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Video codecs on the HDR

Discussion in 'HDR-FOX T2 Freeview Recorder' started by parish, Feb 2, 2011.

  1. parish

    parish Member

    Got my media server set up (MediaTomb on Ubuntu Linux) and was trying it out last night.

    There seems to be a limited number of codecs installed on the HDR as it was only able to decode about half the files. The rest it just said "Unable to support this format". Judging by the time it takes before giving up it does appear to be looking in the files rather than just relying on the file extension.

    Trying to narrow it down is a bit tricky as the file extensions are somewhat generic - .AVI covers a mass of different encodings for example.

    Surprisingly though, it couldn't play any MPEG file which I thought rather odd as, AFAIK, Freeview transmissions are MPEG.

    Is there a detailed list anywhere of what it does support and is it likely that Humax will add to this list with s/w upgrades?
     
  2. MartinLiddle

    MartinLiddle Super Moderator Staff Member

    I think Humax have said they intend to add more codecs at some point.
     
  3. I have the same setup (Mediatomb on Ubuntu 10.10) and I've found that out-of-the-box, my HD-T2 plays about 75% of the files I've thrown at it.

    I'm planning on doing some proper investigation as to what formats it really plays - as you say, the file extension AVI doesn't really tell you much. It's just a container in which there can be many video and audio streams.

    I've decided not to do this yet as I'm hoping the new version of the firmware will support more formats, so I'm going to wait until that has hit the floor.

    If you want to persue this yourself, a good starting point would be to use ffmpeg to discover what your containers are containing, e.g.:

    $ ffmpeg -i somefile.avi

    Input #0, avi, from 'somefile.avi':
    Duration: 01:12:19.44, start: 0.000000, bitrate: 1353 kb/s
    Stream #0.0: Video: mpeg4, yuv420p, 624x352 [PAR 1:1 DAR 39:22], 23.98 tbr, 23.98 tbn, 23.98 tbc
    Stream #0.1: Audio: mp3, 48000 Hz, stereo, s16, 128 kb/s

    tells me that the video stream is mpeg4 (which isn't actually that helpful, it could be xvid or h264) at 1151 kb/s and the audio stream is mp3.

    The Humax appears to cope with with xvid (and hence divx) and h264 and mp3 audio, so this file will probably play. I think it can't cope with many other audio formats (such as aac), and might have problems with high bitrates in the video stream.

    so if you find some files that won't play, and compare this info with files that will play, you might discover what you need to fix. Then you can use ffmpeg to recode the file into something suitable. Annoyingly, I don't think you can sue the built in transcoding mode in Mediatomb as it won't be able to distinguish good from bad files as they'll all have the same Mime Type (and file extension).
     
  4. Mr Lazy

    Mr Lazy New Member

    There's a fairly comprehensive list here: http://www.redsilico.com/humax-hdr-video-playback by a user who has done some testing. Not aware of any official list from Humax. I've done some similar testing myself over UPnP (off Synology DiskStation) though not as extensive and I didn't make notes. Certainly I could play MPEG2 files fine including those recorded by the HDR-FOX T2 itself (.ts files), though I could not ffwd/rwd which is a shame. Like David my intention was to wait for the next software update before testing further.
     
  5. parish

    parish Member

    Thanks for all the help guys. I know about ffmpeg to identify the encoding used and to transcode but was hoping for a list of available codecs to avoid trial and error. Good to hear Humax plan on adding more - though if and when obviously apply here :p

    Very useful link that Mr. Lazy - thanks :)
     
  6. James

    James Member

    It should not be that difficult to add other codecs to the box as it basicly runs a modified version of linux, andthe codecs are publicly available to them. I suspect that the audio will be handled by the standard Linux audio system so installing audio codecs should be a relatively straight forward, and we are expecting them to be in the next release.

    Hopefully they will get it like the popcorn hour - will play anything you throw at it!

    If they don't get it sorted soon I'm going to have to start some hacking of the box - anybody got any idea as to what video and audio chips the box has? I know it's a MIPS processor (so in theory you could run windows NT 4.0 on it ;) ) if only I could find a video driver for it and some way of getting NT to support USB and the flash drive - unlikely!
     
  7. now that folks have had some time to play with the streaming - what formats are you using ...
     
  8. note : reason for asking is that I am looking to transcode all of my old DV AVI files (which dont work on the humax) into something that does using MediaCoder... I am currently targeting XVid in an AVI container but since the coding takes a while I was wondering if this is ok ?
     
  9. Mr Lazy

    Mr Lazy New Member

    I would say that XVid was an unusual codec choice for transcoding DV (though the benefit would probably be reasonably small files). MPEG2 is actually probably the best fit (for SD). I chose H.264 so that I could play mine on my WD TV and I'm pretty sure I tested these and they played back on the HDR (I'm going to test again now that it's on the new software). I chose an MP4 container which wouldn't be many people's first choice (it wasn't mine) but the reasons are documented in my 'blog' plus it's fairly common and the container is less relevant (unless you need specific features like chapters etc.) so long as the playback device supports it

    http://mrlazy.wordpress.com/2009/08/14/converting-dv-files-to-play-on-the-wd-tv/

    HTH

    By the way, MediaCoder is one of the few (at least that's how it feels) converters I haven't tried, is it any good?
     
