[gst-devel] Video transitions using gnloperation

Lane Brooks lane at brooks.nu
Tue Jan 4 19:28:31 CET 2011


A little more information: src2 likes to have a higher priority that 
src1. If I remove the gnloperation completely and run only with 
gnlfilesources for src1 and src2, if src2 has a higher priority than 
src1, the pipeline hangs when src2 turns on.

So if I then add the gnloperation with priority 0 and set src2 
priority=1 and src1 priority=2, the pipeline hangs when the gnloperation 
turns on. I verify this by having src1 turn at time 0 second. Then src2 
turns on at time 2 second, and it takes over as seen previously. Then I 
have gnloperation turn on at 3 seconds, and that is when the pipeline hangs.

See the answers to questions below:

On 01/04/2011 11:08 AM, Timothy Braun wrote:
> What do you get when you set GST_DEBUG=2?  The pipeline is most likely 
> freezing because of a caps filter or a pad issue. 
Here is the output I get when I run wiht GST_DEBUG=2. This is the same 
output I get if I remove the gnloperation all together, so I am not sure 
it is related to the issue I am having.

0:00:00.038328446  1353      0x1ed8af0 WARN               gnlsource 
gnlsource.c:545:gnl_source_change_state:<gnlfilesource0> Couldn't find a 
valid source pad
0:00:00.054148884  1353      0x22ccd20 WARN                 qtdemux 
qtdemux_types.c:170:qtdemux_type_get: unknown QuickTime node type avc1
0:00:00.054183522  1353      0x22ccd20 WARN                 qtdemux 
qtdemux_types.c:170:qtdemux_type_get: unknown QuickTime node type avcC
0:00:01.354701757  1353      0x1ed8af0 WARN               gnlsource 
gnlsource.c:545:gnl_source_change_state:<gnlfilesource1> Couldn't find a 
valid source pad
0:00:01.369736423  1353      0x20aad30 WARN                 qtdemux 
qtdemux_types.c:170:qtdemux_type_get: unknown QuickTime node type avc1
0:00:01.369785865  1353      0x20aad30 WARN                 qtdemux 
qtdemux_types.c:170:qtdemux_type_get: unknown QuickTime node type avcC

> What is the pipeline connected to for output?

The output is connected to a "queue" and an "autovideosink". The 
pipeline runs fine when no gnloperation is in place, and the second 
video takes priority. When I add the gnloperation but do not set any 
priorities, the pipeline runs as if the gnloperation is not there. When 
I set the priority on src2 to anything other than 1, then the pipeline 
hangs. By changing around the "start" time property on the gnloperation, 
the hanging seems to correspond to whenever the gnloperation starts up.

