audio track with delay +21000 " not recognized and ignored"

[darekpro]

Hello,

When I want create new blu-ray folder and I adding new audio track with delay +21000 after creating folder the same folder can not be open again in tsmuxer.

BDMV sample
https://drive.google.com/file/d/1ahX4_jtOihYTAyVKXj2hmAGg7jKRfVEx/view?usp=sharing

[jcdr428]

@darekpro you need to grant access to your drive link.

[darekpro]

Upsss sorry :) done

[jcdr428]

tsMuxer scans the beginning of the m2ts to analyze the tracks. The size of the analyzed chunk is DETECT_STREAM_BUFFER_SIZE = 16 MB (line 42 of vod_common.h). With your delay of 21 ms, the AC3 track starts after this 16 MB chunk, so is not detected.

One solution would be to increase the buffer size, with the detrimental effect of increasing memory need / time needed to scan. An audio starting 21 sec. after video being quite uncommon, in such situation it would be preferable to append a 21 sec. "silence" AC3 before your AC3 track.

Edit: on the other side, tsMuxer was originally written for HD and not UHD, so maybe it would be logical to increase the detect buffer to 64 MB. @xavery @justdan96, any thought on the inconvenient of doing so ?

[darekpro]

"in such situation it would be preferable to append a 21 sec. "silence" AC3 before your AC3 track."
True but not with DTS-MA, TRUEHD itd :P

[jcdr428]

@darekpro True... I'll propose the one-line patch to increase buffer to 64 MB, let's see what @xavery thinks about this.

[xavery]

@darekpro True... I'll propose the one-line patch to increase buffer to 64 MB, let's see what @xavery thinks about this.

Sounds okay, the whole algorithm should start with a small-ish value and gradually work its way up to larger ones anyway. However, since we have no real performance/memory usage targets, and no real way to compare them across changes or versions, simply increasing the buffer size here is the natural way to go.

[jcdr428]

Thanks @xavery.
@darekpro could you please test latest bintray nightly, and close the issue if your problem is fixed.

[darekpro]

Perfect now everything it is ok. Thank you.