[Kdenlive-devel] Audio sync issue

el jefe delito eljefedelito at gmail.com
Mon Feb 11 03:41:05 UTC 2013


> Can you reproduce the problem by simply placing a clip on a timeline
> by itself, rendering that, make a new project, add the rendered clip
> to a timeline by itself, and render that?
> You should use lossless for an intermediate file

Using Debian Sid on the single file named 'DSC_0124.MOV':

   - *If i export DSC_0124.MOV to a Lossless H.264 Slow (the audio is in
   sync after), and then export again to every format that I tried (H264,
   MERG-4, MPEG2), I had sync issues after that second render.*
   - If I export DSC_0124.MOV to mpeg2 the audio was correct the first
   time, but exporting again to anything had audio sync issues after the
   second render
   - If I export DSC_0124.MOV to an h.264 and reexport to h.264, for
   completeness, it still has sync issues after the second render.

> If so, can you reproduce it using one of the binary builds I provided
 > to this thread yesterday?

Using DD's Ubuntu x64 build (on Debian) I have:

   - If I export DSC_0124.MOV to lossless H.264 Slow and then export again
   to anything, it had audio sync issues issues.
   - If I export DSC_0124.MOV to FFV1 and export again to anything, *I
   don't have sync issues*
   - If I export my complex project (which started this conversation) to
   FFV1 Lossless, and then to Youtube or MPeg4 or H264, *no issues*; the
   audio syncs and things look and sound good
   - If I export my complex project (which started this conversation) to
   FFV1 Lossless, and then to Android, the render crashes

Dan, I think that your builds have fixed or improved the syncing.  Is this
coincidence that I'm asking about these issues now?

It seems, the answers lie in
the newer release;
the matching of profiles, clips, export framerates;
and the use of Lossless as an intermediary format


> Understandable, but for future reference you can also add the first
> project to the second project as a clip.

I've read this but I don't understand how.  If I try to "Add Clip", I get
video formats to pick from but none of the projectname.kdenlive files
appear.  I don't see an option to "Add Project" or "Embed Project".  How
can I add a project?

Thanks everyone!


On Fri, Feb 8, 2013 at 3:06 PM, el jefe delito <eljefedelito at gmail.com>wrote:

> Thanks for getting back to me.
>
> > Are you referring to just image quality or also A/V sync?
> Both the visual and the syncing look good.
>
> > Does the A/V sync look good in Kdenlive's monitors even after scrubbing
> or seeking?
> Yes, at all points during my editing process the sync seems to be just
> fine.
>
> > Can you reproduce the problem by simply placing a clip on a timeline
> > by itself, rendering that, make a new project, add the rendered clip
> > to a timeline by itself, and render that?
> I will try this tonight and get back to you.
>
> > If so, can you reproduce it using one of the binary builds I provided
> > to this thread yesterday?
> I will try this as well.
>
>
> Thanks again!
>
>
>
>
> On Fri, Feb 8, 2013 at 2:59 PM, Dan Dennedy <dan at dennedy.org> wrote:
>
>> On Fri, Feb 8, 2013 at 6:05 AM, el jefe delito <eljefedelito at gmail.com>
>> wrote:
>> > Thanks for the help.
>> >
>> >
>> >> To the original poster, you need to provide a sample file, the project
>> >> settings, and the render settings in order to investigate.
>> >
>> > My Nikon clips are 1280x720 at 23.98 FPS so that's what I changed my
>> project
>> > file to use.  I exported this at the H.264 setting with default values,
>> and
>> > the output appears perfect.  However, I need a logo overlay / watermark
>> and
>> > trying to do that in the original project, the KDEnlive editor wanted to
>> > composite that image with a specific video track; my video is edited
>> and on
>> > multiple tracks so I thought it'd be easier to add as a new project (and
>> > yes, I'd lose some quality with the re-render).
>>
>> Understandable, but for future reference you can also add the first
>> project to the second project as a clip. However, this H.264 profile
>> is a very poor choice for this because it is designed for distribution
>> not for editing because the GOP size (keyframe interval)) is set to
>> 250 frames. At 23.98 fps, that makes the GOP over 10 seconds! That
>> will make seeking and thereby a/v sync more challenging. You should
>> use lossless for an intermediate file, and they are faster to encode
>> as well.
>>
>> > Ok, so the first output looks great.
>>
>> Are you referring to just image quality or also A/V sync? Does the A/V
>> sync look good in Kdenlive's monitors even after scrubbing or seeking?
>>
>> >  The next run, new project, same
>> > project settings and using only the recently exported file and a
>> > transparent-background jpg, however, tells me at Render time that there
>> are
>> > No Matching Profiles for the H.264 option — which should be the exact
>> > profile that I just used!  How can it not match itself?  If I use it
>>
>> There appears to be a cosmetic bug here. In a fresh project, the first
>> time you open the Render dialog it defaults to the HDV group, and
>> indeed HDV is not compatible with 720p23.98 (according to MLT and
>> Kdenlive). This message should not apply to the H.264 render profile
>> as it has no restrictions like that, but I saw the warning as well
>> when I used your overlay project. So, there is some state bug that
>> makes the render dialog erroneously issue that warning.
>>
>> > anyways, I get audio sync issues worse than ever.
>> >
>> > Attached are the two projects I've been working on (normal edit, and
>> then
>> > where I just add the overlay watermark).  However, I don't have a short,
>> > decent clip to use to demo these sync issues so I'll have to shoot that
>> > later and send it in 10 hours or so.
>> >
>>
>> Based on this info, I do not need the original camera clip because it
>> is the render output of the first project that is giving you a
>> problem. I have not yet been able to reproduce this. I am not trying
>> to use your complex first project because that would take some time to
>> recreate with my own assets, and it does not appear to be necessary.
>>
>> So, I locate a 1280x720 at 23.98 clip in my library, add it a kdenlive
>> project with same settings, place it on a track by itself, and render
>> it with the H.264 profile. I check the output in a couple of players
>> including Shotcut (MLT-based) and Quicktime Player on OS X, both of
>> which are playing it with good sync.
>>
>> I open your overlay kdenlive project and replace the clip that is on a
>> track with the output from the preceding step. I render that out using
>> the render settings stored in the project file you provided (dual pass
>> H.264). The A/V sync of that output is good as well checked using same
>> players.
>>
>> Can you reproduce the problem by simply placing a clip on a timeline
>> by itself, rendering that, make a new project, add the rendered clip
>> to a timeline by itself, and render that?
>> If so, can you reproduce it using one of the binary builds I provided
>> to this thread yesterday?
>>
>>
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>
>
>
> --
>
>
> http://tinyurl.com/8zt5jux
> e: eljefedelito at gmail.com
> t: @robodioxide
>



-- 


http://tinyurl.com/8zt5jux
e: eljefedelito at gmail.com
t: @robodioxide
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