rtsai1111 at comcast
Apr 19, 2005, 7:22 PM
Views: 1322
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[PATCH] transcoding profiles
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Today, HDTV recordings are limited to either no transcoding, or
transcoding to the parameters in the MPEG2 recording profile. They
aren't encoded at capture time, so there is no subsequent option to
save a configurable amount of disk space.
Attached is a patch to allow the configuration of a fixed number of
transcoding profiles ("High Quality", "Medium Quality", and "Low
Quality").
Summary:
- Upgrade DB schema:
- The option to automatically transcode a recording
has been moved out of the recording profile and into
the record (so that the currently-unused
"autotranscode" column is now useful).
When the database is upgraded, recording schedules
using recording profiles with auto-transcode enabled
will have auto-transcode carried over.
- Each record, in addition to a now-used
"autotranscode" option, also gets a new "transcoder"
option, which defaults to "Autodetect".
- Delete the now-unused "autotranscode" option from
the codecparams table.
- Provide some fixed transcoders: "High Quality",
"Medium Quality", and "Low Quality". Unfortunately,
no default values are actually provided, the user
must configure their desired values for these
transcoders. Also unfortunately, there is no UI to
add or remove transcoders (just like there is no UI
to add or remove recording profiles). However,
transcoders may be added to the database and things
should work, if people need more than these three
transcoders.
- The default transcoder for all recordings is "0"
(autodetect) to preserve current behavior.
- Add some logging to indicate when transcoding is
starting/stopping (both to the regular log as well as the
database logs).
- MythFrontend UI changes:
- Remove "automatically transcode" option from
recording profiles; auto-transcode is now a
per-recording option (parallel with per-recording
recording profiles).
- Add auto-transcode and transcoder options to each
recording schedule, configurable at the time the
recording is scheduled. Default values are:
- No auto-transcode.
- "Autodetect" transcoder.
The "Autodetect" transcoder will choose between the
"From MPEG4/RTjpeg" and "From MPEG2" transcoders,
like it does today. Eventually the choice of
transcoder can be made more configuration (e.g.,
select transcoder based on 1080i/720p/480i
resolution of recording). For now, just preserve
behavior.
- Add global settings UI to configure default values
for auto-transcode and transcoder, near default
values for commflagging and userjobs.
- MythTranscode changes:
- Fix a typo in the "help" text. :)
- Add some output to reflect transcoding parameters.
This bit is mostly unnecessary, but can be useful
for identifying exactly what is happening for
"autodetect" transcoder jobs.
Possible breakage:
- I'm not exactly sure how the "Live TV" recording profile is
used when saving "Live TV" during live TV (is this even
possible?). For normally-scheduled recordings that just
happen to be configured with the "Live TV" recording
profile, things are fine. But I'm unsure of the
save-live-TV-on-the-fly implied by this code.
See the diff for libs/libmythtv/tv_rec.cpp.
If this is broken, let me know and I'll fix it; I would make
auto-transcode-saved-live-TV a global option rather than a
per-profile option. Other suggestions are welcome.
Thanks,
--Rob
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myth-dev.diff.bz2
[PATCH] transcoding profiles
