[uvch264src in 1.1.1.1] "Got data flow before segment event" warnings until crash
Robert Krakora
rob.krakora at messagenetsystems.com
Fri Jul 26 06:24:53 PDT 2013
If the only thing that I do is set the copy threshold to 100 I can run
until the memory leak that I mentioned before invokes the OS to kill
gst-launch...I don't see the error reported...
On Fri, Jul 26, 2013 at 9:03 AM, Peter Rennert <p.rennert at cs.ucl.ac.uk>wrote:
> Hmm that is not the solution. It still fails after some minutes,
> reporting the same error as before. I am trying to find the right way to
> manipulate the buffer numbers now.
>
>
>
> On 07/26/2013 01:13 PM, Peter Rennert wrote:
>
> Rob,
>
> Well spotted!
>
> It works for me. I am monitoring the memory only with htop at the moment,
> but it seems to be stable. I think the memory leak stems from the fact that
> max_buffers is set to 0, so it will always make the buffer bigger and
> bigger. I think that is generally a bad idea. This might affect also plain
> v4l2src applications.
>
> Try this patch to get rid of the memory leak:
>
> diff --git a/sys/v4l2/gstv4l2bufferpool.c
> b/sys/v4l2/gstv4l2bufferpool.c
>
> index 1e74fc7..282ac2b
> 100644
>
> --- a/sys/v4l2/gstv4l2bufferpool.c
> +++ b/sys/v4l2/gstv4l2bufferpool.c
> @@ -411,7 +411,7 @@ gst_v4l2_buffer_pool_set_config (GstBufferPool *
> bpool, GstStructure * config)
> if (max_buffers == 0 || num_buffers < max_buffers) {
> /* if we are asked to provide more buffers than we have
> allocated, start
> * copying buffers when we only have 2 buffers left in the pool */
> - copy_threshold = 2;
> + copy_threshold = 15;// 2;
> } else {
> /* we are certain that we have enough buffers so we don't need to
> * copy */
> diff --git a/sys/v4l2/gstv4l2src.c b/sys/v4l2/gstv4l2src.c
> index 107ea21..0c5d91a 100644
> --- a/sys/v4l2/gstv4l2src.c
> +++ b/sys/v4l2/gstv4l2src.c
> @@ -529,7 +529,8 @@ gst_v4l2src_decide_allocation (GstBaseSrc * bsrc,
> GstQuery * query)
> update = TRUE;
> } else {
> pool = NULL;
> - min = max = 0;
> + min = 0;
> + max = 100;
> size = 0;
> update = FALSE;
> }
>
>
> On 07/25/2013 09:52 PM, Robert Krakora wrote:
>
> Hi Peter,
>
> I also wanted to note that when you apply the aforementioned "hack" to
> emulate the default operation of v4l2src in version 0.10
> ("always-copy=true") with the pipeline below, your system will run out of
> memory due to a memory leak. It will then kill off the gst-launch process
> instantiated to run your pipeline. However, your pipeline will run for
> quite a bit (a lot longer than the previous 36 seconds noted by Yusuf a
> couple of months ago).
>
> gst-launch-1.0 uvch264src device=/dev/video0 name=src auto-start=true
> src.vfsrc ! queue ! fakesink src.vidsrc ! queue ! video/x-h264 ! fakesink
>
> Best Regards,
>
> Rob Krakora
>
>
>
> On Thu, Jul 25, 2013 at 4:27 PM, Robert Krakora <
> rob.krakora at messagenetsystems.com> wrote:
>
>> Hi Peter,
>>
>> I forgot to mention that the file that needs modification is named
>> gstv4l2bufferpool.c and is under sys/v4l2 under plugins-good.
