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.
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?
It might be a change on the # of channels
i.e. 6 channels -> stereo -> 6 channels
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.
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.
Wetransfer asks for a destination email address,what do I use?
use your own, you get 2 emails, use the one with short web link ;)
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.
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.
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 (https://www.dropbox.com/s/o6zj551p5lvvyqf/4HD6seconds.ts?dl=0) 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.
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.
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:
avprobe '/home/jan/Downloads/Audio fault.ts'
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
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[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
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[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
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[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
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[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
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[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
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[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
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[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
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[aac @ 0x11a5900] channel element 1.0 is not allocated
[aac @ 0x11a5900] channel element 1.0 is not allocated
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[aac @ 0x11a5900] channel element 1.0 is not allocated
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[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
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[aac @ 0x11a5900] channel element 1.0 is not allocated
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[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
ubuntu 16.04.1 64-bit:
ffprobe '/media/jan/1404/home/jan/Downloads/Audio fault.ts'
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
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.
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.
Confirm the shorter clip audio fault.ts does play correctly on VLC on my 14.4.1 machine also. But not on 16.4.1. The results playing the files on Avidemux are the same on both systems in so far as the film title section music is unintelligible. One oddity is that the sound track of the Honda promotion on VLC cuts the final word "Honda" and then plays the title music correctly while Avidemux includes the word "Honda" but then fails to reproduce the title music. It appears that VLC is switching audio mode in some way at this point but Avidemux is not.
The TV headend program does not recode and the system records HD without problems most of the time. Random recordings in HD today from Channel4 and BBC1 all edited without problems. Note that the two uploaded clips were from a Channel4HD transmission.
Quote from: mean on August 08, 2016, 02:30:22 PM
It might be a change on the # of channels
i.e. 6 channels -> stereo -> 6 channels
Stream has mixed audio going from stereo to 5.1 as you just found out
Don't know how this will evolve in avidemux, developer wise.
re-encoding audio with mixer set to stereo *might* work
I have now found that the file audio problem.mkv which has unintelligible sound in Avidemux and VLC, plays cleanly using smplayer on Ubuntu 16.4.1. So it is "just" a matter of correctly identifying the audio tracks and having the appropriate codecs. Any chance of this being added to the to do list? (The .ts file is silent on smplayer). Smplayer uses lavc:aac.
VLC results are not the same as Avidemux. VLC audio is identifiable but overlayed with a loud 50 Hz buzz, Avidemux sounds as-though the speaker is underwater.
Can I suggest a way that might get your job done. I use quite an old PCTV USB stick to make the recordings, so I'm not sure whether the problem is with that, as it gets a bit warm/hot after an hour or two of use. Most of the recordings have garbled audio after passing through Avidemux, even if no edits are made. These are files that play fine in Windows Media Player Classic after they are recorded but even when I just drop the file into Avidemux, video (copy), audio (copy), output (.ts) or (.mkv) or (.mp4) and then output without any edits, the audio in the resulting file is garbled.
I fix this (if fix is the appropriate word) by first passing the recorded file through MKVToolNix and then into Avidemux for editing. When dropped into Avidemux the file from MKVToolNix crashes Avidemux but when Avidemux is restarted and the option to reload the crash file is chosen, I edit the file and get good audio. There is nothing elegant about this workflow but until I find the cause and/or a better way, it gets the job done.
Passing the file through MKVToolNix takes out some text files that are in the original .ts file. They may be teletext, as enabling subtitles doesn't show any subtitles in the original .ts file but a file of eg 1907Mb shrinks to 1674Mb after going through MKVToolNix.
Actually just now I have updated to MKVToolNix v9.4.0 ('knurl') and it's output no longer crashes Avidemux.
Edit. Spoke too soon, the next file crashed Avidemux but it still restarts ok.
for old PCTV USB try with avidemux 2.5.6
I have found v2.5.6 can neither display or edit DVB-T HD files, it can edit DVB-T (SD) files. It's old but it's not that old.