Lane

>
> On Tue, Jan 4, 2011 at 12:56 PM, Lane Brooks <lane at brooks.nu 
> <mailto:lane at brooks.nu>> wrote:
>
>     On 01/04/2011 10:33 AM, Timothy Braun wrote:
>
>         Make sure the gnl input sources have different priorities and
>         set the gnloperations priority to 0.
>
>
>     Thanks for the idea. I tried setting the priority of the op to 0,
>     src1 to 1, and src2 to 2. Now when I run it the stream hangs after
>     2 seconds, which is when the gnloperation and src2 are starting
>     up. I did some testing and the hanging only occurs if I set the
>     priority on src2 to anything other than 0. I can set the
>     priorities on the op and src1 without hanging (it still doesn't
>     work, however). Here is my code again with the updates:
>
>
>            comp = gst.element_factory_make("gnlcomposition")
>            src1 = gst.element_factory_make("gnlfilesource")
>            src2 = gst.element_factory_make("gnlfilesource")
>
>            comp.add(src1)
>            src1.set_property("location", "/test1.mp4")
>            src1.set_property("start",          0 * gst.SECOND)
>            src1.set_property("duration",       5 * gst.SECOND)
>            src1.set_property("media-start",    0 * gst.SECOND)
>            src1.set_property("media-duration", 5 * gst.SECOND)
>            src1.set_property("priority",       1)
>
>
>            comp.add(src2)
>            src2.set_property("location", "/test2.mp4")
>            src2.set_property("start",          2 * gst.SECOND)
>            src2.set_property("duration",       5 * gst.SECOND)
>            src2.set_property("media-start",    0 * gst.SECOND)
>            src2.set_property("media-duration", 5 * gst.SECOND)
>            src2.set_property("priority",       2)
>
>
>            op = gst.element_factory_make("gnloperation")
>            tran = gst.element_factory_make("smpte")
>            tran.set_property("type", 234)
>            tran.set_property("duration", 3 * gst.SECOND)
>            op.add(tran)
>            op.set_property("start",          2 * gst.SECOND)
>            op.set_property("duration",       3 * gst.SECOND)
>            op.set_property("media-start",    0 * gst.SECOND)
>            op.set_property("media-duration", 3 * gst.SECOND)
>            op.set_property("priority",       0)
>            comp.add(op)
>
>     I can get the smpte transition to work correctly on these two
>     streams when not using the gnonlin elements, but that is not very
>     interesting as I have to run the two streams in parallel.
>
>     Any other ideas?
>
>     Lane
>
>
>
>         On Jan 4, 2011, at 12:01 PM, Lane Brooks<lane at brooks.nu
>         <mailto:lane at brooks.nu>>  wrote:
>
>             On 01/04/2011 05:39 AM, Edward Hervey wrote:
>
>                 On Mon, 2011-01-03 at 23:23 -0700, Lane Brooks wrote:
>
>                     I have a gnlcomposition containing two video
>                     sources. I would like to
>                     apply a smpte transition from one source to the next.
>
>                     I have tried overlapping the two gnlsources by 3
>                     seconds. I then put a
>                     'smpte' element in a 'gnloperation' and add the
>                     'gnloperation' to the
>                     'gnlcompostion'. The addition of the gnloperation
>                     doesn't seem to do
>                     anything. The resulting video is the same
>                     regardless of whether I add
>                     the gnloperation or not. The result is always that
>                     the second video
>                     takes over during the period of overlap. Here is
>                     code I have (in python):
>
>                              comp =
>                     gst.element_factory_make("gnlcomposition")
>                              src1 =
>                     gst.element_factory_make("gnlfilesource")
>                              src2 =
>                     gst.element_factory_make("gnlfilesource")
>
>                              comp.add(src1)
>                              src1.set_property("location", "/test1.mp4")
>                              src1.set_property("start",          0 *
>                     gst.SECOND)
>                              src1.set_property("duration",       5 *
>                     gst.SECOND)
>                              src1.set_property("media-start",    0 *
>                     gst.SECOND)
>                              src1.set_property("media-duration", 5 *
>                     gst.SECOND)
>
>                              comp.add(src2)
>                              src2.set_property("location", "/test2.mp4")
>                              src2.set_property("start",          2 *
>                     gst.SECOND)
>                              src2.set_property("duration",       5 *
>                     gst.SECOND)
>                              src2.set_property("media-start",    0 *
>                     gst.SECOND)
>                              src2.set_property("media-duration", 5 *
>                     gst.SECOND)
>
>                              op = gst.element_factory_make("gnloperation")
>                              tran = gst.element_factory_make("smpte")
>                              tran.set_property("type", 234)
>                              tran.set_property("duration", 3 * gst.SECOND)
>                              op.add(tran)
>
>
>                   Set the [media-]{start|duration} propertie son op also
>
>
>             I had already tried this as well.
>
>                     op.set_property("start",          2 * gst.SECOND)
>                     op.set_property("duration",       3 * gst.SECOND)
>                     op.set_property("media-start",    0 * gst.SECOND)
>                     op.set_property("media-duration", 3 * gst.SECOND)
>
>             I am not sure what I should put the media-start at, but I
>             have tried
>             both 0 and 2 and neither works. Any other ideas?
>
>
>
>                              comp.add(op)
>
>                     Anyone know if using an smpte transition is
>                     possible, and if so, what I
>                     am doing wrong?
>
>                     Thanks,
>                     Lane
>
>
>

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