Why don't Blu-ray players use SSD/HDDs?

[Jonathan McLeod]

Couldn't find a suitable general thread to drop this question in and googling isn't bringing up many relevant results.

Anyone know if there is a technical/practicality reason why Blu-ray players don't utilise SSD/HDD to copy the entire disc as it plays rather than constantly spinning the disc?

Playback from a drive would avoid read errors/difficult layer transitions that always reading from the disc causes and would mean that the disc only had to be spun up during the beginning of playback.

You can still require a disc check to permit continuous playback so I don't see any piracy issues.

Anyone any idea why this isn't done?

[gkolb]

Since you mentioned the exact copy/ piracy angle, my guess is it’s the huge reason.

[Jonathan McLeod]

But you can still have it checking that the actual disc is present in the drive. I know these checks can be spoofed, but at that point your looking at more effort that just obtaining the disc ISO.

[gkolb]

Originally Posted by Jonathan McLeod

But you can still have it checking that the actual disc is present in the drive. I know these checks can be spoofed, but at that point your looking at more effort that just obtaining the disc ISO.

The BDA will be worried the copy will be cracked and thusly pirated, imo.

[nick4Knight]

Originally Posted by gkolb

The BDA will be worried the copy will be cracked and thusly pirated, imo.

Yeah that would be bad if they did even slightly less it would allow open piracy. Because zero of them have ever been cracked on home video format while they were putting anti-measures in.

[Lee A Stewart]

Just Google Japanese Blu-ray Player/Recorder. It won't do what you want though - copy a disc to the HDD

[David M]

Originally Posted by Jonathan McLeod

Couldn't find a suitable general thread to drop this question in and googling isn't bringing up many relevant results.

Anyone know if there is a technical/practicality reason why Blu-ray players don't utilise SSD/HDD to copy the entire disc as it plays rather than constantly spinning the disc?

Playback from a drive would avoid read errors/difficult layer transitions that always reading from the disc causes and would mean that the disc only had to be spun up during the beginning of playback.

You can still require a disc check to permit continuous playback so I don't see any piracy issues.

Anyone any idea why this isn't done?

Because there'd be little to no point, on top of greatly increasing the price of the player and greatly reducing the convenience/ease of use.

You'd rather wait 40-50 minutes to "install" the film to some kind of in-built storage before watching it? And then presumably have to manage what was stored on the drive when it got full?

Streaming off the disc in real time isn't so unreliable that it would warrant this sort of thing.

[Fendergopher]

I suspect it's the content owners/rights holders that get antsy about copy protection, more so than the BDA as such. And no content = no lucrative format.

[Jonathan McLeod]

Originally Posted by David M

You'd rather wait 40-50 minutes to "install" the film to some kind of in-built storage before watching it? And then presumably have to manage what was stored on the drive when it got full?

Little-to-no wait required. I was thinking of it as a sort of full disc sized cache, where instead of just the next few minutes or however long being held in the buffer and it having to be constantly read "on demand", the whole disc was copied across at the beginning.

It would solve the stuttering problem Sony/LG players have with layer transitions, as it wouldn't matter if the drive had to retry reading data and/or stop start between layers.

I wasn't thinking in terms of actually permanently storing the data on a drive, because as you point out it would take a long time to transfer and 4K films take up enormous amounts of storage capacity that doesn't come cheap.

[Geoff D]

So you want it copied/buffered to the drive just for 'then and there' playback? I get the reasoning behind it but no, no manufacturer is going near that. It's a shame that 4K has had so many playback issues - which David could perhaps illuminate for us as to why - but no-one's going to change the entire way the discs are played back in hardware terms this late in the game. Hell, the major players that remain in the hardware market haven't even released any new models for a good few years, never mind adding in such an esoteric feature as this.

[David M]

Originally Posted by Jonathan McLeod

Little-to-no wait required. I was thinking of it as a sort of full disc sized cache, where instead of just the next few minutes or however long being held in the buffer and it having to be constantly read "on demand", the whole disc was copied across at the beginning.

You're very mistaken if you think copying an entire disc would involve little to no wait. I don't imagine that the drives in BD players are designed for anything faster than standard speed playback.

I wasn't thinking in terms of actually permanently storing the data on a drive, because as you point out it would take a long time to transfer

The permanance or impermanence of it wouldn't make any difference. The data would still need to be copied, regardless if it was deleted afterwards.

[BrownianMotion]

Theoretically, using a super fast SSD - such as a PCIe 4.0, or even the upcoming PCIe 5.0, NVMe SSD would result in extremely fast transfer times, especially if the storage stack of the Blu-ray player was optimized for batch I/O requests. Just look at what they are doing with fast SSDs in gaming.

The problem is that this would substantially increase the price of the player and it won't improve the real-time playback performance (I would know - I've played back numerous movies off of my PCIe 4.0 SSD.) While even a slow HDD will be faster than a blu-ray disc, video playback is not an I/O heavy task at all.

Additionally, SSDs aren't particularly good devices if you are looking for long term archival storage due to "bit rot."

It wouldn't make much sense for Blu-ray players to use SSDs or HDDs.

[Anthony P]

Originally Posted by Jonathan McLeod

Anyone know if there is a technical/practicality reason why Blu-ray players don't utilize SSD/HDD to copy the entire disc as it plays rather than constantly spinning the disc?

there is no benefit just extra expense to do that.
1) If the disk is damaged does not change anything
2) if the drive is much faster then playback speed it won't help much at the beginning the difference will be at the end where the data will be waiting longer on the SSD
3) if the data is read wrong and it creates the issue in playback that issue would have been transferred to the SSD and only found out when it is getting processed for viewing.


I guess the decoding could be done in real time and uncompressed AV saved on SSD for playback and it goes back to the disk if there is an issue but then you would need a huge SSD for that and you would still have #2

Originally Posted by David M

You're very mistaken if you think copying an entire disc would involve little to no wait. I don't imagine that the drives in BD players are designed for anything faster than standard speed playback.

don't know what drives are in most players. But you can easily and cheaply buy a drive that can read/write more than 4x that of UHD BD.