General technical overview[]

Programme IDs[]

All programme episodes on BBC TV are assigned a programme ID (PID) made up of lower-case letter and numbers of around 8 characters. More information on the format of the PID's can be found at the BBC Programme Guide. For Instance for Torchwood, you can see which programmes are available on iPlayer.

In addition to this, it is possible for episodes in iPlayer to have several published "versions". Every episode of a programme should have at least one version - the "original". Other versions that exist are:

version_type_id name
AudioDescribed Audio description
Lengthened Lengthened
OpenSubtitled Open subtitles
Original Original version
Other Other
Shortened Shortened
Signed Sign language
WarningsHigher Stronger content warnings
WarningsLower Milder content warnings
WarningsNone No content warnings
Retrieving programme meta-data[]

See IPlayer_Metadata


Subtitles are available on some iPlayer programmes. The subtitles are in W3C Timed-Text format. The S button on the Flash based iPlayer makes use of this file. The URL for a specific subtitle feed is determined by obtaining the 'version pid' for the programme. Retrieving programme media stream information as described above. It will have a stanza with something like:

<media kind="captions"
        type="application/ttaf+xml"   >

The subtitle feed can be downloaded from the URL pointed to in the href field, e.g.:

Scripts and programs[]

See Programs

Windows P2P Version[]

See Windows P2P

Flash / RTMP Version[]

See Flash iPlayer

iPhone Version[]

See IPhone H.264 version

Nintendo Wii Flash Version[]

See Nintendo Wii

Nokia N96 / RTSP Version[]

See Nokia H.264 version

Note about technical image quality[]

Please note: the technical image quality varies widely across the different versions of iPlayer output, particularly between the DRM-enabled version for Windows, and the iPhone version. Taking one program as an example, "House of Saddam" episode 1, broadcast on Wed 30th July 2008, the compression details are as follows (iphone and Windows DRM versions only were compared):

Comparison Table[]
Reception Method Access Method Video Codec Video Resolution Video Bitrate Video Quality Audio Codec Audio Bitrate OverallBitrate
Nokia N95 3G (n95_3g - iplayer_streaming_n95_3g) RTSP streaming H.264 176 x 96 80 kbps Very Low AAC 32 kbps 113 kbps
Mobile WMV DRM HTTP download WMV 9 320 x 176 ??? kbps Well Below VHS WMA9.1 ??? kbps ??? kbps
Nokia N95 Wifi (n95_wifi - iplayer_streaming_n95_wifi) RTSP streaming H.264 320 x 176 128 kbps Well Below VHS AAC 64 kbps 192 kbps
Flash (flashnormal - iplayer_broadband_streaming) RTMP streaming On2 VP6 512 x 288 372 kbps Below VHS MP3 44kHz CBR 128 kbps 500 kbps
Flash (flashstd - iplayer_streaming_h264_flv_lo) RTMP streaming H.264 640 x 360 352 kbps Below VHS AAC 128 kbps 480 kbps
Nintendo Wii Flash (flashlow - iplayer_streaming_flv7) RTMP streaming Sorenson Spark 512 x 288 Below VHS 820 kbps
iPhone (iphone - iplayer_streaming_http_mp4) HTTP download H.264 483 x 272 400 kbps Below VHS AAC 112 kbps 512 kbps
Windows WMV DRM Kontiki p2p WMV 9 672 x 544 475 kbps VHS WMA 9.1 128 kbps 608 kbps
Flash (flashhigh - iplayer_streaming_h264_flv) RTMP streaming H.264 640 x 360 704 kbps Near VHS AAC+ 96 kbps 800 kbps
Flash (flashvhigh - iplayer_streaming_h264_flv_high) RTMP streaming H.264 832 x 468 1404 kbps better than VHS AAC+ 96 kbps 1500 kbps
Flash (flashhd - iplayer_streaming_h264_flv_hd) RTMP streaming H.264 1280 x 720 3072 kbps better than DVD AAC 128 kbps 3200 kbps