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Download quality

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    GordyBoy

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    Is it possible to improve the quality of downloaded video from the Humax Aura?

    An hour of SD TV is about 1.1GB - downloaded this is just over 0.5GB. This is not good enough.

    Is the App (if it ever appears) likely to offer a choice of quality download?

    | Tue 5 Jan 2021 23:13:21 #1 |
  2. grahamlthompson

    grahamlthompson

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    GordyBoy - 10 hours ago  » 
    Is it possible to improve the quality of downloaded video from the Humax Aura?
    An hour of SD TV is about 1.1GB - downloaded this is just over 0.5GB. This is not good enough.
    Is the App (if it ever appears) likely to offer a choice of quality download?

    Downloaded content is 720 x 576 SD quality. If I remember correctly the Video is compressed using H264 AVC. As this is a lot more efficient the lower bitrate should not have the impact on quality you imagine. I will download a file and check.

    The Freeview Play spec does not allow HD quality to be exported. If you really need this you would have to use on of the Enigma 2 Linux based pvrs.

    | Wed 6 Jan 2021 10:00:33 #2 |
  3. grahamlthompson

    grahamlthompson

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    The Content is reduced in size compared to a SD channel in a number of ways.

    1 The video is compressed using H264 AVC as used on HD channels. This allows a much lower bitrate. eg the BBC uses bitrates as low as 7000kbps. That's the sort of bitrate the best SD channels used about a decade ago. SD channels use mpeg2 video compression

    2 It uses variable bitrate. The bitrate is adjusted dynamically according to the amount of movement. This also reduces the final file size

    3 SD channels use mpeg1 layer 2 audio compression. This is is replaced by the superior AAC (advanced audio codec).

    4 Footage is deinterlaced to create 720p25. SD broadcast is 720i50

    Complete analysis

    General
    ID : 0 (0x0)
    Complete name : D:\Downloads\Antiques Road Trip.ts
    Format : MPEG-TS
    File size : 753 MiB
    Duration : 44 min 41 s
    Overall bit rate mode : Variable
    Overall bit rate : 2 356 kb/s

    Video
    ID : 100 (0x64)
    Menu ID : 1 (0x1)
    Format : AVC
    Format/Info : Advanced Video Codec
    Format profile : High@L4

    Format settings, CABAC : Yes
    Format settings, RefFrames : 2 frames
    Frame mode : Frame doubling
    Format settings, GOP : M=1, N=30
    Codec ID : 27
    Duration : 44 min 39 s
    Width : 720 pixels
    Height : 576 pixels
    Display aspect ratio : 16:9
    Frame rate : 25.000 FPS
    Standard : PAL
    Color space : YUV
    Chroma subsampling : 4:2:0
    Bit depth : 8 bits
    Scan type : Progressive

    Audio
    ID : 200 (0xC8)
    Menu ID : 1 (0x1)
    Format : AAC
    Format/Info : Advanced Audio Codec
    Format version : Version 2
    Format profile : LC
    Muxing mode : ADTS
    Codec ID : 15
    Duration : 44 min 38 s
    Bit rate mode : Variable
    Channel(s) : 2 channels
    Channel positions : Front: L R
    Sampling rate : 48.0 kHz
    Frame rate : 46.875 FPS (1024 SPF)
    Compression mode : Lossy

    | Wed 6 Jan 2021 10:26:57 #3 |
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    larkim

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    Surely it isn't the file size that counts, it's what it looks like.

    Does the downloaded content look worse than an SD recording when played back on the same device? If not, who cares if this is done with a lower file size than the broadcast stream would imply?

    | Thu 7 Jan 2021 9:46:12 #4 |
  5. grahamlthompson

    grahamlthompson

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    larkim - 1 hour ago  » 
    Surely it isn't the file size that counts, it's what it looks like.
    Does the downloaded content look worse than an SD recording when played back on the same device? If not, who cares if this is done with a lower file size than the broadcast stream would imply?

    The capability is designed to allow viewing using a offline device like a phone or a tablet when no WiFi is available. As clearly it won't be a large 4K oled display the quality is OK. I will take a photo of playback on my Samsung tablet.

    | Thu 7 Jan 2021 11:01:03 #5 |
  6. grahamlthompson

    grahamlthompson

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    Downloaded SD From the Aura

    Attachments

    1. Antiques-RoadTrip.jpg (158.9 KB, 7 downloads) 1 week old
    | Thu 7 Jan 2021 11:21:10 #6 |
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    GordyBoy

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    It would have been nice if a choice of download quality could be offered.

    Could this be made possible with a future software update or is there more to it than this?

    | Thu 7 Jan 2021 17:07:38 #7 |
  8. grahamlthompson

    grahamlthompson

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    GordyBoy - 10 mins ago  » 
    It would have been nice if a choice of download quality could be offered.
    Could this be made possible with a future software update or is there more to it than this?

    If you are hoping for a Full-HD 1920 x 1080 it will not happen. This is only possible on older Humax units that have custom firmware add ons. Although we have not yet got the Aura app. The files you will get are the same as using the box built in Web interface.

    There are boxes out there that can do what you want. They are more expensive and nowhere near as user friendly

    | Thu 7 Jan 2021 17:22:56 #8 |
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    larkim

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    The limitation on streaming only in SD does feel odd to me after the EE TV box streamed both live and recorded HD recordings to iPads / Android Phones etc. I fully understand this is part of the spec required by Freeview, so it's just odd that I've had a device for a few years that did allow for it.

    I don't think the EE TV box was doing conversion on the fly, and it was certainly re-broadcasting the HD channels live (e.g. you could tell it was the HD channel as you'd just see the ident screen etc when the regional news was on for example), accepting that it could have been doing some SD down-conversion that was invisible to the user when it was playing back recordings. The EE box did allow for download of episodes, but only within it's fairly tight app, so if a programme was downloaded it wouldn't have been available for transfer to another device, which I can see owuld be a legitimate fear for an HD broadcast recording given the way the Humax allows for users to access recordings etc.

    I only occasionally used the live re-broadcast functionality, but it was nice to have from time to time - I presume when the app comes live this won't be available for HD channels?

    | Fri 8 Jan 2021 11:37:07 #9 |
  10. grahamlthompson

    grahamlthompson

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    larkim - 31 mins ago  » 
    The limitation on streaming only in SD does feel odd to me after the EE TV box streamed both live and recorded HD recordings to iPads / Android Phones etc. I fully understand this is part of the spec required by Freeview, so it's just odd that I've had a device for a few years that did allow for it.
    I don't think the EE TV box was doing conversion on the fly, and it was certainly re-broadcasting the HD channels live (e.g. you could tell it was the HD channel as you'd just see the ident screen etc when the regional news was on for example), accepting that it could have been doing some SD down-conversion that was invisible to the user when it was playing back recordings. The EE box did allow for download of episodes, but only within it's fairly tight app, so if a programme was downloaded it wouldn't have been available for transfer to another device, which I can see owuld be a legitimate fear for an HD broadcast recording given the way the Humax allows for users to access recordings etc.
    I only occasionally used the live re-broadcast functionality, but it was nice to have from time to time - I presume when the app comes live this won't be available for HD channels?

    Not sure but in theory HD channel viewing should be allowable. I have another make Android TV box that I can watch live HD channels in HD on a Samsung tablet.

    If you download recordings for off air viewing then just like the Aura they are reduced to the same quality as the Aura ones. I can also watch LIVE HD TV on my Full-HD laptop in full-HD. Kodi comes with TV gateway pvr driver built in.

    | Fri 8 Jan 2021 12:11:45 #10 |

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