duration and media-duration in GnlObject

[Vineeth-2]

Hi,
  I wanted to know the difference between "duration" and  "media-duration"  in GnlObject and I couldn't comprehend this clearly from the documentation.
  If I want the Gnl pipeline to render at a faster rate, (but without changing the timestamp of sources) which property should I change? I read that rate is a read-only property.
  Thanks.
--vineeth

_______________________________________________
gstreamer-devel mailing list
[hidden email]
http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel

[Edward Hervey]

Hi,

On Fri, 2011-08-05 at 17:11 +0530, vineeth wrote:
> Hi,
>   I wanted to know the difference between "duration" and
> "media-duration"  in GnlObject and I couldn't comprehend this clearly
> from the documentation.

  Duration is for how long something will be played from the outside.
  Media-duration is how long you're taking from the contained media.

  99.99% of the time you want media_duration == duration.

  If you want a source to play faster/slower (without any extra cost),
you can modify those values accordingly.
  Ex : I want to playback an intro video two times slower. That video is
originally 3s:
   media_duration = 3s
   duration = 6s

  The rate is computed from the duration/media_duration values
automatically, it's just provided as a convenience.

>   If I want the Gnl pipeline to render at a faster rate, (but without
> changing the timestamp of sources) which property should I change? I
> read that rate is a read-only property.

  You can either:
  * Seek with a rate of 0.5 if you just want to play it back slower
  * OR you'll have to modify all the source duration/media_duration
values accordingly.

    Edward

>   Thanks.
> --vineeth
> _______________________________________________
> gstreamer-devel mailing list
> [hidden email]
> http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel


_______________________________________________
gstreamer-devel mailing list
[hidden email]
http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel

[Vineeth-2]

Hi,

  Thanks for the clarifications.

On Sat, Aug 6, 2011 at 1:48 PM, Edward Hervey <[hidden email]> wrote:

Hi,

On Fri, 2011-08-05 at 17:11 +0530, vineeth wrote:
> Hi,
>   I wanted to know the difference between "duration" and
> "media-duration"  in GnlObject and I couldn't comprehend this clearly
> from the documentation.

 Duration is for how long something will be played from the outside.
 Media-duration is how long you're taking from the contained media.

 99.99% of the time you want media_duration == duration.

 If you want a source to play faster/slower (without any extra cost),
you can modify those values accordingly.
 Ex : I want to playback an intro video two times slower. That video is
originally 3s:
  media_duration = 3s
  duration = 6s

 The rate is computed from the duration/media_duration values
automatically, it's just provided as a convenience.

>   If I want the Gnl pipeline to render at a faster rate, (but without
> changing the timestamp of sources) which property should I change? I
> read that rate is a read-only property.

 You can either:
 * Seek with a rate of 0.5 if you just want to play it back slower
 * OR you'll have to modify all the source duration/media_duration
values accordingly.

 

I was trying a mp4 (with h264) trim on 0.10.32

When the duration was made half of media-duration, I was expecting the pipeline to run faster, however, I didn't see any significant change in save time (compared to case where duration and media-duration are same).

for ex:

gst-launch gnlcomposition { gnlfilesource name="s1" location="/mnt/hgfs/ubuntu_shared/h264/4.mp4"  start=0 duration=10000000000 media-start=0 media-duration=10000000000 } ! ffmpegcolorspace ! x264enc ! mp4mux ! filesink location="/mnt/hgfs/ubuntu_shared/output-d-10-md-10.mp4"

Time take : ~41 seconds

gst-launch gnlcomposition { gnlfilesource name="s1" location=/mnt/hgfs/ubuntu_shared/h264/4.mp4  start=0 duration=5000000000 media-start=0 media-duration=10000000000 } ! ffmpegcolorspace ! x264enc ! mp4mux ! filesink location=/mnt/hgfs/ubuntu_shared/output-d-5-md-10.mp4

Time take : ~41 seconds
 
Our intention is to speed up the gnl pipeline so that the media content is saved faster. Is there anything missing / incorrect in the above pipeline?

 

   Edward

>   Thanks.
> --vineeth
> _______________________________________________
> gstreamer-devel mailing list
> [hidden email]
> http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel


_______________________________________________
gstreamer-devel mailing list
[hidden email]
http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel

_______________________________________________
gstreamer-devel mailing list
[hidden email]
http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel