BM1000-HDMI (HDMI Encoder) Review

[EnterNoEscape]

This device was brought up in this thread. I figured I should start a new thread to review it.

When I opened the box, one thing I checked immediately was that the power cord voltage matched the unit voltage of 12v. One commenter discovered he got the wrong power cord and had all kinds of issues with the unit dropping out. I like that the enclosure is made of decent quality aluminum. Throughout testing the box didn’t even get warm. Everything was easy to understand and hooked up without any issues. I assume my STB uses HDCP and it was not an obstacle to being able to stream.

The default IP address is 192.168.1.168 which thankfully can be changed. It would have been even nicer if there was a way to auto-discover the device, but I guess we can’t have everything. Once in the web interface I was a little disappointed to see that the video capture rate tops out at 30fps (this can be worked around, see below). Also, when you change any “main stream” (video encoding) settings, the device needs to be rebooted which takes at least 20-40 seconds (it seems to depend on what you changed). The latest firmware (4.0) was already installed.

The default video quality is ok for 1080i encoded to 1080p 30fps, and it gets better when you bump the bitrate up to 12000. The default of cbr is good with 1080i and that bitrate. However, I think the biggest impact comes from using a vbr stream and playing around with the video quantizers. I set qmin to 1 and qmax to 51. The result is when the picture isn’t moving much it’s very sharp and when there is a lot of action it gets a little softer. If you make these values too narrow and aggressive, the picture can get jumpy, so you need to find a balance or if the defaults are good enough for you, leave it alone. I settled on key frame 30, qmin 3, qmax 32. My wife couldn’t decide which one looked better when watching a both as a live feed side-by-side, so that’s a very good sign.

I was very skeptical about how well the deinterlace filter would perform. It’s better than I expected, so I think I’m ok with using it full time. I noticed on a few commercials that it seemed to forget the content was interlaced, but I didn’t see this happen once on actual show content. Tickers at 1080i to me look about the same as they do when using an average quality deinterlacer; acceptable unless you can’t stop looking for flaws.

720p content upscaled to 1080i by the STB looks ok until there’s fast motion. Then things get far too blurry; it could be the STB, I don’t have much experience on this one. My first STB was rented because I was buying an HD-PVR. Note that on normal TV such as sitcoms, this doesn’t seem to be an issue, but when watching baseball for example, it’s very distracting. I think this might have to do with the shows source content framerate. Also 720p content straight from the STB upscaled by the encoder to 1080p looks noticeably worse than just encoding it at 720p. Since 720p is normally 60fps, tickers have a little bit of flutter as they are scaled to 30fps. If you watch a lot of sports, I don’t think this will make you happy. I understand that you can find encoders similar to this one that can positively do 60fps, but they are a little pricier (this limitation can be worked around, see below).

1080i downscaled to 720p by the STB, then captured at 720p 30fps looks just as bad as it does on the HD-PVR when it’s doing it at 60fps. There’s nothing good to say about this configuration. 1080i downscaled by the encoder to 720p 30fps is only marginally better.

Beyond the encoders trueness to the source material in sharpness and clarity. The colors are a little washed out with the defaults, but maybe not enough for everyone to notice. Fortunately everything you should need is available in the web interface. MythTV has a whole page on these tuning devices and recommends: brightness 37, contrast 60, hue 50 and saturation 30. I found those in direct comparison to the source content produced a picture that was a little too bright. I ended up using 45, 50, 50 and 45. As demonstrated, your mileage will vary.

I was able to load this capture device up in OpenDCT using the new Generic HTTP Capture Device I just added last week and will be available in the next beta. I was very excited that it worked instantly with absolutely no surprises! Playback on the HD300 and HD200 went without issue. The android miniclient using ijkplayer (ExoPlayer didn't want to work at all for me) really doesn’t like the 12mb/s bitrate. I had to cut that down to 6mb/s, just to be able to play anything back. I then had to cut it down to 3mb/s so it would stop stuttering constantly. Even then every so often it stutters probably because it’s getting ahead of the stream. Interestingly enough 3mb/s was more than enough to be watchable. There’s no reason not to just use the raw consumer for this one since it creates perfectly useable TS files.

You’ll noticed on the web interface a feature called HDMI OSD display. It would be a neat way to display messages, but I couldn’t figure out how to clear the message once it was there. The only way I could get rid of it was to reset the configuration. Providing blank input didn’t make it go away. Good thing we’re looking at this from a video recording perspective.

I hope this helps anyone unsure if this is the right capture device for them.

Update: I read the rest of the MythTV information for this and it looks like the chip itself can handle 60fps just fine, just not on both streams at the same time. I'll need to test this a little more since this is a big find, but maybe this will be good for sports too.

For 60 fps the Main stream:
http://YourEncoderIP/set_codec?type=hdmi&input_fps=60 Followed by an encoder reboot
or .....
For the 60 fps Secondary stream:
http://YourEncoderIP/set_codec?type=...t&input_fps=60 Followed by an encoder reboot
To reboot the encoder you can use the following web API -- http://YourEncoderIP/reboot -- or use the normal web menus

Resolution changing aware tuning script for BM1000-HDMI ONLY
General guidance on how to configure this kind of capture device

[KryptoNyte]

Audio? 5.1 passthrough?

[EnterNoEscape]

Originally Posted by KryptoNyte

Audio? 5.1 passthrough?

As expected you only get stereo.

Edit: I know this hasn't been an issue in the past, but I'll mention it anyway. Since it's digital going in, it comes out indistinguishable from the source audio quality-wise.

[SHS]

Just wondering EnterNoEscape what is your STB make and model ?

