Subject: [Cellar] Adding cues for audio tracks

From: Tobias Rapp <[email-masked]>
Date: Fri, 1 Sep 2017 14:27:26 +0200

Hello,

the recommendations section of the "Cues" chapter (43.2) contains the 
following paragraph:

"""
Audio tracks SHOULD only be referenced in "CuePoint Elements" if
no video track is present.  In this case "CuePoint Elements"
SHOULD reference audio keyframes at most once every 500
milliseconds.
"""

I understand this helps optimizing Matroska file size but at the cost of 
seeking performance. When video bitrate is large (FFV1 1080p) and 
seeking latency is high (tape-based storage system) the additional 
round-trips to find the accurate audio track position can be in the 
range of minutes. So for this scenario adding audio tracks to the 
cluster index makes sense and index size overhead is still small 
compared to the total file size.

In my opinion it would be better to indicate that the recommendation is 
fully optional, using text like:

"""
References to audio tracks MAY be skipped in "CuePoint Elements" if a 
video track is present.  When included the "CuePoint Elements" SHOULD 
reference audio keyframes at most once every 500 milliseconds.
"""

Regards,
Tobias

---

From: Moritz Bunkus <[email-masked]>
Date: Fri, 01 Sep 2017 14:33:20 +0200

Hey,

I'd be fine with such a change. Care to create a pull request?

Kind regards,
mosu

---

From: Tobias Rapp <[email-masked]>
Date: Fri, 1 Sep 2017 14:54:01 +0200

> I'd be fine with such a change. Care to create a pull request?

Will try to educate myself on GitHub pull requests and create one.

Thanks for feedback,
Tobias

---

From: Ashley Blewer <[email-masked]>
Date: Fri, 1 Sep 2017 11:11:54 -0400

I agree with this change too.

Tobias (and everyone else), Happy to help if you have any questions about
using Github! Just send me an email off-list!

Ashley

On Fri, Sep 1, 2017 at 8:54 AM, Tobias Rapp <[email-masked]> wrote:

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