Garbled sound on some HD recordings

[Post producer]

Using both Avidemux versions QT5 on Ubuntu 16.04.1 and QT4 on Ubuntu 14.4. On some HD recordings, the audio is ok, (during ads), until the programme starts when the sound becomes gabled and unintelligible. The unedited recording plays ok on VLC. If I ignore the sound and edit anyway, using copy and copy, saving as MKV, the result also plays correctly on VLC but remains faulty if replayed by Avidemux. There must be a change in the broadcast audio (bit rate?) that the codec used by VLC can cope with but that in Avidemux cannot. Any advice gratefully received.

Thanks to Mean and Jan for all their good work on Avidemux.

[Jan Gruuthuse]

I'm using in Preferences: Audio:
Local playback downmixing: [Pro logic]
AudioDevice: Pulse AudioS
Verify against the used audio device in VLC

Intel Core i7-3770K @ 3.90GHz (8 Cores) and Intel HD audio (Audio: Intel 7 /C210),  Chipset: Intel Xeon E3-1200 v2/3rd, ASRock Z77 Extreme3 (a little aged)

If all decoding is done by CPU (Video and Audio) this could go beyond the available CPU processing power.
Have not yet come across this phenomenon on core I5 or core I7 with standard HD Video upto 1080p
CPU processing is partly offloaded with HW Accel: VDPAU (NVIDIA) GTX 960.
4K video would/could pose this problem. (hardware bottleneck)
Keep in mind avidemux is not a videoplayer and should not be used as such.

If you could upload a fragment with this audio issue? Is your provider switching audio streams on commercial brakes?

[mean]

It might be a change on the # of channels
i.e. 6 channels -> stereo -> 6 channels

[Post producer]

Thanks for your replies. CPU is IntelÃ,® Coreâ„¢ i5-2500K CPU @ 3.30GHz Ãâ€" 4 with sandy bridge chips. Intel internal audio. Changing downmixing from stereo to Prologic has no effect on the audio. Monitoring CPU usage gives 18% before and after the change point.

Please remind me how to upload the clip (263Mb), I do not have a Dropbox account.

[Jan Gruuthuse]

Use a free: dropbox account, mega, https://www.wetransfer.com/ or similar webservice (free public access, without registration to download your uploaded video) thank you.

[Post producer]

Wetransfer asks for a destination email address,what do I use?

[Jan Gruuthuse]

use your own, you get 2 emails, use the one with short web link

[Jan Gruuthuse]

To short was only 14 MB (1 fragmented Image frame)
There are 2 Audiotracks:
- English 48 kHz, 2 channels; AAC (LC) (Stereo) duration 64 ms
- English 24 kHz, 1 channels; AAC (LC) (mono) empty

the sound to short too make anything out.

In avidemux Menu: Audio enable disable the tracks alternatively and hear if that makes a difference.

[Post producer]

Not sure where that went wrong. Here is a new link. should run about i minute 30 with the faulty sound about halfway at the film start. I have checked the download works.

https://we.tl/w2sPjOl4pg

I have found another problem recording but in this case VLC plays the original recording OK but replay of the edited version audio on VLC is garbled. I can upload a section of that too if useful. Thanks.

[Jan Gruuthuse]

This is not the original recording, you did send! the link goes to 'Audio problem.mkv' 42 MB in size
Where did you record this from? And what did you do afterwards to make this mkv?

Load the movie into avidemux, goto where the movie logo starts, mark with [A ] and at end of movie logo mark with [ B] leave Video and Audio Output in  [Copy] and Output Format [Mpeg TS Muxer (ff)) and save the marked video.

Wow this is very odd. Avidemux and Mediainfo don't recognises correctly the audio tracks? They think track is AAC (LC) and stutter heavely when movie logo starts.

Here is a 6 seconds cut mpeg-ts from an original channel 4 HD recording (dvb-s2) 8 MB download.
This cut will be only available for a couple of days.

[Post producer]

No, the first link was to a clip that had not saved correctly, so the second link was to a new attempt. This was intended to show that the advertising material played correctly while the following film did not. "Audio problem.mkv" was a clip from an off air recording .ts file. Video and audio set to COPY and the output set to MKV.

Note that although avidemux cannot play the film section audio of this clip correctly, VLC does.  I have edited the original recording to produce the TS file as you suggested. This is handed by avidemux as before but now VLC cannot play the  audio either. This is the link to that clip.    https://we.tl/6oDaye4iLs.

The audio problem always occurs as a new programme starts even though the end of the previous programme and any links or ads play correctly. There must be some change in the audio stream that upsets avidemux. The problem is not confined to any particular muliplexer.

Your six second download plays perfectly in Avidemux and VLC on my 16.4.1 machine. 

