Roku player error: malformed data - BigRic

[BigRic]

I am having this problem on two brand-new TCL/ROKU devices. I have an older HiSense/ROKU on the same network that works fine (and a Samsung that natively supports browsing channels using the media player). I noticed on the TCL that if I run the Roku Media Player (which is what the error shows during the HDHR app launch of a channel), it fails too - basically, it thinks the MPEG stream/file is corrupt. I've tried wired and wireless with no change. I bought these TVs specifically for the ROKU functionality after trying it on the HiSense (moved to TCL as they support Alexa too). Anyone find a fix for this yet? Both TV's straight from registration to app install and both do the same thing. Splash screen, successful grid load of channels and then as soon as I launch a channel, the screen goes blank and then throws the mediap player / malformed data errror and about 1/2 bar across the screen.

Model: HDHR3-CC
Device ID: 1321C0FC
Firmware: 20250623

[NedS]

Unfortunately there's not much that can be done in that situation when it comes to Cable TV channels in the Roku app. They tend to have extra data that confuses the Roku video player.

[BigRic]

Isn't the whole purpose of the HDHomeRun app to be able to watch cable via the Prime from other devices? I use it on my laptop and half of my TV's (2 of which are also Roku devices). That's the only reason I have the device to begin with...

[nickk]

I can check the channel data...

Clicking the following link will make a 60 second capture of channel 2:
http://hdhomerun.local:5004/auto/v2?duration=60

(ok to replace v2 with a different channel number)

Once the download is complete please upload to a share site such as Google Drive and PM me the link.

I will replay the capture here on my Roku and check what is happening.

[BigRic]

@Nickk, Not able to PM yet as a new user, but I don't think there's much risk in posting this here: [link removed by moderator]

Downloaded file plays perfectly fine on my PC... This channel (2), doesn't play on Roku, but many others do. It's a total crap shoot. If you want to see an example of one that works fine, let me know. Out of curiosity, doesn't the PRIME convert the incoming cable into MPEG for viewing by the end-station? If so, why would the channel matter? Wouldn't the conversion eliminate any native cable channel differences?

[BigRic]

Another question / suggestion - is there any way that the app could "trap" this error before bombing out? There's no way to know which channels this will happen on and when it occurs, you have to completely exit the app and start over. When you do, you still don't know which channels will be impacted, so you have to basically use trial and error to watch anything. Would be helpful if the app would try loading the stream in the background and if it throws the error, prevent the user from selecting it (perhaps mark the channel as not streaming properly). Otherwise, it's really burdensome to use it at all, negating many of the benefits. I've been using this product forever and just started to use it on SmartTVs (didn't know there was an app for Roku). The web version works so well that this is a real disappointment.

[nickk]

Downloaded - thanks. I will test here...

[BigRic]

One more piece of the puzzle. I have a Samsung TV that has a discovered devices app, which identifies the HDHR. If I browse the channels and play them, they all work without any issues. It just seems to be the Roku app / Media Player that's having problems.

[jasonl]

Many cable providers insert signaling data for local ad insertions and other behind the scenes stuff on the ID used for the program map table, which tells the decoder where to find the audio, video, and other data associated with a single service in the overall data stream. This is a perfectly valid thing to do, and parsers that are designed to handle cable TV look at a header in the table and decide it isn't something they care about and just ignore it and look for other tables they do care about. Roku's parser, not being designed to handle cable TV, does not do this, and barfs when it comes across it. It is 100% a Roku bug and also one that has been reported to them and is one they will not fix because they do not support cable TV and do not fix bugs related to unsupported uses.

[BigRic]

Kind of frustrating. Customers who pay both SiliconDust and Roku for what would seem to be a pretty basic feature (and the main reason the HDHomeRun platform exists, no?), end up without a workable solution. Can't we at least get an app that traps the problem instead of locking up the app, requiring us to start over with hit or miss attempts to figure out which channels work and which don't? Many of them work, but figuring it out for hundreds of possible channels, on every TV, is a nightmare.

[NedS]

Roku works overwhelmingly with over-the-air broadcasts, which is the bulk of our users. When we came out with the Roku version of our app we had already discontinued the PRIME, but we were able to bring the PRIME back for one last production run. Roku actually improved their video player a little bit and some cable TV channels started to work, when before almost none of them did. Roku is the only one who can fix this, because on their platform we are forced to use their video player. On other platforms we are able to write our own video player code.

We do what we can to support CableCARD/PRIME users for as long as we can, but CableCARD is on its last legs. Most major cable TV providers won't even issue new CableCARDs.

[BigRic]

Thanks Ned, but then what are the options for those of us that want to leverage a single cable connection to get channels to all of our new TVs, using the same Ethernet (or wireless) that runs to those locations? Those channels are still familiar and used by everyone in our home. It simplifies streaming as I don't need to parse together a bunch of other streaming accounts to aggregate all of the channels I care about. Also, I did some experimentation and it's starting to make more sense to me (the “malformed data” errors some of us encounter when using the HDHomeRun Roku app). I understand from previous replies that Roku’s MPEG-2 transport stream parser is strict and can reject certain streams if the initial PAT/PMT tables or headers aren’t perfectly in place at the moment playback begins.

That explanation makes sense — but I’d like to share my experience with Plex as a point of comparison. On the same Roku device, with the same HDHomeRun Prime channels (including those that fail in the HDHomeRun Roku app), Plex’s Roku app in “experimental MPEG-2” mode is able to play them without the malformed data error. From what I can tell, Plex still Direct Plays MPEG-2 to Roku, but based on some research, it does a small amount of session prep before handing off the stream:

- Waiting for a complete PAT/PMT set and a keyframe before playback begins
- Optionally trimming the first few packets if needed
- Initiating playback only after the stream start is “safe” for Roku’s parser

This isn’t a full remux or transcode — the video and audio are untouched — but it’s enough to avoid the error. That suggests it’s technically possible to mitigate the issue in software without waiting on Roku to change their firmware. I realize Roku’s TS parser limitations are outside your control, and you’ve got to prioritize your engineering time across many platforms. Still, given that Roku is a large part of the streaming device market, and that this approach seems to work in other apps, maybe SD could consider adding a short buffer/startup validation step in the Roku app’s playback path? Even if it added a fraction of a second to channel changes, I suspect many users would prefer that over the current error behavior.

I’m not suggesting a rewrite of the app — just a lightweight “stream sanity check” at tune-in, similar to what Plex appears to be doing. If that’s on the roadmap or being explored, I think it would make a noticeable difference for Roku users and reduce support frustration on both sides.

Thanks for considering, and for all the work you do keeping HDHomeRun platforms running across so many different devices.

Thanks again for your time. I appreciate all of the feedback!