There are a lot of details we still don’t know about the Fire TV Recast, Amazon’s newly announced over-the-air DVR for Fire TVs that also works with the Echo Show and mobile devices. There are some things that we probably won’t learn until the device ships, but through reading Amazon’s lengthy FAQs page and asking Amazon directly, here are details about the codecs and specs of how the Fire TV Recast records video, stores it, and how it’s played back.
The Fire TV Recast stores all content to its internal hard drive as unprotected raw MPEG-2 video files in their native resolution. This is important because it means that the full 1920×1080 resolution of channels that broadcast in 1080i is maintained for all recordings. Remember, no US channels broadcast in 1080p. They all broadcast in either 1080i or 720p.
When watching content from the Fire TV Recast, whether it’s live or recorded, and regardless of whether you’re watching through a Fire TV, Echo Show, or mobile device, the raw MPEG-2 video files are transcoded to H.264 with a maximum resolution of 1440×720 at 60 frames per second. This is done to ensure compatibility with a wide range of devices, including older Fire TVs that cannot de-interlace 1080i video.
The bitrate and resolution of the transcoded video are adjusted, on the fly, to ensure a highly reliable stream. This is the same procedure used by streaming video from services like Prime Video and Netflix. So, if you’re watching content at home through a Fire TV with a solid connection, you’ll see the maximum resolution and bitrate, but if you’re watching on a spotty mobile connection, the video quality will automatically adjust to keep the stream from dropping. When viewing content through a Fire TV, the Fire TV Recast may switch to a direct one-to-one WiFi connection between the two devices to bypass your home network if it determines that the direct connection will result in a superior video stream.
Transcoding video is a very CPU intensive process, so due to the need to transcode video in real-time, only two devices may watch content from the Fire TV Recast simultaneously. Since recordings are stored in MPEG-2, in order to maintain their full quality, and are transcoded each time they are played, this means that the 2 simultaneous stream limit applies to both live and recorded content.
The number of programs that can be recorded simultaneously is not affected by the number of active viewing streams. Recording is only limited by the number of available tuners in the device. This means that, for the 4-tuner Fire TV Recast, you can be recording 4 channels while two devices are watching pre-recorded content, all simultaneously. For the 2-tuner Fire TV Recast, 2 channels can be recorded while 2 devices stream pre-recorded content. Obviously, if a live channel is being viewed, that will reduce the number of channels that can be recorded simultaneously on either model.
The fact that viewing pre-recorded content does not affect active recordings is important for anyone who was hoping to have 3 or more devices viewing content simultaneously. If two devices are watching something and a third device hops on to watch a live show, while that third device will not be able to watch live, they will still be able to set their program to be recorded so that they can watch it later and not miss it. Again, this assumes there is an unused tuner to use for the new recording.
As far as audio goes, the Fire TV Recast supports Dolby 5.1 surround sound, both for live channel viewing and for recordings. If the playback device does not support Dolby 5.1, then 2-channel stereo audio will automatically be played instead.
Knowing all these video specifications is probably not important for the average consumer who just wants to tune-in and watch a high-quality reliable video stream, which it sounds like the Fire TV Recast will provide. For those of you who have made it this far in the article, you, like me, probably have other plans beyond basic watching.
Amazon’s official stance is that the Fire TV Recast does not support external storage and video files cannot be transferred off of the device. As for external storage, I’d like to point your attention to the unused USB port on the back of the Fire TV Recast. The last time Amazon shipped a device with an unused USB port was the original Fire TV, which they soon updated to enable the USB port for, you guessed it, external storage. I’d say that there’s a pretty good chance the Fire TV Recast will support external USB storage through a future update that arrives after the device is launched.
As for pulling video files off of the internal hard drive of the Fire TV Recast, while it may not be officially supported, I’m confident that the savvy Fire TV community will figure out a way to get to those tantalizing full-quality 1920×1080 MPEG-2 files stored on the device.