BackEnd

Implemented by : Hastur, Cyclops

Back end

Record and playback on DVB-T
DVB-T (Freeview)
Simultaneous record and playback
Media sharing

Hardware

Back-end

Dual TV and DVB-T tuner card(s)
Storage Server connection

Operating Systems

Debian
OpenSolaris
Nexenta - Ubuntu/Solaris

Data Partitioning

Separate metadata and library trees allows some clients to collect metadata

Single Volume

Each MEDIATYPE has separate library and metadata trees
Data trees are grouped for export using "bind" mounts
Matches nfs export concept

Logical Volumes Option

Each MEDIATYPE has a logical volume, lv-MEDIATYPE
Each lv-MEDIATYPE has separate library and metadata trees
Trees are grouped for export using normal mounts
Requires a resizeable filesystem (i.e. not XFS)

File Permissions

Requires ACLs ?

Users

| media-centre | Default owner | rw all media | ||

Groups

Group	Role	Permissions
mc-music	Plays music	ro music lib
mc-videos	Plays videos	ro video lib
mc-movies	Plays movies	ro movies lib
mc-photos	Shows photos	ro photos lib
mc-tv	Plays recordings	ro recordings
mc-games	Plays games	ro game roms lib
mcadm-music	Manages music	rw music library
mcadm-videos	Manages videos	rw video library
mcadm-movies	Manages movies	rw movie library
mcadm-photos	Manages photos	rw photo library
mcadm-tv	Manages recordings	rw recordings
mcadm-games	Manages games	rw game roms lib

All media files have owner permissions "rwx"
All media files have group (ACL mask) permissions "rwx"
All media files have other permissions "---|"
All MEDIATYPE files have named group "mcadm-MEDIATYPE" permissions "rw-"
All MEDIATYPE files have named group "mc-MEDIATYPE" permissions "r--"
All MEDIATYPE directories have default ACLs ? reflecting the above permissions

Example Configuration

/etc/passwd

media-centre3000:3000:Media Centre:/nonexistent:/usr/sbin/nologin

Example /etc/group

mc-movies3003:mythtv,mediatomb,admin1,user1
mc-music3001:mythtv,mediatomb,mpd,admin1,user1
mc-photos3007:mythtv,admin1,user1
mc-tv3009:mythtv,mediatomb,admin1,user1
mc-videos3002:mediatomb,admin1,user1
mcadm-movies3006:,admin1
mcadm-music3004:mpd,admin1
mcadm-photos3008:,admin1
mcadm-tv3010:,admin1
mcadm-videos3005:,admin1
mc-users3011:admin1,user1

Example ACL (getfacl /mnt/media/movies)

# file: library
# owner: media-centre
# group: mcadm-movies
user::rwx
group::---
group:mc-movies:r-x
group:mcadm-movies:rwx
mask::rwx
other::---
default:user::rwx
default:group::r-x
default:group:mc-movies:r-x
default:group:mcadm-movies:rwx
default:rwx
default:other::---

User Contributed Files

All users have a $user/shared-media directory with write permission
$user/shared-media ACLs ? allow access by mediasys groups
mediasys/users/$user is a symlink to $user/shared-media
CIFS requires wide links = yes for the mediasys share.
Not compatible with NFS.

Data Export

A single shared tree for mediasys
Each MEDIATYPE library and metadata directory is mapped into the single tree.
Shares per MEDIATYPE writeable by the admin group for that MEDIATYPE.

Example fstab

/etc/fstab

# Media mounts
/dev/vg-media/home        /home   ext4    defaults,noatime,nosuid,noauto,acl      0       0
/dev/vg-media/media       /mnt/media  ext4    defaults,noatime,nosuid,noauto,acl      0       0
# Export mounts
/mnt/media/movies/library /export/mediasys/movies/library none bind,noauto    0       0
/mnt/media/movies/metadata /export/mediasys/movies/meta none bind,noauto      0       0
/mnt/media/music/library /export/mediasys/music/library none bind,noauto      0       0
/mnt/media/music/metadata /export/mediasys/music/meta none bind,noauto        0       0
/mnt/media/tvshows/library /export/mediasys/tvshows/library none bind,noauto  0       0
/mnt/media/tvshows/metadata /export/mediasys/tvshows/meta none bind,noauto    0       0
/mnt/media/recordings /export/mediasys/recordings none bind,noauto    0       0
/mnt/media/photos/library /export/mediasys/photos/library none bind,noauto    0       0
/mnt/media/photos/metadata /export/mediasys/photos/meta none bind,noauto      0       0

Samba/CIFS

Requires username/password

Example Configuration

/etc/smb.conf

[mediasys]
   path=/export/mediasys
   browseable = yes
   writable = yes
   mangled names = no
   follow symlinks = yes # for per-user shared-media
   wide links = yes  # for per-user shared-media
   valid users = mythtv,@mc-users

[homes]
   path=/home/%S
   comment = Home Directories
   browseable = no
   writable = yes
   create mask = 0700
   directory mask = 0700
   valid users = %S
   mangled names = no

# Administrative shares - not browseable by default
[movies]
   path=/mnt/media/movies
   browseable = no
   writable = yes
   mangled names = no
   valid users = @mcadm-movies

...

