AW: gst-omx decoding H264 from Logitech C920 stream

[Thornton, Keith]

The file you provided as a link is an MP4 file encoded in H264 constrained-baseline profile. If the decoder doesn't support constrained-baseline it won't decode it. I don't have a copy of the omx decoder so I can't check it.

-----Ursprüngliche Nachricht-----
Von: gstreamer-devel [mailto:gstreamer-devel-bounces at lists.freedesktop.org] Im Auftrag von Paulo Neves
Gesendet: Dienstag, 7. April 2015 17:35
An: gstreamer-devel at lists.freedesktop.org
Betreff: gst-omx decoding H264 from Logitech C920 stream

Thornton, Keith: I am not sure I understand what the difference is.
The sample h264 that was successfully tested can be found in apple's
site:

http://a1408.g.akamai.net/5/1408/1388/2005110403/1a1a1ad948be278cff2d96046ad90768d848b41947aa1986/sample_iPod.m4v.zip

In the camera description page it says the camera does AVC h264 compression:
http://www.logitech.com/en-gb/product/hd-pro-webcam-c920

If you can tell me a way to peek at this information I can do it.

Regarding the pipelines tried here are some examples, I am sorry I omitted them:

I am streaming the camera video from a remote computer with the following pipeline:

gst-launch-1.0 -v -e v4l2src device=/dev/video0 !
video/x-h264,width=1920,height=1080,framerate=30/1 ! h264parse !
rtph264pay pt=127 config-interval=8 ! udpsink host=192.168.1.109
port=6000

For the h264 video coming from the file the only thing that changes is the source of the video on the remote computer and the addition of the
demuxer:

gst-launch-1.0 -v -e filesrc location=~/Downloads/sample_iPod.m4v !
qtdemux ! h264parse ! rtph264pay pt=127 config-interval=8 ! udpsink
host=192.168.1.109 port=6000

Receiving on the Raspberry PI (omx decoder) is done, for both cases through this pipeline:

gst-launch-1.0 udpsrc port=6000 !  application/x-rtp, payload=127 !
rtph264depay ! h264parse ! omxh264dec ! queue ! autovideosink sync=false

To test that the omxh264dec works well with the omxh264enc i tried the following pipeline:

gst-launch-1.0 videotestsrc ! omxh264enc ! h264parse ! omxh264dec !
autovideosink sync=false

To further test if different encoders would produce different renderings in a remote computer I encoded videotestsrc and apple's file(pipeline below) with x264enc:

gst-launch-1.0 -v -e filesrc location=~/Downloads/sample_iPod.m4v !
qtdemux ! h264parse ! avdec_h264 ! x264enc tune=zerolatency !
rtph264pay pt=127 config-interval=1 ! queue ! udpsink
host=192.168.1.109 port=6000

In this test no corruption seemed to appear while preparing the pipelines for this email contrary to my previous email. I have not tried another movie with more scene change so this might be a fluke.

In the following link you can also find a video of the corruption which I am talking about:
https://youtu.be/JxOvCCan3Ro
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