What video compression does Comcast/Xfinity use?

[peggypwr1]

Hello when recording shows on the DVR, what compression or codec do they use?

Is the same codec used for streaming?

OTA HD is mpeg 2 ...do they use the same thing?

[johnmeyer]

Hello when recording shows on the DVR, what compression or codec do they use?

Most DVRs use no compression at all. Instead, they just record the bits coming in from the satellite/cable/phone company and then, when you want to watch the program, those bits are just streamed off the hard disk. You therefore get the identical bits as if you watched the program live.

Absolutely zero degradation or difference from live, unlike what happens when you code and decode (codec) a video signal.

Years ago (late 1990s) when DVRs first came on the scene, we were still watching analog video off the air or analog video over cable. Those analog signals DID need to be encoded, and companies like ReplayTV (who pioneered the original DVR) had a codec embedded in the DVR that would take the analog signal and convert it to digital so it could be stored on a hard drive.

However, once TV started being delivered digitally, the need for a codec vanished.

[edit]In re-reading the OP's post, I note that the heading for the post actually asks a different question than the post itself. If you are asking what compression Comcast/Xfinitiy uses when compressing their signal for delivery, I have no idea, but I'm sure you can find the answer via Google.

[usually_quiet]

Hello when recording shows on the DVR, what compression or codec do they use?

Is the same codec used for streaming?

OTA HD is mpeg 2 ...do they use the same thing?

I have Comcast/Xfinity service. They broadcast both HD and SD local OTA channels and cable-only SD channels using MPEG-2 but they broadcast HD cable-only channels using H.264. HD locals are broadcast at their OTA resolution. All HD cable-only channels are broadcast at 720p.

I've never used one of their DVRs or their Cloud DVR service so I don't know if any of their DVR options compress recordings again to use less space for storage. I read that the new X1 DVRs don't allow keeping your recordings indefinitely. The X1 boxes allow keeping recordings for one year at most.

Streaming uses H.264, for the most part, but YouTube uses VP8 or VP9 and UHD streams tend to use H.265.