NFS

Read-only Exports (without security)

/etc/exports

/export/mediasys  192.168.0.0/24(ro,fsid=0,sync,no_subtree_check)
/export/mediasys/movies/library   192.168.0.0/24(ro,nohide,sync,no_subtree_check)
/export/mediasys/movies/meta      192.168.0.0/24(ro,nohide,sync,no_subtree_check)
/export/mediasys/tvshows/library  192.168.0.0/24(ro,nohide,sync,no_subtree_check)
/export/mediasys/tvshows/meta     192.168.0.0/24(ro,nohide,sync,no_subtree_check)
/export/mediasys/music/library    192.168.0.0/24(ro,nohide,sync,no_subtree_check)
/export/mediasys/music/meta       192.168.0.0/24(ro,nohide,sync,no_subtree_check)
/export/mediasys/photos/library   192.168.0.0/24(ro,nohide,sync,no_subtree_check)
/export/mediasys/photos/meta      192.168.0.0/24(ro,nohide,sync,no_subtree_check)

Permissions fixes for NFSv3 ?

/export/mediasys 192.168.0.0/24(ro,fsid=0,sync,no_subtree_check,all_squash,anongid=3000)
/export/mediasys/movies/library 192.168.0.0/24(ro,nohide,sync,no_subtree_check,anongid=3003)
...

mount -t nfs4 -o ro media: /mnt/media

$[Get Code]9

Capture Cards

Linux Chipset Support

ivtv Driver supported hardware

CX23415 ?
CX23416 ?

DVB-T

| Card | HD | SD tuners | DVB-T tuners | Price | Notes | || | Nova-T-PCI | Yes | | 1 | £28 Ebuyer | Supported | | Nova-T-500 | Yes | | 2 | £55 Ebuyer | USB bridge device; not fully supported | | Pinnacle PCTV DVB-T Pro PCI | No | | 2 | £56 scan | No support | | DViCO FusionHDTV Dual Digital | Yes | | 2 | | | | AverTV ? DVB-T A771 | | | | £35 SpecialTech | | | AverTV ? DVB-T A777 | Yes | | 1 | Supplier?? | Replaces A771 | | TerraTec ? Cinergy 2400i PCI-E | | | 2 | | No support yet | | Compro VideoMate ? DVB-T200 PCI | Yes | | 1 | | |

CAMs ?

http://www.divineo.co.uk/cgi-bin/div-uk/elv-phoenix.html (can use for Nova-T PCI)

DVD Encoding

Profiles

High Quality Compressed

H.264 video
AC3 ? audio
mp4 container
~2GB

High Quality Raw

MPEG2 ?
AC3 ? audio
VOB
~9GB

Notes

Hardware or software encoding?
- Hard enc more expensive, Soft enc needs more powerful CPU
  - No encoder needed, DVB-T is MPEG2 ?. MPEG2 ?->MPEG4 ? needed anyway
Does a software encoder require encoding to MPEG2??
- Yes, or some other codec
Can a software encoder encode to something else in Realtime?
- DivX ?, Xvid, H.264 check processor requirements
MPEG-4 encoders
- Hauppauge HVR-4000 does H.264
Front end may need up to 1GB RAM to store MythTV ? UI elements for 1080p displays
VIA UniChromePro ? graphics may eventually be capable of H.264 acceleration with XvMC ?
VIA & nVidia cards can accelerate decoding of MPEG2 ?

BackEnd

BackEnd

Back end

Hardware

Back-end

Operating Systems

Data Partitioning

Single Volume

Logical Volumes Option

File Permissions

Users

Groups

Example Configuration

User Contributed Files

Data Export

Example fstab

Samba/CIFS

Example Configuration

NFS

Capture Cards

Linux Chipset Support

DVB-T

CAMs?

DVD Encoding

Profiles

High Quality Compressed

High Quality Raw

Notes

SideBar

CAMs ?