Fix for recordings with audio only format detected

[Narflex]

I just committed a change into GitHub that works around a problem where TV recordings sometimes had their format improperly detected as being audio only.

This should only be relevant to those that were using a network encoder w/ SageTV which was recording from cable directly. I know I encountered this issue on Fios (now Frontier); but not sure if it happens on other providers or not.

If you have this problem...the way to know if this fix helps you is to just run "ffmpeg -i <file>" on one of the problematic recordings, and if FFMPEG says there's a video stream...but SageTV on the Detailed Info page for the recordings does not say there is one...then this fix is for you.

After updating to this fix, to be sure it redetects the format on all your recordings to apply this fix, you also would need to set this property before you startup SageTV: "force_full_content_reindex=true"

This fix will automatically apply to any new recordings created, so you'd only need to do that once.

Here's the checkin comment which explains what it's doing in more detail:

Worked around issue where sometimes TV recordings were detected as audio only

The actual bug here is in the native format detector. However, after analyzing that, it ended up being a corner case where a certain stream type in the TS map (DC-II) was being considered video if it was a TV recording and audio otherwise because both things existed in the wild. Changing that behavior would likely have unintended side effects.

Normally, it worked around this problem because it would get a hint that something was a TV recording and then use that to prefer video when it saw the DC-II marker rather than audio. However, that hint was not being set when you were using a network encoder because then the format detection was being done through a higher level mechanism.

The workaround, which defaults to being on via the property "double_check_audioonly_tv_formats" will redo the format detection with FFMPEG when it sees that only an audio stream was detected in an MPEG file. If FFMPEG also does not detect a video stream, then it will use the originally detected internal format; but if FFMPEG does detect a video stream, then it will return FFMPEG's format instead.

I don't see any potential negative effects from making this change, but please let me know if anything comes up.


Here's an example of it working in action.

1. First it uses the internal format detector, and only finds an audio stream:

Tue 5/17 15:10:43.787 [main@de6f34] File Format Parsed-2b /var/media/tv/AmericanDad-ABoyNamedMichael-52486032-0.ts=MPEG2-TS 0:29:57 640 kbps [#0 Audio[AC3 48000 Hz 6 channels
448 kbps MAIN idx=0 id=1df8 eng]#1 Audio[AC3 48000 Hz 2 channels 192 kbps idx=0 id=1df9 spa]{EpisodeNumber=2, AiringDuration=1800000, HDTV=true, SeasonNumber=10, Guest Voice
=Jane Krakowski, ForcedUnique=true, Voice=Seth MacFarlane;Wendy Schaal;Rachael MacFarlane;Scott Grimes;Dee Bradley Baker;Jeff Fischer, Title=American Dad, ExternalID=EP716445
0185, AiringTime=1411448400000, Genre=Comedy;Animation, CC=true, ParentalRating=TV14, OriginalAirDate=1410739200000, Stereo=true, SeriesID=185040, ShowcardID=10932944, Descri
ption=Roger moves in with Greg and Terry., EpisodeName=A Boy Named Michael}]

2. It recognizes this and invokes the new workaround:

Tue 5/17 15:10:43.787 [main@de6f34] Using external format detector because we only detected audio on the internal format...

3. Now with FFMPEG, it detects both the audio and the video stream:

Tue 5/17 15:10:43.787 [main@de6f34] Now using external format detector for: /var/media/tv/AmericanDad-ABoyNamedMichael-52486032-0.ts
Tue 5/17 15:10:44.365 [main@de6f34] File Format Parsed /var/media/tv/AmericanDad-ABoyNamedMichael-52486032-0.ts=MPEG2-TS 0:29:58 11040 kbps [#0 Video[MPEG2-Video 29.97 fps 1920x1080 16:9 18000 kbps interlaced id=1df7]#1 Audio[AC3 48000 Hz 6 channels 448 kbps idx=1 id=1df8 eng]#2 Audio[AC3 48000 Hz 2 channels 192 kbps idx=2 id=1df9 spa]{EpisodeNumber=2, AiringDuration=1800000, HDTV=true, SeasonNumber=10, Guest Voice=Jane Krakowski, ForcedUnique=true, Voice=Seth MacFarlane;Wendy Schaal;Rachael MacFarlane;Scott Grimes;Dee Bradley Baker;Jeff Fischer, Title=American Dad, ExternalID=EP7164450185, AiringTime=1411448400000, Genre=Comedy;Animation, CC=true, ParentalRating=TV14, OriginalAirDate=1410739200000, Language=eng, Stereo=true, SeriesID=185040, ShowcardID=10932944, Description=Roger moves in with Greg and Terry., EpisodeName=A Boy Named Michael}]

[egeller]

Let me be the first to say thank you. This will probably decommission a rube goldberg of a work-around I have used to deal with the issue.

[KryptoNyte]

Yes, thank you. This is an annoying issue, even for those of us still using V7.