I discovered something interesting and nice during 2x playback speed.
On two of my units (Homeworx HW-150PVR) that have v14 firmware (HW Version 7816-ATSC-03), I can press the volume up once and the sound will play back at the 2x speed without the chipmunk effect better than when using Windows media player for Windows 7 on .mp4 files. Every time that the unit auto-mutes the sound for 2x speed, you can unmute the sound via the remote control by pressing volume up once (successfully).
I have a third Homeworx HW-150PVR that has v1 firmware (HW Version 7816-1237-ASTC-v2) and this same functionality is missing
--why is that so if all these listed firmware configurations are supposedly the "latest." Evidently this is not exactly true unless the CPU hardware is not up to snuff on the units that "cannot" support this supposed undocumented nice feature. If this is not the case, why not issue updated v1 (etc other versions) firmware to include this missing functionality?
Missing functions that might improve recorded show playback are 1.1x, 1.2x, 1.3x, 1.4x, 1.5x, etc, up to the existing 2x speed playback, and a means to skip forward in the show 1 minute, skip forward 10 seconds, skip backward 1 minute, skip backward 30 seconds so that commercial ads can be "navigated" as nicely as possible.
I have two of my units working with half-full 4 Tbyte WD or Seagate USB 3.0 external drives (My Book and Backup Plus respectively) and the third is using a 2.5 inch 1 Tbyte WD blue series inside a Vantec brand USB 3.0/eSata external HDD enclosure.
So far, the only corruption that I see happening on the larger drives is when multipath signal interference causes a HW-150PVR to crash in the middle of a recording, thereby causing a misallocation of free disk space that is easily correctable via Windows 7 disk check function.
When the PVR checks the bigger drives, the HW-150PVR reports the total and unused disk space correctly. GNU-Linux / Unix file system drivers seem to nicely deal with these matters?
During Live TV the closed captions work, but during playback they do not. What's up with that? Can't this be "fixed" to work in both situations?--after all, the recorded file data is just what the broadcaster sent out in the first place...
When I get this multipath signal interference, the signal strength is 60-95%, but the picture is pixelated and the sound breaks up, and often the picture blanks out completely or the video displays the last frame that was received properly with some pixelation noise scattered all over it. Unfortunately, these files cause some windows video playback software to halt or give up and playback within the HW-150PVR is also pretty useless.
This multipath interference happens at irregular times of the day on a channel that I would like to record. Some really weak signal stations come in perfectly with only 3 to 7% signal strength--no pixelation at all. In windows 7 explorer when the "Length" property column is enabled for display, the corrupted recording .mts files have a blank, but the low error or error-free recording files have a proper video duration displayed. It is then just a matter of me manually selecting and deleting the files having no "Length" information being displayed (after suitably long enough time for Windows to have computed those numbers).
I have 3 antennas now:
- 1 on roof mast on top of 2 story house unused fireplace chimney with pre-amp (Digiwave $78.99  ANT-7286 Super 8 Bay Ultra Clear Outdoor HD TV Antenna) (preamp=Digital Signal Amplifier for Indoor Antennas @ Princess Auto--RCA Model AMP1450R that I encapsulated in a thick clear plastic milk bag along with its ac adapter for use outdoors attached to antenna with a 4 to 6 inch coax input lead),
- 1 second story attic on a two-way cable TV distribution amp (Digiwave $39.99  ANT-7285 8 Bay Ultra Clear Outdoor HD TV Antenna) (amp=RCA Model DT140M Mini Drop Amplifier "Video Signal Amplifier
- a wall mounted flat unamplified indoor unit on the first floor of my two story house (Digiwave $12.99  ANT-4500 HDTV Super Thin Flat Digital Indoor Antenna).
I have tried these antenna signal sources:
- one at a time either amplified or unamplified,
- diplexed two at a time (backward through 2-way splitter into the distribution amplifier or not), and
- triplexed three at a time (backwards through a 4-way splitter into the input of the distribution amplifier or not)
All of these combinations worked, but did nothing to eliminate or mitigate the multipath signal interference.
I suppose that in a future robust design OTA digital TV receiver / PVR would include a DSP that will manage 3 or more spatially distinct incoming antenna signals to cancel out such multipath signal errors via phase delays, signal arithmetic, signal filtering or "what have you" to eliminate this bothersome situation of multipath signal interference that caused poor reception / pixelation display errors.