[mythtv-users] How to transcode HD recording

[HP-mini]

On Thu, 2014-01-09 at 20:14 +0000, John Pilkington wrote:
> On 07/01/14 23:29, John Pilkington wrote:
> > I made comments earlier in this thread about wide and variable spacing
> > of keyframes in FreeviewHD UK programmes.  I've been looking at this a
> > bit more, and my latest test recordings have been better behaved.  The
> > problem certainly exists, but it may be unusual.
> 
> I have just found that for a recording from DVB-T2 FreeviewHD (h264), a 
> listing of the markup data generated after mythcommflag --rebuild 
> contains only a small subset of the lines in a similar listing made 
> immediately after recording.
> 
> In the 'original' table, keyframe separation is typically around 24 
> frames.  In the 'rebuilt' table the spacing is variable, sometimes in 
> the hundreds.  Points listed there are also in the original table.
> 
> In my experiments I have often been working with recordings having a 
> rebuilt seektable.  This explains why editing has sometimes been difficult.
> 
> Should I open a Ticket?
> 

How about a 100MB sample cut from beginning of recording using "dd" ?

The UK freeview H264 HD sample clips (I have here) behave well..my
seektables had to be generated by mythcommflag..

Broadcast OTA H264 uses intra-refresh so the peak bitrate is
constrained. All the broadcast samples (I have seen) use this & have
about 2 sec keyframe intervals.