Hi. I've got a TS file and want to extract the audio track without re-encoding. I tried using the "Demux" mode in tsmuxer and got an AAC file but its length (02:57:56) is a bit shorter than the original video length (02:58:38) when played in MPC-HC. The AAC file length shown in the windows-included music player groove music becomes more than 3 hours long.
I also tried just muxing the audio track to a new TS file. This time the output audio TS file length has no problem no matter what player it is being played in.
But am I doing it right? I think demuxing is what should work not re-muxing it to a new TS file?
Below is the video mediainfo. Thanks a lot!
Code:Format : MPEG-TS File size : 7.41 GiB Duration : 2 h 58 min Overall bit rate mode : Variable Overall bit rate : 5 938 kb/s Video ID : 481 (0x1E1) Menu ID : 1 (0x1) Format : AVC Format/Info : Advanced Video Codec Format profile : High@L4 Format settings : CABAC / 2 Ref Frames Format settings, CABAC : Yes Format settings, ReFrames : 2 frames Format settings, GOP : M=3, N=60 Codec ID : 27 Duration : 2 h 58 min Bit rate mode : Variable Maximum bit rate : 6 000 kb/s Width : 1 920 pixels Height : 1 080 pixels Display aspect ratio : 16:9 Frame rate : 29.970 (30000/1001) FPS Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Scan type : Progressive Color range : Limited Color primaries : BT.709 Transfer characteristics : BT.709 Matrix coefficients : BT.709 Audio ID : 482 (0x1E2) Menu ID : 1 (0x1) Format : AAC Format/Info : Advanced Audio Codec Format version : Version 4 Format profile : LC Muxing mode : ADTS Codec ID : 15 Duration : 2 h 58 min Bit rate mode : Variable Maximum bit rate : 208 kb/s Channel(s) : 2 channels Channel positions : Front: L R Sampling rate : 96.0 kHz Frame rate : 93.750 FPS (1024 SPF) Compression mode : Lossy Delay relative to video : -17 ms Language : English
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If the audio is in synch, then it's fine.
Maybe the original Ts file has a timestamp problem.
In this case a simple remux can help, because the timestamps are rewritten.
I would say with out a doubt that there are identical and no need to analyze them,as to the length of the audio lots of videos have shorter audio than video time,as long as the audio is in sync then all is ok.I think,therefore i am a hamster.
Is there any reason why the audio length is shorter than the video length? Do they use different units of time? If thereís no silence part at the start or at the end of the original file, then why would the audio length be shorter than video? Iím just really curious what leads to this situation.
No specific reason I think. Very often audio- and videolength don't (exactly) match. They simply don't have to and will play fine. You'll find it even on dvd and blu-ray. So why bother.
If you want to ask the creator, who is "they"? Everybody and his dog nowadays is busy with recoding, speedchanging, crossmuxing and whatnot. I bet that a lot wouldn't even be aware (or care) if audio playtime don't match video's.
MediaInfo says then.
The ADTS container doesn't use a global header and so it may be read differently by different applications /demuxers...
and if the application or "filter" is not very versatile (so to speak), weird results may happen.
Last edited by El Heggunte; 3rd Aug 2022 at 05:10. Reason: edit"Like this facility, I don't exist."
I use mkvtoolnix and just output the audio track as .m4a. Shown below is the mediainfo of the output file. Am I doing it correctly? Are there any other softwares that can remux just the audio files? Avidemux doesn't allow me to input a single audio track and tsmuxer has no option of outputting as mp4 or m4a.
Edit: But this does solve the problem of different players showing different audio lengths. Thanks.
Format : Matroska Format version : Version 4 / Version 2 File size : 459 MiB Duration : 2 h 58 min Overall bit rate : 359 kb/s Encoded date : UTC 2022-08-03 09:32:40 Writing application : mkvmerge v62.0.0 ('Apollo') 64-bit Writing library : libebml v1.4.2 + libmatroska v1.6.4 FileExtension_Invalid : mkv mk3d mka mks Audio ID : 1 Format : AAC Format/Info : Advanced Audio Codec Format profile : LC Codec ID : A_AAC-2 Duration : 2 h 58 min Bit rate : 353 kb/s Channel(s) : 2 channels Channel positions : Front: L R Sampling rate : 96.0 kHz Frame rate : 93.750 FPS (1024 SPF) Compression mode : Lossy Stream size : 456 MiB (99%) Language : English Default : Yes Forced : No
Last edited by Tsubasa; 3rd Aug 2022 at 04:55.