I stand corrected, I tried to edit a short DVB-T HD clip in v2.5.6 (32bit) just after posting. On loading the file there was the usual green screen and the next I frame button seemed to take the play head to I frames but with no video in the display. Then when the play head got to near the end the first frame appeared in the display. I then moved the play head to the start, hit play and got 'Trouble initializing audio device' , I hit ok and the video played. There are a few weird things happening, which may make it unusable for this type of file but that is further than I have got before with v2.5.6 and this sort of file. The problem seems to be audio related and messing around with settings seems to make things worse. v2.5.6 is a version I go back to if I have a faulty video file, it seems to tolerate them better than v2.6.
For troublesome DVB-T HD files that Avidemux refuses, I always fall back on an editor called 'H264 TS Cutter', it only handles H264 TS files and I'm not that familiar with the GUI but it has never failed to edit any troublesome DVB-T HD file I have thrown it's way. I think development has stopped quite a while ago at v111.
Thanks for the comments. I have installed MKVtoolsNix but after remuxing the problem file, the audio is still unintelligible playing on Avidemus, (app version 30). However, a second HD recording on a TS file that also has garbled audio on Avidemux is ok when remuxed to MKV. Four other recent HD recordings play correctly as recorded To recap, the problem file is fine until the film starts at which point the audio fails. The number of audio tracks switches at this point. The audio is normal during the ads. If I ignore the audio and edit the file, then save as MKV (but not TS) using copy/copy. VLC plays only the music without dialogue while smplayer is silent. All very confusing!
Note that the source recording MKV file plays correctly on smpayer (before editing) but not on VLC which sounds as though it is adding the sutitlles in with the audio
My systems are both Ubuntu so H264 TS Cutter is not an option.
In cases like that I would treat the video and audio separately. I would demux the video and audio using 'Yamb' (not sure if that runs in Ubuntu). Yamb will also allow you to choose which streams to keep or remove without re-encoding anything.
http://www.videohelp.com/software/YAMB
Actually looking at that it seems to be Windows only but either way treating the video/audio separately seems the way to go.
I hope something here will help get your task completed.
http://www.videohelp.com/software/sections/linux-video-tools
Actually just doing a bit of editing now and notice MKVtoolsNix will demux the video and audio for you. You might be able to remove any offending audio stream that way. Either way converting the audio, in a separate app, to uncompressed PCM might make more likely that the video and audio will sync without any shifting and you can recompress the audio (or not) while or after editing.
It seems that one stereo track has music and effects, another has dialogue. There seems no consistency in the tracks used by any of the programs tested including Avidemux.
If i recode the audio in Avidemux, (rather than COPY), the replay of the result on both VLC and smplayer has the same "under water" effect. I cannot find any method of editing this recording with satisfactory audio although the source file plays perfectly on smplayer. I tried importing the source file into AUDACITY but although three audio tracks appeared, the dialogue track was missing and the third track seemed to be audio description. Unless Avidemux can be persuaded to cope with this audio track combination, time to give up I think!
That audio description is for the partially sighted I think, I have come across that in some broadcasts. How many audio tracks do you see in MKVtoolsNix, did you try demuxing the audio and video? If you don't like to be beaten and let's face it, you've probably spent more time on it now than it's worth, you could drop the original file into Handbrake, it doesn't refuse any valid file I've tried, just to see if that will give you a workable audio file, choose a low resolution for the video, it's the audio you're after. You could just edit what comes out of Handbrake's standard 'High Profile' or demux the audio from that output, if it's good, then mux it with the video from the original. Think of it as practice to save something you really don't want to lose, or you could just give up, maybe a glitch in the broadcast or a broadcast flag or a glitch in you receiving the broacast, has messed things up and anyway you still have the original recording.
Just to answer your question, MkvtoolsNix sees one stereo track and one mono track. Track one has dialogue and music, track two has the audio description. Using MkvtoolsNix, muxing with 1 and 2 or just 1 give the same result. Track two is not present. This results in a file with good audio on smplayer but burbling on Avidemux. Muxing with track 2 only, smplayer plays the audio description, (Avidemux is silent). As a further twist, the audio description has no connection what ever with the video.
I give up!
I'm still convinced the problems start with recording (dvb-t/t2) is a multiplex (Crystal Palace muxes: several TV channels in one stream). Recording takes out the TV channel from that stream and probably there goes something wrong. Possibly something similar as happens here: ac3 audio unusable after a channel number switch (http://avidemux.org/smif/index.php/topic,17079.0.html)
Having no access to that signal/hardware there is no testing possible from this side.
