, on the purchase price of a new HDTV. You got told what the lowest bit rate you can use is. I told you. Use AC3 audio at 32 Kbps. It will sound like crap but it will meet your needs. For your needs even if you decide to use a higher bit rate, you need to stick with AC3 audio. If you're not going to pay attention to what I'm telling you then I've got better things to do with my time so I'm done here.

[VideoFanatic]

Nice attitude jman98. You told me "We can't really answer your question on what audio formats are supported until we know what your final format is". So I gave you the information you asked for and then you tell me I'm not paying attention to what you're telling me so you're not helping me anymore! You also said "If you're looking for a good quality "pretty much everything can play it" audio format to use, I recommend AC3". Statements like that do not help me. I need to know, yes or no if a standards compliant Bluray that you play on a Bluray player connected to your TV will work with AC3 at 32 Kbps, not "pretty much everything can".

The video is h264 .ts 352 x 240 with borders to make a standards compliant 720 x 480 Bluray. As I said before they are low quality samples of my work. I figured out that if I lower the bitrate of the audio then I can fit all my stuff on 1 single layer Bluray disc.

[El Heggunte]

Stereo AC3 at "average quality" usually means 192kbps (this is Aften's default). 256kbps should be "acoustically transparent" to most people's ears. As for 5.1 channels, you can choose between 448kbps and 384kbps.

Of course, you may use 128kbps (or less) for stereo and 320kbps (or less) for 5.1, but unless it's absolutely necessary, you really should avoid very-low audio bitrates in a Blu-Ray.

[VideoFanatic]

Thanks. Also does AC3 support variable bitrates or just a constant bitrate?

My audio is just 2 channel stereo. Could you also confirm if there's a better compression audio format I could use than AC3 which will still give me a standards compliant Bluray and does that have a minimum bitrate?

[El Heggunte]

AC3 itself does support VBR-encoding, however I serious doubt the firmware of most / any BD-players supports VBR AC3, even if the BD specs happen to allow that. AFAIK, only the lossless formats (TrueHD and DTS-HD Master Audio) use VBR, and only because they MUST do so.

Unfortunately there is no better "bitrate-saving" audio format for Blu-Ray than AC3.
AAC is not part of the Blu-Ray specs because of purely commercial/political reasons.

[VideoFanatic]

OK that's concrete enough. Thanks for your help.

[yoda313]

I guess I'm curious as to why you (holygamer) are so concerned about space on a bluray disc. Especially for standard def material.

Can you burn dual layer bluray discs? If so than you would not have to sacrifice audio quality at all. Yes it would be pricier but if you are this concerned about quality on standard def material on the bluray format why not invest in a dual layer and max out everything?