What Is Bitstream(Re-encode) And Do I Need A Special Av Receiver

PCM

Bitstream (Audiophile)

Bitstream (Re-encode)

PCM output means that the Blu-ray Disc player itself either passes along the uncompressed multichannel PCM stream that is recorded on the disc, or decodes the high-resolution audio tracks, depending on which soundtrack you select in the disc’s menu (or the player defaults to), and sends the resulting uncompressed digital audio signal to a receiver or surround sound processor via an HDMI. The external processor then performs the digital-to-analog conversion and sends the audio to your speakers.

Bitstream (Audiophile) works just like the Bitstream pass-through option. Instead of decoding the compressed high-resolution audio on the disc itself, it instead sends this information as an un-decoded bitstream via an HDMI to a connected receiver or surround sound processor, which then does all of the heavy lifting, decoding, bass management, and digital-to-analog conversion.

Bitstream (Re-encode), on the other hand, is designed to work with surround sound receivers or processors that lack HDMI connectivity. So, far from requiring a special receiver or processor, this setting was actually designed to allow owners of legacy surround sound systems to enjoy some of the upgraded audio functionality of the Blu-ray format without having to run out and buy a new audio system.

In practice, Bitstream (Re-encode) works a bit like a cross between PCM output and the Bitstream (Audiophile) approach. As with the PCM method, the Blu-ray Disc player takes the disc’s PCM track or decodes the high resolution track to PCM and then mixes all of the disc’s audio internally, including all secondary audio features, like director’s commentary, as well as effects audio, such as the bleeps and blips that accompany menu navigation. PCM is set by default.

Instead of outputting this uncompressed digital audio though, the player then re-encodes the audio as high-bitrate compressed DTS, which virtually any receiver or processor with an optical digital audio input can accept and decode. This, of course, won’t quite rival the audio quality of fully uncompressed digital audio, but it should be a noticeable upgrade from what you’re used to hearing from old-school DVDs.