Possible causes:
DVBSky T9580 driver issue
TVheadend it seems you're behind with 4.0 :https://tvheadend.org/builds/tvheadend.
Except that this is an issue with one HD recording only. On this contiguous recording, the previous programme and all links and ads during the recording play fine on Avidemux, but not the film sections.
Smplayer plays the entire recording without problems. On tvheadend, I am running 4.0.9 which is the current release source code. Development of 4.2 has been almost (99%) finished for quite a while.
Appreciate it's been a while since last post but I am also experiencing this or similar issues with files sourced from recorded program in UK and would like to understand the cause, but more importantly would like to have a workflow and set of tools that could cope with this.
I'm not really up on content of various container formats or how the video and audio are kept together but happy to learn as I need to try to get round this. Historically I used to use Womble VCR edit and that had a really neat "fix up" mode that sorted out most audio/video synch problems in recorded TS files, but it can't cope well with HD content so I'm trying out non-commercial options at the present time as many of the commercial editors are quite pricey for the use I'm likely to make of them.
Here I'm using Windows 64 bit version. Most files recorded on Humax HDR Fox T2, one or two on an old Humax 9200. Avidemux is current 2.6 version
Essentially some files, and to me there's no obvious common area, edit fine using AvideMux and some don't. The ones that don't get garbled sound, sort of like a fast underwater bubbly sound that I think is described here.
VLC and MPC Player can play the original files fine, but the edited ones I can't play with anything.
Only thing I can add to this mix is that I have also experienced another sound issue before that appeared equally random whereby sound was sometimes there and sometimes not (on an original recording xferred to the PC). Sometimes MPC player would be able to play sound when VLC couldn't and sometimes MPC Player couldn't either. That issue lasted around 3 months but I haven't noticed it in a while.
Conclusions for that were pretty much as one of the contributors mentioned here, that the audio was chopping and changing and some players cope and some don't. This I believe is under control of the content creator, but I guess it could also happen when the file gets moved around internally prior to broadcast or indeed when it gets reassembled by the recorder. Any corrections to my naive view welcome.
Basically when the ads happen, it switches from 5.1 to stereo and back
For broadcast content it's fine, because the player expects that to happen
For stored content it's not, and it 's not managed at the container format i.e. mkv or mp4 for example
Thank you for your response mean.
So the random nature of the issue is just down to whether the broadcaster does this or not on a programme, which presumably is content dependant (among other causes).
Without going down the "why can't players for stored content do what receivers do" route I assume therefore that correction is all about replacing audio streams, as has been alluded to in the previous thread. If there's a simple explanation as to how these are stored in the container formats and how the audio and video are linked so that synchronisation can occur, please point me at it because it will probably reduce the number of questions I need to ask to understand any answer to the basic one below.
Practically then, does this mean that to fix things the audio and video need to be separated, then bits of audio changed, spliced back into one (set of) audio and then recombined with the video? If so, does this then require video to be re-encoded in order for the linking to happen or can that be done some other way?
...and more importantly what of all the somethings out there can help me do this easily and reliably? If it means switching to processing the files under Linux that's fine, happy to do so.
From some searching I've done it looks like ffmpeg will help a fair bit but until I understand what I need to cut and splice...
Many thanks.
PS. Just a thought... If I am cutting out all the ads, and all pre- and post- stuff from a recorded program why is there an issue with switching audio types - there shouldn't be any, or is this down to Avidemux and other editors having to process thing sequentially?
On track switching, just a reminder that the last sample I uploaded had no track switching but the sound was "backwards" throughout the recording on Avidemux. Seems there may be more than one cause for the problem. Other samples definitely fail at the link - programme switch point. The only common feature is they are all HD recordings but only one here and there, usually the ones I particularly want!
Fish's suggestion of using MKVToolNix does work on some of the problem recordings.
