HDMI cable issues

[vdherik]

Hi guys,

Current setup:

RPi <<1m hdmi cable>> AMP <<1m hdmi cable>> TV

For an upcoming renovation the RPi will be moving further away from the rest (it will eventually be replaced by a home server with XBMC), so I've replaced the cable between RPi and AMP with a 10m (30 ft) one.
Now, some (!) video files won't play anymore. The amp will either switch back to PCM or loose the audio signal altogether, and the TV will eventually come up with a "unsupported video signal" (or similar) complaint.
I'm aware that 10m is stretching the limits of HDMI, and this probably isn't the best quality cable either. And yes.. plugging the old cable back in solves these problems.

Still, couple of questions remain:

- If this is (very likely) a cable issue, why would only some files fail to play, where others still play fine. File size/format doesn't seem to be a factor here.

- Is there some way to debug this further (like hdmi handshake) to see if there's any difference with the different videos?

- Would these problems be likely to persist once the RPi is replaced with a dedicated server running XBMC?

- Any other suggestions (besides the obvious "don't change the cable")?

I've also tried "config_hdmi_boost=7" (and other values), but no change there.

Thanks!

[rikardo1979]

just a quick response
using such a long HDMI cable is really bad solution (dont even know why someone manufacture such a things) and yes you probably will have same issue with any device connected to such long(low quality) cable.
solution:
get the extender HDMI>CAT

[vdherik]

Indeed a quick response, thanks for that!

As said, I'm aware that 10m is a poor choice, but for my specific situation this would be the best solution (if it works). But there's other options I can consider, and I'll surely look into the extender!

The 10m cable is fairly thin (probably the cause for the low quality) because it ends in Micro-HDMI on one end. I need that to be able to pull it trough an empty PVC tube that's embedded in the wall (old elec. tube), so to have no visible wires.

I've tested with another (proper HDMI-HDMI) cable of 10m and that works fine, so the other cable is to blame.

Still curious though why it only affects certain files (it does this consistently).

Does anyone know of a good quality 10m HDMI-MicroHDMI cable?

Regards!

[rikardo1979]

not sure as there are many aspects, but it may depend on bit rate of the files

[BartOtten]

What rikardo wrote is the same thing I thought of. Could you compare the bit rates of those files and see if there is a bottleneck?

PS. HDMI has versions. Maybe it's related so check your cables if they are the same version

[vdherik]

Bitrates:

File 1, ripped TV show, size 340 MB. Consistently fails to play.

Code:

Input #0, matroska,webm, from 'filename1.mkv':
Duration: 00:21:00.67, start: 0.000000, bitrate: 2251 kb/s
Stream #0:0(eng): Video: h264 (High), yuv420p, 1280x720,
  SAR 1:1 DAR 16:9, 29.97 fps, 29.97 tbr, 1k tbn, 59.94 tbc (default)
Stream #0:1: Audio: ac3, 48000 Hz, stereo, s16, 384 kb/s (default)

File 2, 1080p movie, size 6.6 GB. Plays without problems.

Code:

Input #0, matroska,webm, from 'filename2.mkv':
Duration: 02:18:35.35, start: 0.000000, bitrate: 6780 kb/s
Stream #0:0(eng): Video: h264 (High), yuv420p, 1440x600
[SAR 1:1 DAR 12:5], 23.98 fps, 23.98 tbr, 1k tbn, 47.95 tbc (default)
Stream #0:1(eng): Audio: dts (DTS), 48000 Hz, 5.1(side), s16, 1536 kb/s (default)

Only real difference I see here is the fps, I'll look into that further.

Hard to tell the cable version, but it was sold as 1.4 (ebay item 330799347748).

Writing on the cable states High Speed HDMI Cable E301195 AWM Style 20276 80°C 30V VW-1

[rikardo1979]

hmm,did expect something else tbh I would say HB would cause more trouble but I seems to be wrong here
so its not bitrate what causing it for sure