>>
>>
>> if (max_buffers == 0 || num_buffers < max_buffers) {
>> /* if we are asked to provide more buffers than we have
>> allocated, start
>> * copying buffers when we only have 2 buffers left in the pool */
>> copy_threshold = 100; //2;
>> } else {
>> /* we are certain that we have enough buffers so we don't need to
>> * copy */
>> copy_threshold = 0;
>> }
>>
>>
>> On Thu, Jul 25, 2013 at 4:21 PM, Robert Krakora <
>> rob.krakora at messagenetsystems.com> wrote:
>>
>>> Hi Peter,
>>>
>>> In version 0.10 v4l2src used to have a property to force buffers from
>>> it's pool to always be copied prior to being pushed out. This property was
>>> called "always-copy" and defaulted to "true". It seems that this was
>>> removed in version 1.x. If you go to version 1.x good plugins and change
>>> "copy_threadhold" from 2 to 100 you effectively get the same behaviour with
>>> 1.x in this regard (same as "always-copy=true" default in 0.10 v4l2src) and
>>> there is no error after 30 some odd seconds that causes the stream to abort.
>>>
>>> if (max_buffers == 0 || num_buffers < max_buffers) {
>>> /* if we are asked to provide more buffers than we have
>>> allocated, start
>>> * copying buffers when we only have 2 buffers left in the pool
>>> */
>>> copy_threshold = 100; //2;
>>> } else {
>>> /* we are certain that we have enough buffers so we don't need to
>>> * copy */
>>> copy_threshold = 0;
>>> }
>>>
>>> Best Regards,
>>>
>>> Rob Krakora
>>>
>>>
>>>
>>> On Thu, Jul 25, 2013 at 1:06 PM, Robert Krakora <
>>> rob.krakora at messagenetsystems.com> wrote:
>>>
>>>> Hi Peter,
>>>>
>>>> I did some work yesterday on this and enabled logging on uvcvideo.ko
>>>> and was able to correlate the buffer sizes reported by it and by the
>>>> uvch264src plugin. Below is the frame that failed...the size in the
>>>> kernel module was the same as the size of the buffer once it got back up to
>>>> the application to v4l2src and uvch264src.
>>>>
>>>> uvcvideo: Frame complete (EOF found).
>>>> uvcvideo: EOF in empty payload.
>>>> uvcvideo: uvc_v4l2_poll
>>>> uvcvideo: uvc_v4l2_ioctl(VIDIOC_DQBUF)
>>>> uvcvideo: HD Pro Webcam C920: PTS 1029592232 y 2948.098587 SOF
>>>> 2948.098587 (x1 2149480048 x2 2179588048 y1 193593344 y2 199426048 SOF
>>>> offset 39)
>>>> uvcvideo: HD Pro Webcam C920: SOF 2948.098587 y 927116325 ts 589.071670
>>>> buf ts 589.232519 (x1 197984256/205/906 x2 204537856/49/995 y1 1000000000
>>>> y2 1099975668)
>>>> uvcvideo: uvc_dequeue_buffer - buf->bytesused = 220410
>>>> uvcvideo: uvc_v4l2_ioctl(VIDIOC_QBUF)
>>>>
>>>> Best Regards,
>>>>
>>>> Rob
>>>>
>>>>
>>>> On Thu, Jul 25, 2013 at 12:22 PM, Peter Rennert <p.rennert at cs.ucl.ac.uk
>>>> > wrote:
>>>>
>>>>> A bit of an update today.