[Jan Gruuthuse]

Can you make yourself an original recording from channel 4HD (10 seconds to 1 Minute)
You still did not tell us how the recording was made and what the source is.
Give details: satellite, transponder, your hardware used to receive and record this FTA stream?
vlc does play your Audio fault.ts here on 14.04.5

I think this needs developers attention.
ubuntu 14.04.5 64-bit:

Code Select Expand

avprobe '/home/jan/Downloads/Audio fault.ts'

Code Select Expand

avprobe version 9.18-6:9.18-0ubuntu0.14.04.1, Copyright (c) 2007-2014 the Libav developers
  built on Mar 16 2015 13:19:10 with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1)
[h264 @ 0x11a3960] mmco: unref short failure
[h264 @ 0x11a3960] mmco: unref short failure
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
[mpegts @ 0x119e180] max_analyze_duration reached
[NULL @ 0x11a6180] start time is not set in estimate_timings_from_pts
Input #0, mpegts, from '/home/jan/Downloads/Audio fault.ts':
  Duration: 00:00:23.68, start: 0.404000, bitrate: 4768 kb/s
  Program 1
    Metadata:
      service_name    : Service01
      service_provider: FFmpeg
    Stream #0.0[0x100]: Video: h264 (High), yuv420p, 1920x1080 [PAR 1:1 DAR 16:9], 24.83 fps, 50 tbr, 90k tbn, 50 tbc
    Stream #0.1[0x101](eng): Audio: aac, mono, fltp, 314 kb/s
    Stream #0.2[0x102](eng): Audio: aac, 0 channels, fltp
[h264 @ 0x11a41e0] Ignoring NAL unit 9 during extradata parsing
# avprobe output

[Jan Gruuthuse]

ubuntu 16.04.1 64-bit:

Code Select Expand

ffprobe '/media/jan/1404/home/jan/Downloads/Audio fault.ts'

Code Select Expand

ffprobe version 2.8.6-1ubuntu2 Copyright (c) 2007-2016 the FFmpeg developers
  built with gcc 5.3.1 (Ubuntu 5.3.1-11ubuntu1) 20160311
  configuration: --prefix=/usr --extra-version=1ubuntu2 --build-suffix=-ffmpeg --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --cc=cc --cxx=g++ --enable-gpl --enable-shared --disable-stripping --disable-decoder=libopenjpeg --disable-decoder=libschroedinger --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librtmp --enable-libschroedinger --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzvbi --enable-openal --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzmq --enable-frei0r --enable-libx264 --enable-libopencv
  libavutil      54. 31.100 / 54. 31.100
  libavcodec     56. 60.100 / 56. 60.100
  libavformat    56. 40.101 / 56. 40.101
  libavdevice    56.  4.100 / 56.  4.100
  libavfilter     5. 40.101 /  5. 40.101
  libavresample   2.  1.  0 /  2.  1.  0
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  2.101 /  1.  2.101
  libpostproc    53.  3.100 / 53.  3.100
[h264 @ 0x23c21a0] mmco: unref short failure
    Last message repeated 1 times
[aac @ 0x23c2d40] channel element 1.0 is not allocated
    Last message repeated 221 times
[mpegts @ 0x23bdca0] decoding for stream 1 failed
[NULL @ 0x23c38e0] start time for stream 2 is not set in estimate_timings_from_pts
[mpegts @ 0x23bdca0] Could not find codec parameters for stream 1 (Audio: aac (LC) ([15][0][0][0] / 0x000F), stereo, fltp, 316 kb/s): unspecified sample rate
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mpegts @ 0x23bdca0] Could not find codec parameters for stream 2 (Audio: aac ([15][0][0][0] / 0x000F), 0 channels, fltp): unspecified sample rate
Consider increasing the value for the 'analyzeduration' and 'probesize' options
Input #0, mpegts, from '/media/jan/1404/home/jan/Downloads/Audio fault.ts':
  Duration: 00:00:23.70, start: 0.404000, bitrate: 4764 kb/s
  Program 1
    Metadata:
      service_name    : Service01
      service_provider: FFmpeg
    Stream #0:0[0x100]: Video: h264 (High) ([27][0][0][0] / 0x001B), yuv420p(tv, bt709), 1920x1080 [SAR 1:1 DAR 16:9], 25 fps, 50 tbr, 90k tbn, 50 tbc
    Stream #0:1[0x101](eng): Audio: aac (LC) ([15][0][0][0] / 0x000F), stereo, fltp, 316 kb/s
    Stream #0:2[0x102](eng): Audio: aac ([15][0][0][0] / 0x000F), 0 channels, fltp

[Post producer]

The source is freeview from Crystal Palace, receiver card for HD is DVBSky T9580, recording software is tv headend version 4.0.

Is this audio problem something to do with copy protection?

Will test ch4 recording later today.

[Jan Gruuthuse]

I don't think so on freeview? There should be no drm. (compliant to the DVB-T standard, and uses a UK specific profile of MHEG-5)
I'm not familiar with DVB recording on PC. I would think one of your profiles is not set correctly or you are re-encoding the stream while recording?
I'm using OpenPLi DVB-S2 sat receiver - records the (channel) stream as it is onto harddisc.
Perhaps UK dvb-t users are reading here and can provide you with more info.
Or you have to find more info on tv headend version 4.0 with DVBSky T9580 card on Crystal Palace muxes.