Choices for Recording Profile and Transcoder

For discussion related to MythTV which doesn't belong in another forum.

Moderator: Forum Moderators

Post Reply
nello
Junior
Posts: 27
Joined: Sun Mar 08, 2015 7:33 pm
United States of America

Choices for Recording Profile and Transcoder

Post by nello » Fri Jun 10, 2016 5:58 pm

I having trouble understanding the implications of the "Advanced Options" in the web interface for scheduling recordings:

http://<mythServer>/tv/detail?recordid=<recordingNumber>

I'm focused on two specific items, with the following options in their dropdowns:

Recording Profile
- Default
- Live TV
- High Quality
- Low Quality

Transcoder
- Autodetect
- High Quality
- Medium Quality
- Quality

All of my recordings come from over the air (OTC) broadcasts; they vary from crumby 1950s reruns to modern HDTV. I'm displaying my recordings on a 65" TV so I'd like to capture the input's full resolution. I've allocated 2TB of storage space for MythTV recordings on my FreeNAS server, so I'm not too concerned with file size.

Recordings are processed by a (bash) user script; the basic flow is is to call:
- mythcommflag: Flag commercials
- mythutil: Create cutlist of flagged commercials
- mythtranscode: Create commercial-free file
- HandBrakeCLI: Transcode commercial-free file to h.264

Yes, I've already (tried to) read the fine manual, or at least these pages:
- https://www.mythtv.org/wiki/Transcoding
- https://www.mythtv.org/wiki/Recording_Parameters
- https://www.mythtv.org/wiki/Recording_Profiles

I still don't understand which settings are appropriate for my usecase. For example, none of these pages seems to address the appropriate settings for HDTV (1080p, 1920x1080)

To summarize ...

I'd like an explanation of how the settings for Recording Profile and Transcoder effect a recording's quality and file format, e.g., mpeg2 vs. h.264.

Thank you.

- nello

daraden
Senior
Posts: 169
Joined: Tue Feb 23, 2016 7:33 am
United States of America

Re: Choices for Recording Profile and Transcoder

Post by daraden » Sat Jun 11, 2016 6:05 pm

what tuner are you using?
you are looking for https://www.mythtv.org/wiki/Setup_Recording_Profiles
depending on the tuner you use you may not need or have any settings to change. digital tuners just copy the incoming data so there is no need to configure for a specific resolution. you will want to make sure auto transcode is disabled.
since you intend on transcoding with handbrake, you don't need to worry about the transcoder.

OTC?

notes about your script
flagging commercials can be done in the recording rule with Auto-flag commercials
comm-flagging is not 100% accurate so it is not recommended to be used as a cut list without manual verification.
your mythtranscode command in your other post you have the output file as mp2. mp2 is for audio you want .mpg

nello
Junior
Posts: 27
Joined: Sun Mar 08, 2015 7:33 pm
United States of America

Re: Choices for Recording Profile and Transcoder

Post by nello » Sat Jun 11, 2016 6:33 pm

daraden wrote:what tuner are you using?
I'm using a HDHomeRun (model HDTC-2US).
daraden wrote:... depending on the tuner you use you may not need or have any settings to change. digital tuners just copy the incoming data so there is no need to configure for a specific resolution. you will want to make sure auto transcode is disabled.
since you intend on transcoding with handbrake, you don't need to worry about the transcoder.
Yes, I figured that out on the SiliconDust support forum. Thank you for confirming it. I mistakenly configured the HDHomeRun to transcode to H.264 and reduce the resolution. I changed the HDHomeRun configuration to just pass through the broadcast at full resolution and without transcoding.
daraden wrote:OTC?
OTC=Over The Air
daraden wrote:flagging commercials can be done in the recording rule with Auto-flag commercials
Yes, that's true. But it wasn't clear to me that the commercial flagging would be done before user scripts are launched. So, I went ahead and included commercial-flagging in the user script.
daraden wrote:comm-flagging is not 100% accurate so it is not recommended to be used as a cut list without manual verification.
Yes, thank you for pointing this out. I realize that I'm taking a risk. I've found that it's correct often enough to be okay for me.
daraden wrote:your mythtranscode command in your other post you have the output file as mp2. mp2 is for audio you want .mpg
Yes, you are correct. I named my commercial-free recording with the .mp2 extension. My mistake. Thank you for pointing it out.

Post Reply