[mythtv-users] Lossless Cut and keyframe cuts off

Gary Buhrmaster gary.buhrmaster at gmail.com
Wed Nov 14 17:18:51 UTC 2012


On Wed, Nov 14, 2012 at 7:21 AM, John Pilkington <J.Pilk at tesco.net> wrote:
...
> AIUI the HDHomeRun stores the programme stream as encoded before
> transmission.

Correct.  The HDHR is (essentially) just a tuner and filter for
the stream.  Whatever stream it gets, you get.  This really
is no different than for most other DVB devices that
pretty much do the same thing (i.e. it is not HDHR specific,
although many people may have a HDHR).

> You may well find that
> different production companies work to different guidelines.

Not only do broadcasters vary, cable companies are likely
to decode the original stream, and then re-encode (to
different qualities/bandwidths) in order to fit into their
channels.  It is not unknown to see a good, high
bandwidth, 1080i sports event (quick movements) seen
OTA with good quality turn into something less good when
a cable company has re-encoded it.  As with much else,
your mileage (and quality) will vary.  Note that almost all
of the broadcast/cable quality encoders can be configured
extensively (keyframe distance, etc.).  Even two
broadcasters with the same (commercial) encoders
often produce difference results based on the expertice
of the broadcast engineer that set it up (or, sometimes,
the service company that was hired to set it up).

Gary


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