[mythtv] H.264 over MPEG-2 TS recording and playback

[Jean-Francois Roy]

Greetings,

I'm currently working in a research group focusing on digital radio
applications, more specifically on the distribution of rich media and
data over digital radio standards (DMB and DVB-H at this time). The
project I'm responsible for is the creation of a PVR-like program for
digital radio, mostly for demonstration purposes. We obviously chose
MythTV as a starting point.

To cut the long story short, digital radio standards pretty much all use
H.264 as the main video codec, and MythTV has a little bit of trouble
with it, at least with the sample MPEG-2 TS bitstreams we have created
here using VLC. Specifically, the TS bitstream seems to be recorded on
disk properly, and marks seem to be correct in the database, but the
frontend is unable to playback the recording (LiveTV mode or recording
mode).

I was wondering if anyone had started working on patches or if I could
get some suggestions from the developers (I'm relatively new to the
MythTV codebase) as to what needs to be done.

I'm including in this message a diff file of my current changes (against
MythTV trunk r9378), as well as a new recorder class (named after the
vloopback project, but right now it's short-circuited to read from a
file -- I know, very hacky, but good enough for research work) which is
able to scan for NAL units in a H.264 bitstream and apply a very simple
(simplistic?) algorithm to detect keyframes (IDR slice NAL units).

I'm also including a backend / frontend log file pair of a LiveTV session.

Best regards,

--
Jean-Francois Roy
Research Engineer                       Ingénieur en recherche
Communications Research Centre          Centre de recherches sur
Canada                                  les communications Canada
3701 Carling Ave.                       3701, avenue Carling
PO Box 11490, Station H                 CP 11490, succursale H
Ottawa, Ontario                         Ottawa, Ontario
Canada  K2H 8S2                         Canada  K2H 8S2
Tel: (613) 998-2479                     Tél.:   (613) 998-2479
Fax: (613) 993-9950                     Téléc.: (613) 993-9950
Email: roy.jean-francois at crc.ca         Cour.: roy.jean-francois at crc.ca
Web site: www.crc.ca                    Site web: www.crc.ca
Government of Canada                    Gouvernement du Canada


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