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manolito · 8th February 2019, 15:24

Thanks mkver for the detailed analysis, but this is not really my point...

The average user will not have such analysis skills (I certainly don't), and we have software like mkvextract and mkvmerge to do this automatically. This is all I am asking for.

You are correct, I did not extract the video track at all, I just extracted the audio track and remuxed it into the source MKV. And this resulted in the sync error. I just tried again and extracted both the video and audio tracks, then imported both tracks into MKVMerge to create a new MKV. And yes, this time the only way to avoid sync errors was to honor the audio delay for the muxing process. So it does make a difference if I add an audio track with a delay to an already existing MKV with a video track, or if I create a brandnew MKV with video and audio tracks. Weird, and basically I do not want to deal with this.

The reason why I need to extract the audio track(s) from the source MKV is that I use StaxRip (an older 32-bit version) to recode the HD source HEVC / AAC-LATM (or E-AC3) into an SD AVC / AAC file. And StaxRip processes the audio separately from the video, and the extracted audio always needs to be decompressed to PCM first to make frame accurate editing possible.

And if the captured source has transmission errors, you do have a point. If I have repacked a captured MTS file to MKV first and there are glitches in this file, I will loose audio sync. But by trial and error I found out that this does not happen if I use the original MTS or TS as the source for StaxRip. My source filter is DSS2Mod, and when the source has transmission errors and I use the original Transport Stream as the source then I will see the broken frames, but sync is maintained.

Using the original Transport Stream as the source has its problems, though, and I try to avoid it when I can. Editing out commercials is a major PITA when using HEVC Transport streams, seeking the desired frame by stepping through the frames always brings up corrupt frames because the next I-Frame cannot be found. After repacking the source to MKV these problems disappear completely.

Luckily transmission errors are very rare for me with the DVB-T2 format. I always use TSDoctor to check for transmission errors, and about 95% of my captures are error-free.

Cheers
manolito

8th February 2019, 15:24	#384 \| Link
manolito Registered User Join Date: Sep 2003 Location: Berlin, Germany Posts: 3,079	Thanks mkver for the detailed analysis, but this is not really my point... The average user will not have such analysis skills (I certainly don't), and we have software like mkvextract and mkvmerge to do this automatically. This is all I am asking for. You are correct, I did not extract the video track at all, I just extracted the audio track and remuxed it into the source MKV. And this resulted in the sync error. I just tried again and extracted both the video and audio tracks, then imported both tracks into MKVMerge to create a new MKV. And yes, this time the only way to avoid sync errors was to honor the audio delay for the muxing process. So it does make a difference if I add an audio track with a delay to an already existing MKV with a video track, or if I create a brandnew MKV with video and audio tracks. Weird, and basically I do not want to deal with this. The reason why I need to extract the audio track(s) from the source MKV is that I use StaxRip (an older 32-bit version) to recode the HD source HEVC / AAC-LATM (or E-AC3) into an SD AVC / AAC file. And StaxRip processes the audio separately from the video, and the extracted audio always needs to be decompressed to PCM first to make frame accurate editing possible. And if the captured source has transmission errors, you do have a point. If I have repacked a captured MTS file to MKV first and there are glitches in this file, I will loose audio sync. But by trial and error I found out that this does not happen if I use the original MTS or TS as the source for StaxRip. My source filter is DSS2Mod, and when the source has transmission errors and I use the original Transport Stream as the source then I will see the broken frames, but sync is maintained. Using the original Transport Stream as the source has its problems, though, and I try to avoid it when I can. Editing out commercials is a major PITA when using HEVC Transport streams, seeking the desired frame by stepping through the frames always brings up corrupt frames because the next I-Frame cannot be found. After repacking the source to MKV these problems disappear completely. Luckily transmission errors are very rare for me with the DVB-T2 format. I always use TSDoctor to check for transmission errors, and about 95% of my captures are error-free. Cheers manolito