Update on "described video" aka "narration"

I am a newbie to the forum so please forgive me if I’ve posted this question incorrectly. I switched to OTA HD about year ago (rural Ontario Canada). To control initial costs and not knowing how this would work out, I went with 2 inexpensive Mediasonic PVR boxes. It turned out OK but the boxes are a bit unreliable regularly missing recording events, loosing connection to the external HDD and recording described video whenever it is transmitted by the station. I am considering an upgrade to the Tablo dual 128 but would like to determine if it is likely to also record any or all described video. Tablo support indicated that it’s pvrs “do not transcode audio” which I take to mean it will also record the described video. I see some posts in the community from 2018 discussing the problem and then nothing noted in the years after. Are users still having this issue or doe’s the lack of posting mean it’s no longer an issue,
Stay safe folks.

1 Like

From my understanding, the Tablo does not record the described video audio track. It just records the main audio track which doesn’t have the described video audio.

My understanding - this is not accurate – Tablo Tech Support Knowledge Base article , Advanced & Technical Questions: In what format does Tablo save the video/audio stream to the hard drive?

This article also states audio is transcoded: What compression/audio video codes does Tablo use?

I know the *.ts segments play audio and video and have not seen audio and video stored separately

also to note: If tablo’s tech support are referring to their devices as “pvr” while all their products pages and marketing uses DVR… well, yea, they do transcode audio along with video

1 Like

You are correct. The audio is transcoded if the surround sound feature is off. The links you posted are right.

Thank you to theuser86 and djk44883. Maybe I just misunderstood the response I received from support. In any case, it looks like the Tablo is an appropriate choice…thanks again

Isn’t the audio transcoded either way? It either takes the AC3 track or the stereo track depending on how the user sets it up.

I may be wrong but usually “transcodes” means to convert from one format to another.

When surround sound is off, the Tablo transcodes the 5.1 AC3 audio track to 2.0 AAC.

When surround sound is on, the Tablo just extracts the 5.1 AC3 audio track from the OTA stream. It doesn’t touch the audio. No transcoding going on here (if I’m using the term correctly).

Still having issues with described audio on fox kljb-dt quad cities.

AC3 vs AAC isn’t the issue here, it looks like the TabloTV is only streaming one audio channel. Is there are way to get multiple audio streams output? I alos thought there was a legal requirement not to strip out DV in the US.

1 Like

You mean one audio track? The transcoded 2.0 AAC audio is 2 channels, and the 5.1 AC3 audio is 6 channels.

No not channels. I mean the two (or more) AC3 audio mpeg-ts streams that are typically in ATSC 1 broadcasts. They all need to be available.

This was my local broadcasters response. It seems Bob Berger is waiting to hear bac from Tablo TV Support. So they are ready to address the problem when Tablo TV is. Please respond, Tablo TV Support. I also emailed this to info tablotv.com and put it on the contact page. Waiting for a response.

Date: Thu, Mar 10, 2022 at 9:37 AM
Subject: RE: Broadcasting Fox 18 kljb descriptive audio by default

Hi Tom,

Thanks for reaching out and we’re sorry for your issues watching KLJB. I can assure you that the broadcast signal for KLJB meets and exceeds federal broadcast requirements of the FCC. We’ve had a handful of Tablo users contact the station. Our Chief Engineer, Bob Berger has been attempting to reach out to Tablo Support for specific information, but they have not responded to his calls and emails.

This issue only affects Tablo users. Tablo support has been less than helpful and trying to blame the broadcasters for the wrong audio. But as all cable, satellite and antenna viewers, other than Tablo users are receiving the correct audio, this would suggest that their equipment locks onto the secondary audio program in the stream (SAP), which is a feature we are required to broadcast, as Tablo is also required to have the ability to turn this feature on and off on the DVR. By what we have heard from other Tablo users, there is no option for SAP/MTS to select descriptive audio or available foreign languages on their equipment.

As I’ve mentioned, we have asked Tablo support for user manuals to assist in resolving this issue and have received no response. Bob, do you know of any short cuts or ways Tom can enhance his viewer experience?


Patty Gilbert
Operations Manager


231 18th Street
Rock Island, IL 61201

Bob’s response.

Thank you Tom,

We have gone rounds and rounds with Tablo over this. Only their equipment is affected. All antenna viewers, cable companies and satellite companies are receiving us fine.

We believe the problem is that the Tablo equipment does not have the ability to switch between audio programs, such as descriptive audio, secondary audio (foreign) program, which we are required to broadcast along with the standard audio.

All receiving equipment is required by the FCC to be able to select/deselect these options. All cable boxes and satellite receives and HDTV’s have this option.

Tablo has been less than responsive to put it mildly. I will attempt to reach out again.

Bob Berger

Chief Engineer


231 18th Street

Rock Island, IL

309-283-2393 Direct

309-786-5441 ext. 305 Office

701-720-8208 Cell

Do other stations in area do this also?

no. and this does not happen for WHBF Channel 4 which the same television provider manages WHBF Channel 4 and Fox 18 KLJB which does have the described video issue happening. Please advise and work with the chief engineer who is reaching out to Tablo TV.

Every sunday I record WHBF CBS Sunday morning and watch it and it does not describe the video, every wednesday while watching/recording KLJB Masked singer it has a woman’s voice drone on describing the video action that is occuring.

After further investigation, we have confirmed the broadcaster has these stations configured with non-compliant values resulting in incorrect audio track being selected. We have sent the details to the broadcaster with instructions on how to resolve the issue for users in this area.

Ok. I am checking with the broadcaster to confirm they have received your instructions and am confirming a scheduled time when those instructions can be carried out.

Just to confirm/clarify, the instructions you provided to the broadcaster will allow the to send to me and me to receive the broadcast over my Tablo TV device in English without descriptive audio. There is no way for me to control my Tablo TV device so that if in the unlikely event I as a user want to turn on descriptive audio or Spanish dubbed TV shows that I am able to turn that feature on. Correct? Please confirm.

All I see in these posts is that the station’s channels can/will fix their metadata so that tablo doesn’t select the descriptive audio as the default audio.

Is there anything in these posts that indicates that after the change a user can select a language or descriptive audio for playback?

Also in quad cities… Having same issue with wrong audio being recorded. I’ve had Spanish recordings during football games and descriptive audio during sitcoms.

Tablo, please update your software to allow users to choose the audio stream. I don’t mind a larger recorded file as much as I am annoyed about not being able to choose my audio stream. If my blind friend were over, it would be nice to have the option to switch.