[theduke6578]

Ok im looked for a while before i posted and couldnt find anything so i hope someone can help. I have a ps3 hooked up hdmi to my receiver the samsung htas720 with 5.1 expandable to 7.1. I know the ps3 can decode dd true hd and dts hd master audio. I am just wondering how to increase my audio bit rate. I just watched the dark knight running in dd true hd and it was running on average about 2.3 Mbps. Dolby says it can go Up to 18 Mbps bit rate. I am wondering what effects the bitrate and how can i maximize it? Is my ps3 or receiver limiting it? Is that how much everyone gets with their setup because the disc only puts out that much? Does 7.1 put out a higher bit rate? Anything info helps ill even take a link if you dont want to explain. Thanks a lot.

 

[RBFC]

The bit rate is set by the encoding on each disc. The maximum bit rates you referred to are just the "ceiling", not the typical actual bit rate. So, each disc gives you what you get. You can't adjust it.


Lee

 

[theduke6578]

thank you. just one more thing does sending the audio bitstream or pcm effect the bitrate? I know people freak out when it comes to that and claim one is better then the other but i cant find anywhere if it effects the bitrate. Thank you

 

[SiriuslyCold]

compressed audio is compressed so that the bit-rate is lower than uncompressed audio. High bitrates used to be an issue because the transport bandwidth was limited. With HDMI, the bandwidth is much more.


for example: 6 channels of PCM audio at 24b/96kHz has a bit rate of >13MBps; using MLP (lossless compression) brings the bit rate down to below 10MBps. Using DTS or DD brought the bit rate down so they can be transmitted via SPDI/F


(see the calculations here )


so to answer your question - compressed audio bitstream will have a lower bitrate than uncompressed PCM

 

[William]



Quote:
Originally Posted by theduke6578 /forum/post/15493144


thank you. just one more thing does sending the audio bitstream or pcm effect the bitrate? I know people freak out when it comes to that and claim one is better then the other but i cant find anywhere if it effects the bitrate. Thank you

Yes, of course since the whole idea of TrueHD and DTS-MA is to compress the data rate.


LPCM data rate for 24-bit/48K is about 1.1Mbps per channel.


EDIT: SiriuslyCold beat me to it. Nice spread sheet. Also would like to add a clarifying caveat. Going to DTS or DD requires perceptual coding which results in a data loss that TrueHD (MPL) or DTS-MA don't.