>>>>>
>>>>> To figure out what is going on normally and what is different in the
>>>>> diseased frame I printed out the debug line [line 508] that was already in
>>>>> the code, augmented with the total size of the buffer. The original line
>>>>> was:
>>>>>
>>>>> GST_DEBUG_OBJECT (self,
>>>>> "Found APP4 marker (%d). JPG: %d-%d - APP4: %d - %d",
>>>>> segment_size,
>>>>> last_offset, i, i, i + 2 + segment_size);
>>>>>
>>>>> I print for each time in the loop (before the sanity test that will
>>>>> fail finally):
>>>>>
>>>>> printf("Found APP4 marker (%d). JPG: %d-%d - APP4: %d - %d - size:
>>>>> %d\n", segment_size,
>>>>> last_offset, i, i, i + 2 + segment_size, (int)size);
>>>>>
>>>>> What I get for a normal frame is about this. The total buffer size
>>>>> changes and also the size of the first APP4 chunk, however, I always seem
>>>>> to get 4 blocks for each frame. The segment size of the first marker
>>>>> differs between the individual frames, while the 2nd, 3rd and 4th markers
>>>>> are the same size all the time as far as I can tell:
>>>>>
>>>>> Found APP4 marker (13010). JPG: 0-8 - APP4: 8 - 13020 - size: 166660
>>>>>
>>>>> Found APP4 marker (65533). JPG: 13020-13020 - APP4: 13020 - 78555 -
>>>>> size: 166660
>>>>>
>>>>> Found APP4 marker (65533). JPG: 78555-78555 - APP4: 78555 - 144090 -
>>>>> size: 166660
>>>>>
>>>>> Found APP4 marker (22566). JPG: 144090-144090 - APP4: 144090 - 166658
>>>>> - size: 166660
>>>>>
>>>>>
>>>>> The frame that causes the failure of the system has the following
>>>>> output:
>>>>>
>>>>> Found APP4 marker (12084). JPG: 0-8 - APP4: 8 - 12094 - size: 165485
>>>>>
>>>>> Found APP4 marker (65533). JPG: 12094-12094 - APP4: 12094 - 77629 -
>>>>> size: 165485
>>>>>
>>>>> Found APP4 marker (65533). JPG: 77629-77629 - APP4: 77629 - 143164 -
>>>>> size: 165485
>>>>>
>>>>> Found APP4 marker (22566). JPG: 143164-143164 - APP4: 143164 - 165732
>>>>> - size: 165485
>>>>>
>>>>>
>>>>> As you can see it seems as the last segment reaches out of the total
>>>>> size of the buffer. As the last segment seems to be always of a length
>>>>> 22566, I think for some reason (that does not happen in gstreamer 0.10) a
>>>>> piece of the h264 stream is missing in this particular buffer.
>>>>>
>>>>> The number of bytes getting lost is not the same for different trials,
>>>>> neither is the cut-off. For my second trial I got:
>>>>>
>>>>> Found APP4 marker (22566). JPG: 144796-144796 - APP4: 144796 - 167364
>>>>> - size: 165815
>>>>>
>>>>> So where are these bytes? And why are they missing so regularly?
>>>>>
>>>>> _______________________________________________
>>>>> gstreamer-devel mailing list
>>>>> gstreamer-devel at lists.freedesktop.org
>>>>> http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> Rob Krakora
>>>> MessageNet Systems
>>>> 101 East Carmel Dr. Suite 105
>>>> Carmel, IN 46032
>>>> (317)566-1677 Ext 212
>>>> (317)663-0808 Fax
>>>>
>>>
>>>
>>>
>>> --
>>> Rob Krakora
>>> MessageNet Systems
>>> 101 East Carmel Dr. Suite 105
>>> Carmel, IN 46032
>>> (317)566-1677 Ext 212
>>> (317)663-0808 Fax
>>>
>>
>>
>>
>> --
>> Rob Krakora
>> MessageNet Systems
>> 101 East Carmel Dr. Suite 105
>> Carmel, IN 46032
>> (317)566-1677 Ext 212
>> (317)663-0808 Fax
>>
>
>
>
> --
> Rob Krakora
> MessageNet Systems
> 101 East Carmel Dr. Suite 105
> Carmel, IN 46032
> (317)566-1677 Ext 212
> (317)663-0808 Fax
>
>
> _______________________________________________
> gstreamer-devel mailing listgstreamer-devel at lists.freedesktop.orghttp://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
>
>
>
>
> _______________________________________________
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>
>
>
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> gstreamer-devel at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
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>
--
Rob Krakora
MessageNet Systems
101 East Carmel Dr. Suite 105
Carmel, IN 46032
(317)566-1677 Ext 212
(317)663-0808 Fax
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