  10. ejstubbs

    ejstubbs Member

    I wouldn't hold your breath. According to this post on AV Forums the video decoding is handled entirely in hardware so cannot be amended or upgraded:

    It can only decode what it was made to decode, the CPU isn't powerful enough to decode using software codecs, so it can't be upgraded or made to decode everything known to man. For software decoders you would need a powerful graphics card and 2 or 4 core CPU running at Gigahertz speeds, even this spec of PC can struggle with HD video. If you want a device to do this you need to buy a PC or multi-media centre.
     
  11. MartinLiddle

    MartinLiddle Super Moderator Staff Member

    However in this Digital Spy post http://www.digitalspy.co.uk/forums/showthread.php?p=46971898&highlight=codecs#post46971898 Bob_cat who works in a senior postion for Humax said "The software version that is currently in production doesn't have support for a wide range of video formats but will play music and pictures. More codecs will be upgraded in the impending updates." This might suggest that all the capabilities of the hardware are not currently being made available.
     
  12. Ubik

    Ubik New Member

    I'm not convinced that the the codecs are completely in the hardware. The codec code may be hardware accelerated but I always assumed that the main codec code is in the firmware.
     
  13. ejstubbs

    ejstubbs Member

    Indeed it might. To be fair, PhilipL who wrote the first AV Forums post I quoted, also wrote in an earlier post:

    the Broadcom chip in this CE device (same goes for most CE devices) does all the video decoding in hardware. This means these devices don't need huge powerful CPUs like a PC that would typically decode in software. So they can only support what they are made to support, in the case of the Humax the chip spec's show support for:

    HD/SD H.264/AVC Main and High profile
    VC-1 (includes Windows Media Video)
    MPEG2 SD/HD
    MPEG4, DivX 3.11/4.11/5.x

    It might be that some of the video hardware is programmable to allow some more support of similar codecs.

    (Emphasis is mine).

    There seems to be a lack of reliable information on this topic, beyond the results of actual tests such as those carried out by Mr Lazy and Andy Jenkinson. The situation is complicated by the related issue about support for container formats, which seems to differ depending on whether the file is presented on the DLNA interface, or the HDD/USB port.

    If people are going to make assumptions about how the box works then they need to have good evidence to base those assumptions on otherwise they risk ending up with their expectations not being met.
     
  14. Many thanks Lazy boy !!! Your link was very interesting.

    As you may detect, I'm still finding my way with this vieo format stuff so your findings are very useful. I will do some experimenting and find out.

    Good info - I'm starting to get a feel for where I should be heading with thsi stuff.

    Thanks
     
  15. James

    James Member

    The fact that there is a chip to do harware decoding does not mean it has to be used! The CPU is not that bad, and could be made to decode other codecs via software as well. Its all about who has the time and resources to get into the box properly and have a look around the software in details (resources yes - time no at present i'm afraid!)
     
  16. Sandholme

    Sandholme Member

    Even if the video codec is done in hardware would it be possible for the software to deal with the container as it seems that the T2 doesn't like some containers even though the codec is recognised.
     
    Peter Galbavy likes this.
  17. ejstubbs

    ejstubbs Member

    I'd have thought that the containers would always be handled in software/firmware. I suspect that is why some containers work differently depending on whether they are presented via DLNA or HDD/USB ie there are different code modules for those two interfaces. My expectation would be that the Broadcom chip would simply do the decoding, which is processor-intensive, whereas unpacking a container is pretty straightforward and doesn't benefit much from dedicated hardware.
     
  18. Jfirth8187

    Jfirth8187 Member

    I just encode using Handbrake. I've got two presets one for SD and one for HD. If anyone uses Handbrake. My main problem was audio support within the container. As you can see from below I've not stored any AC3 audio rips on the HDR yet? Anybody else had a go?

    SD:
    Container: MP4
    Picture: keep aspect ratio, auto cropping
    Video Filters: None
    Video: MPEG-4 (FFmpeg), Framerate same as source, Quality Avg Bitrate (kbps) 2000
    Audio: AAC (faac), Dolby Pro Logic II Mixdown, Samplerate Auto, Bitrate 192, DRC 0.0
    Subtitiles: None
    Advanced Options: None Used

    HD:
    Container: MP4
    Picture: keep aspect ratio, auto cropping
    Video Filters: None
    Video: MPEG-4 (FFmpeg), Framerate same as source, Quality Avg Bitrate (kbps) 2500, 2 Pass encoding.
    Audio: AAC (faac), Dolby Pro Logic II Mixdown, Samplerate Auto, Bitrate 192, DRC 0.0
    Subtitiles: None
    Advanced Options: None Used

    On the above the picture looks fine as long as I change the aspect ratio on the box to 4:3 (Letterbox). Otherwise the box stretches all the horizontally.

    Oh and make sure that Handbrake doesn't rename the extension to *.m4v
    It has a habbit of changing the default, the HDR didn't even recognise an m4v file for me?

    Jon.
     
    parish likes this.
  19. parish

    parish Member

    Thanks for that Jon. I've been playing around with Handbrake.

    Re. sound, in the link Mr Lazy posted in post #4 it seems that the HDR supports ACC but not AC3 - it crashes the box!!
     
  20. Jfirth8187

    Jfirth8187 Member

    Ah right I'll leave that alone then. Out of interest I've just experimented with getting recordings off the box (as per another post on the forum) and a sd recording off BBC was 3444kbps. A lot higher bitrate than what I've been using. Anybody know if it would be worth going this high on rips? For me that would give a massive filesize?
    Just out of interest what bitrate would a true hd recording be?

    Jon.