I am also experiencing this problem (BBC on FreeViewHD in UK, i.e. DVB-T2). At the point of switchover from link to program (a film) the audio in Avidemux becomes garbled. This is no doubt a switch from stereo to 6 channel and may be the reason for some recordings to not have the problem as anything broadcast just in stereo will not suffer from this. The problem only seems to occur in 6 channel audio and as others have mentioned, it can manifest itself as clear audio, but missing the dialog which is no doubt just in the (missing) centre channel. Basically it appears that just the L and R channels are being played and the other channels simply discarded/ignored. Hence no centre channel and no dialog. This is how it starts in VLC, but if I switch to the other audio track (Audio Described) and back, VLC then includes the centre channel and plays full and correct audio. So it IS there. What we need is a way to fix it so that is the ONLY way it can be played.
Whatever the reasons behind this, i.e. what is actually broadcast, the significant fact to me is that whatever the cause, VLC can handle if (albeit after switching audio tracks and back again), while Avidemux cannot at all, whatever you do. Not only is it unable to produce intelligible audio, but it is unable to 'copy' the correct audio to any output. Avidemux is not the only program to have such problems, but the fact remains that VLC is able to play it correctly, so this problem is surely an Avidemux problem.
Interestingly, MediaInfo shows just a single audio track, yet there exists the main track and also the Audio Described track, between which VLC is able to switch. But Avidemux only shows a single track. Is it perhaps getting confused and trying to play them both as the same track, not realising there are 2 distinct tracks, which being digital means garbled sound as it's not like simply mixing analog audio. For some other recordings with no apparent problem, both the main and AD tracks appear independently, but when e.g. MediaInfo only sees a single audio track, Avidemux has the problem which is likely to be connected.
I don't believe this was an error by FreeView. It is how they are transmitting some programs and it is likely to re-occur. So it would be wonderful if Avidemux was able to deal with this audio configuration.
There seems to have been considerable interest in this topic but the post is sinking into oblivion!
Has anybody any thoughts on a solution?
Just to let you know ... I have the same issue with recordings from my Humax box. Although I only ever get the problem on ITV and C4. I don't think I've ever experience it on a BBC channel.
If you have a multi track and AC3 is the 1st audio track:
Switch audio tracks position so MPEG-Audio is the 1st track and AC3 / E-AC3 is the 2nd. See if this helps.
- Load recorded video
- with [Copy] for both Video and Audio Output
- Avidemux menu: Audio: Select Tracks
- in Track 1 select [Track 1 from video (MP2, Stereo, 256kbps)
- in Track 2 select [Track 0 from video (AC3, Stereo, 448kbps)
see if this helps,
You need to cut out the parts with stereo (commercials, ...) and leave only 5.1 video (main feature, program, ...)
Otherwise export main audio track and change either the whole track to 5.1 or Stereo.
Quote from: Jan Gruuthuse on September 19, 2017, 03:07:17 AM
If you have a multi track and AC3 is the 1st audio track:
Switch audio tracks position so MPEG-Audio is the 1st track and AC3 / E-AC3 is the 2nd. See if this helps.
- Load recorded video
- with [Copy] for both Video and Audio Output
- Avidemux menu: Audio: Select Tracks
- in Track 1 select [Track 1 from video (MP2, Stereo, 256kbps)
- in Track 2 select [Track 0 from video (AC3, Stereo, 448kbps)
see if this helps,
You need to cut out the parts with stereo (commercials, ...) and leave only 5.1 video (main feature, program, ...)
Otherwise export main audio track and change either the whole track to 5.1 or Stereo.
I appreciate this is a very old thread but I am having exactly the same issue 3 years on when recording UK Channel 4 using my HD Homerun Connect via Plex. I am converting from.ts files to 720 x 1280 mp4. The sound is fine for the commercials but as soon as the program starts the sound is garbled. If I select the second track this is better but this track is for visually impaired viewers.
Do Jan's instructions above work with Avidemux? I have the same issue when trying to convert with VLC but handbrake seems to work OK?
Avidemux can't handle format and codec changes, this is a design limitation. In case of a MPEG-TS file, ensure the file starts with the program, not with a commercial (use tail or dd if you are on an unixoid OS or some sort of a binary file splitter if not).
Ok Thanks eumagga0x2a Ill carry on using handrake on windows for these awkward shows.