KryptoNyte you may as well give it up on DD5.1

The Only down side with thoses device is lack of on board IR

EnterNoEscape keep in mind that some problems can be cuase by the STB as you can see with up/down scaling and in some cases it can be cuase by source content that you rev from the boardcast or tv provider.

iOS, Android and even most Windows Mobile device where never build to handel high bitrate.

[stanger89]

Wild curiosity, will it accept 1080p60? Maybe setting the STB to that would help with some of the scaling/deinterlacing issues.

[Telecore]

Is it possible to set up your STB to output native (720p or 1080i)? I can do this on FIOS with my two QIP7100's via a hidden menu option. If so, would it be possible to re-configure your encoder to use the appropriate format based on the channel #? For example, 720p, 60fps for ESPN, FX, NGC, FOX, etc. and 1080i for everything else? I am assuming that when SageTV tunes a channel, it could pass that info. to your encoder somehow.

[EnterNoEscape]

Originally Posted by SHS

Just wondering EnterNoEscape what is your STB make and model ?

KryptoNyte you may as well give it up on DD5.1

The Only down side with thoses device is lack of on board IR

EnterNoEscape keep in mind that some problems can be cuase by the STB as you can see with up/down scaling and in some cases it can be cuase by source content that you rev from the boardcast or tv provider.

iOS, Android and even most Windows Mobile device where never build to handel high bitrate.

I'm still fiddling around with settings, but I don't think 5.1 is ever going to be a reality at least with this capture device. I know some of the quality issues might be the STB, but I still wanted to be through and detail out my experience in many difference scenarios. My Android test was on a Nexus Player, so I actually did expect a little more capability.

Originally Posted by stanger89

Wild curiosity, will it accept 1080p60? Maybe setting the STB to that would help with some of the scaling/deinterlacing issues.

Via the STB options menu, then best I could get at 1080p30. The colors were completely wrong, so I need to play with that a little more.

Originally Posted by Telecore

Is it possible to set up your STB to output native (720p or 1080i)? I can do this on FIOS with my two QIP7100's via a hidden menu option. If so, would it be possible to re-configure your encoder to use the appropriate format based on the channel #? For example, 720p, 60fps for ESPN, FX, NGC, FOX, etc. and 1080i for everything else? I am assuming that when SageTV tunes a channel, it could pass that info. to your encoder somehow.

I went home over lunch to play around with the native resolution settings and my newly discovered 60fps "hack." I haven't had an STB in a while (I got a QIP7100 just for this experiment), so I forgot about the STB menu, but rediscovered it very quickly after Googling a little. I checked off 1080i, 720p and 480p as resolutions that my "TV" supports. When I checked 1080p30, it causes the capture to have strange colors, but I didn't have enough time to work out why so I have it unchecked for now. It's noted in many places that this encoder doesn't do well on 480i, so I didn't even bother checking that one. I also change the resolution to auto and set the capture FPS to 60 in the web interface and disabled the secondary encoder. It turns out that if less than 60FPS is coming in, the device will encode at the lower framerate. I'm actually completely sold on it after these changes, pending long term stability verification. I've been recording non-stop all night, through this morning and it did not have a single hiccup. At first glance it appears to be stable, but I'm going to try using it as a primary recording device over the rest of the week and see how it fairs.

[Telecore]

Originally Posted by EnterNoEscape

I went home over lunch to play around with the native resolution settings and my newly discovered 60fps "hack." I haven't had an STB in a while (I got a QIP7100 just for this experiment), so I forgot about the STB menu, but rediscovered it very quickly after Googling a little. I checked off 1080i, 720p and 480p as resolutions that my "TV" supports. When I checked 1080p30, it causes the capture to have strange colors, but I didn't have enough time to work out why so I have it unchecked for now. It's noted in many places that this encoder doesn't do well on 480i, so I didn't even bother checking that one. I also change the resolution to auto and set the capture FPS to 60 in the web interface and disabled the secondary encoder. It turns out that if less than 60FPS is coming in, the device will encode at the lower framerate. I'm actually completely sold on it after these changes, pending long term stability verification. I've been recording non-stop all night, through this morning and it did not have a single hiccup. At first glance it appears to be stable, but I'm going to try using it as a primary recording device over the rest of the week and see how it fairs.

Just to be clear - 4 questions/verifications:
(1) The encoder will automatically encode in either 720p/60 or 1080i/30 from a QIP7100 depending on the channel selected?
(2) Therefore, the only downside to this encoder is the lack of 5.1?
(3) This box does not require a "splitter" to record DRM content?
(4) What are you using to tune the STB - USB-UIRT?

I recently went through QIP7100 setup with HD-PVRs and can provide you with IR files with a "MENU-EXIT" prefix (to try and wake up the STB if asleep),sage.properties info. and details on building electrical-IR-electrical cable for connecting the USB-UIRT IR emitter port to the IR receiver ports of the QIP7100 if you want. I have always been interested in getting to an HDMI solution - although the HD-PVR works pretty good.

[will]

Originally Posted by EnterNoEscape

As expected you only get stereo.

Edit: I know this hasn't been an issue in the past, but I'll mention it anyway. Since it's digital going in, it comes out indistinguishable from the source audio quality-wise.

These devices sound great, much better than the HD-PVR 1212, I just wish they make one that could do 5.1.

[wayner]

I wonder why they don't? Is it because that these encoders are not generally meant for encoding TV?

These devices actually seem very similar to the HDMI-ethernet devices that are used to distribute video through your house, often connected to matrix switches.

[SHS]

Originally Posted by wayner

I wonder why they don't? Is it because that these encoders are not generally meant for encoding TV?

These devices actually seem very similar to the HDMI-ethernet devices that are used to distribute video through your house, often connected to matrix switches.

No generally meant for encoding for mobile device steaming.