3 ms·

eARC is important not only because cable management and CEC, but because it's the only high bitrate digital audio output on most TVs: the only other commonly av

eARC is important not only because cable management and CEC, but because it's the only high bitrate digital audio output on most TVs: the only other commonly available digital audio output, TOSLINK, is limited to two-channel PCM[1], AC3, and DTS. [1] While the physical TOSLINK cable is able to support higher channel counts via ADAT[2], I'm not aware of any TVs with ADAT support. Similarly, while 192 kHz / 24-bit TOSLINK support is common in pro audio and audiophile gear, the standard only requires 48 kHz / 20-bit. I imagine most TVs output 48 kHz / 20-bit, if only for the sake of configuration simplicity: TOSLINK is strictly unidirectional, so automatically negotiating format support beyond mandatory minima is impossible. [2] https://en.wikipedia.org/wiki/ADAT_Lightpipe https://en.wikipedia.org/wiki/ADAT_Lightpipe

simoncion 3y ago
> ...[eARC is] the only high bitrate digital audio output on most TVs... Great news! DisplayPort supports: > 1–8 channels, 16 or 24-bit linear PCM; 32–192 kHz sampling rate; maximum bitrate 36,864 kbit/s (4,608 kB/s)
- babypuncher 3y ago
  But it doesn't support any of the common bitstreamed audio formats like Dolby Atmos or DTS. eARC lets your TV pass those along to your compatible receiver even if the TV itself can't make heads or tails of the format.
  - simoncion 3y ago
    > But it doesn't support ... Dolby Atmos or DTS. No, I think you're wrong about that. > DisplayPort v1.2 also adds new audio enhancements including the following: — Audio Copy Protection and category codes — High definition audio formats such as Dolby MAT, DTS HD, all Blu-Ray formats, and the DRA standard from China — Synchronization assist between audio and video, multiple audio channels, and multiple audio sink devices using Global Time Code (GTC) MAT claims to require an Atmos-capable decoder, so that sure seems like Atmos to me. I dunno what DTS HD, but that sounds like a souped-up DTS. Also take note of the "High definition audio formats such as" statement... that list of formats is incomplete. The quote comes from: <https://vesa.org/press/vesa%C2%AE-introduces-displayporttm-v1-2-the-most-comprehensive-and-innovative-display-interface-available/ https://vesa.org/press/vesa%C2%AE-introduces-displayporttm-v...>
  - simoncion 3y ago
    > eARC lets your TV pass those along to your compatible receiver even if the TV itself can't make heads or tails of the format. DisplayPort Multi Stream Transport (MST) serves that role. Given that you'd only be passing along the audio data, rather than the video data, you could save money by putting the slowest available hardware (only BRR-capable) into the receiver. Or, the TV could "just" pass along the audio stream to any plugged-in receiver. You don't gotta have a standard for that... just a standardized way to ask the TV to do it (assuming that you want to control the behavior and not have the conditional be "Is there a receiver plugged in? Pass along the audio and don't send it to the TV speakers.").

simoncion 3y ago

> ...[eARC is] the only high bitrate digital audio output on most TVs... Great news! DisplayPort supports: > 1–8 channels, 16 or 24-bit linear PCM; 32–192 kHz sampling rate; maximum bitrate 36,864 kbit/s (4,608 kB/s)

babypuncher 3y ago
But it doesn't support any of the common bitstreamed audio formats like Dolby Atmos or DTS. eARC lets your TV pass those along to your compatible receiver even if the TV itself can't make heads or tails of the format.
- simoncion 3y ago
  > But it doesn't support ... Dolby Atmos or DTS. No, I think you're wrong about that. > DisplayPort v1.2 also adds new audio enhancements including the following: — Audio Copy Protection and category codes — High definition audio formats such as Dolby MAT, DTS HD, all Blu-Ray formats, and the DRA standard from China — Synchronization assist between audio and video, multiple audio channels, and multiple audio sink devices using Global Time Code (GTC) MAT claims to require an Atmos-capable decoder, so that sure seems like Atmos to me. I dunno what DTS HD, but that sounds like a souped-up DTS. Also take note of the "High definition audio formats such as" statement... that list of formats is incomplete. The quote comes from: <https://vesa.org/press/vesa%C2%AE-introduces-displayporttm-v1-2-the-most-comprehensive-and-innovative-display-interface-available/ https://vesa.org/press/vesa%C2%AE-introduces-displayporttm-v...>
- simoncion 3y ago
  > eARC lets your TV pass those along to your compatible receiver even if the TV itself can't make heads or tails of the format. DisplayPort Multi Stream Transport (MST) serves that role. Given that you'd only be passing along the audio data, rather than the video data, you could save money by putting the slowest available hardware (only BRR-capable) into the receiver. Or, the TV could "just" pass along the audio stream to any plugged-in receiver. You don't gotta have a standard for that... just a standardized way to ask the TV to do it (assuming that you want to control the behavior and not have the conditional be "Is there a receiver plugged in? Pass along the audio and don't send it to the TV speakers.").