No length or seeking on Saorview recordings

[kjeacle]

Recordings from the Irish DVB-T service (Saorview) never show length and it's not possible to seek.

I have tried increasing TS Search Packets to 100000.

This happens on both Shield and Fire Stick. Mythfrontend works OK.

Sample recording here: http://159.69.45.92/saorview.ts

Thanks!

[Jpilk]

I see the same with your clip on my Sony Android TV. My usual script for h264 does, essentially,

mythffmpeg -fflags +genpts -i inputfile -acodec copy -vcodec copy -scodec copy -f mpegts outputfile

similar to the suggestion in the Readme, and then rebuilds the seektable. It cures the problem, and unlike the mkv option leaves the recording in standard MythTV format.

[Jpilk]

In fact I keep only the video and audio streams. For info, here are mythffprobe results for the raw and processed clips, omitting most of the complaints.

Raw: Input #0, mpegts, from '/home/john/SGs/RecsSG4/20055_20221231100000.ts': Duration: 00:03:06.74, start: 75887.521289, bitrate: 2155 kb/s Program 1 Stream #0:0[0x451]: Video: h264 (Main) ([27][0][0][0] / 0x001B), yuv420p(tv, bt470bg, top first), 704x576 [SAR 16:11 DAR 16:9], 25 fps, 50 tbr, 90k tbn Stream #0:1[0x3e9]: Data: dsmcc_b Stream #0:20x4b5: Audio: mp2 ([3][0][0][0] / 0x0003), 48000 Hz, stereo, fltp, 192 kb/s Stream #0:30x519: Subtitle: dvb_teletext ([6][0][0][0] / 0x0006) Unsupported codec with id 94236 for input stream 1 Unsupported codec with id 94215 for input stream 3

Processed: Input #0, mpegts, from '/home/john/SGs/RecsSG4/20055_20221231102400.ts': Duration: 00:03:06.74, start: 1.400000, bitrate: 2095 kb/s Program 1 Metadata: service_name : Service01 service_provider: FFmpeg Stream #0:0[0x100]: Video: h264 (Main) ([27][0][0][0] / 0x001B), yuv420p(tv, bt470bg, top first), 704x576 [SAR 16:11 DAR 16:9], 25 fps, 50 tbr, 90k tbn Stream #0:10x101: Audio: mp2 ([3][0][0][0] / 0x0003), 48000 Hz, stereo, fltp, 192 kb/s

[kjeacle]

John, thanks for the info. Your example does indeed fix the problem.

As these are standard recordings from a national broadcaster (and not files that have been mangled in some way) I was hoping to avoid any transcoding as I don't run any other user jobs at present and the files are OK in Mythfrontend.

Perhaps there is no other option and this is the recommended fix for Leanfront.

[Jpilk]

I'm glad it worked for you. I suspect that this problem is another result of the treatment of timestamps during recording. See perhaps https://github.com/MythTV/mythtv/issues/600#issuecomment-1173058981

[bennettpeter]

I have downloaded your sample and I can recreate the problem. I will trace the error to find the cause and see if there is a solution that does not involve post-processing the file.

[bennettpeter]

leanfront Exoplayer requires that it know the length of the video in order to skip. The problem is that it is unable to find the length.

I tested playing this file with vlc and it also is unable to find the length (length shows as 0)

Tracing the code I found that it goes wrong when searching for timestamps at the beginning and end of the file. It never finds a valid timestamp.

I am not familiar with the layout of packets, I rely on Exoplayer for that. I cannot see the reason for the problem, other than there is a different layout from normal. If I could figure out a fix, I could submit it to Exoplayer, they are very receptive to fixed. Since vlc also cannot find the length, I assume there is an error in the stream. I am giving up on trying to fix this. or on asking Exoplayer to fix it.

You could easily add the ffmpeg command suggested by John as a user job to run after every recording. It should be very quick to run. Let me know if you need assistance with that.

[kjeacle]

Peter, thanks for looking into this. Unless something changes in how the stream is broadcast, it looks like a user job is the only option. I already have an ffmpeg script ready to go. Thanks again.